class JSWebAssert

class JSWebAssert extends WebAssert {
    
    /**
     * Waits for AJAX request to be completed.
     *
     * @param int $timeout
     *   (Optional) Timeout in milliseconds, defaults to 10000.
     * @param string $message
     *   (optional) A message for exception.
     *
     * @throws \RuntimeException
     *   When the request is not completed. If left blank, a default message will
     *   be displayed.
     */
    public function assertWaitOnAjaxRequest($timeout = 10000, $message = 'Unable to complete AJAX request.') {
        // Wait for a very short time to allow page state to update after clicking.
        usleep(5000);
        $condition = <<<JS
      (function() {
        function isAjaxing(instance) {
          return instance && instance.ajaxing === true;
        }
        return (
          // Assert no AJAX request is running (via jQuery or Drupal) and no
          // animation is running.
          (typeof jQuery === 'undefined' || (jQuery.active === 0 && jQuery(':animated').length === 0)) &&
          (typeof Drupal === 'undefined' || typeof Drupal.ajax === 'undefined' || !Drupal.ajax.instances.some(isAjaxing))
        );
      }())
JS;
        $result = $this->session
            ->wait($timeout, $condition);
        if (!$result) {
            throw new \RuntimeException($message);
        }
    }
    
    /**
     * Waits for the specified selector and returns it when available.
     *
     * @param string $selector
     *   The selector engine name. See ElementInterface::findAll() for the
     *   supported selectors.
     * @param string|array $locator
     *   The selector locator.
     * @param int $timeout
     *   (Optional) Timeout in milliseconds, defaults to 10000.
     *
     * @return \Behat\Mink\Element\NodeElement|null
     *   The page element node if found, NULL if not.
     *
     * @see \Behat\Mink\Element\ElementInterface::findAll()
     */
    public function waitForElement($selector, $locator, $timeout = 10000) {
        return $this->waitForHelper($timeout, function (Element $page) use ($selector, $locator) {
            return $page->find($selector, $locator);
        });
    }
    
    /**
     * Looks for the specified selector and returns TRUE when it is unavailable.
     *
     * @param string $selector
     *   The selector engine name. See ElementInterface::findAll() for the
     *   supported selectors.
     * @param string|array $locator
     *   The selector locator.
     * @param int $timeout
     *   (Optional) Timeout in milliseconds, defaults to 10000.
     *
     * @return bool
     *   TRUE if not found, FALSE if found.
     *
     * @see \Behat\Mink\Element\ElementInterface::findAll()
     */
    public function waitForElementRemoved($selector, $locator, $timeout = 10000) {
        return (bool) $this->waitForHelper($timeout, function (Element $page) use ($selector, $locator) {
            return !$page->find($selector, $locator);
        });
    }
    
    /**
     * Waits for the specified selector and returns it when available and visible.
     *
     * @param string $selector
     *   The selector engine name. See ElementInterface::findAll() for the
     *   supported selectors.
     * @param string|array $locator
     *   The selector locator.
     * @param int $timeout
     *   (Optional) Timeout in milliseconds, defaults to 10000.
     *
     * @return \Behat\Mink\Element\NodeElement|null
     *   The page element node if found and visible, NULL if not.
     *
     * @see \Behat\Mink\Element\ElementInterface::findAll()
     */
    public function waitForElementVisible($selector, $locator, $timeout = 10000) {
        return $this->waitForHelper($timeout, function (Element $page) use ($selector, $locator) {
            $element = $page->find($selector, $locator);
            if (!empty($element) && $element->isVisible()) {
                return $element;
            }
            return NULL;
        });
    }
    
    /**
     * Waits for the specified text and returns TRUE when it is available.
     *
     * @param string $text
     *   The text to wait for.
     * @param int $timeout
     *   (Optional) Timeout in milliseconds, defaults to 10000.
     *
     * @return bool
     *   TRUE if found, FALSE if not found.
     */
    public function waitForText($text, $timeout = 10000) {
        return (bool) $this->waitForHelper($timeout, function (Element $page) use ($text) {
            $actual = preg_replace('/\\s+/u', ' ', $page->getText());
            $regex = '/' . preg_quote($text, '/') . '/ui';
            return (bool) preg_match($regex, $actual);
        });
    }
    
