class PagerTest

class PagerTest extends BrowserTestBase {
    use AssertPageCacheContextsAndTagsTrait;
    
    /**
     * {@inheritdoc}
     */
    protected static $modules = [
        'dblog',
        'image',
        'pager_test',
    ];
    
    /**
     * {@inheritdoc}
     */
    protected $defaultTheme = 'stark';
    
    /**
     * A user with permission to access site reports.
     *
     * @var \Drupal\user\UserInterface
     */
    protected $adminUser;
    
    /**
     * {@inheritdoc}
     */
    protected function setUp() : void {
        parent::setUp();
        // Start from a clean log.
        \Drupal::database()->delete('watchdog')
            ->execute();
        // Insert 300 log messages.
        $logger = $this->container
            ->get('logger.factory')
            ->get('pager_test');
        for ($i = 0; $i < 300; $i++) {
            $logger->debug($this->randomString());
        }
        $this->adminUser = $this->drupalCreateUser([
            'access site reports',
            'administer image styles',
        ]);
        $this->drupalLogin($this->adminUser);
    }
    
    /**
     * Tests markup and CSS classes of pager links.
     */
    public function testActiveClass() : void {
        // Verify first page.
        $this->drupalGet('admin/reports/dblog');
        $current_page = 0;
        $this->assertPagerItems($current_page);
        // Verify any page but first/last.
        $current_page++;
        $this->drupalGet('admin/reports/dblog', [
            'query' => [
                'page' => $current_page,
            ],
        ]);
        $this->assertPagerItems($current_page);
        // Verify last page.
        $element = $this->assertSession()
            ->elementExists('xpath', '//li[contains(@class, "pager__item--last")]/a');
        preg_match('@page=(\\d+)@', $element->getAttribute('href'), $matches);
        $current_page = (int) $matches[1];
        $this->drupalGet($this->getAbsoluteUrl(parse_url($this->getUrl())['path'] . $element->getAttribute('href')), [
            'external' => TRUE,
        ]);
        $this->assertPagerItems($current_page);
        // Verify the pager does not render on a list without pagination.
        $this->drupalGet('admin/config/media/image-styles');
        $this->assertSession()
            ->elementNotExists('css', '.pager');
    }
    
    /**
     * Tests pager query parameters and cache context.
     */
    public function testPagerQueryParametersAndCacheContext() : void {
        // First page.
        $this->drupalGet('pager-test/query-parameters');
        $this->assertSession()
            ->pageTextContains('Pager calls: 0');
        $this->assertSession()
            ->pageTextContains('[url.query_args.pagers:0]=0.0');
        $this->assertCacheContext('url.query_args');
        // Go to last page, the count of pager calls need to go to 1.
        $this->assertSession()
            ->elementExists('xpath', '//li[contains(@class, "pager__item--last")]/a')
            ->click();
        $this->assertSession()
            ->pageTextContains('Pager calls: 1');
        $this->assertSession()
            ->pageTextContains('[url.query_args.pagers:0]=0.60');
        $this->assertCacheContext('url.query_args');
        // Reset counter to 0.
        $this->drupalGet('pager-test/query-parameters');
        // Go back to first page, the count of pager calls need to go to 2.
        $this->assertSession()
            ->elementExists('xpath', '//li[contains(@class, "pager__item--last")]/a')
            ->click();
        $this->assertSession()
            ->elementExists('xpath', '//li[contains(@class, "pager__item--first")]/a')
            ->click();
        $this->assertSession()
            ->pageTextContains('Pager calls: 2');
        $this->assertSession()
            ->pageTextContains('[url.query_args.pagers:0]=0.0');
        $this->assertCacheContext('url.query_args');
    }
    
