From 23dd4721ece298ba7d2d01ab1ed32c5e6aedcac4 Mon Sep 17 00:00:00 2001
From: Thomas Gelf <thomas@gelf.net>
Date: Mon, 29 Feb 2016 12:23:08 +0100
Subject: [PATCH] ExtensibleSet: basic implementation & tests

---
 .../Director/IcingaConfig/ExtensibleSet.php   | 199 ++++++++++++++++++
 .../IcingaConfig/ExtensibleSetTest.php        | 135 ++++++++++++
 2 files changed, 334 insertions(+)
 create mode 100644 library/Director/IcingaConfig/ExtensibleSet.php
 create mode 100644 test/php/library/Director/IcingaConfig/ExtensibleSetTest.php

diff --git a/library/Director/IcingaConfig/ExtensibleSet.php b/library/Director/IcingaConfig/ExtensibleSet.php
new file mode 100644
index 00000000..98bd6b89
--- /dev/null
+++ b/library/Director/IcingaConfig/ExtensibleSet.php
@@ -0,0 +1,199 @@
+<?php
+
+namespace Icinga\Module\Director\IcingaConfig;
+
+use Icinga\Exception\InvalidPropertyException;
+
+class ExtensibleSet
+{
+    protected $ownValues;
+
+    protected $plusValues = array();
+
+    protected $minusValues = array();
+
+    protected $resolvedValues;
+
+    protected $allowedValues;
+
+    protected $inheritedValues = array();
+
+    public function __construct($values = null)
+    {
+        if (null !== $values) {
+            $this->override($values);
+        }
+    }
+
+    public function override($values)
+    {
+        $this->ownValues       = array();
+        $this->inheritedValues = array();
+
+        $this->addValuesTo($this->ownValues, $values);
+
+        return $this->addResolvedValues($values);
+    }
+
+    public function extend($values)
+    {
+        $this->addValuesTo($this->plusValues, $values);
+        return $this->addResolvedValues($values);
+    }
+
+    public function blacklist($values)
+    {
+        $this->addValuesTo($this->minusValues, $values);
+
+        if ($this->hasBeenResolved()) {
+            $this->removeValuesFrom($this->resolvedValues, $values);
+        }
+
+        return $this;
+    }
+
+    public function getResolvedValues()
+    {
+        if (! $this->hasBeenResolved()) {
+            $this->recalculate();
+        }
+
+        sort($this->resolvedValues);
+
+        return $this->resolvedValues;
+    }
+
+    protected function hasBeenResolved()
+    {
+        return $this->resolvedValues !== null;
+    }
+
+    public function inheritFrom(ExtensibleSet $parent)
+    {
+        if ($this->ownValues !== null) {
+            return $this;
+        }
+
+        if ($this->hasBeenResolved()) {
+            $this->reset();
+        }
+
+        $this->inheritedValues = array();
+
+        $this->addValuesTo(
+            $this->inheritedValues,
+            $this->stripBlacklistedValues($parent->getResolvedValues())
+        );
+
+        return $this->recalculate();
+    }
+
+    protected function stripBlacklistedValues($array)
+    {
+        $this->removeValuesFrom($array, $this->minusValues);
+
+        return $array;
+    }
+
+    public function forgetInheritedValues()
+    {
+        $this->inheritedValues = array();
+        return $this;
+    }
+
+    protected function assertValidValue($value)
+    {
+        if (null === $this->allowedValues) {
+            return $this;
+        }
+
+        if (in_array($value, $this->allowedValues)) {
+            return $this;
+        }
+
+        throw new InvalidPropertyException(
+            'Got invalid property "%s", allowed are: (%s)',
+            $value,
+            implode(', ', $this->allowedValues)
+        );
+    }
+
+    protected function addValuesTo(&$array, $values)
+    {
+        foreach ($this->wantArray($values) as $value) {
+            $this->addTo($array, $value);
+        }
+
+        return $this;
+    }
+
+    protected function addResolvedValues($values)
+    {
+        if (! $this->hasBeenResolved()) {
+            $this->resolvedValues  = array();
+        }
+
+        return $this->addValuesTo(
+            $this->resolvedValues,
+            $this->stripBlacklistedValues($this->wantArray($values))
+        );
+    }
+
+    protected function removeValuesFrom(&$array, $values)
+    {
+        foreach ($this->wantArray($values) as $value) {
+            $this->removeFrom($array, $value);
+        }
+
+        return $this;
+    }
+
+    protected function addTo(&$array, $value)
+    {
+        if (! in_array($value, $array)) {
+            $this->assertValidValue($value);
+            $array[] = $value;
+        }
+
+        return $this;
+    }
+
+    protected function removeFrom(&$array, $value)
+    {
+        if (false !== ($pos = array_search($value, $array))) {
+            unset($array[$pos]);
+        }