    /**
     * Wraps waits in a function to catch curl exceptions to continue waiting.
     *
     * @param int $timeout
     *   Timeout in milliseconds.
     * @param callable $callback
     *   Callback, which result is both used as waiting condition and returned.
     *
     * @return mixed
     *   The result of $callback.
     */
    private function waitForHelper(int $timeout, callable $callback) {
        return $this->session
            ->getPage()
            ->waitFor($timeout / 1000, $callback);
    }
    
    /**
     * Waits for the button specified by the locator and returns it.
     *
     * @param string $locator
     *   The button ID, value or alt string.
     * @param int $timeout
     *   (Optional) Timeout in milliseconds, defaults to 10000.
     *
     * @return \Behat\Mink\Element\NodeElement|null
     *   The page element node if found, NULL if not.
     */
    public function waitForButton($locator, $timeout = 10000) {
        return $this->waitForElement('named', [
            'button',
            $locator,
        ], $timeout);
    }
    
    /**
     * Waits for a link with specified locator and returns it when available.
     *
     * @param string $locator
     *   The link ID, title, text or image alt.
     * @param int $timeout
     *   (Optional) Timeout in milliseconds, defaults to 10000.
     *
     * @return \Behat\Mink\Element\NodeElement|null
     *   The page element node if found, NULL if not.
     */
    public function waitForLink($locator, $timeout = 10000) {
        return $this->waitForElement('named', [
            'link',
            $locator,
        ], $timeout);
    }
    
    /**
     * Waits for a field with specified locator and returns it when available.
     *
     * @param string $locator
     *   The input ID, name or label for the field (input, textarea, select).
     * @param int $timeout
     *   (Optional) Timeout in milliseconds, defaults to 10000.
     *
     * @return \Behat\Mink\Element\NodeElement|null
     *   The page element node if found, NULL if not.
     */
    public function waitForField($locator, $timeout = 10000) {
        return $this->waitForElement('named', [
            'field',
            $locator,
        ], $timeout);
    }
    
    /**
     * Waits for an element by its id and returns it when available.
     *
     * @param string $id
     *   The element ID.
     * @param int $timeout
     *   (Optional) Timeout in milliseconds, defaults to 10000.
     *
     * @return \Behat\Mink\Element\NodeElement|null
     *   The page element node if found, NULL if not.
     */
    public function waitForId($id, $timeout = 10000) {
        return $this->waitForElement('named', [
            'id',
            $id,
        ], $timeout);
    }
    
    /**
     * Waits for the jQuery autocomplete delay duration.
     *
     * @see https://api.jqueryui.com/autocomplete/#option-delay
     */
    public function waitOnAutocomplete() {
        // Wait for the autocomplete to be visible.
        return $this->waitForElementVisible('css', '.ui-autocomplete li');
    }
    
    /**
     * Tests that a node, or its specific corner, is visible in the viewport.
     *
     * Note: Always set the viewport size. This can be done in your test with
     * \Behat\Mink\Session->resizeWindow(). Drupal CI JavaScript tests by default
     * use a viewport of 1024x768px.
     *
     * @param string $selector_type
     *   The element selector type (css, xpath).
     * @param string|array $selector
     *   The element selector. Note: the first found element is used.
     * @param bool|string $corner
     *   (Optional) The corner to test:
     *   topLeft, topRight, bottomRight, bottomLeft.
     *   Or FALSE to check the complete element (default).
     * @param string $message
     *   (optional) A message for the exception.
     *
     * @throws \Behat\Mink\Exception\ElementHtmlException
     *   When the element doesn't exist.
     * @throws \Behat\Mink\Exception\ElementNotFoundException
     *   When the element is not visible in the viewport.
     */
    public function assertVisibleInViewport($selector_type, $selector, $corner = FALSE, $message = 'Element is not visible in the viewport.') {
        $node = $this->session
            ->getPage()
            ->find($selector_type, $selector);
        if ($node === NULL) {
            if (is_array($selector)) {
                $selector = implode(' ', $selector);
            }
            throw new ElementNotFoundException($this->session
                ->getDriver(), 'element', $selector_type, $selector);
        }
        // Check if the node is visible on the page, which is a prerequisite of
        // being visible in the viewport.
        if (!$node->isVisible()) {
            throw new ElementHtmlException($message, $this->session
                ->getDriver(), $node);
        }
        $result = $this->checkNodeVisibilityInViewport($node, $corner);
        if (!$result) {
            throw new ElementHtmlException($message, $this->session
                ->getDriver(), $node);
        }
    }
    