    /**
     * Tests proper functioning of multiple pagers.
     */
    public function testMultiplePagers() : void {
        // First page.
        $this->drupalGet('pager-test/multiple-pagers');
        // Test data.
        // Expected URL query string param is 0-indexed.
        // Expected page per pager is 1-indexed.
        $test_data = [
            // With no query, all pagers set to first page.
[
                'input_query' => '',
                'expected_page' => [
                    0 => '1',
                    1 => '1',
                    4 => '1',
                ],
                'expected_query' => '?page=0,0,,,0',
            ],
            // Blanks around page numbers should not be relevant.
[
                'input_query' => '?page=2  ,    10,,,   5     ,,',
                'expected_page' => [
                    0 => '3',
                    1 => '11',
                    4 => '6',
                ],
                'expected_query' => '?page=2,10,,,5',
            ],
            // Blanks within page numbers should lead to only the first integer
            // to be considered.
[
                'input_query' => '?page=2  ,   3 0,,,   4  13    ,,',
                'expected_page' => [
                    0 => '3',
                    1 => '4',
                    4 => '5',
                ],
                'expected_query' => '?page=2,3,,,4',
            ],
            // If floats are passed as page numbers, only the integer part is
            // returned.
[
                'input_query' => '?page=2.1,6.999,,,5.',
                'expected_page' => [
                    0 => '3',
                    1 => '7',
                    4 => '6',
                ],
                'expected_query' => '?page=2,6,,,5',
            ],
            // Partial page fragment, undefined pagers set to first page.
[
                'input_query' => '?page=5,2',
                'expected_page' => [
                    0 => '6',
                    1 => '3',
                    4 => '1',
                ],
                'expected_query' => '?page=5,2,,,0',
            ],
            // Partial page fragment, undefined pagers set to first page.
[
                'input_query' => '?page=,2',
                'expected_page' => [
                    0 => '1',
                    1 => '3',
                    4 => '1',
                ],
                'expected_query' => '?page=0,2,,,0',
            ],
            // Partial page fragment, undefined pagers set to first page.
[
                'input_query' => '?page=,',
                'expected_page' => [
                    0 => '1',
                    1 => '1',
                    4 => '1',
                ],
                'expected_query' => '?page=0,0,,,0',
            ],
            // With overflow pages, all pagers set to max page.
[
                'input_query' => '?page=99,99,,,99',
                'expected_page' => [
                    0 => '16',
                    1 => '16',
                    4 => '16',
                ],
                'expected_query' => '?page=15,15,,,15',
            ],
            // Wrong value for the page resets pager to first page.
[
                'input_query' => '?page=bar,5,foo,qux,bet',
                'expected_page' => [
                    0 => '1',
                    1 => '6',
                    4 => '1',
                ],
                'expected_query' => '?page=0,5,,,0',
            ],
        ];
        // We loop through the page with the test data query parameters, and check
        // that the active page for each pager element has the expected page
        // (1-indexed) and resulting query parameter
        foreach ($test_data as $data) {
            $input_query = str_replace(' ', '%20', $data['input_query']);
            $this->drupalGet($this->getAbsoluteUrl(parse_url($this->getUrl())['path'] . $input_query), [
                'external' => TRUE,
            ]);
            foreach ([
                0,
                1,
                4,
            ] as $pager_element) {
                $active_page = $this->cssSelect("div.test-pager-{$pager_element} ul.pager__items li.is-active:contains('{$data['expected_page'][$pager_element]}')");
                $destination = str_replace('%2C', ',', $active_page[0]->find('css', 'a')
                    ->getAttribute('href'));
                $this->assertEquals($data['expected_query'], $destination);
            }
        }
    }
    
    /**
     * Tests proper functioning of the ellipsis.
     */
    public function testPagerEllipsis() : void {
        // Insert 100 extra log messages to get 9 pages.
        $logger = $this->container
            ->get('logger.factory')
            ->get('pager_test');
        for ($i = 0; $i < 100; $i++) {
            $logger->debug($this->randomString());
        }
        $this->drupalGet('admin/reports/dblog');
        $elements = $this->cssSelect(".pager__item--ellipsis:contains('…')");
        $this->assertCount(0, $elements, 'No ellipsis has been set.');
        // Insert an extra 50 log messages to get 10 pages.
        $logger = $this->container
            ->get('logger.factory')
            ->get('pager_test');
        for ($i = 0; $i < 50; $i++) {
            $logger->debug($this->randomString());
        }
        $this->drupalGet('admin/reports/dblog');
        $elements = $this->cssSelect(".pager__item--ellipsis:contains('…')");
        $this->assertCount(1, $elements, 'Found the ellipsis.');
    }
    
