<?php

namespace SilverStripe\ORM\Tests;

use SilverStripe\ORM\ValidationException;
use SilverStripe\ORM\Versioning\Versioned;
use SilverStripe\ORM\DataObject;
use SilverStripe\Dev\CSSContentParser;
use SilverStripe\Dev\SapphireTest;

class HierarchyTest extends SapphireTest
{

    protected static $fixture_file = 'HierarchyTest.yml';

    protected $extraDataObjects = array(
        HierarchyTest\TestObject::class,
        HierarchyTest\HideTestObject::class,
        HierarchyTest\HideTestSubObject::class,
    );

    /**
     * Test the Hierarchy prevents infinite loops.
     */
    public function testPreventLoop()
    {
        $this->setExpectedException(
            ValidationException::class,
            sprintf('Infinite loop found within the "%s" hierarchy', HierarchyTest\TestObject::class)
        );

        $obj2 = $this->objFromFixture(HierarchyTest\TestObject::class, 'obj2');
        $obj2aa = $this->objFromFixture(HierarchyTest\TestObject::class, 'obj2aa');

        $obj2->ParentID = $obj2aa->ID;
        $obj2->write();
    }

    /**
     * Test Hierarchy::AllHistoricalChildren().
     */
    public function testAllHistoricalChildren()
    {
        // Delete some objs
        $this->objFromFixture(HierarchyTest\TestObject::class, 'obj2b')->delete();
        $this->objFromFixture(HierarchyTest\TestObject::class, 'obj3a')->delete();
        $this->objFromFixture(HierarchyTest\TestObject::class, 'obj3')->delete();

        // Check that obj1-3 appear at the top level of the AllHistoricalChildren tree
        $this->assertEquals(
            array("Obj 1", "Obj 2", "Obj 3"),
            singleton(HierarchyTest\TestObject::class)->AllHistoricalChildren()->column('Title')
        );

        // Check numHistoricalChildren
        $this->assertEquals(3, singleton(HierarchyTest\TestObject::class)->numHistoricalChildren());

        // Check that both obj 2 children are returned
        $obj2 = $this->objFromFixture(HierarchyTest\TestObject::class, 'obj2');
        $this->assertEquals(
            array("Obj 2a", "Obj 2b"),
            $obj2->AllHistoricalChildren()->column('Title')
        );

        // Check numHistoricalChildren
        $this->assertEquals(2, $obj2->numHistoricalChildren());


        // Obj 3 has been deleted; let's bring it back from the grave
        $obj3 = Versioned::get_including_deleted(HierarchyTest\TestObject::class, "\"Title\" = 'Obj 3'")->First();

        // Check that all obj 3 children are returned
        $this->assertEquals(
            array("Obj 3a", "Obj 3b", "Obj 3c", "Obj 3d"),
            $obj3->AllHistoricalChildren()->column('Title')
        );

        // Check numHistoricalChildren
        $this->assertEquals(4, $obj3->numHistoricalChildren());
    }

    /**
     * Test that you can call Hierarchy::markExpanded/Unexpanded/Open() on a obj, and that
     * calling Hierarchy::isMarked() on a different instance of that object will return true.
     */
    public function testItemMarkingIsntRestrictedToSpecificInstance()
    {
        // Mark a few objs
        $this->objFromFixture(HierarchyTest\TestObject::class, 'obj2')->markExpanded();
        $this->objFromFixture(HierarchyTest\TestObject::class, 'obj2a')->markExpanded();
        $this->objFromFixture(HierarchyTest\TestObject::class, 'obj2b')->markExpanded();
        $this->objFromFixture(HierarchyTest\TestObject::class, 'obj3')->markUnexpanded();

        // Query some objs in a different context and check their m
        $objs = DataObject::get(HierarchyTest\TestObject::class, '', '"ID" ASC');
        $marked = $expanded = array();
        foreach ($objs as $obj) {
            if ($obj->isMarked()) {
                $marked[] = $obj->Title;
            }
            if ($obj->isExpanded()) {
                $expanded[] = $obj->Title;
            }
        }

