ci: add PHP 8.4 to test matrix

The cleanup request was no longer precessed since we refactored the
settings page in v1.7.0 to use the WP settings API. Process the request
including nonce verification during page creation restores it.

.distignore

@@ -0,0 +1,18 @@
+/.git
+/.github
+/assets
+/dist
+/test
+/vendor
+/.distignore
+/.editorconfig
+/.gitattributes
+/.gitignore
+/.travis.yml
+/composer.json
+/composer.lock
+/CONTRIBUTING.md
+/package.json
+/package-lock.json
+/phpcs.xml
+/phpunit.xml

.editorconfig

@@ -0,0 +1,21 @@
+# This file is for unifying the coding style for different editors and IDEs
+# editorconfig.org
+
+# WordPress Coding Standards
+# https://make.wordpress.org/core/handbook/coding-standards/
+
+root = true
+
+[*]
+charset = utf-8
+end_of_line = lf
+insert_final_newline = true
+trim_trailing_whitespace = true
+indent_style = tab
+
+[{.jshintrc,*.json,*.yml,*.feature}]
+indent_style = space
+indent_size = 2
+
+[{*.txt,wp-config-sample.php}]
+end_of_line = crlf

.gitattributes

@@ -0,0 +1,14 @@
+/.github export-ignore
+/assets export-ignore
+/dist export-ignore
+/test export-ignore
+.distignore export-ignore
+.gitattributes export-ignore
+.gitignore export-ignore
+.travis.yml export-ignore
+composer.json export-ignore
+composer.lock export-ignore
+CONTRIBUTING.md export-ignore
+package.json export-ignore
+phpcs.xml export-ignore
+phpunit.xml export-ignore

.github/workflows/test.yml

@@ -0,0 +1,55 @@
+name: CI
+on: [ push, pull_request ]
+jobs:
+  unit-test:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        php: [ '5.6', '7.4', '8.0', '8.2', '8.4' ]
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+      - name: Setup PHP
+        uses: shivammathur/setup-php@v2
+        with:
+          php-version: ${{ matrix.php }}
+          coverage: xdebug
+          tools: composer
+      - name: Install
+        run: composer install --no-interaction
+      - name: Unit tests
+        run: |
+          composer test
+          sed -i "s#<file name=\"${GITHUB_WORKSPACE}#<file name=\"/github/workspace#g" tests-clover.xml
+      - name: Analyze with SonarCloud
+        if: matrix.php == '8.2' && env.SONAR_TOKEN != ''
+        uses: sonarsource/sonarcloud-github-action@master
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          SONAR_TOKEN: ${{ secrets.SONAR_TOKEN }}
+        with:
+          args: >
+            -Dsonar.organization=stklcode-github
+            -Dsonar.projectKey=stklcode:statify-blacklist
+            -Dsonar.sources=inc,statify-blacklist.php
+            -Dsonar.tests=test
+            -Dsonar.php.tests.reportPath=tests-junit.xml
+            -Dsonar.php.coverage.reportPaths=tests-clover.xml
+            -Dsonar.coverage.exclusions=test/**/*.php
+
+  quality:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+      - name: Setup PHP
+        uses: shivammathur/setup-php@v2
+        with:
+          php-version: '8.2'
+          tools: composer
+      - name: Install
+        run: composer install --no-interaction
+      - name: Code style checks for PHP
+        run: composer test-cs

.github/workflows/wordpress-plugin-asset-update.yml

@@ -0,0 +1,20 @@
+name: Plugin asset/readme update
+on:
+  push:
+    branches:
+      - stable
+jobs:
+  master:
+    name: Push to stable
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - name: Clean README.md
+        run: tail -n +6 README.md > README.md.tmp && mv README.md.tmp README.md
+      - name: WordPress.org plugin asset/readme update
+        uses: 10up/action-wordpress-plugin-asset-update@stable
+        env:
+          ASSETS_DIR: assets
+          README_NAME: README.md
+          SVN_PASSWORD: ${{ secrets.WP_SVN_PASSWORD }}
+          SVN_USERNAME: ${{ secrets.WP_SVN_USERNAME }}

.github/workflows/wordpress-plugin-check.yml

@@ -0,0 +1,23 @@
+name: Plugin check
+on:
+  push:
+    branches: [ 'stable', 'release/*' ]
+  pull_request:
+    branches: [ 'stable' ]
+jobs:
+  check:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Package plugin
+        run: |
+          mkdir -p ./dist
+          tail -n +6 README.md > README.md.tmp && mv README.md.tmp README.md
+          rsync -rc --exclude-from=.distignore ./ ./dist/statify-blacklist --delete --delete-excluded
+
+      - name: Check WP plugin
+        uses: wordpress/plugin-check-action@v1
+        with:
+          build-dir: ./dist/statify-blacklist

.github/workflows/wordpress-plugin-deploy.yml

@@ -0,0 +1,20 @@
+name: Deploy to WordPress.org
+on:
+  push:
+    tags:
+      - "v*"
+      - "!v*-*"
+jobs:
+  tag:
+    name: New tag
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - name: Clean README.md
+        run: tail -n +6 README.md > README.md.tmp && mv README.md.tmp README.md
+      - name: WordPress Plugin Deploy
+        uses: 10up/action-wordpress-plugin-deploy@stable
+        env:
+          ASSETS_DIR: assets
+          SVN_PASSWORD: ${{ secrets.WP_SVN_PASSWORD }}
+          SVN_USERNAME: ${{ secrets.WP_SVN_USERNAME }}

.gitignore

@@ -0,0 +1,8 @@
+composer.lock
+/vendor/
+/node_modules/
+/dist/
+.idea
+tests-clover.xml
+tests-junit.xml
+.phpunit.result.cache

CONTRIBUTING.md

@@ -0,0 +1,132 @@
+# How to contribute
+
+As for all great Open Source projects, contributions in form of bug reports and code are welcome and important to keep the project alive.
+
+In general, this project follows the [GitHub Flow](https://guides.github.com/introduction/flow/). 
+Fork the project, commit your changes to your branch, open a pull request and it will probably be merged.
+However, to ensure maintainability and quality of the code, there are some guidelines you might be more or less familiar with. 
+For that purpose, this document describes the important points.
+
+## Opening an Issue
+
+If you experience any issues with the plugin or the code, don't hesitate to file an issue.
+
+### Bug Reports
+
+Think you found a bug?
+Please clearly state what happens and describe your environment to help tracking down the issue.
+ 
+* Which version of the plugin are you running?
+* Which version of WordPress?
+* Which version(s) of related plugin(s) (e.g. Statify)?
+* Which version of PHP and - if of interest - which webserver are you running?
+
+### Feature Requests
+
+Missing a feature or like to have certain functionality enhanced?
+No problem, please open an issue and describe what and why you think this change is required.
+
+## Pull Requests
+
+If you want to contribute your code to solve an issue or implement a desired feature yourself, you might open a pull request.
+If the changes introduce new functionality or affect major parts of existing code, please consider opening an issue for discussion first.
+
+For adding new functionality a new test case the corresponding PHPUnit test would be nice (no hard criterion though).
+
+The `master` branch should also be target for most pull requests.
+However it it features new functionality you might want to target the `develop` branch instead (see next section for details on branches).
+
+### Branches
+
+The `master` branch represents the current state of development.
+Please ensure your initial code is up to date with it at the time you start development.
+
+In addition, this project features a `develop` branch, which holds bleeding edge developments, not necessarily considered stable or even compatible.
+Do not expect this code to run smoothly, but you might have a look into the history to see if some work on an issue has already been started there.
+
+For fixes and features, there might be additional branches, likely prefixed by `hotfix/` or `feature/` followed by an issue number (if applicable) and/or a title.
+Feel free to adapt this naming scheme to your forks.
+
+### Merge Requirements
+
+To be merged into the master branch, your code has to pass the automated continuous integration tests, to ensure compatibility.
+In Addition your code has to be approved by a project member.
+
+#### What if my code fails the tests?
+
+Don't worry, you can submit your PR anyway. 
+The reviewing process might help you to solve remaining issues.
+
+### Commit messages
+
+Please use speaking titles and messages for your commits, to ensure a transparent history.
+If your patch fixes an issue, reference the ID in the first line.
+If you feel like you have to _briefly_ explain your changes, do it (for long explanations and discussion, consider opening an issue or describe in the PR).
+
+**Example commit:**
+```text
+Fix nasty bug from #1337
+
+This example commit fixes the issue that some people write non-speaking commit messages like 'done magic'.
+A short description is helpful sometimes.
+```
+
+You might sign your work, although that's no must.
+
+### When will it be merged?
+
+Short answer: When it makes sense.
+
+Bugfixes should be merged in time - assuming they pass the above criteria.
+New features might be assigned to a certain milestone and as a result of this be scheduled according to the planned release cycle.
+
+## Compatibility
+
+To ensure usability for a wide range of users, please take note on the software requirements stated in the `README`.
+This includes especially the minimum PHP version and also the minimum version of WordPress.
+
+If you are unsure if your code matches these versions, the test will probably tell you.
+
+In case you think, your change is more important than maintaining backwards compatibility, please start a discussion to see, 
+if we might increase the minimum version or find a workaround for legacy systems. 
+
+## Build Environment
+
+All you need to start off - besides your favorite IDE of course - is [Composer](https://getcomposer.org). 
+Running `composer install` will fetch all dependencies and build tools required. 
+You might have noticed that this project contains a [Robo](http://robo.li) build script.
+Running the _build_-task (`./vendor/bin/robo build`) executes the full chain from cleanup over test to bundling the final product in the `dist` directory.
+A complete list of the available tasks and options can be shown by running `robo list`.
+
+## Unit Tests
+
+The PHP code is tested by a PHPUnit tests.
+All test files are located in the `test` directory. 
+Files ending with `-test.php` will be automatically included into the test suite.
+The coverage is not yet perfect, but be invited to write tests for methods not yet covered or newly introduced by your patch.
+
+## Code Style
+
+This project, as part of the WordPress ecosystem adheres to the [WordPress Coding Standards](https://codex.wordpress.org/WordPress_Coding_Standards).
+Please make sure that you are at least roughly familiar with those guidelines.
+
+The code style is automatically checked for commits (including pull requests) using [PHP CodeSniffer](https://github.com/squizlabs/PHP_CodeSniffer).
+You can check your code against the configured ruleset yourself by running
+ `./vendor/bin/phpcs --standard=phpcs.xml your-edited-file.php` (assuming `composer install` has been executed) or the Robo task `robo test:cs` for a complete scan.
+
+Please see these standards as guidelines. 
+If code style this is the only test that fails and your code's semantics are fine, don't hesitate to submit your pull request anyway.
+We probably find a solution for that.
+
+## Continuous Integration
+
+Automated tests are run using [Travis CI](https://travis-ci.org/stklcode/statify-blacklist) for every commit including pull requests.
+They ensure compatibility with the supported PHP versions and the WP Coding Standards.
+
+There is also a semi-automated code quality analysis pushing results to [SonarCloud](https://sonarcloud.io/dashboard?id=de.stklcode.web.wordpress.plugins%3Astatify-blacklist).
+Keep in mind that the ruleset is not yet perfect, so not every minor issue has to be fixed immediately.
+
+## Still Open Questions?
+
+If anything is still left unanswered and you're unsure if you got it right, don't hesitate to contact a team member.
+in any case you might submit your request/issue anyway, we won't refuse good code only for formal reasons.

LICENSE.md

@@ -1,643 +1,317 @@
-                    GNU GENERAL PUBLIC LICENSE
-                       Version 3, 29 June 2007
+### GNU GENERAL PUBLIC LICENSE
+
+Version 2, June 1991
+
+    Copyright (C) 1989, 1991 Free Software Foundation, Inc.  
+    51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 
- Copyright (C) 2007 Free Software Foundation, Inc. <http://fsf.org/>
     Everyone is permitted to copy and distribute verbatim copies
     of this license document, but changing it is not allowed.
 
-                            Preamble
+### Preamble
 
-  The GNU General Public License is a free, copyleft license for
-software and other kinds of works.
-
-  The licenses for most software and other practical works are designed
-to take away your freedom to share and change the works.  By contrast,
-the GNU General Public License is intended to guarantee your freedom to
-share and change all versions of a program--to make sure it remains free
-software for all its users.  We, the Free Software Foundation, use the
-GNU General Public License for most of our software; it applies also to
-any other work released this way by its authors.  You can apply it to
+The licenses for most software are designed to take away your freedom
+to share and change it. By contrast, the GNU General Public License is
+intended to guarantee your freedom to share and change free
+software--to make sure the software is free for all its users. This
+General Public License applies to most of the Free Software
+Foundation's software and to any other program whose authors commit to
+using it. (Some other Free Software Foundation software is covered by
+the GNU Lesser General Public License instead.) You can apply it to
 your programs, too.
 
-  When we speak of free software, we are referring to freedom, not
+When we speak of free software, we are referring to freedom, not
 price. Our General Public Licenses are designed to make sure that you
 have the freedom to distribute copies of free software (and charge for
-them if you wish), that you receive source code or can get it if you
-want it, that you can change the software or use pieces of it in new
-free programs, and that you know you can do these things.
+this service if you wish), that you receive source code or can get it
+if you want it, that you can change the software or use pieces of it
+in new free programs; and that you know you can do these things.
 
-  To protect your rights, we need to prevent others from denying you
-these rights or asking you to surrender the rights.  Therefore, you have
-certain responsibilities if you distribute copies of the software, or if
-you modify it: responsibilities to respect the freedom of others.
+To protect your rights, we need to make restrictions that forbid
+anyone to deny you these rights or to ask you to surrender the rights.
+These restrictions translate to certain responsibilities for you if
+you distribute copies of the software, or if you modify it.
 
-  For example, if you distribute copies of such a program, whether
-gratis or for a fee, you must pass on to the recipients the same
-freedoms that you received.  You must make sure that they, too, receive
-or can get the source code.  And you must show them these terms so they
-know their rights.
+For example, if you distribute copies of such a program, whether
+gratis or for a fee, you must give the recipients all the rights that
+you have. You must make sure that they, too, receive or can get the
+source code. And you must show them these terms so they know their
+rights.
 
-  Developers that use the GNU GPL protect your rights with two steps:
-(1) assert copyright on the software, and (2) offer you this License
-giving you legal permission to copy, distribute and/or modify it.
+We protect your rights with two steps: (1) copyright the software, and
+(2) offer you this license which gives you legal permission to copy,
+distribute and/or modify the software.
 
-  For the developers' and authors' protection, the GPL clearly explains
-that there is no warranty for this free software.  For both users' and
-authors' sake, the GPL requires that modified versions be marked as
-changed, so that their problems will not be attributed erroneously to
-authors of previous versions.
+Also, for each author's protection and ours, we want to make certain
+that everyone understands that there is no warranty for this free
+software. If the software is modified by someone else and passed on,
+we want its recipients to know that what they have is not the
+original, so that any problems introduced by others will not reflect
+on the original authors' reputations.
 
-  Some devices are designed to deny users access to install or run
-modified versions of the software inside them, although the manufacturer
-can do so.  This is fundamentally incompatible with the aim of
-protecting users' freedom to change the software.  The systematic
-pattern of such abuse occurs in the area of products for individuals to
-use, which is precisely where it is most unacceptable.  Therefore, we
-have designed this version of the GPL to prohibit the practice for those
-products.  If such problems arise substantially in other domains, we
-stand ready to extend this provision to those domains in future versions
-of the GPL, as needed to protect the freedom of users.
+Finally, any free program is threatened constantly by software
+patents. We wish to avoid the danger that redistributors of a free
+program will individually obtain patent licenses, in effect making the
+program proprietary. To prevent this, we have made it clear that any
+patent must be licensed for everyone's free use or not licensed at
+all.
 
-  Finally, every program is threatened constantly by software patents.
-States should not allow patents to restrict development and use of
-software on general-purpose computers, but in those that do, we wish to
-avoid the special danger that patents applied to a free program could
-make it effectively proprietary.  To prevent this, the GPL assures that
-patents cannot be used to render the program non-free.
-
-  The precise terms and conditions for copying, distribution and
+The precise terms and conditions for copying, distribution and
 modification follow.
 