    /**
     * Asserts pager items and links.
     *
     * @param int $current_page
     *   The current pager page the internal browser is on.
     *
     * @internal
     */
    protected function assertPagerItems(int $current_page) : void {
        $elements = $this->xpath('//ul[contains(@class, :class)]/li', [
            ':class' => 'pager__items',
        ]);
        $this->assertNotEmpty($elements, 'Pager found.');
        // Make current page 1-based.
        $current_page++;
        // Extract first/previous and next/last items.
        // first/previous only exist, if the current page is not the first.
        if ($current_page > 1) {
            $first = array_shift($elements);
            $previous = array_shift($elements);
        }
        // next/last always exist, unless the current page is the last.
        if ($current_page != count($elements)) {
            $last = array_pop($elements);
            $next = array_pop($elements);
        }
        // We remove elements from the $elements array in the following code, so
        // we store the total number of pages for verifying the "last" link.
        $total_pages = count($elements);
        // Verify items and links to pages.
        foreach ($elements as $page => $element) {
            // Make item/page index 1-based.
            $page++;
            if ($current_page == $page) {
                $this->assertClass($element, 'is-active', 'Element for current page has .is-active class.');
                $link = $element->find('css', 'a');
                $this->assertNotEmpty($link, 'Element for current page has link.');
                $destination = $link->getAttribute('href');
                // URL query string param is 0-indexed.
                $this->assertEquals('?page=' . ($page - 1), $destination);
            }
            else {
                $this->assertNoClass($element, 'is-active', "Element for page {$page} has no .is-active class.");
                $this->assertClass($element, 'pager__item', "Element for page {$page} has .pager__item class.");
                $link = $element->find('css', 'a');
                $this->assertNotEmpty($link, "Link to page {$page} found.");
                // Pager link has an attribute set in pager_test_preprocess_pager().
                $this->assertEquals('yes', $link->getAttribute('pager-test'));
                $destination = $link->getAttribute('href');
                $this->assertEquals('?page=' . ($page - 1), $destination);
            }
            unset($elements[--$page]);
        }
        // Verify that no other items remain untested.
        $this->assertEmpty($elements, 'All expected items found.');
        // Verify first/previous and next/last items and links.
        if (isset($first)) {
            $this->assertClass($first, 'pager__item--first', 'Element for first page has .pager__item--first class.');
            $link = $first->find('css', 'a');
            $this->assertNotEmpty($link, 'Link to first page found.');
            $this->assertNoClass($link, 'is-active', 'Link to first page is not active.');
            $this->assertEquals('first', $link->getAttribute('pager-test'));
            $destination = $link->getAttribute('href');
            $this->assertEquals('?page=0', $destination);
        }
        if (isset($previous)) {
            $this->assertClass($previous, 'pager__item--previous', 'Element for first page has .pager__item--previous class.');
            $link = $previous->find('css', 'a');
            $this->assertNotEmpty($link, 'Link to previous page found.');
            $this->assertNoClass($link, 'is-active', 'Link to previous page is not active.');
            $this->assertEquals('previous', $link->getAttribute('pager-test'));
            $destination = $link->getAttribute('href');
            // URL query string param is 0-indexed, $current_page is 1-indexed.
            $this->assertEquals('?page=' . ($current_page - 2), $destination);
        }
        if (isset($next)) {
            $this->assertClass($next, 'pager__item--next', 'Element for next page has .pager__item--next class.');
            $link = $next->find('css', 'a');
            $this->assertNotEmpty($link, 'Link to next page found.');
            $this->assertNoClass($link, 'is-active', 'Link to next page is not active.');
            $this->assertEquals('next', $link->getAttribute('pager-test'));
            $destination = $link->getAttribute('href');
            // URL query string param is 0-indexed, $current_page is 1-indexed.
            $this->assertEquals('?page=' . $current_page, $destination);
        }
        if (isset($last)) {
            $link = $last->find('css', 'a');
            $this->assertClass($last, 'pager__item--last', 'Element for last page has .pager__item--last class.');
            $this->assertNotEmpty($link, 'Link to last page found.');
            $this->assertNoClass($link, 'is-active', 'Link to last page is not active.');
            $this->assertEquals('last', $link->getAttribute('pager-test'));
            $destination = $link->getAttribute('href');
            // URL query string param is 0-indexed.
            $this->assertEquals('?page=' . ($total_pages - 1), $destination);
        }
    }
    
    /**
     * Asserts that an element has a given class.
     *
     * @param \Behat\Mink\Element\NodeElement $element
     *   The element to test.
     * @param string $class
     *   The class to assert.
     * @param string $message
     *   (optional) A verbose message to output.
     *
     * @internal
     */
    protected function assertClass(NodeElement $element, string $class, ?string $message = NULL) : void {
        if (!isset($message)) {
            $message = "Class .{$class} found.";
        }
        $this->assertTrue($element->hasClass($class), $message);
    }
    
    /**
     * Asserts that an element does not have a given class.
     *
     * @param \Behat\Mink\Element\NodeElement $element
     *   The element to test.
     * @param string $class
     *   The class to assert.
     * @param string $message
     *   (optional) A verbose message to output.
     *
     * @internal
     */
    protected function assertNoClass(NodeElement $element, string $class, ?string $message = NULL) : void {
        if (!isset($message)) {
            $message = "Class .{$class} not found.";
        }
        $this->assertFalse($element->hasClass($class), $message);
    }

}