+
+        return $this;
+    }
+
+    protected function recalculate()
+    {
+        $this->resolvedValues = array();
+        if ($this->ownValues === null) {
+            $this->addValuesTo($this->resolvedValues, $this->inheritedValues);
+        } else {
+            $this->addValuesTo($this->resolvedValues, $this->ownValues);
+        }
+        $this->addValuesTo($this->resolvedValues, $this->plusValues);
+        $this->removeFrom($this->resolvedValues, $this->minusValues);
+
+        return $this;
+    }
+
+    protected function reset()
+    {
+        $this->resolvedValues = null;
+
+        return $this;
+    }
+
+    protected function wantArray($values)
+    {
+        if (is_array($values)) {
+            return $values;
+        }
+
+        return array($values);
+    }
+}
diff --git a/test/php/library/Director/IcingaConfig/ExtensibleSetTest.php b/test/php/library/Director/IcingaConfig/ExtensibleSetTest.php
new file mode 100644
index 00000000..f1fa189b
--- /dev/null
+++ b/test/php/library/Director/IcingaConfig/ExtensibleSetTest.php
@@ -0,0 +1,135 @@
+<?php
+
+namespace Tests\Icinga\Module\Director\IcingaConfig;
+
+use Icinga\Module\Director\IcingaConfig\ExtensibleSet;
+use Icinga\Module\Director\Test\BaseTestCase;
+
+class ExtensibleSetTest extends BaseTestCase
+{
+    public function testNoValuesResultInEmptySet()
+    {
+        $set = new ExtensibleSet();
+
+        $this->assertEquals(
+            array(),
+            $set->getResolvedValues()
+        );
+    }
+
+    public function testValuesPassedToConstructorAreAccepted()
+    {
+        $values = array('Val1', 'Val2', 'Val4');
+        $set = new ExtensibleSet($values);
+
+        $this->assertEquals(
+            $values,
+            $set->getResolvedValues()
+        );
+    }
+
+    public function testSingleValuesCanBeBlacklisted()
+    {
+        $values = array('Val1', 'Val2', 'Val4');
+        $set = new ExtensibleSet($values);
+        $set->blacklist('Val2');
+
+        $this->assertEquals(
+            array('Val1', 'Val4'),
+            $set->getResolvedValues()
+        );
+    }
+
+    public function testMultipleValuesCanBeBlacklisted()
+    {
+        $values = array('Val1', 'Val2', 'Val4');
+        $set = new ExtensibleSet($values);
+        $set->blacklist(array('Val4', 'Val1'));
+
+        $this->assertEquals(
+            array('Val2'),
+            $set->getResolvedValues()
+        );
+    }
+
+    public function testSimpleInheritanceWorksFine()
+    {
+        $values = array('Val1', 'Val2', 'Val4');
+        $parent = new ExtensibleSet($values);
+        $child = new ExtensibleSet();
+        $child->inheritFrom($parent);
+
+        $this->assertEquals(
+            $values,
+            $child->getResolvedValues()
+        );
+    }
+
+    public function testWeCanInheritFromMultipleParents()
+    {
+        $p1set = array('p1a', 'p1c');
+        $p2set = array('p2a', 'p2d');
+        $parent1 = new ExtensibleSet($p1set);
+        $parent2 = new ExtensibleSet($p2set);
+        $child = new ExtensibleSet();
+        $child->inheritFrom($parent1)->inheritFrom($parent2);
+
+        $this->assertEquals(
+            $p2set,
+            $child->getResolvedValues()
+        );
+    }
+
+    public function testOwnValuesOverrideParents()
+    {
+        $cset = array('p1a', 'p1c');
+        $pset = array('p2a', 'p2d');
+        $child = new ExtensibleSet($cset);
+        $parent = new ExtensibleSet($pset);
+        $child->inheritFrom($parent);
+
+        $this->assertEquals(
+            $cset,
+            $child->getResolvedValues()
+        );
+    }
+
+    public function testInheritedValuesCanBeBlacklisted()
+    {
+        $pset = array('p1', 'p2', 'p3');
+
+        $child = new ExtensibleSet();
+        $child->blacklist('p2');
+
+        $parent = new ExtensibleSet($pset);
+        $child->inheritFrom($parent);
+        $child->blacklist(array('not', 'yet', 'p1'));
+
+        $this->assertEquals(
+            array('p3'),
+            $child->getResolvedValues()
+        );
+
+        $child->blacklist(array('p3'));
+        $this->assertEquals(
+            array(),
+            $child->getResolvedValues()
+        );
+    }
+
+    public function testInheritedValuesCanBeExtended()
+    {
+        $pset = array('p1', 'p2', 'p3');
+
+        $child = new ExtensibleSet();
+        $child->extend('p5');
+
+        $parent = new ExtensibleSet($pset);
+        $child->inheritFrom($parent);
+
+        $this->assertEquals(
+            array('p1', 'p2', 'p3', 'p5'),
+            $child->getResolvedValues()
+        );
+    }
+}