        $this->assertEquals(array('Obj 2', 'Obj 3', 'Obj 2a', 'Obj 2b'), $marked);
        $this->assertEquals(array('Obj 2', 'Obj 2a', 'Obj 2b'), $expanded);
    }

    public function testNumChildren()
    {
        $this->assertEquals($this->objFromFixture(HierarchyTest\TestObject::class, 'obj1')->numChildren(), 0);
        $this->assertEquals($this->objFromFixture(HierarchyTest\TestObject::class, 'obj2')->numChildren(), 2);
        $this->assertEquals($this->objFromFixture(HierarchyTest\TestObject::class, 'obj3')->numChildren(), 4);
        $this->assertEquals($this->objFromFixture(HierarchyTest\TestObject::class, 'obj2a')->numChildren(), 2);
        $this->assertEquals($this->objFromFixture(HierarchyTest\TestObject::class, 'obj2b')->numChildren(), 0);
        $this->assertEquals($this->objFromFixture(HierarchyTest\TestObject::class, 'obj3a')->numChildren(), 2);
        $this->assertEquals($this->objFromFixture(HierarchyTest\TestObject::class, 'obj3d')->numChildren(), 0);

        $obj1 = $this->objFromFixture(HierarchyTest\TestObject::class, 'obj1');
        $this->assertEquals($obj1->numChildren(), 0);
        $obj1Child1 = new HierarchyTest\TestObject();
        $obj1Child1->ParentID = $obj1->ID;
        $obj1Child1->write();
        $this->assertEquals(
            $obj1->numChildren(false),
            1,
            'numChildren() caching can be disabled through method parameter'
        );
        $obj1Child2 = new HierarchyTest\TestObject();
        $obj1Child2->ParentID = $obj1->ID;
        $obj1Child2->write();
        $obj1->flushCache();
        $this->assertEquals(
            $obj1->numChildren(),
            2,
            'numChildren() caching can be disabled by flushCache()'
        );
    }

    public function testLoadDescendantIDListIntoArray()
    {
        $obj2 = $this->objFromFixture(HierarchyTest\TestObject::class, 'obj2');
        $obj2a = $this->objFromFixture(HierarchyTest\TestObject::class, 'obj2a');
        $obj2b = $this->objFromFixture(HierarchyTest\TestObject::class, 'obj2b');
        $obj2aa = $this->objFromFixture(HierarchyTest\TestObject::class, 'obj2aa');
        $obj2ab = $this->objFromFixture(HierarchyTest\TestObject::class, 'obj2ab');

        $obj2IdList = $obj2->getDescendantIDList();
        $obj2aIdList = $obj2a->getDescendantIDList();

        $this->assertContains($obj2a->ID, $obj2IdList);
        $this->assertContains($obj2b->ID, $obj2IdList);
        $this->assertContains($obj2aa->ID, $obj2IdList);
        $this->assertContains($obj2ab->ID, $obj2IdList);
        $this->assertEquals(4, count($obj2IdList));

        $this->assertContains($obj2aa->ID, $obj2aIdList);
        $this->assertContains($obj2ab->ID, $obj2aIdList);
        $this->assertEquals(2, count($obj2aIdList));
    }

    /**
     * The "only deleted from stage" argument to liveChildren() should exclude
     * any page that has been moved to another location on the stage site
     */
    public function testLiveChildrenOnlyDeletedFromStage()
    {
        $obj1 = $this->objFromFixture(HierarchyTest\TestObject::class, 'obj1');
        $obj2 = $this->objFromFixture(HierarchyTest\TestObject::class, 'obj2');
        $obj2a = $this->objFromFixture(HierarchyTest\TestObject::class, 'obj2a');
        $obj2b = $this->objFromFixture(HierarchyTest\TestObject::class, 'obj2b');

        // Get a published set of objects for our fixture
        $obj1->copyVersionToStage(Versioned::DRAFT, Versioned::LIVE);
        $obj2->copyVersionToStage(Versioned::DRAFT, Versioned::LIVE);
        $obj2a->copyVersionToStage(Versioned::DRAFT, Versioned::LIVE);
        $obj2b->copyVersionToStage(Versioned::DRAFT, Versioned::LIVE);

        // Then delete 2a from stage and move 2b to a sub-node of 1.
        $obj2a->delete();
        $obj2b->ParentID = $obj1->ID;
        $obj2b->write();

        // Get live children, excluding pages that have been moved on the stage site
        $children = $obj2->liveChildren(true, true)->column("Title");

        // 2a has been deleted from stage and should be shown
        $this->assertContains("Obj 2a", $children);