    /**
     * Tests that a node, or its specific corner, is not visible in the viewport.
     *
     * Note: the node should exist in the page, otherwise this assertion fails.
     *
     * @param string $selector_type
     *   The element selector type (css, xpath).
     * @param string|array $selector
     *   The element selector. Note: the first found element is used.
     * @param bool|string $corner
     *   (Optional) Corner to test: topLeft, topRight, bottomRight, bottomLeft.
     *   Or FALSE to check the complete element (default).
     * @param string $message
     *   (optional) A message for the exception.
     *
     * @throws \Behat\Mink\Exception\ElementHtmlException
     *   When the element doesn't exist.
     * @throws \Behat\Mink\Exception\ElementNotFoundException
     *   When the element is not visible in the viewport.
     *
     * @see \Drupal\FunctionalJavascriptTests\JSWebAssert::assertVisibleInViewport()
     */
    public function assertNotVisibleInViewport($selector_type, $selector, $corner = FALSE, $message = 'Element is visible in the viewport.') {
        $node = $this->session
            ->getPage()
            ->find($selector_type, $selector);
        if ($node === NULL) {
            if (is_array($selector)) {
                $selector = implode(' ', $selector);
            }
            throw new ElementNotFoundException($this->session
                ->getDriver(), 'element', $selector_type, $selector);
        }
        $result = $this->checkNodeVisibilityInViewport($node, $corner);
        if ($result) {
            throw new ElementHtmlException($message, $this->session
                ->getDriver(), $node);
        }
    }
    
    /**
     * Check the visibility of a node, or its specific corner.
     *
     * @param \Behat\Mink\Element\NodeElement $node
     *   A valid node.
     * @param bool|string $corner
     *   (Optional) Corner to test: topLeft, topRight, bottomRight, bottomLeft.
     *   Or FALSE to check the complete element (default).
     *
     * @return bool
     *   Returns TRUE if the node is visible in the viewport, FALSE otherwise.
     *
     * @throws \Behat\Mink\Exception\UnsupportedDriverActionException
     *   When an invalid corner specification is given.
     */
    private function checkNodeVisibilityInViewport(NodeElement $node, $corner = FALSE) {
        $xpath = $node->getXpath();
        // Build the JavaScript to test if the complete element or a specific corner
        // is in the viewport.
        switch ($corner) {
            case 'topLeft':
                $test_javascript_function = <<<JS
          function t(r, lx, ly) {
            return (
              r.top >= 0 &&
              r.top <= ly &&
              r.left >= 0 &&
              r.left <= lx
            )
          }
JS;
                break;
            case 'topRight':
                $test_javascript_function = <<<JS
          function t(r, lx, ly) {
            return (
              r.top >= 0 &&
              r.top <= ly &&
              r.right >= 0 &&
              r.right <= lx
            );
          }
JS;
                break;
            case 'bottomRight':
                $test_javascript_function = <<<JS
          function t(r, lx, ly) {
            return (
              r.bottom >= 0 &&
              r.bottom <= ly &&
              r.right >= 0 &&
              r.right <= lx
            );
          }
JS;
                break;
            case 'bottomLeft':
                $test_javascript_function = <<<JS
          function t(r, lx, ly) {
            return (
              r.bottom >= 0 &&
              r.bottom <= ly &&
              r.left >= 0 &&
              r.left <= lx
            );
          }
JS;
                break;
            case FALSE:
                $test_javascript_function = <<<JS
          function t(r, lx, ly) {
            return (
              r.top >= 0 &&
              r.left >= 0 &&
              r.bottom <= ly &&
              r.right <= lx
            );
          }
JS;
                break;
            // Throw an exception if an invalid corner parameter is given.
            default:
                throw new UnsupportedDriverActionException($corner, $this->session
                    ->getDriver());
        }
        // Build the full JavaScript test. The shared logic gets the corner
        // specific test logic injected.
        $full_javascript_visibility_test = <<<JS
      (function(t){
        var w = window,
        d = document,
        e = d.documentElement,
        n = d.evaluate("{<span class="php-variable">$xpath</span>}", d, null, XPathResult.FIRST_ORDERED_NODE_TYPE, null).singleNodeValue,
        r = n.getBoundingClientRect(),
        lx = (w.innerWidth || e.clientWidth),
        ly = (w.innerHeight || e.clientHeight);

        return t(r, lx, ly);
      }({<span class="php-variable">$test_javascript_function</span>}));
JS;
        // Check the visibility by injecting and executing the full JavaScript test
        // script in the page.
        return $this->session
            ->evaluateScript($full_javascript_visibility_test);
    }
    