-                       TERMS AND CONDITIONS
-
-  0. Definitions.
-
-  "This License" refers to version 3 of the GNU General Public License.
-
-  "Copyright" also means copyright-like laws that apply to other kinds of
-works, such as semiconductor masks.
-
-  "The Program" refers to any copyrightable work licensed under this
-License.  Each licensee is addressed as "you".  "Licensees" and
-"recipients" may be individuals or organizations.
-
-  To "modify" a work means to copy from or adapt all or part of the work
-in a fashion requiring copyright permission, other than the making of an
-exact copy.  The resulting work is called a "modified version" of the
-earlier work or a work "based on" the earlier work.
-
-  A "covered work" means either the unmodified Program or a work based
-on the Program.
-
-  To "propagate" a work means to do anything with it that, without
-permission, would make you directly or secondarily liable for
-infringement under applicable copyright law, except executing it on a
-computer or modifying a private copy.  Propagation includes copying,
-distribution (with or without modification), making available to the
-public, and in some countries other activities as well.
-
-  To "convey" a work means any kind of propagation that enables other
-parties to make or receive copies.  Mere interaction with a user through
-a computer network, with no transfer of a copy, is not conveying.
-
-  An interactive user interface displays "Appropriate Legal Notices"
-to the extent that it includes a convenient and prominently visible
-feature that (1) displays an appropriate copyright notice, and (2)
-tells the user that there is no warranty for the work (except to the
-extent that warranties are provided), that licensees may convey the
-work under this License, and how to view a copy of this License.  If
-the interface presents a list of user commands or options, such as a
-menu, a prominent item in the list meets this criterion.
-
-  1. Source Code.
-
-  The "source code" for a work means the preferred form of the work
-for making modifications to it.  "Object code" means any non-source
-form of a work.
-
-  A "Standard Interface" means an interface that either is an official
-standard defined by a recognized standards body, or, in the case of
-interfaces specified for a particular programming language, one that
-is widely used among developers working in that language.
-
-  The "System Libraries" of an executable work include anything, other
-than the work as a whole, that (a) is included in the normal form of
-packaging a Major Component, but which is not part of that Major
-Component, and (b) serves only to enable use of the work with that
-Major Component, or to implement a Standard Interface for which an
-implementation is available to the public in source code form.  A
-"Major Component", in this context, means a major essential component
-(kernel, window system, and so on) of the specific operating system
-(if any) on which the executable work runs, or a compiler used to
-produce the work, or an object code interpreter used to run it.
-
-  The "Corresponding Source" for a work in object code form means all
-the source code needed to generate, install, and (for an executable
-work) run the object code and to modify the work, including scripts to
-control those activities.  However, it does not include the work's
-System Libraries, or general-purpose tools or generally available free
-programs which are used unmodified in performing those activities but
-which are not part of the work.  For example, Corresponding Source
-includes interface definition files associated with source files for
-the work, and the source code for shared libraries and dynamically
-linked subprograms that the work is specifically designed to require,
-such as by intimate data communication or control flow between those
-subprograms and other parts of the work.
-
-  The Corresponding Source need not include anything that users
-can regenerate automatically from other parts of the Corresponding
-Source.
-
-  The Corresponding Source for a work in source code form is that
-same work.
-
-  2. Basic Permissions.
-
-  All rights granted under this License are granted for the term of
-copyright on the Program, and are irrevocable provided the stated
-conditions are met.  This License explicitly affirms your unlimited
-permission to run the unmodified Program.  The output from running a
-covered work is covered by this License only if the output, given its
-content, constitutes a covered work.  This License acknowledges your
-rights of fair use or other equivalent, as provided by copyright law.
-
-  You may make, run and propagate covered works that you do not
-convey, without conditions so long as your license otherwise remains
-in force.  You may convey covered works to others for the sole purpose
-of having them make modifications exclusively for you, or provide you
-with facilities for running those works, provided that you comply with
-the terms of this License in conveying all material for which you do
-not control copyright.  Those thus making or running the covered works
-for you must do so exclusively on your behalf, under your direction
-and control, on terms that prohibit them from making any copies of
-your copyrighted material outside their relationship with you.
-
-  Conveying under any other circumstances is permitted solely under
-the conditions stated below.  Sublicensing is not allowed; section 10
-makes it unnecessary.
-
-  3. Protecting Users' Legal Rights From Anti-Circumvention Law.
-
-  No covered work shall be deemed part of an effective technological
-measure under any applicable law fulfilling obligations under article
-11 of the WIPO copyright treaty adopted on 20 December 1996, or
-similar laws prohibiting or restricting circumvention of such
-measures.
-
-  When you convey a covered work, you waive any legal power to forbid
-circumvention of technological measures to the extent such circumvention
-is effected by exercising rights under this License with respect to
-the covered work, and you disclaim any intention to limit operation or
-modification of the work as a means of enforcing, against the work's
-users, your or third parties' legal rights to forbid circumvention of
-technological measures.
-
-  4. Conveying Verbatim Copies.
-
-  You may convey verbatim copies of the Program's source code as you
-receive it, in any medium, provided that you conspicuously and
-appropriately publish on each copy an appropriate copyright notice;
-keep intact all notices stating that this License and any
-non-permissive terms added in accord with section 7 apply to the code;
-keep intact all notices of the absence of any warranty; and give all
-recipients a copy of this License along with the Program.
-
-  You may charge any price or no price for each copy that you convey,
-and you may offer support or warranty protection for a fee.
-
-  5. Conveying Modified Source Versions.
-
-  You may convey a work based on the Program, or the modifications to
-produce it from the Program, in the form of source code under the
-terms of section 4, provided that you also meet all of these conditions:
-
-    a) The work must carry prominent notices stating that you modified
-    it, and giving a relevant date.
-
-    b) The work must carry prominent notices stating that it is
-    released under this License and any conditions added under section
-    7.  This requirement modifies the requirement in section 4 to
-    "keep intact all notices".
-
-    c) You must license the entire work, as a whole, under this
-    License to anyone who comes into possession of a copy.  This
-    License will therefore apply, along with any applicable section 7
-    additional terms, to the whole of the work, and all its parts,
-    regardless of how they are packaged.  This License gives no
-    permission to license the work in any other way, but it does not
-    invalidate such permission if you have separately received it.
-
-    d) If the work has interactive user interfaces, each must display
-    Appropriate Legal Notices; however, if the Program has interactive
-    interfaces that do not display Appropriate Legal Notices, your
-    work need not make them do so.
-
-  A compilation of a covered work with other separate and independent
-works, which are not by their nature extensions of the covered work,
-and which are not combined with it such as to form a larger program,
-in or on a volume of a storage or distribution medium, is called an
-"aggregate" if the compilation and its resulting copyright are not
-used to limit the access or legal rights of the compilation's users
-beyond what the individual works permit.  Inclusion of a covered work
-in an aggregate does not cause this License to apply to the other
-parts of the aggregate.
-
-  6. Conveying Non-Source Forms.
-
-  You may convey a covered work in object code form under the terms
-of sections 4 and 5, provided that you also convey the
-machine-readable Corresponding Source under the terms of this License,
-in one of these ways:
-
-    a) Convey the object code in, or embodied in, a physical product
-    (including a physical distribution medium), accompanied by the
-    Corresponding Source fixed on a durable physical medium
-    customarily used for software interchange.
-
-    b) Convey the object code in, or embodied in, a physical product
-    (including a physical distribution medium), accompanied by a
-    written offer, valid for at least three years and valid for as
-    long as you offer spare parts or customer support for that product
-    model, to give anyone who possesses the object code either (1) a
-    copy of the Corresponding Source for all the software in the
-    product that is covered by this License, on a durable physical
-    medium customarily used for software interchange, for a price no
-    more than your reasonable cost of physically performing this
-    conveying of source, or (2) access to copy the
-    Corresponding Source from a network server at no charge.
-
-    c) Convey individual copies of the object code with a copy of the
-    written offer to provide the Corresponding Source.  This
-    alternative is allowed only occasionally and noncommercially, and
-    only if you received the object code with such an offer, in accord
-    with subsection 6b.
-
-    d) Convey the object code by offering access from a designated
-    place (gratis or for a charge), and offer equivalent access to the
-    Corresponding Source in the same way through the same place at no
-    further charge.  You need not require recipients to copy the
-    Corresponding Source along with the object code.  If the place to
-    copy the object code is a network server, the Corresponding Source
-    may be on a different server (operated by you or a third party)
-    that supports equivalent copying facilities, provided you maintain
-    clear directions next to the object code saying where to find the
-    Corresponding Source.  Regardless of what server hosts the
-    Corresponding Source, you remain obligated to ensure that it is
-    available for as long as needed to satisfy these requirements.
-
-    e) Convey the object code using peer-to-peer transmission, provided
-    you inform other peers where the object code and Corresponding
-    Source of the work are being offered to the general public at no
-    charge under subsection 6d.
-
-  A separable portion of the object code, whose source code is excluded
-from the Corresponding Source as a System Library, need not be
-included in conveying the object code work.
-
-  A "User Product" is either (1) a "consumer product", which means any
-tangible personal property which is normally used for personal, family,
-or household purposes, or (2) anything designed or sold for incorporation
-into a dwelling.  In determining whether a product is a consumer product,
-doubtful cases shall be resolved in favor of coverage.  For a particular
-product received by a particular user, "normally used" refers to a
-typical or common use of that class of product, regardless of the status
-of the particular user or of the way in which the particular user
-actually uses, or expects or is expected to use, the product.  A product
-is a consumer product regardless of whether the product has substantial
-commercial, industrial or non-consumer uses, unless such uses represent
-the only significant mode of use of the product.
-
-  "Installation Information" for a User Product means any methods,
-procedures, authorization keys, or other information required to install
-and execute modified versions of a covered work in that User Product from
-a modified version of its Corresponding Source.  The information must
-suffice to ensure that the continued functioning of the modified object
-code is in no case prevented or interfered with solely because
-modification has been made.
-
-  If you convey an object code work under this section in, or with, or
-specifically for use in, a User Product, and the conveying occurs as
-part of a transaction in which the right of possession and use of the
-User Product is transferred to the recipient in perpetuity or for a
-fixed term (regardless of how the transaction is characterized), the
-Corresponding Source conveyed under this section must be accompanied
-by the Installation Information.  But this requirement does not apply
-if neither you nor any third party retains the ability to install
-modified object code on the User Product (for example, the work has
-been installed in ROM).
-
-  The requirement to provide Installation Information does not include a
-requirement to continue to provide support service, warranty, or updates
-for a work that has been modified or installed by the recipient, or for
-the User Product in which it has been modified or installed.  Access to a
-network may be denied when the modification itself materially and
-adversely affects the operation of the network or violates the rules and
-protocols for communication across the network.
-
-  Corresponding Source conveyed, and Installation Information provided,
-in accord with this section must be in a format that is publicly
-documented (and with an implementation available to the public in
-source code form), and must require no special password or key for
-unpacking, reading or copying.
-
-  7. Additional Terms.
-
-  "Additional permissions" are terms that supplement the terms of this
-License by making exceptions from one or more of its conditions.
-Additional permissions that are applicable to the entire Program shall
-be treated as though they were included in this License, to the extent
-that they are valid under applicable law.  If additional permissions
-apply only to part of the Program, that part may be used separately
-under those permissions, but the entire Program remains governed by
-this License without regard to the additional permissions.
-
-  When you convey a copy of a covered work, you may at your option
-remove any additional permissions from that copy, or from any part of
-it.  (Additional permissions may be written to require their own
-removal in certain cases when you modify the work.)  You may place
-additional permissions on material, added by you to a covered work,
-for which you have or can give appropriate copyright permission.
-
-  Notwithstanding any other provision of this License, for material you
-add to a covered work, you may (if authorized by the copyright holders of
-that material) supplement the terms of this License with terms:
-
-    a) Disclaiming warranty or limiting liability differently from the
-    terms of sections 15 and 16 of this License; or
-
-    b) Requiring preservation of specified reasonable legal notices or
-    author attributions in that material or in the Appropriate Legal
-    Notices displayed by works containing it; or
-
-    c) Prohibiting misrepresentation of the origin of that material, or
-    requiring that modified versions of such material be marked in
-    reasonable ways as different from the original version; or
-
-    d) Limiting the use for publicity purposes of names of licensors or
-    authors of the material; or
-
-    e) Declining to grant rights under trademark law for use of some
-    trade names, trademarks, or service marks; or
-
-    f) Requiring indemnification of licensors and authors of that
-    material by anyone who conveys the material (or modified versions of
-    it) with contractual assumptions of liability to the recipient, for
-    any liability that these contractual assumptions directly impose on
-    those licensors and authors.
-
-  All other non-permissive additional terms are considered "further
-restrictions" within the meaning of section 10.  If the Program as you
-received it, or any part of it, contains a notice stating that it is
-governed by this License along with a term that is a further
-restriction, you may remove that term.  If a license document contains
-a further restriction but permits relicensing or conveying under this
-License, you may add to a covered work material governed by the terms
-of that license document, provided that the further restriction does
-not survive such relicensing or conveying.
-
-  If you add terms to a covered work in accord with this section, you
-must place, in the relevant source files, a statement of the
-additional terms that apply to those files, or a notice indicating
-where to find the applicable terms.
-
-  Additional terms, permissive or non-permissive, may be stated in the
-form of a separately written license, or stated as exceptions;
-the above requirements apply either way.
-
-  8. Termination.
-
-  You may not propagate or modify a covered work except as expressly
-provided under this License.  Any attempt otherwise to propagate or
-modify it is void, and will automatically terminate your rights under
-this License (including any patent licenses granted under the third
-paragraph of section 11).
-
-  However, if you cease all violation of this License, then your
-license from a particular copyright holder is reinstated (a)
-provisionally, unless and until the copyright holder explicitly and
-finally terminates your license, and (b) permanently, if the copyright
-holder fails to notify you of the violation by some reasonable means
-prior to 60 days after the cessation.
-
-  Moreover, your license from a particular copyright holder is
-reinstated permanently if the copyright holder notifies you of the
-violation by some reasonable means, this is the first time you have
-received notice of violation of this License (for any work) from that
-copyright holder, and you cure the violation prior to 30 days after
-your receipt of the notice.
-
-  Termination of your rights under this section does not terminate the
-licenses of parties who have received copies or rights from you under
-this License.  If your rights have been terminated and not permanently
-reinstated, you do not qualify to receive new licenses for the same
-material under section 10.
-
-  9. Acceptance Not Required for Having Copies.
-
-  You are not required to accept this License in order to receive or
-run a copy of the Program.  Ancillary propagation of a covered work
-occurring solely as a consequence of using peer-to-peer transmission
-to receive a copy likewise does not require acceptance.  However,
-nothing other than this License grants you permission to propagate or
-modify any covered work.  These actions infringe copyright if you do
-not accept this License.  Therefore, by modifying or propagating a
-covered work, you indicate your acceptance of this License to do so.
-
-  10. Automatic Licensing of Downstream Recipients.
-
-  Each time you convey a covered work, the recipient automatically
-receives a license from the original licensors, to run, modify and
-propagate that work, subject to this License.  You are not responsible
-for enforcing compliance by third parties with this License.
-
-  An "entity transaction" is a transaction transferring control of an
-organization, or substantially all assets of one, or subdividing an
-organization, or merging organizations.  If propagation of a covered
-work results from an entity transaction, each party to that
-transaction who receives a copy of the work also receives whatever
-licenses to the work the party's predecessor in interest had or could
-give under the previous paragraph, plus a right to possession of the
-Corresponding Source of the work from the predecessor in interest, if
-the predecessor has it or can get it with reasonable efforts.
-
-  You may not impose any further restrictions on the exercise of the
-rights granted or affirmed under this License.  For example, you may
-not impose a license fee, royalty, or other charge for exercise of
-rights granted under this License, and you may not initiate litigation
-(including a cross-claim or counterclaim in a lawsuit) alleging that
-any patent claim is infringed by making, using, selling, offering for
-sale, or importing the Program or any portion of it.
-
-  11. Patents.
-
-  A "contributor" is a copyright holder who authorizes use under this
-License of the Program or a work on which the Program is based.  The
-work thus licensed is called the contributor's "contributor version".
-
-  A contributor's "essential patent claims" are all patent claims
-owned or controlled by the contributor, whether already acquired or
-hereafter acquired, that would be infringed by some manner, permitted
-by this License, of making, using, or selling its contributor version,
-but do not include claims that would be infringed only as a
-consequence of further modification of the contributor version.  For
-purposes of this definition, "control" includes the right to grant
-patent sublicenses in a manner consistent with the requirements of
+### TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
+
+**0.** This License applies to any program or other work which
+contains a notice placed by the copyright holder saying it may be
+distributed under the terms of this General Public License. The
+"Program", below, refers to any such program or work, and a "work
+based on the Program" means either the Program or any derivative work
+under copyright law: that is to say, a work containing the Program or
+a portion of it, either verbatim or with modifications and/or
+translated into another language. (Hereinafter, translation is
+included without limitation in the term "modification".) Each licensee
+is addressed as "you".
+
+Activities other than copying, distribution and modification are not
+covered by this License; they are outside its scope. The act of
+running the Program is not restricted, and the output from the Program
+is covered only if its contents constitute a work based on the Program
+(independent of having been made by running the Program). Whether that
+is true depends on what the Program does.
+
+**1.** You may copy and distribute verbatim copies of the Program's
+source code as you receive it, in any medium, provided that you
+conspicuously and appropriately publish on each copy an appropriate
+copyright notice and disclaimer of warranty; keep intact all the
+notices that refer to this License and to the absence of any warranty;
+and give any other recipients of the Program a copy of this License
+along with the Program.
+
+You may charge a fee for the physical act of transferring a copy, and
+you may at your option offer warranty protection in exchange for a
+fee.
+
+**2.** You may modify your copy or copies of the Program or any
+portion of it, thus forming a work based on the Program, and copy and
+distribute such modifications or work under the terms of Section 1
+above, provided that you also meet all of these conditions:
+
+  
+**a)** You must cause the modified files to carry prominent notices
+stating that you changed the files and the date of any change.
+
+  
+**b)** You must cause any work that you distribute or publish, that in
+whole or in part contains or is derived from the Program or any part
+thereof, to be licensed as a whole at no charge to all third parties
+under the terms of this License.
+
+  
+**c)** If the modified program normally reads commands interactively
+when run, you must cause it, when started running for such interactive
+use in the most ordinary way, to print or display an announcement
+including an appropriate copyright notice and a notice that there is
+no warranty (or else, saying that you provide a warranty) and that
+users may redistribute the program under these conditions, and telling
+the user how to view a copy of this License. (Exception: if the
+Program itself is interactive but does not normally print such an
+announcement, your work based on the Program is not required to print
+an announcement.)
+
+These requirements apply to the modified work as a whole. If
+identifiable sections of that work are not derived from the Program,
+and can be reasonably considered independent and separate works in
+themselves, then this License, and its terms, do not apply to those
+sections when you distribute them as separate works. But when you
+distribute the same sections as part of a whole which is a work based
+on the Program, the distribution of the whole must be on the terms of
+this License, whose permissions for other licensees extend to the
+entire whole, and thus to each and every part regardless of who wrote
+it.
+
+Thus, it is not the intent of this section to claim rights or contest
+your rights to work written entirely by you; rather, the intent is to
+exercise the right to control the distribution of derivative or
+collective works based on the Program.
+
+In addition, mere aggregation of another work not based on the Program
+with the Program (or with a work based on the Program) on a volume of
+a storage or distribution medium does not bring the other work under
+the scope of this License.
+
+**3.** You may copy and distribute the Program (or a work based on it,
+under Section 2) in object code or executable form under the terms of
+Sections 1 and 2 above provided that you also do one of the following:
+
+  
+**a)** Accompany it with the complete corresponding machine-readable
+source code, which must be distributed under the terms of Sections 1
+and 2 above on a medium customarily used for software interchange; or,
+
+  
+**b)** Accompany it with a written offer, valid for at least three
+years, to give any third party, for a charge no more than your cost of
+physically performing source distribution, a complete machine-readable
+copy of the corresponding source code, to be distributed under the
+terms of Sections 1 and 2 above on a medium customarily used for
+software interchange; or,
+
+  
+**c)** Accompany it with the information you received as to the offer
+to distribute corresponding source code. (This alternative is allowed
+only for noncommercial distribution and only if you received the
+program in object code or executable form with such an offer, in
+accord with Subsection b above.)
+
+The source code for a work means the preferred form of the work for
+making modifications to it. For an executable work, complete source
+code means all the source code for all modules it contains, plus any
+associated interface definition files, plus the scripts used to
+control compilation and installation of the executable. However, as a
+special exception, the source code distributed need not include
+anything that is normally distributed (in either source or binary
+form) with the major components (compiler, kernel, and so on) of the
+operating system on which the executable runs, unless that component
+itself accompanies the executable.
+
+If distribution of executable or object code is made by offering
+access to copy from a designated place, then offering equivalent
+access to copy the source code from the same place counts as
+distribution of the source code, even though third parties are not
+compelled to copy the source along with the object code.
+
+**4.** You may not copy, modify, sublicense, or distribute the Program
+except as expressly provided under this License. Any attempt otherwise
+to copy, modify, sublicense or distribute the Program is void, and
+will automatically terminate your rights under this License. However,
+parties who have received copies, or rights, from you under this
+License will not have their licenses terminated so long as such
+parties remain in full compliance.
+
+**5.** You are not required to accept this License, since you have not
+signed it. However, nothing else grants you permission to modify or
+distribute the Program or its derivative works. These actions are
+prohibited by law if you do not accept this License. Therefore, by
+modifying or distributing the Program (or any work based on the
+Program), you indicate your acceptance of this License to do so, and
+all its terms and conditions for copying, distributing or modifying
+the Program or works based on it.
+
+**6.** Each time you redistribute the Program (or any work based on
+the Program), the recipient automatically receives a license from the
+original licensor to copy, distribute or modify the Program subject to
+these terms and conditions. You may not impose any further
+restrictions on the recipients' exercise of the rights granted herein.
+You are not responsible for enforcing compliance by third parties to
 this License.
 
-  Each contributor grants you a non-exclusive, worldwide, royalty-free
-patent license under the contributor's essential patent claims, to
-make, use, sell, offer for sale, import and otherwise run, modify and
-propagate the contents of its contributor version.
+**7.** If, as a consequence of a court judgment or allegation of
+patent infringement or for any other reason (not limited to patent
+issues), conditions are imposed on you (whether by court order,
+agreement or otherwise) that contradict the conditions of this
+License, they do not excuse you from the conditions of this License.
+If you cannot distribute so as to satisfy simultaneously your
+obligations under this License and any other pertinent obligations,
+then as a consequence you may not distribute the Program at all. For
+example, if a patent license would not permit royalty-free
+redistribution of the Program by all those who receive copies directly
+or indirectly through you, then the only way you could satisfy both it
+and this License would be to refrain entirely from distribution of the
+Program.
 
-  In the following three paragraphs, a "patent license" is any express
-agreement or commitment, however denominated, not to enforce a patent
-(such as an express permission to practice a patent or covenant not to
-sue for patent infringement).  To "grant" such a patent license to a
-party means to make such an agreement or commitment not to enforce a
-patent against the party.
+If any portion of this section is held invalid or unenforceable under
+any particular circumstance, the balance of the section is intended to
+apply and the section as a whole is intended to apply in other
+circumstances.
 
-  If you convey a covered work, knowingly relying on a patent license,
-and the Corresponding Source of the work is not available for anyone
-to copy, free of charge and under the terms of this License, through a
-publicly available network server or other readily accessible means,
-then you must either (1) cause the Corresponding Source to be so
-available, or (2) arrange to deprive yourself of the benefit of the
-patent license for this particular work, or (3) arrange, in a manner
-consistent with the requirements of this License, to extend the patent
-license to downstream recipients.  "Knowingly relying" means you have
-actual knowledge that, but for the patent license, your conveying the
-covered work in a country, or your recipient's use of the covered work
-in a country, would infringe one or more identifiable patents in that
-country that you have reason to believe are valid.
+It is not the purpose of this section to induce you to infringe any
+patents or other property right claims or to contest validity of any
+such claims; this section has the sole purpose of protecting the
+integrity of the free software distribution system, which is
+implemented by public license practices. Many people have made
+generous contributions to the wide range of software distributed
+through that system in reliance on consistent application of that
+system; it is up to the author/donor to decide if he or she is willing
+to distribute software through any other system and a licensee cannot
+impose that choice.
 
-  If, pursuant to or in connection with a single transaction or
-arrangement, you convey, or propagate by procuring conveyance of, a
-covered work, and grant a patent license to some of the parties
-receiving the covered work authorizing them to use, propagate, modify
-or convey a specific copy of the covered work, then the patent license
-you grant is automatically extended to all recipients of the covered
-work and works based on it.
+This section is intended to make thoroughly clear what is believed to
+be a consequence of the rest of this License.
 
-  A patent license is "discriminatory" if it does not include within
-the scope of its coverage, prohibits the exercise of, or is
-conditioned on the non-exercise of one or more of the rights that are
-specifically granted under this License.  You may not convey a covered
-work if you are a party to an arrangement with a third party that is
-in the business of distributing software, under which you make payment
-to the third party based on the extent of your activity of conveying
-the work, and under which the third party grants, to any of the
-parties who would receive the covered work from you, a discriminatory
-patent license (a) in connection with copies of the covered work
-conveyed by you (or copies made from those copies), or (b) primarily
-for and in connection with specific products or compilations that
-contain the covered work, unless you entered into that arrangement,
-or that patent license was granted, prior to 28 March 2007.
+**8.** If the distribution and/or use of the Program is restricted in
+certain countries either by patents or by copyrighted interfaces, the
+original copyright holder who places the Program under this License
+may add an explicit geographical distribution limitation excluding
+those countries, so that distribution is permitted only in or among
+countries not thus excluded. In such case, this License incorporates
+the limitation as if written in the body of this License.
 
-  Nothing in this License shall be construed as excluding or limiting
-any implied license or other defenses to infringement that may
-otherwise be available to you under applicable patent law.
+**9.** The Free Software Foundation may publish revised and/or new
+versions of the General Public License from time to time. Such new
+versions will be similar in spirit to the present version, but may
+differ in detail to address new problems or concerns.
 
-  12. No Surrender of Others' Freedom.
+Each version is given a distinguishing version number. If the Program
+specifies a version number of this License which applies to it and
+"any later version", you have the option of following the terms and
+conditions either of that version or of any later version published by
+the Free Software Foundation. If the Program does not specify a
+version number of this License, you may choose any version ever
+published by the Free Software Foundation.
 
-  If conditions are imposed on you (whether by court order, agreement or
-otherwise) that contradict the conditions of this License, they do not
-excuse you from the conditions of this License.  If you cannot convey a
-covered work so as to satisfy simultaneously your obligations under this
-License and any other pertinent obligations, then as a consequence you may
-not convey it at all.  For example, if you agree to terms that obligate you
-to collect a royalty for further conveying from those to whom you convey
-the Program, the only way you could satisfy both those terms and this
-License would be to refrain entirely from conveying the Program.
+**10.** If you wish to incorporate parts of the Program into other
+free programs whose distribution conditions are different, write to
+the author to ask for permission. For software which is copyrighted by
+the Free Software Foundation, write to the Free Software Foundation;
+we sometimes make exceptions for this. Our decision will be guided by
+the two goals of preserving the free status of all derivatives of our
+free software and of promoting the sharing and reuse of software
+generally.
 
-  13. Use with the GNU Affero General Public License.
+**NO WARRANTY**
 
-  Notwithstanding any other provision of this License, you have
-permission to link or combine any covered work with a work licensed
-under version 3 of the GNU Affero General Public License into a single
-combined work, and to convey the resulting work.  The terms of this
-License will continue to apply to the part which is the covered work,
-but the special requirements of the GNU Affero General Public License,
-section 13, concerning interaction through a network will apply to the
-combination as such.
+**11.** BECAUSE THE PROGRAM IS LICENSED FREE OF CHARGE, THERE IS NO
+WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY APPLICABLE LAW.
+EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR
+OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY OF ANY
+KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE
+PROGRAM IS WITH YOU. SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME
+THE COST OF ALL NECESSARY SERVICING, REPAIR OR CORRECTION.
 
-  14. Revised Versions of this License.
+**12.** IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN
+WRITING WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY
+AND/OR REDISTRIBUTE THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU
+FOR DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL OR
+CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE THE
+PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA BEING
+RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD PARTIES OR A
+FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS), EVEN IF
+SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
+DAMAGES.
 
-  The Free Software Foundation may publish revised and/or new versions of
-the GNU General Public License from time to time.  Such new versions will
-be similar in spirit to the present version, but may differ in detail to
-address new problems or concerns.
+### END OF TERMS AND CONDITIONS
 
-  Each version is given a distinguishing version number.  If the
-Program specifies that a certain numbered version of the GNU General
-Public License "or any later version" applies to it, you have the
-option of following the terms and conditions either of that numbered
-version or of any later version published by the Free Software
-Foundation.  If the Program does not specify a version number of the
-GNU General Public License, you may choose any version ever published
-by the Free Software Foundation.
+### How to Apply These Terms to Your New Programs
 
-  If the Program specifies that a proxy can decide which future
-versions of the GNU General Public License can be used, that proxy's
-public statement of acceptance of a version permanently authorizes you
-to choose that version for the Program.
-
-  Later license versions may give you additional or different
-permissions.  However, no additional obligations are imposed on any
-author or copyright holder as a result of your choosing to follow a
-later version.
-
-  15. Disclaimer of Warranty.
-
-  THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY
-APPLICABLE LAW.  EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT
-HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY
-OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO,
-THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
-PURPOSE.  THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM
-IS WITH YOU.  SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF
-ALL NECESSARY SERVICING, REPAIR OR CORRECTION.
-
-  16. Limitation of Liability.
-
-  IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
-WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES AND/OR CONVEYS
-THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY
-GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE
-USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF
-DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD
-PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS),
-EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF
-SUCH DAMAGES.
-
-  17. Interpretation of Sections 15 and 16.
-
-  If the disclaimer of warranty and limitation of liability provided
-above cannot be given local legal effect according to their terms,
-reviewing courts shall apply local law that most closely approximates
-an absolute waiver of all civil liability in connection with the
-Program, unless a warranty or assumption of liability accompanies a
-copy of the Program in return for a fee.
-
-                     END OF TERMS AND CONDITIONS
-
-            How to Apply These Terms to Your New Programs
-
-  If you develop a new program, and you want it to be of the greatest
+If you develop a new program, and you want it to be of the greatest
 possible use to the public, the best way to achieve this is to make it
-free software which everyone can redistribute and change under these terms.
+free software which everyone can redistribute and change under these
+terms.
 
-  To do so, attach the following notices to the program.  It is safest
-to attach them to the start of each source file to most effectively
-state the exclusion of warranty; and each file should have at least
+To do so, attach the following notices to the program. It is safest to
+attach them to the start of each source file to most effectively
+convey the exclusion of warranty; and each file should have at least
 the "copyright" line and a pointer to where the full notice is found.
 