        // 2b has merely been moved to a different parent and so shouldn't be shown
        $this->assertNotContains("Obj 2b", $children);
    }

    public function testBreadcrumbs()
    {
        $obj1 = $this->objFromFixture(HierarchyTest\TestObject::class, 'obj1');
        $obj2 = $this->objFromFixture(HierarchyTest\TestObject::class, 'obj2');
        $obj2a = $this->objFromFixture(HierarchyTest\TestObject::class, 'obj2a');
        $obj2aa = $this->objFromFixture(HierarchyTest\TestObject::class, 'obj2aa');

        $this->assertEquals('Obj 1', $obj1->getBreadcrumbs());
        $this->assertEquals('Obj 2 &raquo; Obj 2a', $obj2a->getBreadcrumbs());
        $this->assertEquals('Obj 2 &raquo; Obj 2a &raquo; Obj 2aa', $obj2aa->getBreadcrumbs());
    }

    /**
     * @covers \SilverStripe\ORM\Hierarchy\Hierarchy::markChildren()
     */
    public function testMarkChildrenDoesntUnmarkPreviouslyMarked()
    {
        $obj3 = $this->objFromFixture(HierarchyTest\TestObject::class, 'obj3');
        $obj3aa = $this->objFromFixture(HierarchyTest\TestObject::class, 'obj3aa');
        $obj3ba = $this->objFromFixture(HierarchyTest\TestObject::class, 'obj3ba');
        $obj3ca = $this->objFromFixture(HierarchyTest\TestObject::class, 'obj3ca');

        $obj3->markPartialTree();
        $obj3->markToExpose($obj3aa);
        $obj3->markToExpose($obj3ba);
        $obj3->markToExpose($obj3ca);

        $expected = <<<EOT
<ul>
<li>Obj 3a
<ul>
<li>Obj 3aa
</li>
<li>Obj 3ab
</li>
</ul>
</li>
<li>Obj 3b
<ul>
<li>Obj 3ba
</li>
<li>Obj 3bb
</li>
</ul>
</li>
<li>Obj 3c
<ul>
<li>Obj 3c
</li>
</ul>
</li>
<li>Obj 3d
</li>
</ul>

EOT;

        $this->assertSame($expected, $obj3->getChildrenAsUL());
    }

    public function testGetChildrenAsUL()
    {
        $obj1 = $this->objFromFixture(HierarchyTest\TestObject::class, 'obj1');
        $obj2 = $this->objFromFixture(HierarchyTest\TestObject::class, 'obj2');
        $obj2a = $this->objFromFixture(HierarchyTest\TestObject::class, 'obj2a');
        $obj2aa = $this->objFromFixture(HierarchyTest\TestObject::class, 'obj2aa');

        $nodeCountThreshold = 30;

        $root = new HierarchyTest\TestObject();
        $root->markPartialTree($nodeCountThreshold);
        $html = $root->getChildrenAsUL(
            "",
            '"<li id=\"" . $child->ID . "\">" . $child->Title',
            null,
            false,
            "AllChildrenIncludingDeleted",
            "numChildren",
            true,  // rootCall
            $nodeCountThreshold
        );
        $this->assertTreeContains(
            $html,
            array($obj2),
            'Contains root elements'
        );
        $this->assertTreeContains(
            $html,
            array($obj2, $obj2a),
            'Contains child elements (in correct nesting)'
        );
        $this->assertTreeContains(
            $html,
            array($obj2, $obj2a, $obj2aa),
            'Contains grandchild elements (in correct nesting)'
        );
    }

    public function testGetChildrenAsULMinNodeCount()
    {
        $obj1 = $this->objFromFixture(HierarchyTest\TestObject::class, 'obj1');
        $obj2 = $this->objFromFixture(HierarchyTest\TestObject::class, 'obj2');
        $obj2a = $this->objFromFixture(HierarchyTest\TestObject::class, 'obj2a');

        // Set low enough that it should be fulfilled by root only elements
        $nodeCountThreshold = 3;

        $root = new HierarchyTest\TestObject();
        $root->markPartialTree($nodeCountThreshold);
        $html = $root->getChildrenAsUL(
            "",
            '"<li id=\"" . $child->ID . "\">" . $child->Title',
            null,
            false,
            "AllChildrenIncludingDeleted",
            "numChildren",
            true,
            $nodeCountThreshold
        );
        $this->assertTreeContains(
            $html,
            array($obj1),
            'Contains root elements'
        );
        $this->assertTreeContains(
            $html,
            array($obj2),
            'Contains root elements'
        );
        $this->assertTreeNotContains(
            $html,
            array($obj2, $obj2a),
            'Does not contains child elements because they exceed minNodeCount'
        );
    }

    public function testGetChildrenAsULMinNodeCountWithMarkToExpose()
    {
        $obj2 = $this->objFromFixture(HierarchyTest\TestObject::class, 'obj2');
        $obj2a = $this->objFromFixture(HierarchyTest\TestObject::class, 'obj2a');
        $obj2aa = $this->objFromFixture(HierarchyTest\TestObject::class, 'obj2aa');