    /**
     * Passes if the raw text IS NOT found escaped on the loaded page.
     *
     * Raw text refers to the raw HTML that the page generated.
     *
     * @param string $raw
     *   Raw (HTML) string to look for.
     */
    public function assertNoEscaped($raw) {
        $this->responseNotContains($this->escapeHtml($raw));
    }
    
    /**
     * Passes if the raw text IS found escaped on the loaded page.
     *
     * Raw text refers to the raw HTML that the page generated.
     *
     * @param string $raw
     *   Raw (HTML) string to look for.
     */
    public function assertEscaped($raw) {
        $this->responseContains($this->escapeHtml($raw));
    }
    
    /**
     * Escapes HTML for testing.
     *
     * Drupal's Html::escape() uses the ENT_QUOTES flag with htmlspecialchars() to
     * escape both single and double quotes. With WebDriverTestBase testing the
     * browser is automatically converting &quot; and &#039; to double and single
     * quotes respectively therefore we can not escape them when testing for
     * escaped HTML.
     *
     * @param $raw
     *   The raw string to escape.
     *
     * @return string
     *   The string with escaped HTML.
     *
     * @see Drupal\Component\Utility\Html::escape()
     */
    protected function escapeHtml($raw) {
        return htmlspecialchars($raw, ENT_NOQUOTES | ENT_SUBSTITUTE, 'UTF-8');
    }
    
    /**
     * Asserts that no matching element exists on the page after a wait.
     *
     * @param string $selector_type
     *   The element selector type (css, xpath).
     * @param string|array $selector
     *   The element selector.
     * @param int $timeout
     *   (optional) Timeout in milliseconds, defaults to 10000.
     * @param string $message
     *   (optional) The exception message.
     *
     * @throws \Behat\Mink\Exception\ElementHtmlException
     *   When an element still exists on the page.
     */
    public function assertNoElementAfterWait($selector_type, $selector, $timeout = 10000, $message = 'Element exists on the page.') {
        $start = microtime(TRUE);
        $end = $start + $timeout / 1000;
        $page = $this->session
            ->getPage();
        do {
            $node = $page->find($selector_type, $selector);
            if (empty($node)) {
                return;
            }
            usleep(100000);
        } while (microtime(TRUE) < $end);
        throw new ElementHtmlException($message, $this->session
            ->getDriver(), $node);
    }
    
    /**
     * Determines if an exception is due to an element not being clickable.
     *
     * @param \WebDriver\Exception $exception
     *   The exception to check.
     *
     * @return bool
     *   TRUE if the exception is due to an element not being clickable,
     *   interactable or visible.
     */
    public static function isExceptionNotClickable(Exception $exception) : bool {
        return (bool) preg_match('/not (clickable|interactable|visible)/', $exception->getMessage());
    }
    
    /**
     * Asserts that a status message exists after wait.
     *
     * @param string|null $type
     *   The optional message type: status, error, or warning.
     * @param int $timeout
     *   Optional timeout in milliseconds, defaults to 10000.
     */
    public function statusMessageExistsAfterWait(string $type = NULL, int $timeout = 10000) : void {
        $selector = $this->buildJavascriptStatusMessageSelector(NULL, $type);
        $status_message_element = $this->waitForElement('xpath', $selector, $timeout);
        if ($type) {
            $failure_message = sprintf('A status message of type "%s" does not appear on this page, but it should.', $type);
        }
        else {
            $failure_message = 'A status message does not appear on this page, but it should.';
        }
        // There is no Assert::isNotNull() method, so we make our own constraint.
        $constraint = new LogicalNot(new IsNull());
        Assert::assertThat($status_message_element, $constraint, $failure_message);
    }
    