-    {one line to give the program's name and a brief idea of what it does.}
-    Copyright (C) {year}  {name of author}
+    one line to give the program's name and an idea of what it does.
+    Copyright (C) yyyy  name of author
 
-    This program is free software: you can redistribute it and/or modify
-    it under the terms of the GNU General Public License as published by
-    the Free Software Foundation, either version 3 of the License, or
-    (at your option) any later version.
+    This program is free software; you can redistribute it and/or
+    modify it under the terms of the GNU General Public License
+    as published by the Free Software Foundation; either version 2
+    of the License, or (at your option) any later version.
 
     This program is distributed in the hope that it will be useful,
     but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ -645,31 +319,43 @@ the "copyright" line and a pointer to where the full notice is found.
     GNU General Public License for more details.
 
     You should have received a copy of the GNU General Public License
-    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 
-Also add information on how to contact you by electronic and paper mail.
+Also add information on how to contact you by electronic and paper
+mail.
 
-  If the program does terminal interaction, make it output a short
-notice like this when it starts in an interactive mode:
+If the program is interactive, make it output a short notice like this
+when it starts in an interactive mode:
 
-    {project}  Copyright (C) {year}  {fullname}
-    This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
-    This is free software, and you are welcome to redistribute it
-    under certain conditions; type `show c' for details.
+    Gnomovision version 69, Copyright (C) year name of author
+    Gnomovision comes with ABSOLUTELY NO WARRANTY; for details
+    type `show w'.  This is free software, and you are welcome
+    to redistribute it under certain conditions; type `show c' 
+    for details.
 
-The hypothetical commands `show w' and `show c' should show the appropriate
-parts of the General Public License.  Of course, your program's commands
-might be different; for a GUI interface, you would use an "about box".
+The hypothetical commands \`show w' and \`show c' should show the
+appropriate parts of the General Public License. Of course, the
+commands you use may be called something other than \`show w' and
+\`show c'; they could even be mouse-clicks or menu items--whatever
+suits your program.
 
-  You should also get your employer (if you work as a programmer) or school,
-if any, to sign a "copyright disclaimer" for the program, if necessary.
-For more information on this, and how to apply and follow the GNU GPL, see
-<http://www.gnu.org/licenses/>.
+You should also get your employer (if you work as a programmer) or
+your school, if any, to sign a "copyright disclaimer" for the program,
+if necessary. Here is a sample; alter the names:
 
-  The GNU General Public License does not permit incorporating your program
-into proprietary programs.  If your program is a subroutine library, you
-may consider it more useful to permit linking proprietary applications with
-the library.  If this is what you want to do, use the GNU Lesser General
-Public License instead of this License.  But first, please read
-<http://www.gnu.org/philosophy/why-not-lgpl.html>.
+    Yoyodyne, Inc., hereby disclaims all copyright
+    interest in the program `Gnomovision'
+    (which makes passes at compilers) written 
+    by James Hacker.
 
+    signature of Ty Coon, 1 April 1989
+    Ty Coon, President of Vice
+
+This General Public License does not permit incorporating your program
+into proprietary programs. If your program is a subroutine library,
+you may consider it more useful to permit linking proprietary
+applications with the library. If this is what you want to do, use the
+[GNU Lesser General Public
+License](https://www.gnu.org/licenses/lgpl.html) instead of this
+License.

README.md

@@ -1,45 +1,197 @@
-# Statify Blacklist #
-* Contributors:      Stefan Kalscheuer
-* Requires at least: 3.9
-* Tested up to:      4.6
-* Stable tag:        1.1.2
-* License:           GPLv3 or later
-* License URI:       https://www.gnu.org/licenses/gpl-3.0.html
+[![CI](https://github.com/stklcode/statify-blacklist/actions/workflows/test.yml/badge.svg?branch=stable)](https://github.com/stklcode/statify-blacklist/actions/workflows/test.yml)
+[![Quality Gate Status](https://sonarcloud.io/api/project_badges/measure?project=stklcode%3Astatify-blacklist&metric=alert_status)](https://sonarcloud.io/summary/new_code?id=stklcode%3Astatify-blacklist)
+[![Packagist Version](https://img.shields.io/packagist/v/stklcode/statify-blacklist)](https://packagist.org/packages/stklcode/statify-blacklist)
+[![License](https://img.shields.io/badge/license-GPL%20v2-blue.svg)](https://github.com/stklcode/statify-blacklist/blob/stable/LICENSE.md)
+
+# Statify Filter #
+* Contributors:      stklcode
+* Requires at least: 4.7
+* Tested up to:      6.8
+* Requires PHP:      5.5
+* Stable tag:        1.7.2
+* License:           GPLv2 or later
+* License URI:       https://www.gnu.org/licenses/gpl-2.0.html
+
+Filter extension for the famous Statify WordPress plugin.
 
 ## Description ##
-A blacklist extension for the famous [Statify](http://statify.de) Wordpress plugin.
+A filter extension for the famous [Statify](https://wordpress.org/plugins/statify/) WordPress plugin.
 
-This plugin adds customizable blacklist to Statify to allow blocking of referer spam or internal interactions.
+This plugin adds customizable filters to Statify to allow blocking of referer spam or internal interactions.
 
-### Current Features ##
-#### Referer Blacklist ####
+### Features ###
+
+#### Referer Filter ####
 Add a list of domains (for simplicity only second-level, e.g. _example.com_ which blocks _everything.example.com_).
 
+#### Target Filter ####
+Add a list of target pages (e.g. _/test/page/_, _/?page_id=123_) that will be excluded from tracking.
+
+#### IP Filter ####
+Add a list of IP addresses or subnets (e.g. _192.0.2.123_, _198.51.100.0/24_, _2001:db8:a0b:12f0::/64_).
+
+#### User Agent Filter ####
+Add a list of (partial) user agent strings to exclude (e.g. _curl_, _my/bot_, _Firefox_).
+
 #### CleanUp Database ####
 Filters can be applied to data stored in database after modifying filter rules or for one-time clean-up.
 
 #### Compatibility ####
-This plugin requires Statify to be installed. The extension has been tested with Statify 1.4.3
+This plugin requires Statify to be installed. The extension has been tested with Statify up to version 1.8
 The plugin is capable of handling multisite installations.
 
+### Support & Contributions ###
+* If you experience any issues, use the [support forums](https://wordpress.org/support/plugin/statify-blacklist).
+* Latest sources and development are handled on [GitHub](https://github.com/stklcode/statify-blacklist). You might contribute there or file an issue for code related bugs.
+* If you want to translate this plugin you can do this on [WordPress Translate](https://translate.wordpress.org/projects/wp-plugins/statify-blacklist).
+
 ### Credits ###
 * Author: Stefan Kalscheuer
-* Special Thanks to [pluginkollektiv](http://pluginkollektiv.org/) for maintaining _Statify_
+* Special Thanks to [pluginkollektiv](https://pluginkollektiv.org/) for maintaining _Statify_
 
 ## Installation ##
-* If you don’t know how to install a plugin for WordPress, [here’s how](http://codex.wordpress.org/Managing_Plugins#Installing_Plugins).
+* If you don’t know how to install a plugin for WordPress, [here’s how](https://wordpress.org/support/article/managing-plugins/#installing-plugins).
 * Make sure _Statify_ plugin is installed and active
-* Goto _Settings_ -> _Statify Blacklist_ to configure the plugin
+* Goto _Settings_ -> _Statify Filter_ to configure the plugin
 
 ### Requirements ###
-* PHP 5.2.4
-* WordPress 3.9
-* Statify plugin installed and activated (tested up to 1.4.3)
+* PHP 5.5 or above
+* WordPress 4.7 or above
+* _Statify_ plugin installed and activated (1.5 or above)
+
+## Frequently Asked Questions ##
+
+### What is blocked by default? ###
+Nothing. By default, all filters are empty and disabled. They can and have to be filled by the blog administrator.
+
+A default filter is not provided, as the plugin itself is totally neutral. If you want to filter out referer spam,
+visitors from search engines, just "false" referrers from 301 redirects or you own IP address used for testing only depends on you.
+
+### Does the filter effect user experience? ###
+No. It only prevents _Statify_ from tracking, nothing more or less.
+
+### Does live filtering impact performance? ###
+Yes, but probably not noticeable. Checking a single referer string against a (usually small) list should be negligible compared to the total loading procedure.
+If this still is an issue for you, consider deactivating the filter and only run the one-time-cleanup or activate the cron job.
+
+### Is any personal data collected? ###
+No. The privacy policy of _Statify_ is untouched. Data is only processed, not stored or exposed to anyone.
+
+### Are regular expression filters possible? ###
+Yes, it is. Just select regular expressions (case-sensitive or insensitive) as matching method instead of exact or keyword match.
+
+### Why is IP and User Agent filtering only available as live filter? ###
+As you might know, _Statify_ does not store any personal information, including IP addresses in the database.
+Because of this, these filters can only be applied while processing the request and not afterwards.
+
+### Can whole IP subnet be blocked? ###
+Yes. The plugin features subnet filters using CIDR notation.
+For example _198.51.100.0/24_ filters all sources from _198.51.100.1_ to _198.51.100.254_.
+Same for IPv6 prefixes like _2001:db8:a0b:12f0::/64_.
+
 
 ## Screenshots ##
-1. Statify Blacklist settings page
+1. Statify Filter settings page
+
+## Upgrade Notice ##
+
+### 1.7.2 ###
+This is a bugfix release to restore the manual cleanup function that was broken since 1.7.0.
+
+### 1.7.1 ###
+This is a service release with minor corrections. Recommended for all users. Tested up to 6.5.
+
+### 1.7.0 ###
+This is a service release with primarily internal rework. Tested up to 6.4 and PHP 8.3.
+
+
+## Changelog
+
+### 1.7.2 / 06.06.2024 ###
+* Restore manual database cleanup functionality
+
+### 1.7.1 / 24.03.2024 ###
+* Fix HTML syntax for checkboxes on settings page
+* Simplify some internal control structures
+* Add plugin dependency to Statify
+* Declared compatibility with WordPress 6.5
+
+### 1.7.0 / 11.03.2024 ###
+* Internal rework of plugin settings
+* Make the IP filter list unique
+* Fix options upgrade routine
+* Declared compatibility with WordPress 6.4
+
+### 1.6.3 / 14.08.2023 ###
+* Minor internal code cleanup
+* Declared compatibility with WordPress 6.3
+
+### 1.6.2 / 25.02.2023 ###
+* Always process IPv6 addresses lowercase
+* Optimize internally used regular expression
+* Minor adjustments to prevent warnings during user agent filtering with PHP 8.2
+
+### 1.6.1 / 28.05.2021 ###
+* Fix storage of user agent filter list (#28, props @BananaSquishee)
+
+### 1.6.0 / 09.12.2020 ###
+
+Plugin renamed to _Statify Filter_.
+
+* Minor accessibility fixes on settings page
+* Introduced new user agent filter (#20)
+* Declared compatibility with WordPress 5.6
+
+### 1.5.2 / 03.09.2020 ###
+* Minor translation updates
+* Declared compatibility with WordPress 5.5
+
+### 1.5.1 / 20.05.2020 ###
+* Fix initialization on AJAX calls for _Statify_ 1.7 compatibility (#22)
+
+### 1.5.0 / 13.05.2020 ###
+* Minimum required WordPress version is 4.7
+* Removed `load_plugin_textdomain()` and `Domain Path` header
+* Added automatic compatibility check for WP and PHP version (#17)
+* Added keyword filter mode for referer blacklist (#15)
+* Layout adjustments on settings page
+* Regular expression filters are validated before saving (#13)
+
+### 1.4.4 / 19.05.2018 ###
+* Fix live filter chain when regular expressions are active (#12)
+
+### 1.4.3 / 09.01.2018 ###
+* Fix issues with multisite installation (#11)
+
+### 1.4.2 / 12.11.2017 ###
+* Minor code fixes
+
+### 1.4.1 / 16.07.2017 ###
+* Relicensed to GPLv2 or later
+* Fix filter hook if referer is disabled (#9)
+* Fix problem with faulty IPv6 netmask in IP blacklist
+* Minor changes for WP Coding Standard
+* Minimum required WordPress version is 4.4 (#10)
+
+### 1.4.0 / 10.06.2017 ###
+* IP blacklist implemented (#7)
+* Target page blacklist implemented (#8)
+* Internal configuration restructured (upgrade on plugin activation)
+* Statify hook name changed to `statify__skip_tracking` (as of Statify 1.5.0)
+
+### 1.3.1 / 09.12.2016 ###
+* Continue filtering if no filter applies (#6)
+
+### 1.3.0 / 17.10.2016 ###
+* Regular expressions filtering implemented
+
+### 1.2.1 / 10.10.2016 ###
+* Fix live filter configuration check
+
+### 1.2.0 / 29.08.2016 ###
+* Switched from `in_array()` to faster `isset()` for referer checking
+* Optional cron execution implemented
 
-## Changelog ##
 ### 1.1.2 / 17.08.2016 ###
 * Prepared for localization
 

assets/blueprints/blueprint.json

@@ -0,0 +1,36 @@
+{
+  "$schema": "https://playground.wordpress.net/blueprint-schema.json",
+  "landingPage": "/wp-admin/options-general.php?page=statify-blacklist",
+  "features": {
+    "networking": true
+  },
+  "steps": [
+    {
+      "step": "login",
+      "username": "admin",
+      "password": "password"
+    },
+    {
+      "step": "installPlugin",
+      "pluginData": {
+        "resource": "wordpress.org/plugins",
+        "slug": "statify"
+      }
+    },
+    {
+      "step": "activatePlugin",
+      "pluginPath": "statify/statify.php"
+    },
+    {
+      "step": "installPlugin",
+      "pluginData": {
+        "resource": "wordpress.org/plugins",
+        "slug": "statify-blacklist"
+      }
+    },
+    {
+      "step": "activatePlugin",
+      "pluginPath": "statify-blacklist/statify-blacklist.php"
+    }
+  ]
+}

composer.json

@@ -0,0 +1,54 @@
+{
+  "name": "stklcode/statify-blacklist",
+  "version": "1.7.2",
+  "description": "A filter extension for the famous Statify WordPress plugin",
+  "keywords": [
+    "wordpress",
+    "plugin",
+    "statistics",
+    "filter"
+  ],
+  "license": "GPL-2.0-or-later",
+  "authors": [
+    {
+      "name": "Stefan Kalscheuer",
+      "email": "stefan@stklcode.de",
+      "homepage": "https://www.stklcode.de"
+    }
+  ],
+  "type": "wordpress-plugin",
+  "require": {
+    "php": ">=5.5",
+    "composer/installers": "~v1.12|~v2.3"
+  },
+  "require-dev": {
+    "dealerdirect/phpcodesniffer-composer-installer": "^v1.0",
+    "phpunit/phpunit": "^5|^6|^7|^8|^9",
+    "phpunit/php-code-coverage": "*",
+    "slowprog/composer-copy-file": "~0.3",
+    "squizlabs/php_codesniffer": "^3.12",
+    "phpcompatibility/phpcompatibility-wp": "^2.1",
+    "wp-coding-standards/wpcs": "^3.1"
+  },
+  "scripts": {
+    "test-all": [
+      "@test",
+      "@test-cs"
+    ],
+    "test": [
+      "phpunit"
+    ],
+    "test-cs": [
+      "phpcs --standard=phpcs.xml -s"
+    ],
+    "fix-cs": [
+      "phpcbf --standard=phpcs.xml"
+    ]
+  },
+  "config": {
+    "allow-plugins": {
+      "composer/installers": true,
+      "dealerdirect/phpcodesniffer-composer-installer": true
+    }
+  }
+}

inc/class-statifyblacklist-admin.php

@@ -0,0 +1,221 @@
+<?php
+/**
+ * Statify Filter: StatifyBlacklist_Admin class
+ *
+ * This file contains the derived class for the plugin's administration features.
+ *
+ * @package   Statify_Blacklist
+ * @subpackge Admin
+ * @since     1.0.0
+ */
+
+// Quit if accessed directly.
+if ( ! defined( 'ABSPATH' ) ) {
+	exit;
+}
+
+/**
+ * Statify Filter admin configuration.
+ */
+class StatifyBlacklist_Admin extends StatifyBlacklist {
+
+	/**
+	 * Initialize admin-only components of the plugin.
+	 *
+	 * @return void
+	 *
+	 * @since 1.5.0
+	 */
+	public static function init() {
+		// Add actions.
+		add_action( 'wpmu_new_blog', array( 'StatifyBlacklist_System', 'install_site' ) );
+		add_action( 'delete_blog', array( 'StatifyBlacklist_System', 'uninstall_site' ) );
+		add_filter( 'plugin_row_meta', array( 'StatifyBlacklist_Admin', 'plugin_meta_link' ), 10, 2 );
+
+		if ( self::$multisite ) {
+			add_action( 'network_admin_menu', array( 'StatifyBlacklist_Admin', 'add_menu_page' ) );
+			add_filter(
+				'network_admin_plugin_action_links',
+				array(
+					'StatifyBlacklist_Admin',
+					'plugin_actions_links',
+				),
+				10,
+				2
+			);
+		} else {
+			add_action( 'admin_init', array( 'StatifyBlacklist_Settings', 'register_settings' ) );
+			add_action( 'admin_menu', array( 'StatifyBlacklist_Admin', 'add_menu_page' ) );
+			add_filter( 'plugin_action_links', array( 'StatifyBlacklist_Admin', 'plugin_actions_links' ), 10, 2 );
+		}
+	}
+
+	/**
+	 * Add configuration page to admin menu.
+	 *
+	 * @since 1.0.0
+	 */
+	public static function add_menu_page() {
+		$title = __( 'Statify Filter', 'statify-blacklist' );
+		if ( self::$multisite ) {
+			add_options_page(
+				$title,
+				$title,
+				'manage_network_plugins',
+				'statify-blacklist',
+				array( 'StatifyBlacklist_Settings', 'create_settings_page' )
+			);
+		} else {
+			add_options_page(
+				$title,
+				$title,
+				'manage_options',
+				'statify-blacklist',
+				array( 'StatifyBlacklist_Settings', 'create_settings_page' )
+			);
+		}
+	}
+
+	/**
+	 * Add plugin meta links
+	 *
+	 * @param array  $links Registered links.
+	 * @param string $file  The filename.
+	 *
+	 * @return array  Merged links.
+	 *
+	 * @since 1.0.0
+	 */
+	public static function plugin_meta_link( $links, $file ) {
+		if ( STATIFYBLACKLIST_BASE === $file ) {
+			$links[] = '<a href="https://github.com/stklcode/statify-blacklist">GitHub</a>';
+		}
+
+		return $links;
+	}
+
+	/**
+	 * Add plugin action links.
+	 *
+	 * @param array  $links Registered links.
+	 * @param string $file  The filename.
+	 *
+	 * @return array  Merged links.
+	 *
+	 * @since 1.0.0
+	 */
+	public static function plugin_actions_links( $links, $file ) {
+		$base = self::$multisite ? network_admin_url( 'settings.php' ) : admin_url( 'options-general.php' );
+
+		if ( STATIFYBLACKLIST_BASE === $file && current_user_can( 'manage_options' ) ) {
+			array_unshift(
+				$links,
+				sprintf( '<a href="%s">%s</a>', esc_attr( add_query_arg( 'page', 'statify-blacklist', $base ) ), __( 'Settings', 'statify-blacklist' ) )
+			);
+		}
+
+		return $links;
+	}
+
+	/**
+	 * Filter database for cleanup.
+	 *
+	 * @since 1.1.0
+	 *
+	 * @global wpdb $wpdb WordPress database.
+	 */
+	public static function cleanup_database() {
+		// Check user permissions.
+		if ( ! current_user_can( 'manage_options' ) && ! ( defined( 'DOING_CRON' ) && DOING_CRON ) ) {
+			die( esc_html__( 'Are you sure you want to do this?', 'statify-blacklist' ) );
+		}
+
+		if ( defined( 'DOING_CRON' ) && DOING_CRON ) {
+			$clean_ref = ( 1 === self::$options['referer']['cron'] );
+			$clean_trg = ( 1 === self::$options['target']['cron'] );
+		} else {
+			$clean_ref = true;
+			$clean_trg = true;
+		}
+
+		if ( $clean_ref ) {
+			if ( isset( self::$options['referer']['regexp'] ) && self::$options['referer']['regexp'] > 0 ) {
+				// Merge given regular expressions into one.
+				$referer_regexp = implode( '|', array_keys( self::$options['referer']['blacklist'] ) );
+			} else {
+				// Sanitize URLs.
+				$referer = self::sanitize_urls( self::$options['referer']['blacklist'] );
+
+				// Build filter regexp.
+				$referer_regexp = str_replace( '.', '\.', implode( '|', array_flip( $referer ) ) );
+			}
+		}
+
+		if ( $clean_trg ) {
+			if ( isset( self::$options['target']['regexp'] ) && self::$options['target']['regexp'] > 0 ) {
+				// Merge given regular expressions into one.
+				$target_regexp = implode( '|', array_keys( self::$options['target']['blacklist'] ) );
+			} else {
+				// Build filter regexp.
+				$target_regexp = str_replace( '.', '\.', implode( '|', array_flip( self::$options['target']['blacklist'] ) ) );
+			}
+		}
+
+		if ( ! empty( $referer_regexp ) || ! empty( $target_regexp ) ) {
+			global $wpdb;
+
+			// Execute filter on database.
+			// phpcs:disable WordPress.DB.PreparedSQL.NotPrepared -- These statements produce warnings, rework in future release (TODO).
+			if ( ! empty( $referer_regexp ) ) {
+				$wpdb->query(
+					$wpdb->prepare(
+						"DELETE FROM `$wpdb->statify` WHERE "
+						. ( ( 1 === self::$options['referer']['regexp'] ) ? ' BINARY ' : '' )
+						. 'referrer REGEXP %s',
+						$referer_regexp
+					)
+				);
+			}
+			if ( ! empty( $target_regexp ) ) {
+				$wpdb->query(
+					$wpdb->prepare(
+						"DELETE FROM `$wpdb->statify` WHERE "
+						. ( ( 1 === self::$options['target']['regexp'] ) ? ' BINARY ' : '' )
+						. 'target REGEXP %s',
+						$target_regexp
+					)
+				);
+			}
+			// phpcs:enable WordPress.DB.PreparedSQL.NotPrepared
+
+			// Optimize DB.
+			$wpdb->query( "OPTIMIZE TABLE `$wpdb->statify`" );
+
+			// Delete transient statify data.
+			delete_transient( 'statify_data' );
+		}
+	}
+
+
+	/**
+	 * Sanitize URLs and remove empty results.
+	 *
+	 * @param array $urls given array of URLs.
+	 *
+	 * @return array  sanitized array.
+	 *
+	 * @since 1.1.1
+	 */
+	private static function sanitize_urls( $urls ) {
+		return array_flip(
+			array_filter(
+				array_map(
+					function ( $r ) {
+						return preg_replace( '/[^\da-z\.-]/i', '', filter_var( $r, FILTER_SANITIZE_URL ) );
+					},
+					array_flip( $urls )
+				)
+			)
+		);
+	}
+}