        // Set low enough that it should be fulfilled by root only elements
        $nodeCountThreshold = 3;

        $root = new HierarchyTest\TestObject();
        $root->markPartialTree($nodeCountThreshold);

        // Mark certain node which should be included regardless of minNodeCount restrictions
        $root->markToExpose($obj2aa);

        $html = $root->getChildrenAsUL(
            "",
            '"<li id=\"" . $child->ID . "\">" . $child->Title',
            null,
            false,
            "AllChildrenIncludingDeleted",
            "numChildren",
            true,
            $nodeCountThreshold
        );
        $this->assertTreeContains(
            $html,
            array($obj2),
            'Contains root elements'
        );
        $this->assertTreeContains(
            $html,
            array($obj2, $obj2a, $obj2aa),
            'Does contain marked children nodes regardless of configured threshold'
        );
    }

    public function testGetChildrenAsULMinNodeCountWithFilters()
    {
        $obj1 = $this->objFromFixture(HierarchyTest\TestObject::class, 'obj1');
        $obj2 = $this->objFromFixture(HierarchyTest\TestObject::class, 'obj2');
        $obj2a = $this->objFromFixture(HierarchyTest\TestObject::class, 'obj2a');
        $obj2aa = $this->objFromFixture(HierarchyTest\TestObject::class, 'obj2aa');

        // Set low enough that it should fit all search matches without lazy loading
        $nodeCountThreshold = 3;

        $root = new HierarchyTest\TestObject();

        // Includes nodes by filter regardless of minNodeCount restrictions
        $root->setMarkingFilterFunction(
            function ($record) use ($obj2, $obj2a, $obj2aa) {
                // Results need to include parent hierarchy, even if we just want to
                // match the innermost node.
                return in_array($record->ID, array($obj2->ID, $obj2a->ID, $obj2aa->ID));
            }
        );
        $root->markPartialTree($nodeCountThreshold);

        $html = $root->getChildrenAsUL(
            "",
            '"<li id=\"" . $child->ID . "\">" . $child->Title',
            null,
            true, // limit to marked
            "AllChildrenIncludingDeleted",
            "numChildren",
            true,
            $nodeCountThreshold
        );
        $this->assertTreeNotContains(
            $html,
            array($obj1),
            'Does not contain root elements which dont match the filter'
        );
        $this->assertTreeContains(
            $html,
            array($obj2, $obj2a, $obj2aa),
            'Contains non-root elements which match the filter'
        );
    }

    public function testGetChildrenAsULHardLimitsNodes()
    {
        $obj1 = $this->objFromFixture(HierarchyTest\TestObject::class, 'obj1');
        $obj2 = $this->objFromFixture(HierarchyTest\TestObject::class, 'obj2');
        $obj2a = $this->objFromFixture(HierarchyTest\TestObject::class, 'obj2a');
        $obj2aa = $this->objFromFixture(HierarchyTest\TestObject::class, 'obj2aa');

        // Set low enough that it should fit all search matches without lazy loading
        $nodeCountThreshold = 3;

        $root = new HierarchyTest\TestObject();

        // Includes nodes by filter regardless of minNodeCount restrictions
        $root->setMarkingFilterFunction(
            function ($record) use ($obj2, $obj2a, $obj2aa) {
                // Results need to include parent hierarchy, even if we just want to
                // match the innermost node.
                return in_array($record->ID, array($obj2->ID, $obj2a->ID, $obj2aa->ID));
            }
        );
        $root->markPartialTree($nodeCountThreshold);