    /**
     * Asserts that a status message does not exist after wait.
     *
     * @param string|null $type
     *   The optional message type: status, error, or warning.
     * @param int $timeout
     *   Optional timeout in milliseconds, defaults to 10000.
     */
    public function statusMessageNotExistsAfterWait(string $type = NULL, int $timeout = 10000) : void {
        $selector = $this->buildJavascriptStatusMessageSelector(NULL, $type);
        $status_message_element = $this->waitForElement('xpath', $selector, $timeout);
        if ($type) {
            $failure_message = sprintf('A status message of type "%s" appears on this page, but it should not.', $type);
        }
        else {
            $failure_message = 'A status message appears on this page, but it should not.';
        }
        Assert::assertThat($status_message_element, Assert::isNull(), $failure_message);
    }
    
    /**
     * Asserts that a status message containing given string exists after wait.
     *
     * @param string $message
     *   The partial message to assert.
     * @param string|null $type
     *   The optional message type: status, error, or warning.
     * @param int $timeout
     *   Optional timeout in milliseconds, defaults to 10000.
     */
    public function statusMessageContainsAfterWait(string $message, string $type = NULL, int $timeout = 10000) : void {
        $selector = $this->buildJavascriptStatusMessageSelector($message, $type);
        $status_message_element = $this->waitForElement('xpath', $selector, $timeout);
        if ($type) {
            $failure_message = sprintf('A status message of type "%s" containing "%s" does not appear on this page, but it should.', $type, $message);
        }
        else {
            $failure_message = sprintf('A status message containing "%s" does not appear on this page, but it should.', $type);
        }
        // There is no Assert::isNotNull() method, so we make our own constraint.
        $constraint = new LogicalNot(new IsNull());
        Assert::assertThat($status_message_element, $constraint, $failure_message);
    }
    
    /**
     * Asserts that no status message containing given string exists after wait.
     *
     * @param string $message
     *   The partial message to assert.
     * @param string|null $type
     *   The optional message type: status, error, or warning.
     * @param int $timeout
     *   Optional timeout in milliseconds, defaults to 10000.
     */
    public function statusMessageNotContainsAfterWait(string $message, string $type = NULL, int $timeout = 10000) : void {
        $selector = $this->buildJavascriptStatusMessageSelector($message, $type);
        $status_message_element = $this->waitForElement('xpath', $selector, $timeout);
        if ($type) {
            $failure_message = sprintf('A status message of type "%s" containing "%s" appears on this page, but it should not.', $type, $message);
        }
        else {
            $failure_message = sprintf('A status message containing "%s" appears on this page, but it should not.', $message);
        }
        Assert::assertThat($status_message_element, Assert::isNull(), $failure_message);
    }
    
    /**
     * Builds a xpath selector for a message with given type and text.
     *
     * The selector is designed to work with the Drupal.theme.message
     * template defined in message.js in addition to status-messages.html.twig
     * in the system module.
     *
     * @param string|null $message
     *   The optional message or partial message to assert.
     * @param string|null $type
     *   The optional message type: status, error, or warning.
     *
     * @return string
     *   The xpath selector for the message.
     *
     * @throws \InvalidArgumentException
     *   Thrown when $type is not an allowed type.
     */
    private function buildJavascriptStatusMessageSelector(string $message = NULL, string $type = NULL) : string {
        $allowed_types = [
            'status',
            'error',
            'warning',
            NULL,
        ];
        if (!in_array($type, $allowed_types, TRUE)) {
            throw new \InvalidArgumentException(sprintf("If a status message type is specified, the allowed values are 'status', 'error', 'warning'. The value provided was '%s'.", $type));
        }
        if ($type) {
            $class = 'messages--' . $type;
        }
        else {
            $class = 'messages__wrapper';
        }
        if ($message) {
            $js_selector = $this->buildXPathQuery('//div[contains(@class, :class) and contains(., :message)]', [
                ':class' => $class,
                ':message' => $message,
            ]);
        }
        else {
            $js_selector = $this->buildXPathQuery('//div[contains(@class, :class)]', [
                ':class' => $class,
            ]);
        }
        // We select based on WebAssert::buildStatusMessageSelector() or the
        // js_selector we have just built.
        return $this->buildStatusMessageSelector($message, $type) . ' | ' . $js_selector;
    }

}