inc/class-statifyblacklist-settings.php

@@ -0,0 +1,752 @@
+<?php
+/**
+ * Statify Filter: StatifyBlacklist_Settings class
+ *
+ * This file contains the plugin's settings capabilities.
+ *
+ * @package Statify_Blacklist
+ * @since 1.7.0
+ */
+
+// Quit if accessed directly.
+defined( 'ABSPATH' ) || exit;
+
+/**
+ * Statify Filter settings handling.
+ */
+class StatifyBlacklist_Settings extends StatifyBlacklist {
+	/**
+	 * Registers all options using the WP Settings API.
+	 *
+	 * @return void
+	 */
+	public static function register_settings() {
+		register_setting(
+			'statify-blacklist',
+			'statify-blacklist',
+			array(
+				'sanitize_callback' =>
+					array( __CLASS__, 'sanitize_options' ),
+			)
+		);
+
+		// Referer filter.
+		add_settings_section(
+			'statifyblacklist-referer',
+			__( 'Referer filter', 'statify-blacklist' ),
+			null,
+			'statify-blacklist'
+		);
+		add_settings_field(
+			'statifyblacklist-referer-active',
+			__( 'Activate live filter', 'statify-blacklist' ),
+			array( __CLASS__, 'option_referer_active' ),
+			'statify-blacklist',
+			'statifyblacklist-referer'
+		);
+		add_settings_field(
+			'statifyblacklist-referer-cron',
+			__( 'CronJob execution', 'statify-blacklist' ),
+			array( __CLASS__, 'option_referer_cron' ),
+			'statify-blacklist',
+			'statifyblacklist-referer'
+		);
+		add_settings_field(
+			'statifyblacklist-referer-regexp',
+			__( 'Matching method', 'statify-blacklist' ),
+			array( __CLASS__, 'option_referer_regexp' ),
+			'statify-blacklist',
+			'statifyblacklist-referer',
+			array( 'label_for' => 'statifyblacklist-referer-regexp' )
+		);
+		add_settings_field(
+			'statifyblacklist-referer-blacklist',
+			__( 'Referer filter', 'statify-blacklist' ),
+			array( __CLASS__, 'option_referer_blacklist' ),
+			'statify-blacklist',
+			'statifyblacklist-referer',
+			array( 'label_for' => 'statifyblacklist-referer-blacklist' )
+		);
+
+		// Target filter.
+		add_settings_section(
+			'statifyblacklist-target',
+			__( 'Target filter', 'statify-blacklist' ),
+			null,
+			'statify-blacklist'
+		);
+		add_settings_field(
+			'statifyblacklist-target-active',
+			__( 'Activate live filter', 'statify-blacklist' ),
+			array( __CLASS__, 'option_target_active' ),
+			'statify-blacklist',
+			'statifyblacklist-target'
+		);
+		add_settings_field(
+			'statifyblacklist-target-cron',
+			__( 'CronJob execution', 'statify-blacklist' ),
+			array( __CLASS__, 'option_target_cron' ),
+			'statify-blacklist',
+			'statifyblacklist-target'
+		);
+		add_settings_field(
+			'statifyblacklist-target-regexp',
+			__( 'Matching method', 'statify-blacklist' ),
+			array( __CLASS__, 'option_target_regexp' ),
+			'statify-blacklist',
+			'statifyblacklist-target',
+			array( 'label_for' => 'statifyblacklist-target-regexp' )
+		);
+		add_settings_field(
+			'statifyblacklist-target-blacklist',
+			__( 'Target filter', 'statify-blacklist' ),
+			array( __CLASS__, 'option_target_blacklist' ),
+			'statify-blacklist',
+			'statifyblacklist-target',
+			array( 'label_for' => 'statifyblacklist-target-blacklist' )
+		);
+
+		// IP filter.
+		add_settings_section(
+			'statifyblacklist-ip',
+			__( 'IP filter', 'statify-blacklist' ),
+			null,
+			'statify-blacklist'
+		);
+		add_settings_field(
+			'statifyblacklist-ip-active',
+			__( 'Activate live filter', 'statify-blacklist' ),
+			array( __CLASS__, 'option_ip_active' ),
+			'statify-blacklist',
+			'statifyblacklist-ip'
+		);
+		add_settings_field(
+			'statifyblacklist-ip-blacklist',
+			__( 'IP filter', 'statify-blacklist' ),
+			array( __CLASS__, 'option_ip_blacklist' ),
+			'statify-blacklist',
+			'statifyblacklist-ip',
+			array( 'label_for' => 'statifyblacklist-ip-blacklist' )
+		);
+
+		// User agent filter.
+		add_settings_section(
+			'statifyblacklist-ua',
+			__( 'User agent filter', 'statify-blacklist' ),
+			null,
+			'statify-blacklist'
+		);
+		add_settings_field(
+			'statifyblacklist-ua-active',
+			__( 'Activate live filter', 'statify-blacklist' ),
+			array( __CLASS__, 'option_ua_active' ),
+			'statify-blacklist',
+			'statifyblacklist-ua'
+		);
+		add_settings_field(
+			'statifyblacklist-ua-regexp',
+			__( 'Matching method', 'statify-blacklist' ),
+			array( __CLASS__, 'option_ua_regexp' ),
+			'statify-blacklist',
+			'statifyblacklist-ua',
+			array( 'label_for' => 'statifyblacklist-ua-regexp' )
+		);
+		add_settings_field(
+			'statifyblacklist-ua-blacklist',
+			__( 'User agent filter', 'statify-blacklist' ),
+			array( __CLASS__, 'option_ua_blacklist' ),
+			'statify-blacklist',
+			'statifyblacklist-ua',
+			array( 'label_for' => 'statifyblacklist-ua-blacklist' )
+		);
+	}
+
+	/**
+	 * Creates the settings pages.
+	 *
+	 * @return void
+	 */
+	public static function create_settings_page() {
+		?>
+		<div class="wrap">
+			<h1><?php esc_html_e( 'Statify Filter', 'statify-blacklist' ); ?></h1>
+			<?php
+			if ( isset( $_SERVER['REQUEST_METHOD'] ) && 'POST' === $_SERVER['REQUEST_METHOD'] && ! empty( $_POST['cleanup'] ) ) {
+				// Database cleanup requested.
+				if ( isset( $_REQUEST['_wpnonce'] ) && wp_verify_nonce( sanitize_key( $_REQUEST['_wpnonce'] ), 'statify-blacklist-options' ) ) {
+					// Nonce verification successful, proceed with cleanup.
+					StatifyBlacklist_Admin::cleanup_database();
+					?>
+					<div class="notice notice-success is-dismissible">
+						<p><?php esc_html_e( 'Database cleanup successful', 'statify-blacklist' ); ?></p>
+					</div>
+					<?php
+				} else {
+					// Nonce verification failed.
+					?>
+					<div class="notice notice-error is-dismissible">
+						<p><?php esc_html_e( 'Database cleanup request failed', 'statify-blacklist' ); ?></p>
+					</div>
+					<?php
+				}
+			}
+			?>
+
+			<form id="statify-settings" method="post" action="options.php">
+				<?php
+				settings_fields( 'statify-blacklist' );
+				do_settings_sections( 'statify-blacklist' );
+				submit_button();
+				?>
+				<hr>
+				<input class="button-secondary" type="submit" name="cleanup"
+					formaction=""
+					value="<?php esc_html_e( 'CleanUp Database', 'statify-blacklist' ); ?>"
+					onclick="return confirm('<?php echo esc_js( __( 'Do you really want to apply filters to database? This cannot be undone.', 'statify-blacklist' ) ); ?>');">
+				<p class="description">
+					<?php esc_html_e( 'Applies referer and target filter (even if disabled) to data stored in database.', 'statify-blacklist' ); ?>
+					<em><?php esc_html_e( 'This cannot be undone!', 'statify-blacklist' ); ?></em>
+				</p>
+			</form>
+		</div>
+
+		<?php
+	}
+
+	/*
+	 * Disable some code style rules that are impractical for textarea content:
+	 *
+	 * phpcs:disable Squiz.PHP.EmbeddedPhp.ContentBeforeOpen
+	 * phpcs:disable Squiz.PHP.EmbeddedPhp.ContentAfterEnd
+	 */
+
+	/**
+	 * Option for activating the live referer filter.
+	 *
+	 * @return void
+	 */
+	public static function option_referer_active() {
+		?>
+		<fieldset>
+			<legend class="screen-reader-text"><?php esc_html_e( 'Activate live filter', 'statify-blacklist' ); ?></legend>
+			<label for="statifyblacklist-referer-active">
+				<input id="statifyblacklist-referer-active" name="statify-blacklist[referer][active]" type="checkbox" value="1" <?php checked( StatifyBlacklist::$options['referer']['active'], 1 ); ?>>
+				<?php esc_html_e( 'Activate', 'statify-blacklist' ); ?>
+			</label>
+			<p class="description">
+				<?php esc_html_e( 'Filter at time of tracking, before anything is stored', 'statify-blacklist' ); ?>
+			</p>
+		</fieldset>
+		<?php
+	}
+
+	/**
+	 * Option for activating cron the referer filter.
+	 *
+	 * @return void
+	 */
+	public static function option_referer_cron() {
+		?>
+		<fieldset>
+			<legend class="screen-reader-text"><?php esc_html_e( 'CronJob execution', 'statify-blacklist' ); ?></legend>
+			<label for="statifyblacklist-referer-cron">
+				<input id="statifyblacklist-referer-cron" name="statify-blacklist[referer][cron]" type="checkbox" value="1" <?php checked( StatifyBlacklist::$options['referer']['cron'], 1 ); ?>>
+				<?php esc_html_e( 'Activate', 'statify-blacklist' ); ?>
+			</label>
+			<p class="description">
+				<?php esc_html_e( 'Periodically clean up database in background', 'statify-blacklist' ); ?>
+			</p>
+		</fieldset>
+		<?php
+	}
+
+	/**
+	 * Option for referer matching method.
+	 *
+	 * @return void
+	 */
+	public static function option_referer_regexp() {
+		?>
+		<select id="statifyblacklist-referer-regexp" name="statify-blacklist[referer][regexp]">
+			<option value="<?php print esc_attr( StatifyBlacklist::MODE_NORMAL ); ?>" <?php selected( StatifyBlacklist::$options['referer']['regexp'], StatifyBlacklist::MODE_NORMAL ); ?>>
+				<?php esc_html_e( 'Domain', 'statify-blacklist' ); ?>
+			</option>
+			<option value="<?php print esc_attr( StatifyBlacklist::MODE_KEYWORD ); ?>" <?php selected( StatifyBlacklist::$options['referer']['regexp'], StatifyBlacklist::MODE_KEYWORD ); ?>>
+				<?php esc_html_e( 'Keyword', 'statify-blacklist' ); ?>
+			</option>
+			<option value="<?php print esc_attr( StatifyBlacklist::MODE_REGEX ); ?>" <?php selected( StatifyBlacklist::$options['referer']['regexp'], StatifyBlacklist::MODE_REGEX ); ?>>
+				<?php esc_html_e( 'RegEx case-sensitive', 'statify-blacklist' ); ?>
+			</option>
+			<option value="<?php print esc_attr( StatifyBlacklist::MODE_REGEX_CI ); ?>" <?php selected( StatifyBlacklist::$options['referer']['regexp'], StatifyBlacklist::MODE_REGEX_CI ); ?>>
+				<?php esc_html_e( 'RegEx case-insensitive', 'statify-blacklist' ); ?>
+			</option>
+		</select>
+		<p class="description">
+			<?php esc_html_e( 'Domain', 'statify-blacklist' ); ?> - <?php esc_html_e( 'Match given domain including subdomains', 'statify-blacklist' ); ?>
+			<br>
+			<?php esc_html_e( 'Keyword', 'statify-blacklist' ); ?> - <?php esc_html_e( 'Match every referer that contains one of the keywords', 'statify-blacklist' ); ?>
+			<br>
+			<?php esc_html_e( 'RegEx', 'statify-blacklist' ); ?> - <?php esc_html_e( 'Match referer by regular expression', 'statify-blacklist' ); ?>
+		</p>
+		<?php
+	}
+
+	/**
+	 * Option for the referer filter list.
+	 *
+	 * @return void
+	 */
+	public static function option_referer_blacklist() {
+		?>
+		<textarea id="statifyblacklist-referer-blacklist" name="statify-blacklist[referer][blacklist]" cols="40" rows="5"><?php
+		print esc_html( implode( "\r\n", array_keys( StatifyBlacklist::$options['referer']['blacklist'] ) ) );
+		?></textarea>
+		<p class="description">
+			<?php esc_html_e( 'Add one domain (without subdomains) each line, e.g. example.com', 'statify-blacklist' ); ?>
+		</p>
+		<?php
+	}
+
+	/**
+	 * Option for activating the live target filter.
+	 *
+	 * @return void
+	 */
+	public static function option_target_active() {
+		?>
+		<fieldset>
+			<legend class="screen-reader-text"><?php esc_html_e( 'Activate live filter', 'statify-blacklist' ); ?></legend>
+			<label for="statifyblacklist-target-active">
+				<input id="statifyblacklist-target-active" name="statify-blacklist[target][active]" type="checkbox" value="1" <?php checked( StatifyBlacklist::$options['target']['active'], 1 ); ?>>
+				<?php esc_html_e( 'Activate', 'statify-blacklist' ); ?>
+			</label>
+			<p class="description">
+				<?php esc_html_e( 'Filter at time of tracking, before anything is stored', 'statify-blacklist' ); ?>
+			</p>
+		</fieldset>
+		<?php
+	}
+
+	/**
+	 * Option for activating cron the target filter.
+	 *
+	 * @return void
+	 */
+	public static function option_target_cron() {
+		?>
+		<fieldset>
+			<legend class="screen-reader-text"><?php esc_html_e( 'CronJob execution', 'statify-blacklist' ); ?></legend>
+			<label for="statifyblacklist-target-cron">
+				<input id="statifyblacklist-target-cron" name="statify-blacklist[target][cron]" type="checkbox" value="1" <?php checked( StatifyBlacklist::$options['target']['cron'], 1 ); ?>>
+				<?php esc_html_e( 'Activate', 'statify-blacklist' ); ?>
+			</label>
+			<p class="description">
+				<?php esc_html_e( 'Clean database periodically in background', 'statify-blacklist' ); ?>
+			</p>
+		</fieldset>
+		<?php
+	}
+
+	/**
+	 * Option for target matching method.
+	 *
+	 * @return void
+	 */
+	public static function option_target_regexp() {
+		?>
+		<select id="statifyblacklist-target-regexp" name="statify-blacklist[target][regexp]">
+			<option value="<?php print esc_attr( StatifyBlacklist::MODE_NORMAL ); ?>" <?php selected( StatifyBlacklist::$options['target']['regexp'], StatifyBlacklist::MODE_NORMAL ); ?>>
+				<?php esc_html_e( 'Exact', 'statify-blacklist' ); ?>
+			</option>
+			<option value="<?php print esc_attr( StatifyBlacklist::MODE_REGEX ); ?>" <?php selected( StatifyBlacklist::$options['target']['regexp'], StatifyBlacklist::MODE_REGEX ); ?>>
+				<?php esc_html_e( 'RegEx case-sensitive', 'statify-blacklist' ); ?>
+			</option>
+			<option value="<?php print esc_attr( StatifyBlacklist::MODE_REGEX_CI ); ?>" <?php selected( StatifyBlacklist::$options['target']['regexp'], StatifyBlacklist::MODE_REGEX_CI ); ?>>
+				<?php esc_html_e( 'RegEx case-insensitive', 'statify-blacklist' ); ?>
+			</option>
+		</select>
+		<p class="description">
+			<?php esc_html_e( 'Exact', 'statify-blacklist' ); ?> - <?php esc_html_e( 'Match only given targets', 'statify-blacklist' ); ?>
+			<br>
+			<?php esc_html_e( 'RegEx', 'statify-blacklist' ); ?> - <?php esc_html_e( 'Match target by regular expression', 'statify-blacklist' ); ?>
+		</p>
+		<?php
+	}
+
+	/**
+	 * Option for the target filter list.
+	 *
+	 * @return void
+	 */
+	public static function option_target_blacklist() {
+		?>
+		<textarea id="statifyblacklist-target-blacklist" name="statify-blacklist[target][blacklist]" cols="40" rows="5"><?php
+		print esc_html( implode( "\r\n", array_keys( StatifyBlacklist::$options['target']['blacklist'] ) ) );
+		?></textarea>
+		<p class="description">
+			<?php esc_html_e( 'Add one target URL each line, e.g.', 'statify-blacklist' ); ?> /, /test/page/, /?page_id=123
+		</p>
+		<?php
+	}
+
+	/**
+	 * Option for activating the live IP filter.
+	 *
+	 * @return void
+	 */
+	public static function option_ip_active() {
+		?>
+		<fieldset>
+			<legend class="screen-reader-text"><?php esc_html_e( 'Activate live filter', 'statify-blacklist' ); ?></legend>
+			<label for="statifyblacklist-ip-active">
+				<input id="statifyblacklist-ip-active" name="statify-blacklist[ip][active]" type="checkbox" value="1" <?php checked( StatifyBlacklist::$options['ip']['active'], 1 ); ?>>
+				<?php esc_html_e( 'Activate', 'statify-blacklist' ); ?>
+			</label>
+			<p class="description">
+				<?php esc_html_e( 'Filter at time of tracking, before anything is stored', 'statify-blacklist' ); ?>
+				<br>
+				<?php esc_html_e( 'Cron execution is not possible for IP filter, because IP addresses are not stored.', 'statify-blacklist' ); ?>
+			</p>
+		</fieldset>
+		<?php
+	}
+
+	/**
+	 * Option for the IP filter list.
+	 *
+	 * @return void
+	 */
+	public static function option_ip_blacklist() {
+		?>
+		<textarea id="statifyblacklist-ip-blacklist" name="statify-blacklist[ip][blacklist]" cols="40" rows="5"><?php
+		print esc_html( implode( "\r\n", StatifyBlacklist::$options['ip']['blacklist'] ) );
+		?></textarea>
+		<p class="description">
+			<?php esc_html_e( 'Add one IP address or range per line, e.g.', 'statify-blacklist' ); ?>
+			127.0.0.1, 192.168.123.0/24, 2001:db8:a0b:12f0::1/64
+		</p>
+		<?php
+	}
+
+	/**
+	 * Option for activating the live user agent filter.
+	 *
+	 * @return void
+	 */
+	public static function option_ua_active() {
+		?>
+		<label for="statifyblacklist-ua-active">
+			<input id="statifyblacklist-ua-active" name="statify-blacklist[ua][active]" type="checkbox" value="1" <?php checked( StatifyBlacklist::$options['ua']['active'], 1 ); ?>>
+			<?php esc_html_e( 'Activate', 'statify-blacklist' ); ?>
+		</label>
+
+		<p class="description">
+			<?php esc_html_e( 'Filter at time of tracking, before anything is stored', 'statify-blacklist' ); ?>
+			<br>
+			<?php esc_html_e( 'Cron execution is not possible for user agent filter, because the user agent is stored.', 'statify-blacklist' ); ?>
+		</p>
+		<?php
+	}
+
+	/**
+	 * Option for user agent matching method.
+	 *
+	 * @return void
+	 */
+	public static function option_ua_regexp() {
+		?>
+		<select id="statifyblacklist-ua-regexp" name="statify-blacklist[ua][regexp]">
+			<option value="<?php print esc_attr( StatifyBlacklist::MODE_NORMAL ); ?>" <?php selected( StatifyBlacklist::$options['ua']['regexp'], StatifyBlacklist::MODE_NORMAL ); ?>>
+				<?php esc_html_e( 'Exact', 'statify-blacklist' ); ?>
+			</option>
+			<option value="<?php print esc_attr( StatifyBlacklist::MODE_KEYWORD ); ?>" <?php selected( StatifyBlacklist::$options['ua']['regexp'], StatifyBlacklist::MODE_KEYWORD ); ?>>
+				<?php esc_html_e( 'Keyword', 'statify-blacklist' ); ?>
+			</option>
+			<option value="<?php print esc_attr( StatifyBlacklist::MODE_REGEX ); ?>" <?php selected( StatifyBlacklist::$options['ua']['regexp'], StatifyBlacklist::MODE_REGEX ); ?>>
+				<?php esc_html_e( 'RegEx case-sensitive', 'statify-blacklist' ); ?>
+			</option>
+			<option value="<?php print esc_attr( StatifyBlacklist::MODE_REGEX_CI ); ?>" <?php selected( StatifyBlacklist::$options['ua']['regexp'], StatifyBlacklist::MODE_REGEX_CI ); ?>>
+				<?php esc_html_e( 'RegEx case-insensitive', 'statify-blacklist' ); ?>
+			</option>
+		</select>
+		<p class="description">
+			<?php esc_html_e( 'Exact', 'statify-blacklist' ); ?> - <?php esc_html_e( 'Match only given user agents', 'statify-blacklist' ); ?>
+			<br>
+			<?php esc_html_e( 'Keyword', 'statify-blacklist' ); ?> - <?php esc_html_e( 'Match every referer that contains one of the keywords', 'statify-blacklist' ); ?>
+			<br>
+			<?php esc_html_e( 'RegEx', 'statify-blacklist' ); ?> - <?php esc_html_e( 'Match user agent by regular expression', 'statify-blacklist' ); ?>
+		</p>
+		<?php
+	}
+
+	/**
+	 * Option for the user agent filter list.
+	 *
+	 * @return void
+	 */
+	public static function option_ua_blacklist() {
+		?>
+		<textarea name="statify-blacklist[ua][blacklist]" id="statifyblacklist-ua-blacklist" cols="40" rows="5"><?php
+		print esc_html( implode( "\r\n", StatifyBlacklist::$options['ua']['blacklist'] ) );
+		?></textarea>
+		<p class="description">
+			<?php esc_html_e( 'Add one user agent string per line, e.g.', 'statify-blacklist' ); ?>
+			MyBot/1.23
+		</p>
+		<?php
+	}
+
+	/**
+	 * Validate and sanitize submitted options.
+	 *
+	 * @param array $options Original options.
+	 *
+	 * @return array Validated and sanitized options.
+	 */
+	public static function sanitize_options( $options ) {
+		// Extract filter lists from multi-line inputs.
+		$referer = self::parse_multiline_option( $options['referer']['blacklist'] );
+		$target  = self::parse_multiline_option( $options['target']['blacklist'] );
+		$ip      = self::parse_multiline_option( $options['ip']['blacklist'] );
+		$ua      = self::parse_multiline_option( $options['ua']['blacklist'] );
+
+		// Generate options.
+		$res = array(
+			'referer' => array(
+				'active'    => isset( $options['referer']['active'] ) ? (int) $options['referer']['active'] : 0,
+				'cron'      => isset( $options['referer']['cron'] ) ? (int) $options['referer']['cron'] : 0,
+				'regexp'    => isset( $options['referer']['regexp'] ) ? (int) $options['referer']['regexp'] : 0,
+				'blacklist' => array_flip( $referer ),
+			),
+			'target'  => array(
+				'active'    => isset( $options['target']['active'] ) ? (int) $options['target']['active'] : 0,
+				'cron'      => isset( $options['target']['cron'] ) ? (int) $options['target']['cron'] : 0,
+				'regexp'    => isset( $options['target']['regexp'] ) ? (int) $options['target']['regexp'] : 0,
+				'blacklist' => array_flip( $target ),
+			),
+			'ip'      => array(
+				'active'    => isset( $options['ip']['active'] ) ? (int) $options['ip']['active'] : 0,
+				'blacklist' => $ip,
+			),
+			'ua'      => array(
+				'active'    => isset( $options['ua']['active'] ) ? (int) $options['ua']['active'] : 0,
+				'regexp'    => isset( $options['ua']['regexp'] ) ? (int) $options['ua']['regexp'] : 0,
+				'blacklist' => array_flip( $ua ),
+			),
+			'version' => StatifyBlacklist::VERSION_MAIN,
+		);
+
+		// Apply sanitizations.
+		self::sanitize_referer_options( $res['referer'] );
+		self::sanitize_target_options( $res['target'] );
+		self::sanitize_ip_options( $res['ip'] );
+
+		return $res;
+	}
+
+	/**
+	 * Sanitize referer options.
+	 *
+	 * @param array $options Original referer options.
+	 *
+	 * @return void
+	 *
+	 * @since 1.7.0
+	 */
+	private static function sanitize_referer_options( &$options ) {
+		$referer_given   = $options['blacklist'];
+		$referer_invalid = array();
+		if ( StatifyBlacklist::MODE_NORMAL === $options['regexp'] ) {
+			// Sanitize URLs and remove empty inputs.
+			$referer_sanitized = self::sanitize_urls( $referer_given );
+		} elseif ( StatifyBlacklist::MODE_REGEX === $options['regexp'] || StatifyBlacklist::MODE_REGEX_CI === $options['regexp'] ) {
+			$referer_sanitized = $referer_given;
+			// Check regular expressions.
+			$referer_invalid = self::sanitize_regex( $referer_given );
+		} else {
+			$referer_sanitized = $referer_given;
+		}
+		$referer_diff         = array_diff_key( $referer_given, $referer_sanitized );
+		$options['blacklist'] = $referer_sanitized;
+
+		// Generate messages.
+		if ( ! empty( $referer_diff ) ) {
+			add_settings_error(
+				'statify-blacklist',
+				'referer-diff',
+				__( 'Some URLs are invalid and have been sanitized.', 'statify-blacklist' ),
+				'warning'
+			);
+		}
+		if ( ! empty( $referer_invalid ) ) {
+			add_settings_error(
+				'statify-blacklist',
+				'referer-invalid',
+				__( 'Some regular expressions for referrers are invalid:', 'statify-blacklist' ) . '<br>' . implode( '<br>', $referer_invalid )
+			);
+		}
+	}
+
+	/**
+	 * Sanitize target options.
+	 *
+	 * @param array $options Original target options.
+	 *
+	 * @return void
+	 *
+	 * @since 1.7.0
+	 */
+	private static function sanitize_target_options( &$options ) {
+		$target_given     = $options['blacklist'];
+		$target_sanitized = $target_given;
+		if ( StatifyBlacklist::MODE_REGEX === $options['regexp'] || StatifyBlacklist::MODE_REGEX_CI === $options['regexp'] ) {
+			// Check regular expressions.
+			$target_invalid = self::sanitize_regex( $target_given );
+		} else {
+			$target_invalid = array();
+		}
+		$options['blacklist'] = $target_sanitized;
+
+		// Generate messages.
+		if ( ! empty( $target_invalid ) ) {
+			add_settings_error(
+				'statify-blacklist',
+				'target-invalid',
+				__( 'Some regular expressions for targets are invalid:', 'statify-blacklist' ) . '<br>' . implode( '<br>', $target_invalid )
+			);
+		}
+	}
+
+	/**
+	 * Sanitize IPs and subnets and remove empty inputs.
+	 *
+	 * @param array $options Original IP options.
+	 *
+	 * @return void
+	 *
+	 * @since 1.7.0
+	 */
+	private static function sanitize_ip_options( &$options ) {
+		$given_ip             = $options['blacklist'];
+		$sanitized_ip         = self::sanitize_ips( $given_ip );
+		$ip_diff              = array_diff( $given_ip, $sanitized_ip );
+		$options['blacklist'] = $sanitized_ip;
+
+		// Generate messages.
+		if ( ! empty( $ip_diff ) ) {
+			add_settings_error(
+				'statify-blacklist',
+				'ip-diff',
+				// translators: List of invalid IP addresses (comma separated).
+				sprintf( __( 'Some IPs are invalid: %s', 'statify-blacklist' ), implode( ', ', $ip_diff ) ),
+				'warning'
+			);
+		}
+	}
+
+	/**
+	 * Sanitize URLs and remove empty results.
+	 *
+	 * @param array $urls given array of URLs.
+	 *
+	 * @return array  sanitized array.
+	 *
+	 * @since 1.1.1
+	 * @since 1.7.0 moved from StatifyBlacklist_Admin to StatifyBlacklist_Settings.
+	 */
+	private static function sanitize_urls( $urls ) {
+		return array_flip(
+			array_filter(
+				array_map(
+					function ( $r ) {
+						return preg_replace( '/[^\da-z\.-]/i', '', filter_var( $r, FILTER_SANITIZE_URL ) );
+					},
+					array_flip( $urls )
+				)
+			)
+		);
+	}
+
+	/**
+	 * Sanitize IP addresses with optional CIDR notation and remove empty results.
+	 *
+	 * @param array $ips given array of URLs.
+	 *
+	 * @return array  sanitized array.
+	 *
+	 * @since 1.4.0
+	 * @since 1.7.0 moved from StatifyBlacklist_Admin to StatifyBlacklist_Settings.
+	 */
+	private static function sanitize_ips( $ips ) {
+		return array_values(
+			array_unique(
+				array_filter(
+					array_map( 'strtolower', $ips ),
+					function ( $ip ) {
+						return preg_match(
+							'/^((25[0-5]|(2[0-4]|1?[0-9])?[0-9])\.){3}(25[0-5]|(2[0-4]|1?[0-9])?[0-9])(\/([0-9]|[1-2][0-9]|3[0-2]))?$/',
+							$ip
+						) ||
+						preg_match(
+							'/^(([0-9a-f]{1,4}:){7}[0-9a-f]{1,4}|([0-9a-f]{1,4}:){1,7}:|([0-9a-f]{1,4}:){1,6}:[0-9a-f]{1,4}' .
+							'|([0-9a-f]{1,4}:){1,5}(:[0-9a-f]{1,4}){1,2}|([0-9a-f]{1,4}:){1,4}(:[0-9a-f]{1,4}){1,3}' .
+							'|([0-9a-f]{1,4}:){1,3}(:[0-9a-f]{1,4}){1,4}|([0-9a-f]{1,4}:){1,2}(:[0-9a-f]{1,4}){1,5}' .
+							'|[0-9a-f]{1,4}:((:[0-9a-f]{1,4}){1,6})|:((:[0-9a-f]{1,4}){1,7}|:)' .
+							'|fe80:(:[0-9a-f]{0,4}){0,4}%[0-9a-zA-Z]+|::(ffff(:0{1,4})?:)?((25[0-5]|(2[0-4]|1?[0-9])?[0-9])\.){3}(25[0-5]|(2[0-4]' .
+							'|1?[0-9])?[0-9])|([0-9a-f]{1,4}:){1,4}:((25[0-5]|(2[0-4]|1?[0-9])?[0-9])\.){3}(25[0-5]|(2[0-4]|1?[0-9])?[0-9]))' .
+							'(\/([0-9]|[1-9][0-9]|1[0-1][0-9]|12[0-8]))?$/',
+							$ip
+						);
+					}
+				)
+			)
+		);
+	}
+
+	/**
+	 * Validate regular expressions, i.e. remove duplicates and empty values and validate others.
+	 *
+	 * @param array $expressions Given pre-sanitized array of regular expressions.
+	 *
+	 * @return array Array of invalid expressions.
+	 *
+	 * @since 1.5.0 #13
+	 * @since 1.7.0 moved from StatifyBlacklist_Admin to StatifyBlacklist_Settings.
+	 */
+	private static function sanitize_regex( $expressions ) {
+		return array_filter(
+			array_flip( $expressions ),
+			function ( $re ) {
+				// Check of preg_match() fails (warnings suppressed).
+
+				// phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged
+				return false === @preg_match( StatifyBlacklist::regex( $re, false ), null );
+			}
+		);
+	}
+
+	/**
+	 * Parse multi-line option string.
+	 *
+	 * @param string $raw Input string.
+	 *
+	 * @return array Parsed options.
+	 */
+	private static function parse_multiline_option( $raw ) {
+		if ( empty( trim( $raw ) ) ) {
+			return array();
+		} else {
+			return array_filter(
+				array_map(
+					function ( $a ) {
+						return trim( $a );
+					},
+					explode( "\r\n", str_replace( '\\\\', '\\', $raw ) )
+				),
+				function ( $a ) {
+					return ! empty( $a );
+				}
+			);
+		}
+	}
+}