        $html = $root->getChildrenAsUL(
            "",
            '"<li id=\"" . $child->ID . "\">" . $child->Title',
            null,
            true, // limit to marked
            "AllChildrenIncludingDeleted",
            "numChildren",
            true,
            $nodeCountThreshold
        );
        $this->assertTreeNotContains(
            $html,
            array($obj1),
            'Does not contain root elements which dont match the filter'
        );
        $this->assertTreeContains(
            $html,
            array($obj2, $obj2a, $obj2aa),
            'Contains non-root elements which match the filter'
        );
    }

    public function testGetChildrenAsULNodeThresholdLeaf()
    {
        $obj1 = $this->objFromFixture(HierarchyTest\TestObject::class, 'obj1');
        $obj2 = $this->objFromFixture(HierarchyTest\TestObject::class, 'obj2');
        $obj2a = $this->objFromFixture(HierarchyTest\TestObject::class, 'obj2a');
        $obj3 = $this->objFromFixture(HierarchyTest\TestObject::class, 'obj3');
        $obj3a = $this->objFromFixture(HierarchyTest\TestObject::class, 'obj3a');

        $nodeCountThreshold = 99;

        $root = new HierarchyTest\TestObject();
        $root->markPartialTree($nodeCountThreshold);
        $nodeCountCallback = function ($parent, $numChildren) {
            // Set low enough that it the fixture structure should exceed it
            if ($parent->ID && $numChildren > 2) {
                return '<span class="exceeded">Exceeded!</span>';
            }
        };

        $html = $root->getChildrenAsUL(
            "",
            '"<li id=\"" . $child->ID . "\">" . $child->Title',
            null,
            true, // limit to marked
            "AllChildrenIncludingDeleted",
            "numChildren",
            true,
            $nodeCountThreshold,
            $nodeCountCallback
        );
        $this->assertTreeContains(
            $html,
            array($obj1),
            'Does contain root elements regardless of count'
        );
        $this->assertTreeContains(
            $html,
            array($obj3),
            'Does contain root elements regardless of count'
        );
        $this->assertTreeContains(
            $html,
            array($obj2, $obj2a),
            'Contains children which do not exceed threshold'
        );
        $this->assertTreeNotContains(
            $html,
            array($obj3, $obj3a),
            'Does not contain children which exceed threshold'
        );
    }

    /**
     * This test checks that deleted ('archived') child pages don't set a css class on the parent
     * node that makes it look like it has children
     */
    public function testGetChildrenAsULNodeDeletedOnLive()
    {
        $obj2 = $this->objFromFixture(HierarchyTest\TestObject::class, 'obj2');
        $obj2a = $this->objFromFixture(HierarchyTest\TestObject::class, 'obj2a');
        $obj2aa = $this->objFromFixture(HierarchyTest\TestObject::class, 'obj2aa');
        $obj2ab = $this->objFromFixture(HierarchyTest\TestObject::class, 'obj2b');

        // delete all children under obj2
        $obj2a->delete();
        $obj2aa->delete();
        $obj2ab->delete();
        // Don't pre-load all children
        $nodeCountThreshold = 1;

        $childrenMethod = 'AllChildren';
        $numChildrenMethod = 'numChildren';

        $root = new HierarchyTest\TestObject();
        $root->markPartialTree($nodeCountThreshold, null, $childrenMethod, $numChildrenMethod);

        // As in LeftAndMain::getSiteTreeFor() but simpler and more to the point for testing purposes
        $titleFn = function (&$child, $numChildrenMethod = "") {
            return '<li class="' . $child->markingClasses($numChildrenMethod).
                '" id="' . $child->ID . '">"' . $child->Title;
        };

        $html = $root->getChildrenAsUL(
            "",
            $titleFn,
            null,
            true, // limit to marked
            $childrenMethod,
            $numChildrenMethod,
            true,
            $nodeCountThreshold
        );

        // Get the class attribute from the $obj2 node in the sitetree, class 'jstree-leaf' means it's a leaf node
        $nodeClass = $this->getNodeClassFromTree($html, $obj2);
        $this->assertEquals('jstree-leaf closed', $nodeClass, 'object2 should not have children in the sitetree');
    }

    /**
     * This test checks that deleted ('archived') child pages _do_ set a css class on the parent
     * node that makes it look like it has children when getting all children including deleted
     */
    public function testGetChildrenAsULNodeDeletedOnStage()
    {
        $obj2 = $this->objFromFixture(HierarchyTest\TestObject::class, 'obj2');
        $obj2a = $this->objFromFixture(HierarchyTest\TestObject::class, 'obj2a');
        $obj2aa = $this->objFromFixture(HierarchyTest\TestObject::class, 'obj2aa');
        $obj2ab = $this->objFromFixture(HierarchyTest\TestObject::class, 'obj2b');

