From b3a02c77e74bb7686ec860a91728af8347e3b26f Mon Sep 17 00:00:00 2001
From: Johannes Meyer <johannes.meyer@icinga.com>
Date: Tue, 16 Mar 2021 14:55:29 +0100
Subject: [PATCH 1/2] Introduce interface `ipl\Stdlib\Contract\Filterable`

---
 src/Contract/Filterable.php | 63 +++++++++++++++++++++++++++++++++++++
 1 file changed, 63 insertions(+)
 create mode 100644 src/Contract/Filterable.php

diff --git a/src/Contract/Filterable.php b/src/Contract/Filterable.php
new file mode 100644
index 0000000..2a6316a
--- /dev/null
+++ b/src/Contract/Filterable.php
@@ -0,0 +1,63 @@
+<?php
+
+namespace ipl\Stdlib\Contract;
+
+use ipl\Stdlib\Filter;
+
+interface Filterable
+{
+    /**
+     * Get the filter of the query
+     *
+     * @return Filter\Chain
+     */
+    public function getFilter();
+
+    /**
+     * Add a filter to the query
+     *
+     * Note that this method does not override an already set filter. Instead, multiple calls to this function add
+     * the specified filter using a {@see Filter\All} chain.
+     *
+     * @param Filter\Rule $filter
+     *
+     * @return $this
+     */
+    public function filter(Filter\Rule $filter);
+
+    /**
+     * Add a filter to the query
+     *
+     * Note that this method does not override an already set filter. Instead, multiple calls to this function add
+     * the specified filter using a {@see Filter\Any} chain.
+     *
+     * @param Filter\Rule $filter
+     *
+     * @return $this
+     */
+    public function orFilter(Filter\Rule $filter);
+
+    /**
+     * Add a filter to the query
+     *
+     * Note that this method does not override an already set filter. Instead, multiple calls to this function add
+     * the specified filter wrapped by a {@see Filter\None} chain and using a {@see Filter\All} chain.
+     *
+     * @param Filter\Rule $filter
+     *
+     * @return $this
+     */
+    public function notFilter(Filter\Rule $filter);
+
+    /**
+     * Add a filter to the query
+     *
+     * Note that this method does not override an already set filter. Instead, multiple calls to this function add
+     * the specified filter wrapped by a {@see Filter\None} chain and using a {@see Filter\Any} chain.
+     *
+     * @param Filter\Rule $filter
+     *
+     * @return $this
+     */
+    public function orNotFilter(Filter\Rule $filter);
+}

From 1aed5a0edb639898f0abafa25196a4d340a4ca31 Mon Sep 17 00:00:00 2001
From: Johannes Meyer <johannes.meyer@icinga.com>
Date: Fri, 19 Mar 2021 12:05:37 +0100
Subject: [PATCH 2/2] Introduce trait `ipl\Stdlib\Filters`

---
 src/Filters.php                   |  58 ++++++++++++++
 tests/FiltersTest.php             | 125 ++++++++++++++++++++++++++++++
 tests/FiltersTest/FiltersUser.php |  11 +++
 3 files changed, 194 insertions(+)
 create mode 100644 src/Filters.php
 create mode 100644 tests/FiltersTest.php
 create mode 100644 tests/FiltersTest/FiltersUser.php