inc/class-statifyblacklist-system.php

@@ -0,0 +1,214 @@
+<?php
+/**
+ * Statify Filter: StatifyBlacklist_System class
+ *
+ * This file contains the derived class for the plugin's system operations.
+ *
+ * @package   Statify_Blacklist
+ * @subpackge System
+ * @since     1.0.0
+ */
+
+// Quit if accessed directly.
+if ( ! defined( 'ABSPATH' ) ) {
+	exit;
+}
+
+/**
+ * Statify Filter system configuration.
+ *
+ * @since   1.0.0
+ */
+class StatifyBlacklist_System extends StatifyBlacklist {
+
+	/**
+	 * Plugin install handler.
+	 *
+	 * @since 1.0.0
+	 *
+	 * @param bool $network_wide Whether the plugin was activated network-wide or not.
+	 *
+	 * @return void
+	 */
+	public static function install( $network_wide = false ) {
+		// Create tables for each site in a network.
+		if ( $network_wide && is_multisite() ) {
+			if ( function_exists( 'get_sites' ) ) {
+				$sites = get_sites();
+			} else {
+				return;
+			}
+
+			foreach ( $sites as $site ) {
+				if ( is_array( $site ) ) {
+					$site_id = $site['blog_id'];
+				} else {
+					$site_id = $site->blog_id;
+				}
+				self::install_site( $site_id );
+			}
+
+			restore_current_blog();
+		} else {
+			add_option(
+				'statify-blacklist',
+				self::default_options()
+			);
+		}
+	}
+
+	/**
+	 * Set up the plugin for a single site on Multisite.
+	 *
+	 * @since 1.4.3
+	 *
+	 * @param integer $site_id Site ID.
+	 *
+	 * @return void
+	 */
+	public static function install_site( $site_id ) {
+		switch_to_blog( (int) $site_id );
+		add_option(
+			'statify-blacklist',
+			self::default_options()
+		);
+		restore_current_blog();
+	}
+
+
+	/**
+	 * Plugin uninstall handler.
+	 *
+	 * @since 1.0.0
+	 *
+	 * @return void
+	 */
+	public static function uninstall() {
+		if ( is_multisite() ) {
+			$old = get_current_blog_id();
+
+			if ( function_exists( 'get_sites' ) ) {
+				$sites = get_sites();
+			} else {
+				return;
+			}
+
+			foreach ( $sites as $site ) {
+				if ( is_array( $site ) ) {
+					$site_id = $site['blog_id'];
+				} else {
+					$site_id = $site->blog_id;
+				}
+				self::uninstall_site( $site_id );
+			}
+
+			switch_to_blog( $old );
+		}
+
+		delete_option( 'statify-blacklist' );
+	}
+
+	/**
+	 * Remove the plugin for a single site on Multisite.
+	 *
+	 * @since 1.4.3
+	 *
+	 * @param integer $site_id Site ID.
+	 *
+	 * @return void
+	 */
+	public static function uninstall_site( $site_id ) {
+		$old = get_current_blog_id();
+		switch_to_blog( (int) $site_id );
+		delete_option( 'statify-blacklist' );
+		switch_to_blog( $old );
+	}
+
+	/**
+	 * Upgrade plugin options.
+	 *
+	 * @since 1.2.0
+	 *
+	 * @return void
+	 */
+	public static function upgrade() {
+		self::update_options();
+		// Check if config array is not associative (pre 1.2.0).
+		if ( array_keys( self::$options['referer'] ) === range( 0, count( self::$options['referer'] ) - 1 ) ) {
+			// Flip referer array to make domains keys.
+			$options            = self::$options;
+			$options['referer'] = array_flip( self::$options['referer'] );
+			if ( self::$multisite ) {
+				update_site_option( 'statify-blacklist', $options );
+			} else {
+				update_option( 'statify-blacklist', $options );
+			}
+		}
+
+		// Version not set (pre 1.3.0) or older than 1.4.
+		if ( ! isset( self::$options['version'] ) || self::$options['version'] < 1.4 ) {
+			// Upgrade options to new schema.
+			$options = array(
+				'referer' => array(
+					'active'    => self::$options['active_referer'],
+					'cron'      => self::$options['cron_referer'],
+					'regexp'    => self::$options['referer_regexp'],
+					'blacklist' => self::$options['referer'],
+				),
+				'target'  => array(
+					'active'    => 0,
+					'cron'      => 0,
+					'regexp'    => 0,
+					'blacklist' => array(),
+				),
+				'ip'      => array(
+					'active'    => 0,
+					'blacklist' => array(),
+				),
+				'version' => 1.4,
+			);
+			if ( self::$multisite ) {
+				update_site_option( 'statify-blacklist', $options );
+			} else {
+				update_option( 'statify-blacklist', $options );
+			}
+			self::update_options();
+		}
+
+		// Version older than 1.6.
+		if ( self::$options['version'] < 1.6 ) {
+			$options = self::$options;
+			if ( ! isset( $options['ua'] ) ) {
+				$options['ua'] = array(
+					'active'    => 0,
+					'regexp'    => 0,
+					'blacklist' => array(),
+				);
+			} elseif ( ! isset( $options['ua']['blacklist'] ) ) {
+				$options['ua']['blacklist'] = array();
+			} else {
+				// User agent strings got stored incorrectly in 1.6.0 - luckily the version was not updated, either.
+				$options['ua']['blacklist'] = array_flip( $options['ua']['blacklist'] );
+			}
+			$options['version'] = 1.6;
+			if ( self::$multisite ) {
+				update_site_option( 'statify-blacklist', $options );
+			} else {
+				update_option( 'statify-blacklist', $options );
+			}
+			self::update_options();
+		}
+
+		// Version older than current major release.
+		if ( self::VERSION_MAIN > self::$options['version'] ) {
+			// Merge default options with current config, assuming only additive changes.
+			$options            = array_replace_recursive( self::default_options(), self::$options );
+			$options['version'] = self::VERSION_MAIN;
+			if ( self::$multisite ) {
+				update_site_option( 'statify-blacklist', $options );
+			} else {
+				update_option( 'statify-blacklist', $options );
+			}
+		}
+	}
+}

inc/class-statifyblacklist.php

@@ -0,0 +1,472 @@
+<?php
+/**
+ * Statify Filter: StatifyBlacklist class
+ *
+ * This file contains the plugin's base class.
+ *
+ * @package Statify_Blacklist
+ * @since   1.0.0
+ */
+
+// Quit if accessed directly.
+if ( ! defined( 'ABSPATH' ) ) {
+	exit;
+}
+
+/**
+ * Statify Filter.
+ */
+class StatifyBlacklist {
+
+	/**
+	 * Plugin major version.
+	 *
+	 * @since 1.4.0
+	 * @var float VERSION_MAIN
+	 */
+	const VERSION_MAIN = 1.7;
+
+	/**
+	 * Operation mode "normal".
+	 *
+	 * @var integer MODE_NORMAL
+	 */
+	const MODE_NORMAL = 0;
+
+	/**
+	 * Operation mode "regular expression".
+	 *
+	 * @var integer MODE_REGEX
+	 */
+	const MODE_REGEX = 1;
+
+	/**
+	 * Operation mode "regular expression case insensitive".
+	 *
+	 * @var integer MODE_REGEX_CI
+	 */
+	const MODE_REGEX_CI = 2;
+
+	/**
+	 * Operation mode "keyword".
+	 *
+	 * @since 1.5.0
+	 * @var integer MODE_KEYWORD
+	 */
+	const MODE_KEYWORD = 3;
+
+	/**
+	 * Plugin options.
+	 *
+	 * @since 1.0.0
+	 * @var array $options
+	 */
+	public static $options;
+
+	/**
+	 * Multisite Status.
+	 *
+	 * @since 1.0.0
+	 * @var bool $multisite
+	 */
+	public static $multisite;
+
+	/**
+	 * Plugin initialization.
+	 *
+	 * @since 1.4.2
+	 *
+	 * @return void
+	 */
+	public static function init() {
+		// Skip on autosave.
+		if ( defined( 'DOING_AUTOSAVE' ) && DOING_AUTOSAVE ) {
+			return;
+		}
+
+		// Get multisite status.
+		self::$multisite = ( is_multisite() && array_key_exists( STATIFYBLACKLIST_BASE, (array) get_site_option( 'active_sitewide_plugins' ) ) );
+
+		// Plugin options.
+		self::update_options();
+
+		// Add Filter to statify hook if enabled.
+		if ( 0 !== self::$options['referer']['active'] ||
+			0 !== self::$options['target']['active'] ||
+			0 !== self::$options['ip']['active'] ||
+			0 !== self::$options['ua']['active'] ) {
+			add_filter( 'statify__skip_tracking', array( 'StatifyBlacklist', 'apply_blacklist_filter' ) );
+		}
+
+		// Statify uses WP AJAX as of 1.7, so we need to reach this point. But there are no further admin/cron actions.
+		if ( defined( 'DOING_AJAX' ) && DOING_AJAX ) {
+			return;
+		}
+
+		// Admin only filters.
+		if ( is_admin() ) {
+			StatifyBlacklist_Admin::init();
+		}
+
+		// CronJob to clean up database.
+		if ( defined( 'DOING_CRON' ) && DOING_CRON &&
+			( 1 === self::$options['referer']['cron'] || 1 === self::$options['target']['cron'] ) ) {
+			add_action( 'statify_cleanup', array( 'StatifyBlacklist_Admin', 'cleanup_database' ) );
+		}
+	}
+
+	/**
+	 * Update options.
+	 *
+	 * @since 1.0.0
+	 * @since 1.2.1 update_options($options = null) Parameter with default value introduced.
+	 *
+	 * @param array $options Optional. New options to save.
+	 *
+	 * @return void
+	 */
+	public static function update_options( $options = null ) {
+		if ( self::$multisite ) {
+			$o = get_site_option( 'statify-blacklist' );
+		} else {
+			$o = get_option( 'statify-blacklist' );
+		}
+		self::$options = wp_parse_args( $o, self::default_options() );
+	}
+
+	/**
+	 * Create default plugin configuration.
+	 *
+	 * @since 1.4.0
+	 *
+	 * @return array The options array.
+	 */
+	protected static function default_options() {
+		return array(
+			'referer' => array(
+				'active'    => 0,
+				'cron'      => 0,
+				'regexp'    => 0,
+				'blacklist' => array(),
+			),
+			'target'  => array(
+				'active'    => 0,
+				'cron'      => 0,
+				'regexp'    => 0,
+				'blacklist' => array(),
+			),
+			'ip'      => array(
+				'active'    => 0,
+				'blacklist' => array(),
+			),
+			'ua'      => array(
+				'active'    => 0,
+				'regexp'    => 0,
+				'blacklist' => array(),
+			),
+			'version' => self::VERSION_MAIN,
+		);
+	}
+
+	/**
+	 * Apply the filter if active
+	 *
+	 * @since 1.0.0
+	 *
+	 * @return bool TRUE if referer matches filter.
+	 */
+	public static function apply_blacklist_filter() {
+		// Referer filter.
+		if (
+		self::apply_single_filter(
+			self::$options['referer'],
+			array(
+				__CLASS__,
+				( ! isset( self::$options['referer']['regexp'] ) || self::MODE_NORMAL === self::$options['referer']['regexp'] ) ? 'get_referer_domain' : 'get_referer',
+			)
+		)
+		) {
+			return true;
+		}
+
+		// Target filter (since 1.4.0).
+		if ( self::apply_single_filter( self::$options['target'], array( __CLASS__, 'get_target' ) ) ) {
+			return true;
+		}
+
+		// IP filter (since 1.4.0).
+		if ( isset( self::$options['ip']['active'] ) && 0 !== self::$options['ip']['active'] ) {
+			$ip = self::get_ip();
+			if ( false !== ( $ip ) ) {
+				foreach ( self::$options['ip']['blacklist'] as $net ) {
+					if ( self::cidr_match( $ip, $net ) ) {
+						return true;
+					}
+				}
+			}
+		}
+
+		// User agent filter (since 1.6).
+		if ( self::apply_single_filter( self::$options['ua'], array( __CLASS__, 'get_user_agent' ) ) ) {
+			return true;
+		}
+
+		// Skip and continue (return NULL), if all filters are inactive.
+		return null;
+	}
+
+	/**
+	 * Apply a single filter, if active.
+	 *
+	 * @param array    $config   Configuration array from plugin options.
+	 * @param callable $value_fn Extractor function for filterable value.
+	 *
+	 * @return bool TRUE if referer matches filter.
+	 *
+	 * @since 1.6 Extracted from "apply_blacklist_filter" to reduce redundancies.
+	 */
+	private static function apply_single_filter( $config, $value_fn ) {
+		// Is the filter active?
+		if ( ! isset( $config['active'] ) || 0 === $config['active'] ) {
+			return false;
+		}
+
+		// Extract the filterable value.
+		$value = call_user_func( $value_fn );
+
+		$mode = isset( $config['regexp'] ) ? intval( $config['regexp'] ) : self::MODE_NORMAL;
+
+		switch ( $mode ) {
+			case self::MODE_REGEX:
+			case self::MODE_REGEX_CI:
+				// Regular Expression filtering since 1.3.0.
+
+				// Merge given regular expressions into one.
+				$regexp = self::regex(
+					array_keys( $config['blacklist'] ),
+					self::MODE_REGEX_CI === $config['regexp']
+				);
+
+				// Check filter (no return to continue filtering #12).
+				if ( 1 === preg_match( $regexp, $value ) ) {
+					return true;
+				}
+				break;
+
+			case self::MODE_KEYWORD:
+				// Keyword filter since 1.5.0 (#15).
+				foreach ( array_keys( $config['blacklist'] ) as $keyword ) {
+					if ( false !== strpos( strtolower( $value ), strtolower( $keyword ) ) ) {
+						return true;
+					}
+				}
+
+				break;
+
+			default:
+				// Standard exact filter.
+				if ( isset( $config['blacklist'][ $value ] ) ) {
+					return true;
+				}
+		}
+
+		return false;
+	}
+
+	/**
+	 * Preprocess regular expression provided by the user, i.e. add delimiters and optional ci flag.
+	 *
+	 * @param string|array $expression       Original expression string or array of expressions.
+	 * @param string|array $case_insensitive Make expression match case-insensitive.
+	 *
+	 * @return string Preprocessed expression ready for preg_match().
+	 */
+	protected static function regex( $expression, $case_insensitive ) {
+		$res = '/';
+		if ( is_string( $expression ) ) {
+			$res .= str_replace( '/', '\/', $expression );
+		} elseif ( is_array( $expression ) ) {
+			$res .= implode(
+				'|',
+				array_map(
+					function ( $e ) {
+						return str_replace( '/', '\/', $e );
+					},
+					$expression
+				)
+			);
+		}
+		$res .= '/';
+		if ( $case_insensitive ) {
+			$res .= 'i';
+		}
+
+		return $res;
+	}
+
+	/**
+	 * Helper method to determine the client's referer.
+	 *
+	 * @return string The referer.
+	 */
+	private static function get_referer() {
+		$referer = wp_get_raw_referer();
+		if ( ! $referer ) {
+			$referer = '';
+		}
+
+		return $referer;
+	}
+
+	/**
+	 * Helper method to determine the host part of the client's referer.
+	 *
+	 * @return string Referer domain.
+	 */
+	private static function get_referer_domain() {
+		$referer = wp_parse_url( self::get_referer() );
+
+		return strtolower( ( isset( $referer['host'] ) ? $referer['host'] : '' ) );
+	}
+
+	/**
+	 * Helper method to determine the client's referer.
+	 *
+	 * @return string The referer.
+	 */
+	private static function get_target() {
+		if ( isset( $_SERVER['REQUEST_URI'] ) ) {
+			$target = filter_var( wp_unslash( $_SERVER['REQUEST_URI'] ), FILTER_SANITIZE_URL );
+			if ( $target ) {
+				return $target;
+			}
+		}
+
+		return '';
+	}
+
+	/**
+	 * Helper method to determine the client's IP address.
+	 *
+	 * If a proxy is used, the X-Real-IP or X-Forwarded-For header is checked, otherwise the default remote address.
+	 * For performance reasons only the most common flags are checked. This might be even reduce by user configuration.
+	 * Maybe some community feedback will ease the decision on that.
+	 *
+	 * @return string|bool the client's IP address or FALSE, if none could be determined.
+	 */
+	private static function get_ip() {
+		foreach (
+
+			/*
+			 * There are more fields, that could possibly be checked, but we only consider the most common for now:
+			 * HTTP_CLIENT_IP, HTTP_X_REAL_IP, HTTP_X_FORWARDED_FOR, HTTP_X_FORWARDED,
+			 * HTTP_X_CLUSTER_CLIENT_IP, HTTP_FORWARDED_FOR, HTTP_FORWARDED, REMOTE_ADDR
+			 */
+			array(
+				'HTTP_X_REAL_IP',
+				'HTTP_X_FORWARDED_FOR',
+				'REMOTE_ADDR',
+			) as $k
+		) {
+			if ( isset( $_SERVER[ $k ] ) ) {
+				// phpcs:ignore
+				foreach ( explode( ',', $_SERVER[ $k ] ) as $ip ) {
+					if ( false !== filter_var( $ip, FILTER_VALIDATE_IP ) ) {
+						return $ip;
+					}
+				}
+			}
+		}
+
+		return false;
+	}
+
+	/**
+	 * Helper method to determine the user agent.
+	 *
+	 * @return string The user agent string.
+	 */
+	private static function get_user_agent() {
+		if ( ! empty( $_SERVER['HTTP_USER_AGENT'] ) ) {
+			$user_agent = filter_var( wp_unslash( $_SERVER['HTTP_USER_AGENT'] ) );
+			if ( $user_agent ) {
+				return $user_agent;
+			}
+		}
+
+		return '';
+	}
+
+	/**
+	 * Helper function to check if an IP address matches a given subnet.
+	 *
+	 * @param string $ip  IP address to check.
+	 * @param string $net IP address or subnet in CIDR notation.
+	 *
+	 * @return bool TRUE, if the given IP addresses matches the given subnet.
+	 */
+	private static function cidr_match( $ip, $net ) {
+		if ( substr_count( $net, ':' ) > 1 ) {  // Check for IPv6.
+			if ( ! ( ( extension_loaded( 'sockets' ) && defined( 'AF_INET6' ) ) || inet_pton( '::1' ) ) ) {
+				return false;
+			}
+
+			if ( false !== strpos( $net, '/' ) ) {   // Parse CIDR subnet.
+				list( $base, $mask ) = explode( '/', trim( $net ), 2 );
+
+				if ( ! is_numeric( $mask ) ) {
+					return false;
+				} else {
+					$mask = (int) $mask;
+				}
+
+				if ( $mask < 1 || $mask > 128 ) {
+					return false;
+				}
+			} else {
+				$base = $net;
+				$mask = 128;
+			}
+
+			$bytes_addr = unpack( 'n*', inet_pton( $base ) );
+			$bytes_est  = unpack( 'n*', inet_pton( $ip ) );
+
+			if ( ! $bytes_addr || ! $bytes_est ) {
+				return false;
+			}
+
+			$ceil = ceil( $mask / 16 );
+			for ( $i = 1; $i <= $ceil; ++$i ) {
+				$left   = $mask - 16 * ( $i - 1 );
+				$left   = ( $left <= 16 ) ? $left : 16;
+				$mask_b = ~( 0xffff >> $left ) & 0xffff;
+				if ( ( $bytes_addr[ $i ] & $mask_b ) !== ( $bytes_est[ $i ] & $mask_b ) ) {
+					return false;
+				}
+			}
+
+			return true;
+		} else {    // Check for IPv4.
+			if ( ! filter_var( $ip, FILTER_VALIDATE_IP, FILTER_FLAG_IPV4 ) ) {
+				return false;
+			}
+
+			if ( false !== strpos( $net, '/' ) ) {  // Parse CIDR subnet.
+				list( $base, $mask ) = explode( '/', $net, 2 );
+
+				if ( '0' === $mask ) {
+					return filter_var( $base, FILTER_VALIDATE_IP, FILTER_FLAG_IPV4 );
+				}
+
+				if ( $mask < 0 || $mask > 32 ) {
+					return false;
+				}
+			} else {    // Use single address.
+				$base = $net;
+				$mask = 32;
+			}
+
+			return ( 0 === substr_compare( sprintf( '%032b', ip2long( $ip ) ), sprintf( '%032b', ip2long( $base ) ), 0, $mask ) );
+		}
+	}
+}