        // delete all children under obj2
        $obj2a->delete();
        $obj2aa->delete();
        $obj2ab->delete();
        // Don't pre-load all children
        $nodeCountThreshold = 1;

        $childrenMethod = 'AllChildrenIncludingDeleted';
        $numChildrenMethod = 'numHistoricalChildren';

        $root = new HierarchyTest\TestObject();
        $root->markPartialTree($nodeCountThreshold, null, $childrenMethod, $numChildrenMethod);

        // As in LeftAndMain::getSiteTreeFor() but simpler and more to the point for testing purposes
        $titleFn = function (&$child, $numChildrenMethod = "") {
            return '<li class="' . $child->markingClasses($numChildrenMethod).
                '" id="' . $child->ID . '">"' . $child->Title;
        };

        $html = $root->getChildrenAsUL(
            "",
            $titleFn,
            null,
            true, // limit to marked
            $childrenMethod,
            $numChildrenMethod,
            true,
            $nodeCountThreshold
        );

        // Get the class attribute from the $obj2 node in the sitetree
        $nodeClass = $this->getNodeClassFromTree($html, $obj2);
        // Object2 can now be expanded
        $this->assertEquals('unexpanded jstree-closed closed', $nodeClass, 'obj2 should have children in the sitetree');
    }

    public function testNoHideFromHeirarchy()
    {
        $obj4 = $this->objFromFixture(HierarchyTest\HideTestObject::class, 'obj4');
        $obj4->copyVersionToStage(Versioned::DRAFT, Versioned::LIVE);

        foreach ($obj4->stageChildren() as $child) {
            $child->copyVersionToStage(Versioned::DRAFT, Versioned::LIVE);
        }
        $this->assertEquals($obj4->stageChildren()->Count(), 2);
        $this->assertEquals($obj4->liveChildren()->Count(), 2);
    }

    public function testHideFromHeirarchy()
    {
        HierarchyTest\HideTestObject::config()->update(
            'hide_from_hierarchy',
            [
            HierarchyTest\HideTestSubObject::class,
            ]
        );
        $obj4 = $this->objFromFixture(HierarchyTest\HideTestObject::class, 'obj4');
        $obj4->copyVersionToStage(Versioned::DRAFT, Versioned::LIVE);

        // load without using stage children otherwise it'll bbe filtered before it's publish
        // we need to publish all of them, and expect liveChildren to return some.
        $children = HierarchyTest\HideTestObject::get()
            ->filter('ParentID', (int)$obj4->ID)
            ->exclude('ID', (int)$obj4->ID);

        foreach ($children as $child) {
            $child->copyVersionToStage(Versioned::DRAFT, Versioned::LIVE);
        }
        $this->assertEquals($obj4->stageChildren()->Count(), 1);
        $this->assertEquals($obj4->liveChildren()->Count(), 1);
    }

    /**
     * @param String $html    [description]
     * @param array  $nodes   Breadcrumb path as array
     * @param String $message
     */
    protected function assertTreeContains($html, $nodes, $message = null)
    {
        $parser = new CSSContentParser($html);
        $xpath = '/';
        foreach ($nodes as $node) {
            $xpath .= '/ul/li[@id="' . $node->ID . '"]';
        }
        $match = $parser->getByXpath($xpath);
        self::assertThat((bool)$match, self::isTrue(), $message);
    }

    /**
     * @param String $html    [description]
     * @param array  $nodes   Breadcrumb path as array
     * @param String $message
     */
    protected function assertTreeNotContains($html, $nodes, $message = null)
    {
        $parser = new CSSContentParser($html);
        $xpath = '/';
        foreach ($nodes as $node) {
            $xpath .= '/ul/li[@id="' . $node->ID . '"]';
        }
        $match = $parser->getByXpath($xpath);
        self::assertThat((bool)$match, self::isFalse(), $message);
    }

    /**
     * Get the HTML class attribute from a node in the sitetree
     *
     * @param  $html
     * @param  $node
     * @return string
     */
    protected function getNodeClassFromTree($html, $node)
    {
        $parser = new CSSContentParser($html);
        $xpath = '//ul/li[@id="' . $node->ID . '"]';
        $object = $parser->getByXpath($xpath);

        foreach ($object[0]->attributes() as $key => $attr) {
            if ($key == 'class') {
                return (string)$attr;
            }
        }
        return '';
    }
}