diff --git a/src/Filters.php b/src/Filters.php
new file mode 100644
index 0000000..defff43
--- /dev/null
+++ b/src/Filters.php
@@ -0,0 +1,58 @@
+<?php
+
+namespace ipl\Stdlib;
+
+trait Filters
+{
+    /** @var Filter\Chain */
+    protected $filter;
+
+    public function getFilter()
+    {
+        return $this->filter ?: Filter::all();
+    }
+
+    public function filter(Filter\Rule $filter)
+    {
+        $currentFilter = $this->getFilter();
+        if ($currentFilter instanceof Filter\All) {
+            $this->filter = $currentFilter->add($filter);
+        } else {
+            $this->filter = Filter::all($filter);
+            if (! $currentFilter->isEmpty()) {
+                $this->filter->insertBefore($currentFilter, $filter);
+            }
+        }
+
+        return $this;
+    }
+
+    public function orFilter(Filter\Rule $filter)
+    {
+        $currentFilter = $this->getFilter();
+        if ($currentFilter instanceof Filter\Any) {
+            $this->filter = $currentFilter->add($filter);
+        } else {
+            $this->filter = Filter::any($filter);
+            if (! $currentFilter->isEmpty()) {
+                $this->filter->insertBefore($currentFilter, $filter);
+            }
+        }
+
+        return $this;
+    }
+
+    public function notFilter(Filter\Rule $filter)
+    {
+        $this->filter(Filter::none($filter));
+
+        return $this;
+    }
+
+    public function orNotFilter(Filter\Rule $filter)
+    {
+        $this->orFilter(Filter::none($filter));
+
+        return $this;
+    }
+}
diff --git a/tests/FiltersTest.php b/tests/FiltersTest.php
new file mode 100644
index 0000000..7ad642d
--- /dev/null
+++ b/tests/FiltersTest.php
@@ -0,0 +1,125 @@
+<?php
+
+namespace ipl\Tests\Stdlib;
+
+use ipl\Stdlib\Contract\Filterable;
+use ipl\Stdlib\Filter;
+use ipl\Tests\Stdlib\FiltersTest\FiltersUser;
+
+class FiltersTest extends \PHPUnit\Framework\TestCase
+{
+    /** @var Filterable */
+    protected $filterable;
+
+    public function setUp()
+    {
+        $this->filterable = new FiltersUser();
+    }
+
+    public function testFilterKeepsCurrentHierarchy()
+    {
+        $this->filterable->filter(Filter::equal('', ''));
+        $this->filterable->filter(Filter::unequal('', ''));
+
+        $this->assertSameFilterHierarchy(Filter::all(
+            Filter::equal('', ''),
+            Filter::unequal('', '')
+        ));
+    }
+
+    public function testFilterWrapsCurrentHierarchy()
+    {
+        $this->filterable->orFilter(Filter::equal('', ''));
+        $this->filterable->filter(Filter::unequal('', ''));
+
+        $this->assertSameFilterHierarchy(Filter::all(
+            Filter::any(Filter::equal('', '')),
+            Filter::unequal('', '')
+        ));
+    }
+
+    public function testOrFilterKeepsCurrentHierarchy()
+    {
+        $this->filterable->orFilter(Filter::equal('', ''));
+        $this->filterable->orFilter(Filter::unequal('', ''));
+
+        $this->assertSameFilterHierarchy(Filter::any(
+            Filter::equal('', ''),
+            Filter::unequal('', '')
+        ));
+    }
+
+    public function testOrFilterWrapsCurrentHierarchy()
+    {
+        $this->filterable->filter(Filter::equal('', ''));
+        $this->filterable->orFilter(Filter::unequal('', ''));
+
+        $this->assertSameFilterHierarchy(Filter::any(
+            Filter::all(Filter::equal('', '')),
+            Filter::unequal('', '')
+        ));
+    }
+
+    public function testNotFilterKeepsCurrentHierarchy()
+    {
+        $this->filterable->notFilter(Filter::equal('', ''));
+        $this->filterable->notFilter(Filter::unequal('', ''));
+
+        $this->assertSameFilterHierarchy(Filter::all(
+            Filter::none(Filter::equal('', '')),
+            Filter::none(Filter::unequal('', ''))
+        ));
+    }
+
+    public function testNotFilterWrapsCurrentHierarchy()
+    {
+        $this->filterable->orFilter(Filter::equal('', ''));
+        $this->filterable->notFilter(Filter::unequal('', ''));
+
+        $this->assertSameFilterHierarchy(Filter::all(
+            Filter::any(Filter::equal('', '')),
+            Filter::none(Filter::unequal('', ''))
+        ));
+    }
+
+    public function testOrNotFilterKeepsCurrentHierarchy()
+    {
+        $this->filterable->orNotFilter(Filter::equal('', ''));
+        $this->filterable->orNotFilter(Filter::unequal('', ''));
+
+        $this->assertSameFilterHierarchy(Filter::any(
+            Filter::none(Filter::equal('', '')),
+            Filter::none(Filter::unequal('', ''))
+        ));
+    }
+
+    public function testOrNotFilterWrapsCurrentHierarchy()
+    {
+        $this->filterable->filter(Filter::equal('', ''));
+        $this->filterable->orNotFilter(Filter::unequal('', ''));
+
+        $this->assertSameFilterHierarchy(Filter::any(
+            Filter::all(Filter::equal('', '')),
+            Filter::none(Filter::unequal('', ''))
+        ));
+    }
+
+    protected function assertSameFilterHierarchy(Filter\Chain $expected)
+    {
+        $actual = $this->filterable->getFilter();
+
+        $checkHierarchy = function ($expected, $actual) use (&$checkHierarchy) {
+            $expectedArray = iterator_to_array($expected);
+            $actualArray = iterator_to_array($actual);
+            foreach ($expectedArray as $key => $rule) {
+                $this->assertTrue(isset($actualArray[$key]));
+                $this->assertInstanceOf(get_class($rule), $actualArray[$key]);
+                if ($rule instanceof Filter\Chain) {
+                    $checkHierarchy($rule, $actualArray[$key]);
+                }
+            }
+        };
+
+        $checkHierarchy($expected, $actual);
+    }
+}
diff --git a/tests/FiltersTest/FiltersUser.php b/tests/FiltersTest/FiltersUser.php
new file mode 100644
index 0000000..7342cf9
--- /dev/null
+++ b/tests/FiltersTest/FiltersUser.php
@@ -0,0 +1,11 @@
+<?php
+
+namespace ipl\Tests\Stdlib\FiltersTest;
+
+use ipl\Stdlib\Contract\Filterable;
+use ipl\Stdlib\Filters;
+
+class FiltersUser implements Filterable
+{
+    use Filters;
+}