inc/statifyblacklist.class.php

@@ -1,124 +0,0 @@
-<?php
-
-/* Quit */
-defined('ABSPATH') OR exit;
-
-/**
- * Statify Blacklist
- *
- * @since 1.0.0
- */
-class StatifyBlacklist
-{
-  /**
-   * Plugin options
-   *
-   * @var array
-   * @since   1.0.0
-   */
-  public static $_options;
-
-  /**
-   * Multisite Status
-   *
-   * @var bool
-   * @since   1.0.0
-   */
-  public static $multisite;
-
-  /**
-   * Class self initialize
-   *
-   * @since   1.0.0
-   */
-  public static function instance()
-  {
-    new self();
-  }
-
-  /**
-   * Class constructor
-   *
-   * @since   1.0.0
-   * @changed 1.1.2
-   */
-  public function __construct()
-  {
-    /* Skip on autosave or AJAX */
-    if ( (defined('DOING_AUTOSAVE') && DOING_AUTOSAVE) OR (defined('DOING_AJAX') && DOING_AJAX) ) {
-      return;
-    }
-
-    /* Plugin options */
-    self::update_options();
-
-    /* Get multisite status */
-    self::$multisite = (is_multisite() && array_key_exists(STATIFYBLACKLIST_BASE, (array)get_site_option('active_sitewide_plugins')));
-
-    /* Add Filter to statify hook */
-    add_filter('statify_skip_tracking', array('StatifyBlacklist', 'apply_blacklist_filter'));
-
-    /* Admin only filters */
-    if (is_admin()) {
-      /* Load Textdomain (only needed for backend */
-      load_plugin_textdomain( 'statifyblacklist', false, STATIFYBLACKLIST_DIR.'/lang/');
-
-      /* Add actions */
-      add_action('wpmu_new_blog', array('StatifyBlacklist_Install', 'init_site'));
-      add_action('delete_blog', array('StatifyBlacklist_System', 'init_site'));
-      add_filter('plugin_row_meta', array('StatifyBlacklist_Admin', 'plugin_meta_link'), 10, 2);
-
-      if (is_multisite()) {
-        add_action('network_admin_menu', array('StatifyBlacklist_Admin', '_add_menu_page'));
-        add_filter('network_admin_plugin_action_links', array('StatifyBlacklist_Admin', 'plugin_actions_links'), 10, 2);
-      } else {
-        add_action('admin_menu', array('StatifyBlacklist_Admin', '_add_menu_page'));
-        add_filter('plugin_action_links', array('StatifyBlacklist_Admin', 'plugin_actions_links'), 10, 2 );
-      }
-    }
-  }
-
-  /**
-   * Update options
-   *
-   * @since   1.0.0
-   * @changed 1.1.1
-   */
-  public static function update_options() {
-    self::$_options = wp_parse_args(
-      get_option('statify-blacklist'),
-      array(
-        'active_referer' => 0,
-        'referer'        => array()
-      )
-    );
-  }
-
-  /**
-   * Apply the blacklist filter if active
-   *
-   * @return  TRUE if referer matches blacklist.
-   *
-   * @since   1.0.0
-   */
-  public static function apply_blacklist_filter() {
-    /* Skip if blacklist is inactive */
-    if (self::$_options['active_referer'] != 1) {
-      return false;
-    }
-
-    /* Extract relevant domain parts */
-    $referer = strtolower( ( isset($_SERVER['HTTP_REFERER']) ? parse_url($_SERVER['HTTP_REFERER'], PHP_URL_HOST) : '' ) );
-    $referer = explode('.', $referer);
-    if( count($referer) >1 )
-      $referer = implode('.', array_slice($referer, -2));
-    else
-      $referer = implode('.', $referer);
-
-    /* Get blacklist */
-    $blacklist = self::$_options['referer'];
-
-    /* Check blacklist */
-    return in_array($referer, $blacklist);
-  }
-}

inc/statifyblacklist_admin.class.php

@@ -1,144 +0,0 @@
-<?php
-
-/* Quit */
-defined('ABSPATH') OR exit;
-
-/**
- * Statify Blacklist admin configuration
- *
- * @since 1.0.0
- */
-class StatifyBlacklist_Admin extends StatifyBlacklist
-{
-  /**
-   * Update options
-   *
-   * @return mixed  array of sanitized array on errors, FALSE if there were none
-   * @since   1.1.1
-   */
-  public static function update_options($options) {
-    if (isset($options) && current_user_can('manage_options')) {
-      /* Sanitize URLs and remove empty inputs */
-      $givenReferer = $options['referer'];
-      $sanitizedReferer = self::sanitizeURLs($givenReferer);
-
-      /* Abort on errors */
-      if (!empty(array_diff($givenReferer, $sanitizedReferer))) {
-        return $sanitizedReferer;
-      }
-
-      /* Update database on success */
-      if ((is_multisite() && array_key_exists(STATIFYBLACKLIST_BASE, (array)get_site_option('active_sitewide_plugins'))))
-        update_site_option('statify-blacklist', $options);
-      else
-        update_option('statify-blacklist', $options);
-    }
-
-    /* Refresh options */
-    parent::update_options();
-
-    return false;
-  }
-
-  /**
-   * Add configuration page to admin menu
-   *
-   * @since   1.0.0
-   */
-  public function _add_menu_page() {
-    $title = __( 'Statify Blacklist', 'statify-blacklist' );
-    if (self::$multisite)
-      add_submenu_page( 'settings.php', $title, $title, 'manage_network_plugins', 'statify-blacklist-settings', array('StatifyBlacklist_Admin', 'settings_page') );
-    else
-      add_submenu_page( 'options-general.php', $title, $title, 'manage_options', 'statify-blacklist', array('StatifyBlacklist_Admin', 'settings_page') );
-
-  }
-
-  public static function settings_page() {
-    include STATIFYBLACKLIST_DIR . '/views/settings_page.php';
-  }
-
-  /**
-   * Add plugin meta links
-   *
-   * @param $links
-   * @param $file
-   * @return array
-   *
-   * @since   1.0.0
-   */
-  public static function plugin_meta_link($links, $file) {
-    if ($file == STATIFYBLACKLIST_BASE) {
-      $links[] = '<a href="https://github.com/stklcode/statify-blacklist">GitHub</a>';
-    }
-    return $links;
-  }
-
-  /**
-   * Add plugin action links
-   *
-   * @param   array   $input  Registered links
-   * @return  array           Merged links
-   *
-   * @since   1.0.0
-   */
-  public static function plugin_actions_links($links, $file) {
-    $base = self::$multisite ? network_admin_url( 'settings.php' ) : admin_url( 'options-general.php' );
-
-    if( $file == STATIFYBLACKLIST_BASE && current_user_can('manage_options') ) {
-      array_unshift(
-        $links,
-        sprintf( '<a href="%s">%s</a>', esc_attr(add_query_arg( 'page', 'statify-blacklist', $base )), __('Settings'))
-      );
-    }
-    return $links;
-  }
-
-  /**
-   * Filter database for cleanup.
-   *
-   * @since   1.1.0
-   * @changed 1.1.1
-   */
-  public static function cleanup_database() {
-    /* Check user permissions */
-    if (!current_user_can('manage_options'))
-      die(_e('Are you sure you want to do this?'));
-
-    global $wpdb;
-
-    /* Sanitize URLs */
-    $referer = self::sanitizeURLs(self::$_options['referer']);
-
-    /* Build filter regexp */
-    $refererRegexp = str_replace('.', '\.', implode('|', $referer));
-    if (!empty($refererRegexp)) {
-      /* Execute filter on database */
-      $wpdb->query(
-        $wpdb->prepare("DELETE FROM `$wpdb->statify` WHERE referrer REGEXP %s", $refererRegexp)
-      );
-
-      /* Optimize DB */
-      $wpdb->query("OPTIMIZE TABLE `$wpdb->statify`");
-    }
-  }
-
-
-  /**
-   * Sanitize URLs and remove empty results
-   * @param $urls array   given array of URLs
-   * @return array  sanitized array
-   *
-   * @since    1.1.1
-   */
-  private static function sanitizeURLs($urls) {
-    return array_filter(
-      array_map(
-        function($r) {
-          return preg_replace('/[^\da-z\.-]/i', '', filter_var($r, FILTER_SANITIZE_URL));
-        },
-        $urls
-      )
-    );
-  }
-}

inc/statifyblacklist_system.class.php

@@ -1,70 +0,0 @@
-<?php
-
-/* Quit */
-defined('ABSPATH') OR exit;
-
-/**
- * Statify Blacklist system configuration
- *
- * @since 1.0.0
- */
-class StatifyBlacklist_System extends StatifyBlacklist
-{
-  /**
-   * Plugin install handler.
-   *
-   * @since 1.0.0
-   *
-   * @param bool $network_wide Whether the plugin was activated network-wide or not.
-   */
-  public static function install( $network_wide = false ) {
-    global $wpdb;
-
-    // Create tables for each site in a network.
-    if ( is_multisite() && $network_wide ) {
-      // Todo: Use get_sites() in WordPress 4.6+
-      $ids = $wpdb->get_col( "SELECT blog_id FROM `$wpdb->blogs`" );
-
-      foreach ( $ids as $site_id ) {
-        switch_to_blog( $site_id );
-        add_option(
-          'statify-blacklist',
-          array()
-        );
-      }
-
-      restore_current_blog();
-    } else {
-      add_option(
-        'statify-blacklist',
-        array()
-      );
-    }
-  }
-
-
-  /**
-   * Plugin uninstall handler.
-   *
-   * @since 1.0.0
-   */
-  public static function uninstall() {
-    global $wpdb;
-
-    if ( is_multisite() ) {
-      $old = get_current_blog_id();
-
-      // Todo: Use get_sites() in WordPress 4.6+
-      $ids = $wpdb->get_col( "SELECT blog_id FROM `$wpdb->blogs`" );
-
-      foreach ( $ids as $id ) {
-        switch_to_blog( $id );
-        delete_option('statify-blacklist');
-      }
-
-      switch_to_blog( $old );
-    }
-
-    delete_option('statify-blacklist');
-  }
-}

package.json

@@ -0,0 +1,7 @@
+{
+  "name": "statify-blacklist",
+  "version": "1.7.2",
+  "description": "A filter extension for the famous Statify WordPress plugin",
+  "author": "Stefan Kalscheuer",
+  "license": "GPL-2.0+"
+}

phpcs.xml

@@ -0,0 +1,29 @@
+<?xml version="1.0"?>
+<ruleset name="StatifyBlacklist">
+	<description>Derived from WordPress Coding Standard</description>
+
+	<arg value="psv"/>
+	<arg name="colors"/>
+
+	<!-- Files to sniff -->
+	<file>statify-blacklist.php</file>
+	<file>inc</file>
+
+	<!-- Compliance with WordPress Coding Standard -->
+	<config name="minimum_supported_wp_version" value="4.7"/>
+	<rule ref="WordPress">
+		<!-- Direct queries used to clean up statify table. -->
+		<exclude name="WordPress.DB.DirectDatabaseQuery.DirectQuery"/>
+		<exclude name="WordPress.DB.DirectDatabaseQuery.NoCaching"/>
+	</rule>
+
+	<rule ref="WordPress.WP.I18n">
+		<properties>
+			<property name="text_domain" type="array" value="statify-blacklist"/>
+		</properties>
+	</rule>
+
+	<!-- PHP compatibility level -->
+	<config name="testVersion" value="5.5-"/>
+	<rule ref="PHPCompatibilityWP"/>
+</ruleset>

phpunit.xml

@@ -0,0 +1,17 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<phpunit bootstrap="test/bootstrap.php">
+	<testsuites>
+		<testsuite name="Statify Blacklist TestSuite">
+			<directory suffix="_Test.php">./test/</directory>
+		</testsuite>
+	</testsuites>
+	<filter>
+		<whitelist processUncoveredFilesFromWhitelist="true">
+			<directory suffix=".php">./inc/</directory>
+		</whitelist>
+	</filter>
+	<logging>
+		<log type="coverage-clover" target="tests-clover.xml"/>
+		<log type="junit" target="tests-junit.xml"/>
+	</logging>
+</phpunit>

statify-blacklist.php

@@ -1,48 +1,143 @@
 <?php
-/*
-Plugin Name: Statify Blacklist
-Description: Extension for the statify plugin to add a customizable blacklists.
-Text Domain: statify-blacklist
-Domain Path: /lang
-Author:      Stefan Kalscheuer
-Author URI:  https://stklcode.de
-Plugin URI:  https://wordpress.org/plugins/statify-blacklist
-License:     GPLv3 or later
-Version:     1.1.2
-*/
+/**
+ * Statify Filter
+ *
+ * @package     PluginPackage
+ * @author      Stefan Kalscheuer <stefan@stklcode.de>
+ * @license     GPL-2.0+
+ *
+ * @wordpress-plugin
+ * Plugin Name:       Statify Filter
+ * Plugin URI:        https://wordpress.org/plugins/statify-blacklist/
+ * Description:       Extension for the Statify plugin to add customizable filters. (formerly "Statify Blacklist")
+ * Version:           1.7.2
+ * Requires at least: 4.7
+ * Requires PHP:      5.5
+ * Requires Plugins:  statify
+ * Author:            Stefan Kalscheuer (@stklcode)
+ * Author URI:        https://www.stklcode.de
+ * Text Domain:       statify-blacklist
+ * License:           GPLv2 or later
+ *
+ * Statify Filter is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * any later version.
+ *
+ * Statify Filter is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Statify Filter. If not, see https://www.gnu.org/licenses/gpl-2.0.html.
+ */
 
-/* Quit */
-defined('ABSPATH') OR exit;
+// Quit if accessed directly.
+if ( ! defined( 'ABSPATH' ) ) {
+	exit;
+}
 
-/*  Constants */
-define('STATIFYBLACKLIST_FILE', __FILE__);
-define('STATIFYBLACKLIST_DIR', dirname(__FILE__));
-define('STATIFYBLACKLIST_BASE', plugin_basename(__FILE__));
+// Constants.
+define( 'STATIFYBLACKLIST_FILE', __FILE__ );
+define( 'STATIFYBLACKLIST_DIR', __DIR__ );
+define( 'STATIFYBLACKLIST_BASE', plugin_basename( __FILE__ ) );
 
-/* System Hooks */
-add_action('plugins_loaded', array('StatifyBlacklist', 'instance'));
+// Check for compatibility.
+if ( statify_blacklist_compatibility_check() ) {
+	// System Hooks.
+	add_action( 'plugins_loaded', array( 'StatifyBlacklist', 'init' ) );
 
-register_activation_hook(STATIFYBLACKLIST_FILE, array('StatifyBlacklist_System', 'install'));
+	register_activation_hook( STATIFYBLACKLIST_FILE, array( 'StatifyBlacklist_System', 'install' ) );
 
-register_uninstall_hook(STATIFYBLACKLIST_FILE, array('StatifyBlacklist_System', 'uninstall'));
+	register_uninstall_hook( STATIFYBLACKLIST_FILE, array( 'StatifyBlacklist_System', 'uninstall' ) );
 
-/* Autoload */
-spl_autoload_register('statifyBlacklist_autoload');
+	// Upgrade hook.
+	register_activation_hook( STATIFYBLACKLIST_FILE, array( 'StatifyBlacklist_System', 'upgrade' ) );
+
+	// Autoload.
+	spl_autoload_register( 'statify_blacklist_autoload' );
+} else {
+	// Disable plugin, if active.
+	add_action( 'admin_init', 'statify_blacklist_disable' );
+}
 
 /**
  * Autoloader for StatifyBlacklist classes.
  *
- * @param $class
+ * @param string $class_name Name of the class to load.
+ *
  * @since 1.0.0
  */
-function statifyBlacklist_autoload($class) {
+function statify_blacklist_autoload( $class_name ) {
 	$plugin_classes = array(
 		'StatifyBlacklist',
 		'StatifyBlacklist_Admin',
-    'StatifyBlacklist_System'
+		'StatifyBlacklist_Settings',
+		'StatifyBlacklist_System',
 	);
 
-  if (in_array($class, $plugin_classes)) {
-    require_once(sprintf('%s/inc/%s.class.php', STATIFYBLACKLIST_DIR, strtolower($class)));
+	if ( in_array( $class_name, $plugin_classes, true ) ) {
+		require_once sprintf(
+			'%s/inc/class-%s.php',
+			STATIFYBLACKLIST_DIR,
+			strtolower( str_replace( '_', '-', $class_name ) )
+		);
 	}
 }
+
+/**
+ * Check for compatibility with PHP and WP version.
+ *
+ * @since 1.5.0
+ *
+ * @return boolean Whether minimum WP and PHP versions are met.
+ */
+function statify_blacklist_compatibility_check() {
+	return version_compare( $GLOBALS['wp_version'], '4.7', '>=' ) &&
+		version_compare( phpversion(), '5.5', '>=' );
+}
+
+/**
+ * Disable plugin if active and incompatible.
+ *
+ * @since 1.5.0
+ *
+ * @return void
+ */
+function statify_blacklist_disable() {
+	if ( is_plugin_active( STATIFYBLACKLIST_BASE ) ) {
+		deactivate_plugins( STATIFYBLACKLIST_BASE );
+		add_action( 'admin_notices', 'statify_blacklist_disabled_notice' );
+		// phpcs:disable WordPress.Security.NonceVerification.Recommended
+		if ( isset( $_GET['activate'] ) ) {
+			unset( $_GET['activate'] );
+		}
+		// phpcs:enable
+	}
+}
+
+/**
+ * Admin notification for unmet requirements.
+ *
+ * @since 1.5.0
+ *
+ * @return void
+ */
+function statify_blacklist_disabled_notice() {
+	echo '<div class="notice notice-error is-dismissible"><p><strong>';
+	printf(
+		/* translators: minimum version numbers for WordPress and PHP inserted at placeholders */
+		esc_html__( 'Statify Filter requires at least WordPress %1$s and PHP %2$s.', 'statify-blacklist' ),
+		'4.7',
+		'5.5'
+	);
+	echo '<br>';
+	printf(
+		/* translators: current version numbers for WordPress and PHP inserted at placeholders */
+		esc_html__( 'Your site is running WordPress %1$s on PHP %2$s, thus the plugin has been disabled.', 'statify-blacklist' ),
+		esc_html( $GLOBALS['wp_version'] ),
+		esc_html( phpversion() )
+	);
+	echo '</strong></p></div>';
+}

test/StatifyBlacklist_Settings_Test.php

@@ -0,0 +1,330 @@
+<?php
+/**
+ * Statify Filter: Unit Test
+ *
+ * This is a PHPunit test class for the plugin's functionality
+ *
+ * @package Statify_Blacklist
+ */
+
+/**
+ * Class StatifyBlacklist_Settings_Test.
+ *
+ * PHPUnit test class for StatifyBlacklist_Settings.
+ */
+class StatifyBlacklist_Settings_Test extends PHPUnit\Framework\TestCase {
+
+	/**
+	 * Test options sanitization.
+	 *
+	 * @return void
+	 */
+	public function test_sanitize_options() {
+		global $settings_error;
+
+		// Emulate default submission: nothing checked, all textareas empty.
+		$raw = array(
+			'referer' => array(
+				'blacklist' => '',
+				'regexp'    => '0',
+			),
+			'target'  => array(
+				'blacklist' => '',
+				'regexp'    => '0',
+			),
+			'ip'      => array( 'blacklist' => '' ),
+			'ua'      => array(
+				'blacklist' => '',
+				'regexp'    => '0',
+			),
+		);
+
+		$sanitized = StatifyBlacklist_Settings::sanitize_options( $raw );
+
+		self::assertEmpty( $settings_error );
+		self::assertEquals(
+			array(
+				'referer' => array(
+					'active'    => 0,
+					'cron'      => 0,
+					'blacklist' => array(),
+					'regexp'    => StatifyBlacklist::MODE_NORMAL,
+				),
+				'target'  => array(
+					'active'    => 0,
+					'cron'      => 0,
+					'blacklist' => array(),
+					'regexp'    => StatifyBlacklist::MODE_NORMAL,
+				),
+				'ip'      => array(
+					'active'    => 0,
+					'blacklist' => array(),
+				),
+				'ua'      => array(
+					'active'    => 0,
+					'regexp'    => StatifyBlacklist::MODE_NORMAL,
+					'blacklist' => array(),
+				),
+				'version' => StatifyBlacklist::VERSION_MAIN,
+			),
+			$sanitized
+		);
+
+		// Some checked options and some valid entries.
+		$raw = array(
+			'referer' => array(
+				'cron'      => '1',
+				'blacklist' => "example.com\r\nexample.net\r\nexample.org",
+				'regexp'    => '0',
+			),
+			'target'  => array(
+				'active'    => '1',
+				'blacklist' => "foo\r\nbar\r\ntest",
+				'regexp'    => '3',
+			),
+			'ip'      => array(
+				'active'    => '1',
+				'blacklist' => "127.0.0.1/8\r\n::1",
+			),
+			'ua'      => array(
+				'blacklist' => 'MyBot/1.23',
+				'regexp'    => '1',
+			),
+		);
+
+		$sanitized = StatifyBlacklist_Settings::sanitize_options( $raw );
+
+		self::assertEmpty( $settings_error );
+		self::assertEquals(
+			array(
+				'referer' => array(
+					'active'    => 0,
+					'cron'      => 1,
+					'blacklist' => array(
+						'example.com' => 0,
+						'example.net' => 1,
+						'example.org' => 2,
+					),
+					'regexp'    => StatifyBlacklist::MODE_NORMAL,
+				),
+				'target'  => array(
+					'active'    => 1,
+					'cron'      => 0,
+					'blacklist' => array(
+						'foo'  => 0,
+						'bar'  => 1,
+						'test' => 2,
+					),
+					'regexp'    => StatifyBlacklist::MODE_KEYWORD,
+				),
+				'ip'      => array(
+					'active'    => 1,
+					'blacklist' => array(
+						'127.0.0.1/8',
+						'::1',
+					),
+				),
+				'ua'      => array(
+					'active'    => 0,
+					'regexp'    => StatifyBlacklist::MODE_REGEX,
+					'blacklist' => array(
+						'MyBot/1.23' => 0,
+					),
+				),
+				'version' => StatifyBlacklist::VERSION_MAIN,
+			),
+			$sanitized
+		);
+
+		// Now we have some additional nonsense fields and invalid entries.
+		$raw = array(
+			'testme ' => 'whatever',
+			'referer' => array(
+				'cron'      => '1',
+				'blacklist' => "  example\\.com   \r\nexample(\\.net\r\nexample\\.com",
+				'regexp'    => '1',
+			),
+			'target'  => array(
+				'active'    => '1',
+				'blacklist' => "fo.\r\n[bar\r\n*test",
+				'regexp'    => '2',
+			),
+			'ip'      => array(
+				'active'    => '1',
+				'blacklist' => "127.0.0.1/8\r\nthisisnotanip\r\n127.0.0.1/8",
+			),
+			'ua'      => array(
+				'blacklist' => 'MyBot/1.23',
+				'regexp'    => '1',
+			),
+		);
+
+		$sanitized = StatifyBlacklist_Settings::sanitize_options( $raw );
+
+		self::assertEquals(
+			array(
+				'referer' => array(
+					'active'    => 0,
+					'cron'      => 1,
+					'blacklist' => array(
+						'example\.com'  => 2,
+						'example(\.net' => 1,
+					),
+					'regexp'    => StatifyBlacklist::MODE_REGEX,
+				),
+				'target'  => array(
+					'active'    => 1,
+					'cron'      => 0,
+					'blacklist' => array(
+						'fo.'   => 0,
+						'[bar'  => 1,
+						'*test' => 2,
+					),
+					'regexp'    => StatifyBlacklist::MODE_REGEX_CI,
+				),
+				'ip'      => array(
+					'active'    => 1,
+					'blacklist' => array(
+						'127.0.0.1/8',
+					),
+				),
+				'ua'      => array(
+					'active'    => 0,
+					'regexp'    => StatifyBlacklist::MODE_REGEX,
+					'blacklist' => array(
+						'MyBot/1.23' => 0,
+					),
+				),
+				'version' => StatifyBlacklist::VERSION_MAIN,
+			),
+			$sanitized
+		);
+
+		self::assertEquals(
+			array(
+				array( 'statify-blacklist', 'referer-invalid', 'Some regular expressions for referrers are invalid:<br>example(\.net', 'error' ),
+				array( 'statify-blacklist', 'target-invalid', 'Some regular expressions for targets are invalid:<br>[bar<br>*test', 'error' ),
+				array( 'statify-blacklist', 'ip-diff', 'Some IPs are invalid: thisisnotanip', 'warning' ),
+			),
+			$settings_error
+		);
+	}
+
+	/**
+	 * Test sanitization of IP addresses.
+	 *
+	 * @return void
+	 */
+	public function test_sanitize_ips() {
+		// IPv4 tests.
+		$valid   = array( '192.0.2.123', '192.0.2.123/32', '192.0.2.0/24', '192.0.2.128/25' );
+		$invalid = array( '12.34.56.789', '192.0.2.123/33', '192.0.2.123/-1' );
+		$result  = invoke_static( StatifyBlacklist_Settings::class, 'sanitize_ips', array( array_merge( $valid, $invalid ) ) );
+		$this->assertNotFalse( $result );
+
+		/*
+		 * Unfortunately this is necessary as long as we run PHP 5 tests, because "assertInternalType" is deprecated
+		 * as of PHPUnit 8, but "assertIsArray" has been introduces in PHPUnit 7.5 which requires PHP >= 7.1.
+		 */
+		if ( method_exists( $this, 'assertIsArray' ) ) {
+			$this->assertIsArray( $result );
+		} else {
+			$this->assertInternalType( 'array', $result );
+		}
+		$this->assertEquals( $valid, $result );
+
+		// IPv6 tests.
+		$valid   = array(
+			'2001:db8:a0b:12f0::',
+			'2001:db8:a0b:12f0::1',
+			'2001:db8:a0b:12f0::1/128',
+			'2001:DB8:A0B:12F0::/64',
+			'fe80::7645:6de2:ff:1',
+			'2001:db8:a0b:12f0::',
+			'::ffff:192.0.2.123',
+		);
+		$invalid = array(
+			'2001:db8:a0b:12f0::x',
+			'2001:db8:a0b:12f0:::',
+			'2001:fffff:a0b:12f0::1',
+			'2001:DB8:A0B:12F0::/129',
+			'1:2:3:4:5:6:7:8:9',
+			'::ffff:12.34.56.789',
+		);
+		$result  = invoke_static( StatifyBlacklist_Settings::class, 'sanitize_ips', array( array_merge( $valid, $invalid ) ) );
+		$this->assertNotFalse( $result );
+		if ( method_exists( $this, 'assertIsArray' ) ) {
+			$this->assertIsArray( $result );
+		} else {
+			$this->assertInternalType( 'array', $result );
+		}
+		$this->assertEquals(
+			array(
+				'2001:db8:a0b:12f0::',
+				'2001:db8:a0b:12f0::1',
+				'2001:db8:a0b:12f0::1/128',
+				'2001:db8:a0b:12f0::/64',
+				'fe80::7645:6de2:ff:1',
+				'::ffff:192.0.2.123',
+			),
+			$result
+		);
+	}
+
+	/**
+	 * Test settings registration.
+	 *
+	 * @return void
+	 */
+	public function test_register_settings() {
+		global $settings;
+		$settings = array();
+
+		StatifyBlacklist_Settings::register_settings();
+		$this->assertEquals( array( 'statify-blacklist' ), array_keys( $settings ), 'unexpected settings pages' );
+		$this->assertEquals(
+			array(
+				'statifyblacklist-referer',
+				'statifyblacklist-target',
+				'statifyblacklist-ip',
+				'statifyblacklist-ua',
+			),
+			array_keys( $settings['statify-blacklist']['sections'] ),
+			'unexpected settings sections'
+		);
+		$this->assertEquals(
+			array(
+				'statifyblacklist-referer-active',
+				'statifyblacklist-referer-cron',
+				'statifyblacklist-referer-regexp',
+				'statifyblacklist-referer-blacklist',
+			),
+			array_keys( $settings['statify-blacklist']['sections']['statifyblacklist-referer']['fields'] ),
+			'unexpected fields in referrer section'
+		);
+		$this->assertEquals(
+			array(
+				'statifyblacklist-target-active',
+				'statifyblacklist-target-cron',
+				'statifyblacklist-target-regexp',
+				'statifyblacklist-target-blacklist',
+			),
+			array_keys( $settings['statify-blacklist']['sections']['statifyblacklist-target']['fields'] ),
+			'unexpected fields in target section'
+		);
+		$this->assertEquals(
+			array( 'statifyblacklist-ip-active', 'statifyblacklist-ip-blacklist' ),
+			array_keys( $settings['statify-blacklist']['sections']['statifyblacklist-ip']['fields'] ),
+			'unexpected fields in ip section'
+		);
+		$this->assertEquals(
+			array(
+				'statifyblacklist-ua-active',
+				'statifyblacklist-ua-regexp',
+				'statifyblacklist-ua-blacklist',
+			),
+			array_keys( $settings['statify-blacklist']['sections']['statifyblacklist-ua']['fields'] ),
+			'unexpected fields in user agent section'
+		);
+	}
+}

test/StatifyBlacklist_System_Test.php

@@ -0,0 +1,91 @@
+<?php
+/**
+ * Statify Filter: Unit Test
+ *
+ * This is a PHPunit test class for the plugin's functionality
+ *
+ * @package Statify_Blacklist
+ */
+
+/**
+ * Class StatifyBlacklist_System_Test.
+ *
+ * PHPUnit test class for StatifyBlacklist_System.
+ */
+class StatifyBlacklist_System_Test extends PHPUnit\Framework\TestCase {
+
+	/**
+	 * Test the upgrade methodology for configuration options.
+	 *
+	 * @return void
+	 */
+	public function test_upgrade() {
+		// Create configuration of version 1.3.
+		$options13 = array(
+			'active_referer' => 1,
+			'cron_referer'   => 0,
+			'referer'        => array(
+				'example.net' => 0,
+				'example.com' => 1,
+			),
+			'referer_regexp' => 0,
+			'version'        => 1.3,
+		);
+
+		// Set options in mock.
+		update_option( 'statify-blacklist', $options13 );
+
+		// Execute upgrade.
+		StatifyBlacklist_System::upgrade();
+
+		// Retrieve updated options.
+		$options_updated = get_option( 'statify-blacklist' );
+
+		// Verify size against default options (no junk left).
+		$this->assertEquals( 5, count( $options_updated ) );
+		$this->assertEquals( 4, count( $options_updated['referer'] ) );
+		$this->assertEquals( 4, count( $options_updated['target'] ) );
+		$this->assertEquals( 2, count( $options_updated['ip'] ) );
+		$this->assertEquals( 3, count( $options_updated['ua'] ) );
+		$this->assertEquals( StatifyBlacklist::VERSION_MAIN, $options_updated['version'] );
+
+		// Verify that original attributes are unchanged.
+		$this->assertEquals( $options13['active_referer'], $options_updated['referer']['active'] );
+		$this->assertEquals( $options13['cron_referer'], $options_updated['referer']['cron'] );
+		$this->assertEquals( $options13['referer'], $options_updated['referer']['blacklist'] );
+		$this->assertEquals( $options13['referer_regexp'], $options_updated['referer']['regexp'] );
+
+		// Verify that new attributes are present in config and filled with default values (disabled, empty).
+		$this->assertEquals( 0, $options_updated['target']['active'] );
+		$this->assertEquals( 0, $options_updated['target']['cron'] );
+		$this->assertEquals( 0, $options_updated['target']['regexp'] );
+		$this->assertEquals( array(), $options_updated['target']['blacklist'] );
+		$this->assertEquals( 0, $options_updated['ip']['active'] );
+		$this->assertEquals( array(), $options_updated['ip']['blacklist'] );
+		$this->assertEquals( 0, $options_updated['ua']['active'] );
+		$this->assertEquals( 0, $options_updated['ua']['regexp'] );
+		$this->assertEquals( array(), $options_updated['ua']['blacklist'] );
+
+		// Verify that version number has changed to current release.
+		$this->assertEquals( StatifyBlacklist::VERSION_MAIN, $options_updated['version'] );
+
+		// Test upgrade of incorrectly stored user agent list in 1.6.
+		$options_updated['version']         = 1.4;
+		$options_updated['ua']['blacklist'] = array( 'user agent 1', 'user agent 2' );
+		update_option( 'statify-blacklist', $options_updated );
+
+		// Execute upgrade.
+		StatifyBlacklist_System::upgrade();
+
+		// Retrieve updated options.
+		$options_updated = get_option( 'statify-blacklist' );
+		$this->assertEquals(
+			array(
+				'user agent 1' => 0,
+				'user agent 2' => 1,
+			),
+			$options_updated['ua']['blacklist']
+		);
+		$this->assertEquals( StatifyBlacklist::VERSION_MAIN, $options_updated['version'] );
+	}
+}

test/StatifyBlacklist_Test.php

@@ -0,0 +1,615 @@
+<?php
+/**
+ * Statify Filter: Unit Test
+ *
+ * This is a PHPunit test class for the plugin's functionality
+ *
+ * @package Statify_Blacklist
+ * @since   1.3.0
+ */
+
+/**
+ * Class StatifyBlacklistTest.
+ *
+ * PHPUnit test class for StatifyBlacklist.
+ *
+ * @since 1.3.0
+ */
+class StatifyBlacklist_Test extends PHPUnit\Framework\TestCase {
+
+	/**
+	 * Test simple referer filter.
+	 *
+	 * @return void
+	 */
+	public function test_referer_filter() {
+		// Prepare Options: 2 filtered domains, disabled.
+		StatifyBlacklist::$options = array(
+			'referer' => array(
+				'active'    => 0,
+				'cron'      => 0,
+				'regexp'    => 0,
+				'blacklist' => array(
+					'example.com' => 0,
+					'example.net' => 1,
+				),
+			),
+			'target'  => array(
+				'active'    => 0,
+				'cron'      => 0,
+				'regexp'    => 0,
+				'blacklist' => array(),
+			),
+			'ip'      => array(
+				'active'    => 0,
+				'blacklist' => array(),
+			),
+			'ua'      => array(
+				'active'    => 0,
+				'regexp'    => StatifyBlacklist::MODE_NORMAL,
+				'blacklist' => array(),
+			),
+			'version' => StatifyBlacklist::VERSION_MAIN,
+		);
+
+		// No multisite.
+		StatifyBlacklist::$multisite = false;
+
+		// No referer.
+		unset( $_SERVER['HTTP_REFERER'] );
+		$this->assertNull( StatifyBlacklist::apply_blacklist_filter() );
+		// Non-filtered referer.
+		$_SERVER['HTTP_REFERER'] = 'http://example.org';
+		$this->assertNull( StatifyBlacklist::apply_blacklist_filter() );
+		// Filtered referer.
+		$_SERVER['HTTP_REFERER'] = 'http://example.com';
+		$this->assertNull( StatifyBlacklist::apply_blacklist_filter() );
+		// Filtered referer with path.
+		$_SERVER['HTTP_REFERER'] = 'http://example.net/foo/bar.html';
+		$this->assertNull( StatifyBlacklist::apply_blacklist_filter() );
+
+		// Activate filter and run tests again.
+		StatifyBlacklist::$options['referer']['active'] = 1;
+
+		unset( $_SERVER['HTTP_REFERER'] );
+		$this->assertNull( StatifyBlacklist::apply_blacklist_filter() );
+
+		$_SERVER['HTTP_REFERER'] = 'http://example.org';
+		$this->assertNull( StatifyBlacklist::apply_blacklist_filter() );
+
+		$_SERVER['HTTP_REFERER'] = 'http://example.com';
+		$this->assertTrue( StatifyBlacklist::apply_blacklist_filter() );
+
+		$_SERVER['HTTP_REFERER'] = 'http://example.net/foo/bar.html';
+		$this->assertTrue( StatifyBlacklist::apply_blacklist_filter() );
+	}
+
+	/**
+	 * Test referer filter using regular expressions.
+	 *
+	 * @return void
+	 */
+	public function test_referer_regex_filter() {
+		// Prepare Options: 2 regular expressions.
+		StatifyBlacklist::$options = array(
+			'referer' => array(
+				'active'    => 1,
+				'cron'      => 0,
+				'regexp'    => 1,
+				'blacklist' => array(
+					'example.[a-z]+' => 0,
+					'test'           => 1,
+				),
+			),
+			'target'  => array(
+				'active'    => 0,
+				'cron'      => 0,
+				'regexp'    => 0,
+				'blacklist' => array(),
+			),
+			'ip'      => array(
+				'active'    => 0,
+				'blacklist' => array(),
+			),
+			'ua'      => array(
+				'active'    => 0,
+				'regexp'    => StatifyBlacklist::MODE_NORMAL,
+				'blacklist' => array(),
+			),
+			'version' => StatifyBlacklist::VERSION_MAIN,
+		);
+
+		// No multisite.
+		StatifyBlacklist::$multisite = false;
+
+		// No referer.
+		unset( $_SERVER['HTTP_REFERER'] );
+		$this->assertNull( StatifyBlacklist::apply_blacklist_filter() );
+		// Non-filtered referer.
+		$_SERVER['HTTP_REFERER'] = 'http://not.evil';
+		$this->assertNull( StatifyBlacklist::apply_blacklist_filter() );
+		// Filtered referer.
+		$_SERVER['HTTP_REFERER'] = 'http://example.com';
+		$this->assertTrue( StatifyBlacklist::apply_blacklist_filter() );
+		// Filtered referer with path.
+		$_SERVER['HTTP_REFERER'] = 'http://foobar.net/test/me';
+		$this->assertTrue( StatifyBlacklist::apply_blacklist_filter() );
+		// Matching both.
+		$_SERVER['HTTP_REFERER'] = 'http://example.net/test/me';
+		$this->assertTrue( StatifyBlacklist::apply_blacklist_filter() );
+		// Matching with wrong case.
+		$_SERVER['HTTP_REFERER'] = 'http://eXaMpLe.NeT/tEsT/mE';
+		$this->assertNull( StatifyBlacklist::apply_blacklist_filter() );
+
+		// Set RegExp filter to case insensitive.
+		StatifyBlacklist::$options['referer']['regexp'] = 2;
+		$this->assertTrue( StatifyBlacklist::apply_blacklist_filter() );
+	}
+
+	/**
+	 * Test referer filter using keywords.
+	 *
+	 * @return void
+	 */
+	public function test_referer_keyword_filter() {
+		// Prepare Options: 2 regular expressions.
+		StatifyBlacklist::$options = array(
+			'referer' => array(
+				'active'    => 1,
+				'cron'      => 0,
+				'regexp'    => StatifyBlacklist::MODE_KEYWORD,
+				'blacklist' => array(
+					'example' => 0,
+					'test'    => 1,
+				),
+			),
+			'target'  => array(
+				'active'    => 0,
+				'cron'      => 0,
+				'regexp'    => StatifyBlacklist::MODE_NORMAL,
+				'blacklist' => array(),
+			),
+			'ip'      => array(
+				'active'    => 0,
+				'blacklist' => array(),
+			),
+			'ua'      => array(
+				'active'    => 0,
+				'regexp'    => StatifyBlacklist::MODE_NORMAL,
+				'blacklist' => array(),
+			),
+			'version' => StatifyBlacklist::VERSION_MAIN,
+		);
+
+		// No multisite.
+		StatifyBlacklist::$multisite = false;
+
+		// No referer.
+		unset( $_SERVER['HTTP_REFERER'] );
+		$this->assertNull( StatifyBlacklist::apply_blacklist_filter() );
+		// Non-filtered referer.
+		$_SERVER['HTTP_REFERER'] = 'http://not.evil';
+		$this->assertNull( StatifyBlacklist::apply_blacklist_filter() );
+		// Filtered referer.
+		$_SERVER['HTTP_REFERER'] = 'http://example.com';
+		$this->assertTrue( StatifyBlacklist::apply_blacklist_filter() );
+		// Filtered referer with path.
+		$_SERVER['HTTP_REFERER'] = 'http://foobar.net/test/me';
+		$this->assertTrue( StatifyBlacklist::apply_blacklist_filter() );
+		// Matching both.
+		$_SERVER['HTTP_REFERER'] = 'http://example.net/test/me';
+		$this->assertTrue( StatifyBlacklist::apply_blacklist_filter() );
+		// Matching with wrong case.
+		$_SERVER['HTTP_REFERER'] = 'http://eXaMpLe.NeT/tEsT/mE';
+		$this->assertTrue( StatifyBlacklist::apply_blacklist_filter() );
+	}
+
+	/**
+	 * Test CIDR address matching for IP filter (#7).
+	 *
+	 * @return void
+	 */
+	public function test_cidr_match() {
+		// IPv4 tests.
+		$this->assertTrue( invoke_static( StatifyBlacklist::class, 'cidr_match', array( '127.0.0.1', '127.0.0.1' ) ) );
+		$this->assertTrue( invoke_static( StatifyBlacklist::class, 'cidr_match', array( '127.0.0.1', '127.0.0.1/32' ) ) );
+		$this->assertFalse(
+			invoke_static(
+				StatifyBlacklist::class,
+				'cidr_match',
+				array( '127.0.0.1', '127.0.0.1/33' )
+			)
+		);
+		$this->assertFalse(
+			invoke_static(
+				StatifyBlacklist::class,
+				'cidr_match',
+				array( '127.0.0.1', '127.0.0.1/-1' )
+			)
+		);
+		$this->assertTrue(
+			invoke_static(
+				StatifyBlacklist::class,
+				'cidr_match',
+				array( '192.0.2.123', '192.0.2.0/24' )
+			)
+		);
+		$this->assertFalse(
+			invoke_static(
+				StatifyBlacklist::class,
+				'cidr_match',
+				array( '192.0.3.123', '192.0.2.0/24' )
+			)
+		);
+		$this->assertTrue(
+			invoke_static(
+				StatifyBlacklist::class,
+				'cidr_match',
+				array( '192.0.2.123', '192.0.2.120/29' )
+			)
+		);
+		$this->assertFalse(
+			invoke_static(
+				StatifyBlacklist::class,
+				'cidr_match',
+				array( '192.0.2.128', '192.0.2.120/29' )
+			)
+		);
+		$this->assertTrue( invoke_static( StatifyBlacklist::class, 'cidr_match', array( '10.11.12.13', '10.0.0.0/8' ) ) );
+		$this->assertFalse(
+			invoke_static(
+				StatifyBlacklist::class,
+				'cidr_match',
+				array( '10.11.12.345', '10.0.0.0/8' )
+			)
+		);
+
+		// IPv6 tests.
+		$this->assertTrue( invoke_static( StatifyBlacklist::class, 'cidr_match', array( '::1', '::1' ) ) );
+		$this->assertTrue( invoke_static( StatifyBlacklist::class, 'cidr_match', array( '::1', '::1/128' ) ) );
+		$this->assertFalse( invoke_static( StatifyBlacklist::class, 'cidr_match', array( '::1', '::1/129' ) ) );
+		$this->assertFalse( invoke_static( StatifyBlacklist::class, 'cidr_match', array( '::1', '::1/-1' ) ) );
+		$this->assertTrue(
+			invoke_static(
+				StatifyBlacklist::class,
+				'cidr_match',
+				array( '2001:db8:a0b:12f0:1:2:3:4', '2001:db8:a0b:12f0::1/64 ' )
+			)
+		);
+		$this->assertTrue(
+			invoke_static(
+				StatifyBlacklist::class,
+				'cidr_match',
+				array( '2001:db8:a0b:12f0::123:456', '2001:db8:a0b:12f0::1/96 ' )
+			)
+		);
+		$this->assertTrue(
+			invoke_static(
+				StatifyBlacklist::class,
+				'cidr_match',
+				array( '2001:DB8:A0B:12F0::123:456', '2001:db8:a0b:12f0::1/96 ' )
+			)
+		);
+		$this->assertTrue(
+			invoke_static(
+				StatifyBlacklist::class,
+				'cidr_match',
+				array( '2001:db8:a0b:12f0::123:456', '2001:DB8:A0B:12F0::1/96 ' )
+			)
+		);
+		$this->assertFalse(
+			invoke_static(
+				StatifyBlacklist::class,
+				'cidr_match',
+				array( '2001:db8:a0b:12f0::1:132:465', '2001:db8:a0b:12f0::1/96 ' )
+			)
+		);
+	}
+
+	/**
+	 * Test IP filter (#7).
+	 *
+	 * @return void
+	 */
+	public function test_ip_filter() {
+		// Prepare Options: 2 filtered IPs, disabled.
+		StatifyBlacklist::$options = array(
+			'referer' => array(
+				'active'    => 0,
+				'cron'      => 0,
+				'regexp'    => StatifyBlacklist::MODE_NORMAL,
+				'blacklist' => array(),
+			),
+			'target'  => array(
+				'active'    => 0,
+				'cron'      => 0,
+				'regexp'    => StatifyBlacklist::MODE_NORMAL,
+				'blacklist' => array(),
+			),
+			'ip'      => array(
+				'active'    => 0,
+				'blacklist' => array(
+					'192.0.2.123',
+					'2001:db8:a0b:12f0::1',
+				),
+			),
+			'ua'      => array(
+				'active'    => 0,
+				'regexp'    => StatifyBlacklist::MODE_NORMAL,
+				'blacklist' => array(),
+			),
+			'version' => StatifyBlacklist::VERSION_MAIN,
+		);
+
+		// No multisite.
+		StatifyBlacklist::$multisite = false;
+
+		// Set matching IP.
+		$_SERVER['REMOTE_ADDR'] = '192.0.2.123';
+		$this->assertNull( StatifyBlacklist::apply_blacklist_filter() );
+		// Activate filter.
+		StatifyBlacklist::$options['ip']['active'] = 1;
+		$this->assertTrue( StatifyBlacklist::apply_blacklist_filter() );
+		// Try matching v6 address.
+		$_SERVER['REMOTE_ADDR'] = '2001:db8:a0b:12f0::1';
+		$this->assertTrue( StatifyBlacklist::apply_blacklist_filter() );
+		// Non-matching addresses.
+		$_SERVER['REMOTE_ADDR'] = '192.0.2.234';
+		$this->assertNull( StatifyBlacklist::apply_blacklist_filter() );
+		$_SERVER['REMOTE_ADDR'] = '2001:db8:a0b:12f0::2';
+		$this->assertNull( StatifyBlacklist::apply_blacklist_filter() );
+		// Subnet matching.
+		StatifyBlacklist::$options['ip']['blacklist'] = array(
+			'192.0.2.0/25',
+			'2001:db8:a0b:12f0::/96',
+		);
+		$_SERVER['REMOTE_ADDR']                       = '192.0.2.123';
+		$this->assertTrue( StatifyBlacklist::apply_blacklist_filter() );
+		$_SERVER['REMOTE_ADDR'] = '192.0.2.234';
+		$this->assertNull( StatifyBlacklist::apply_blacklist_filter() );
+		$_SERVER['REMOTE_ADDR'] = '2001:db8:a0b:12f0::5';
+		$this->assertTrue( StatifyBlacklist::apply_blacklist_filter() );
+		$_SERVER['REMOTE_ADDR'] = '2001:db8:a0b:12f0:0:1111::1';
+		$this->assertNull( StatifyBlacklist::apply_blacklist_filter() );
+
+		// Filter using proxy header.
+		$_SERVER['REMOTE_ADDR'] = '127.0.0.1';
+		$this->assertNull( StatifyBlacklist::apply_blacklist_filter() );
+		$_SERVER['HTTP_X_FORWARDED_FOR'] = '192.0.2.123';
+		$this->assertTrue( StatifyBlacklist::apply_blacklist_filter() );
+		$_SERVER['HTTP_X_REAL_IP'] = '2001:db8:a0b:12f0:0:1111::1';
+		$this->assertNull( StatifyBlacklist::apply_blacklist_filter() );
+		$_SERVER['HTTP_X_REAL_IP'] = '2001:db8:a0b:12f0:0::1';
+		$this->assertTrue( StatifyBlacklist::apply_blacklist_filter() );
+	}
+
+	/**
+	 * Test simple target filter.
+	 *
+	 * @return void
+	 */
+	public function test_target_filter() {
+		// Prepare Options: 2 filtered domains, disabled.
+		StatifyBlacklist::$options = array(
+			'referer' => array(
+				'active'    => 0,
+				'cron'      => 0,
+				'regexp'    => StatifyBlacklist::MODE_NORMAL,
+				'blacklist' => array(),
+			),
+			'target'  => array(
+				'active'    => 0,
+				'cron'      => 0,
+				'regexp'    => StatifyBlacklist::MODE_NORMAL,
+				'blacklist' => array(
+					'/excluded/page/' => 0,
+					'/?page_id=3'     => 1,
+				),
+			),
+			'ip'      => array(
+				'active'    => 0,
+				'blacklist' => array(),
+			),
+			'ua'      => array(
+				'active'    => 0,
+				'regexp'    => StatifyBlacklist::MODE_NORMAL,
+				'blacklist' => array(),
+			),
+			'version' => StatifyBlacklist::VERSION_MAIN,
+		);
+
+		// No multisite.
+		StatifyBlacklist::$multisite = false;
+
+		// Empty target.
+		unset( $_SERVER['REQUEST_URI'] );
+		$this->assertNull( StatifyBlacklist::apply_blacklist_filter() );
+		// Non-filtered targets.
+		$_SERVER['REQUEST_URI'] = '';
+		$this->assertNull( StatifyBlacklist::apply_blacklist_filter() );
+		$_SERVER['REQUEST_URI'] = '/';
+		$this->assertNull( StatifyBlacklist::apply_blacklist_filter() );
+		$_SERVER['REQUEST_URI'] = '/?page_id=1';
+		$this->assertNull( StatifyBlacklist::apply_blacklist_filter() );
+		// Filtered referer.
+		$_SERVER['REQUEST_URI'] = '/excluded/page/';
+		$this->assertNull( StatifyBlacklist::apply_blacklist_filter() );
+		$_SERVER['REQUEST_URI'] = '/?page_id=3';
+		$this->assertNull( StatifyBlacklist::apply_blacklist_filter() );
+
+		// Activate filter and run tests again.
+		StatifyBlacklist::$options['target']['active'] = 1;
+
+		unset( $_SERVER['REQUEST_URI'] );
+		$this->assertNull( StatifyBlacklist::apply_blacklist_filter() );
+
+		$_SERVER['REQUEST_URI'] = '';
+		$this->assertNull( StatifyBlacklist::apply_blacklist_filter() );
+		$_SERVER['REQUEST_URI'] = '/';
+		$this->assertNull( StatifyBlacklist::apply_blacklist_filter() );
+		$_SERVER['REQUEST_URI'] = '/?page_id=1';
+		$this->assertNull( StatifyBlacklist::apply_blacklist_filter() );
+
+		$_SERVER['REQUEST_URI'] = '/excluded/page/';
+		$this->assertTrue( StatifyBlacklist::apply_blacklist_filter() );
+		$_SERVER['REQUEST_URI'] = '/?page_id=3';
+		$this->assertTrue( StatifyBlacklist::apply_blacklist_filter() );
+		$_SERVER['REQUEST_URI'] = '/?page_id=3';
+		$this->assertTrue( StatifyBlacklist::apply_blacklist_filter() );
+	}
+
+	// TODO: Test target regex filter.
+
+
+	/**
+	 * Test user agent filter (#20).
+	 *
+	 * @return void
+	 */
+	public function test_ua_filter() {
+		// Prepare Options: 2 filtered IPs, disabled.
+		StatifyBlacklist::$options = array(
+			'referer' => array(
+				'active'    => 0,
+				'cron'      => 0,
+				'regexp'    => StatifyBlacklist::MODE_NORMAL,
+				'blacklist' => array(),
+			),
+			'target'  => array(
+				'active'    => 0,
+				'cron'      => 0,
+				'regexp'    => StatifyBlacklist::MODE_NORMAL,
+				'blacklist' => array(),
+			),
+			'ip'      => array(
+				'active'    => 0,
+				'blacklist' => array(),
+			),
+			'ua'      => array(
+				'active'    => 0,
+				'regexp'    => StatifyBlacklist::MODE_NORMAL,
+				'blacklist' => array(
+					'TestBot/1.23' => 0,
+				),
+			),
+			'version' => StatifyBlacklist::VERSION_MAIN,
+		);
+
+		// No multisite.
+		StatifyBlacklist::$multisite = false;
+
+		// Set matching user agent.
+		$_SERVER['HTTP_USER_AGENT'] = 'TestBot/1.23';
+		$this->assertNull( StatifyBlacklist::apply_blacklist_filter() );
+		// Activate filter.
+		StatifyBlacklist::$options['ua']['active'] = 1;
+		$this->assertTrue( StatifyBlacklist::apply_blacklist_filter() );
+		// Non-matching addresses.
+		$_SERVER['HTTP_USER_AGENT'] = 'Another Browser 4.5.6 (Linux)';
+		$this->assertNull( StatifyBlacklist::apply_blacklist_filter() );
+		$_SERVER['HTTP_USER_AGENT'] = 'TestBot/2.34';
+		$this->assertNull( StatifyBlacklist::apply_blacklist_filter() );
+		// Keyword matching.
+		StatifyBlacklist::$options['ua']['blacklist'] = array( 'TestBot' => 0 );
+		StatifyBlacklist::$options['ua']['regexp']    = StatifyBlacklist::MODE_KEYWORD;
+		$this->assertTrue( StatifyBlacklist::apply_blacklist_filter() );
+		// RegEx.
+		StatifyBlacklist::$options['ua']['blacklist'] = array( 'T[a-z]+B[a-z]+' => 0 );
+		StatifyBlacklist::$options['ua']['regexp']    = StatifyBlacklist::MODE_REGEX;
+		$this->assertTrue( StatifyBlacklist::apply_blacklist_filter() );
+		StatifyBlacklist::$options['ua']['blacklist'] = array( 't[a-z]+' => 0 );
+		$this->assertNull( StatifyBlacklist::apply_blacklist_filter() );
+		StatifyBlacklist::$options['ua']['regexp'] = StatifyBlacklist::MODE_REGEX_CI;
+		$this->assertTrue( StatifyBlacklist::apply_blacklist_filter() );
+	}
+
+
+	/**
+	 * Test combined filters.
+	 *
+	 * @since 1.4.4
+	 *
+	 * @return void
+	 */
+	public function test_combined_filters() {
+		// Prepare Options: simple referer + simple target + ip.
+		StatifyBlacklist::$options = array(
+			'referer' => array(
+				'active'    => 1,
+				'cron'      => 0,
+				'regexp'    => StatifyBlacklist::MODE_NORMAL,
+				'blacklist' => array(
+					'example.com' => 0,
+				),
+			),
+			'target'  => array(
+				'active'    => 1,
+				'cron'      => 0,
+				'regexp'    => StatifyBlacklist::MODE_NORMAL,
+				'blacklist' => array(
+					'/excluded/page/' => 0,
+				),
+			),
+			'ip'      => array(
+				'active'    => 1,
+				'blacklist' => array(
+					'192.0.2.123',
+				),
+			),
+			'ua'      => array(
+				'active'    => 0,
+				'regexp'    => StatifyBlacklist::MODE_NORMAL,
+				'blacklist' => array(),
+			),
+			'version' => StatifyBlacklist::VERSION_MAIN,
+		);
+
+		// No multisite.
+		StatifyBlacklist::$multisite = false;
+
+		// No match.
+		$_SERVER['HTTP_REFERER'] = 'https://example.net';
+		$_SERVER['REQUEST_URI']  = '/normal/page/';
+		$_SERVER['REMOTE_ADDR']  = '192.0.2.234';
+		unset( $_SERVER['HTTP_X_FORWARDED_FOR'] );
+		unset( $_SERVER['HTTP_X_REAL_IP'] );
+
+		// Matching Referer.
+		$_SERVER['HTTP_REFERER'] = 'https://example.com';
+		$this->assertTrue( StatifyBlacklist::apply_blacklist_filter() );
+
+		// Matching target.
+		$_SERVER['HTTP_REFERER'] = 'https://example.net';
+		$_SERVER['REQUEST_URI']  = '/excluded/page/';
+		$this->assertTrue( StatifyBlacklist::apply_blacklist_filter() );
+
+		// Matching IP.
+		$_SERVER['REQUEST_URI'] = '/normal/page/';
+		$_SERVER['REMOTE_ADDR'] = '192.0.2.123';
+		$this->assertTrue( StatifyBlacklist::apply_blacklist_filter() );
+		$_SERVER['REMOTE_ADDR'] = '192.0.2.234';
+
+		// Same for RegExp filters.
+		StatifyBlacklist::$options['referer']['regexp']    = StatifyBlacklist::MODE_REGEX;
+		StatifyBlacklist::$options['referer']['blacklist'] = array( 'example\.com' => 0 );
+		StatifyBlacklist::$options['target']['regexp']     = StatifyBlacklist::MODE_REGEX;
+		StatifyBlacklist::$options['target']['blacklist']  = array( '/excluded/.*' => 0 );
+
+		$this->assertNull( StatifyBlacklist::apply_blacklist_filter() );
+		$_SERVER['HTTP_REFERER'] = 'https://example.com';
+		$this->assertTrue( StatifyBlacklist::apply_blacklist_filter() );
+		// Check case-insensitive match.
+		$_SERVER['HTTP_REFERER'] = 'https://eXaMpLe.com';
+		$this->assertNull( StatifyBlacklist::apply_blacklist_filter() );
+		StatifyBlacklist::$options['referer']['regexp'] = StatifyBlacklist::MODE_REGEX_CI;
+		$this->assertTrue( StatifyBlacklist::apply_blacklist_filter() );
+		$_SERVER['HTTP_REFERER'] = 'https://example.net';
+		$_SERVER['REQUEST_URI']  = '/excluded/page/';
+		$this->assertTrue( StatifyBlacklist::apply_blacklist_filter() );
+		$_SERVER['REQUEST_URI'] = '/normal/page/';
+		$_SERVER['REMOTE_ADDR'] = '192.0.2.123';
+		$this->assertTrue( StatifyBlacklist::apply_blacklist_filter() );
+		$_SERVER['REMOTE_ADDR'] = '192.0.2.234';
+
+	}
+}

test/bootstrap.php

@@ -0,0 +1,134 @@
+<?php
+/**
+ * PHPUnit bootstrap file
+ *
+ * @package Statify_Blacklist
+ */
+
+/**
+ * Simulating the ABSPATH constant.
+ *
+ * @var boolean ABSPATH
+ */
+const ABSPATH = false;
+
+/*
+ * Include class files.
+ */
+require_once __DIR__ . '/../inc/class-statifyblacklist.php';
+require_once __DIR__ . '/../inc/class-statifyblacklist-admin.php';
+require_once __DIR__ . '/../inc/class-statifyblacklist-settings.php';
+require_once __DIR__ . '/../inc/class-statifyblacklist-system.php';
+
+// Include Composer autoloader.
+require_once __DIR__ . '/../vendor/autoload.php';
+
+
+
+/** @ignore */
+function invoke_static( $class, $method_name, $parameters = array() ) {
+	$reflection = new \ReflectionClass( $class );
+	$method     = $reflection->getMethod( $method_name );
+	$method->setAccessible( true );
+
+	return $method->invokeArgs( null, $parameters );
+}
+
+// Some mocked WP functions.
+$mock_options   = array();
+$mock_multisite = false;
+$settings_error = array();
+$settings       = array();
+
+/** @ignore */
+function is_multisite() {
+	global $mock_multisite;
+
+	return $mock_multisite;
+}
+
+/** @ignore */
+function wp_parse_args( $args, $defaults = '' ) {
+	if ( is_object( $args ) ) {
+		$r = get_object_vars( $args );
+	} elseif ( is_array( $args ) ) {
+		$r =& $args;
+	} else {
+		parse_str( $args, $r );
+	}
+
+	if ( is_array( $defaults ) ) {
+		return array_merge( $defaults, $r );
+	}
+
+	return $r;
+}
+
+/** @ignore */
+function get_option( $option, $default = false ) {
+	global $mock_options;
+
+	return isset( $mock_options[ $option ] ) ? $mock_options[ $option ] : $default;
+}
+
+/** @ignore */
+function update_option( $option, $value, $autoload = null ) {
+	global $mock_options;
+	$mock_options[ $option ] = $value;
+}
+
+/** @ignore */
+function wp_get_raw_referer() {
+	return isset( $_SERVER['HTTP_REFERER'] ) ? $_SERVER['HTTP_REFERER'] : '';
+}
+
+function wp_parse_url( $value ) {
+	return parse_url( $value );
+}
+
+/** @ignore */
+function wp_unslash( $value ) {
+	return is_string( $value ) ? stripslashes( $value ) : $value;
+}
+
+/** @ignore */
+function __( $text, $domain = 'default' ) {
+	return $text;
+}
+
+/** @ignore */
+function add_settings_error( $setting, $code, $message, $type = 'error' ) {
+	global $settings_error;
+	$settings_error[] = array( $setting, $code, $message, $type );
+}
+
+/** @ignore */
+function register_setting( $option_group, $option_name, $args = array() ) {
+	global $settings;
+	$settings[ $option_name ] = array(
+		'group'    => $option_group,
+		'args'     => $args,
+		'sections' => array(),
+	);
+}
+
+/** @ignore */
+function add_settings_section( $id, $title, $callback, $page, $args = array() ) {
+	global $settings;
+	$settings[ $page ]['sections'][ $id ] = array(
+		'title'    => $title,
+		'callback' => $callback,
+		'args'     => $args,
+		'fields'   => array(),
+	);
+}
+
+/** @ignore */
+function add_settings_field( $id, $title, $callback, $page, $section = 'default', $args = array() ) {
+	global $settings;
+	$settings[ $page ]['sections'][ $section ]['fields'][ $id ] = array(
+		'title'    => $title,
+		'callback' => $callback,
+		'args'     => $args,
+	);
+}

views/settings_page.php

@@ -1,94 +0,0 @@
-<?php
-
-/* Quit */
-defined('ABSPATH') OR exit;
-
-/* Update plugin options */
-if ( !empty($_POST['statifyblacklist']) ) {
-  /* Verify nonce */
-  check_admin_referer( 'statify-blacklist-settings' );
-
-  /* Check user capabilities */
-  if (!current_user_can('manage_options')) {
-    die(_e('Are you sure you want to do this?'));
-  }
-
-  if (!empty($_POST['cleanUp'])) {
-    /* CleanUp DB */
-    StatifyBlacklist_Admin::cleanup_database();
-  } else {
-    /* Extract referer array */
-    if (empty(trim($_POST['statifyblacklist']['referer']))) $referer = array();
-    else $referer = explode("\r\n", $_POST['statifyblacklist']['referer']);
-
-    /* Update options (data will be sanitized) */
-    $statifyBlacklistUpdateResult= StatifyBlacklist_Admin::update_options(
-      array(
-        'active_referer' => (int)@$_POST['statifyblacklist']['active_referer'],
-        'referer' => $referer
-      )
-    );
-
-    /* Generate messages */
-    if ($statifyBlacklistUpdateResult !== false) {
-      $statifyBlacklistPostWarning = 'Some URLs are invalid and have been sanitized. Settings have not been saved yet.';
-    } else {
-      $statifyBlacklistPostSuccess = 'Settings updated successfully.';
-    }
-  }
-}
-
-?>
-
-<div class="wrap">
-    <h1><?php _e( 'Statify Blacklist', 'statify-blacklist') ?></h1>
-    <?php
-    if (is_plugin_inactive('statify/statify.php')) {
-      print '<div class="notice notice-warning"><p>';
-      esc_html_e('Statify plugin is not active.', 'statify-blacklist');
-      print '</p></div>';
-    }
-    if (isset($statifyBlacklistPostWarning)) {
-      print '<div class="notice notice-warning"><p>';
-      esc_html_e($statifyBlacklistPostWarning);
-      print '</p></div>';
-    }
-    if (isset($statifyBlacklistPostSuccess)) {
-      print '<div class="notice notice-success"><p>';
-      esc_html_e($statifyBlacklistPostSuccess);
-      print '</p></div>';
-    }
-    ?>
-    <form action="" method="post" id="statify-blacklist-settings">
-        <ul style="list-style: none;">
-            <li>
-                <label for="statify-blacklist_active_referer">
-                    <input type="checkbox" name="statifyblacklist[active_referer]" id="statifyblacklist_active_referer" value="1" <?php checked(StatifyBlacklist::$_options['active_referer'], 1); ?> />
-                    <?php esc_html_e('Activate referer blacklist', 'statify-blacklist'); ?>
-                </label>
-            </li>
-            <li>
-                <label for="statify-blacklist_referer">
-                    <?php  esc_html_e('Referer blacklist:', 'statify-blacklist'); ?><br />
-                    <textarea cols="40" rows="5" name="statifyblacklist[referer]" id="statify-blacklist_referer"><?php
-                      if (isset($statifyBlacklistUpdateResult) &&$statifyBlacklistUpdateResult !== false)
-                        print esc_html(implode("\r\n", $statifyBlacklistUpdateResult));
-                      else
-                        print esc_html(implode("\r\n", StatifyBlacklist::$_options['referer']));
-                    ?></textarea><br />
-                    <small>(<?php esc_html_e('Add one domain (without subdomains) each line, e.g. example.com', 'statify-blacklist'); ?>)</small>
-                </label>
-            </li>
-        </ul>
-        <?php wp_nonce_field('statify-blacklist-settings'); ?>
-
-        <p class="submit">
-            <input class="button-primary" type="submit" name="submit" value="<?php _e('Save Changes') ?>">
-          <hr>
-          <input class="button-secondary" type="submit" name="cleanUp" value="<?php esc_html_e('CleanUp Database', 'statify-blacklist') ?>"
-                 onclick="return confirm('Do you really want to apply filters to database? This cannot be undone.');">
-          <br>
-          <small><?php esc_html_e('Applies filter (even if disabled) to data stored in database. This cannot be undone!', 'statify-blacklist'); ?></small>
-        </p>
-    </form>
-</div>