class WebAssert

class WebAssert extends MinkWebAssert {
    
    /**
     * The absolute URL of the site under test.
     *
     * @var string
     */
    protected $baseUrl = '';
    
    /**
     * Constructor.
     *
     * @param \Behat\Mink\Session $session
     *   The Behat session object;
     * @param string $base_url
     *   The base URL of the site under test.
     */
    public function __construct(Session $session, $base_url = '') {
        parent::__construct($session);
        $this->baseUrl = $base_url;
    }
    
    /**
     * {@inheritdoc}
     */
    protected function cleanUrl($url) {
        if ($url instanceof Url) {
            $url = $url->setAbsolute()
                ->toString();
        }
        // Strip the base URL from the beginning for absolute URLs.
        if ($this->baseUrl !== '' && strpos($url, $this->baseUrl) === 0) {
            $url = substr($url, strlen($this->baseUrl));
        }
        // Make sure there is a forward slash at the beginning of relative URLs for
        // consistency.
        if (parse_url($url, PHP_URL_HOST) === NULL && strpos($url, '/') !== 0) {
            $url = "/{$url}";
        }
        return parent::cleanUrl($url);
    }
    
    /**
     * Checks that specific button exists on the current page.
     *
     * @param string $button
     *   One of id|name|label|value for the button.
     * @param \Behat\Mink\Element\TraversableElement $container
     *   (optional) The document to check against. Defaults to the current page.
     *
     * @return \Behat\Mink\Element\NodeElement
     *   The matching element.
     *
     * @throws \Behat\Mink\Exception\ElementNotFoundException
     *   When the element doesn't exist.
     */
    public function buttonExists($button, TraversableElement $container = NULL) {
        $container = $container ?: $this->session
            ->getPage();
        $node = $container->findButton($button);
        if ($node === NULL) {
            throw new ElementNotFoundException($this->session
                ->getDriver(), 'button', 'id|name|label|value', $button);
        }
        return $node;
    }
    
    /**
     * Checks that the specific button does NOT exist on the current page.
     *
     * @param string $button
     *   One of id|name|label|value for the button.
     * @param \Behat\Mink\Element\TraversableElement $container
     *   (optional) The document to check against. Defaults to the current page.
     *
     * @throws \Behat\Mink\Exception\ExpectationException
     *   When the button exists.
     */
    public function buttonNotExists($button, TraversableElement $container = NULL) {
        $container = $container ?: $this->session
            ->getPage();
        $node = $container->findButton($button);
        $this->assert(NULL === $node, sprintf('A button "%s" appears on this page, but it should not.', $button));
    }
    
    /**
     * Checks that specific select field exists on the current page.
     *
     * @param string $select
     *   One of id|name|label|value for the select field.
     * @param \Behat\Mink\Element\TraversableElement $container
     *   (optional) The document to check against. Defaults to the current page.
     *
     * @return \Behat\Mink\Element\NodeElement
     *   The matching element
     *
     * @throws \Behat\Mink\Exception\ElementNotFoundException
     *   When the element doesn't exist.
     */
    public function selectExists($select, TraversableElement $container = NULL) {
        $container = $container ?: $this->session
            ->getPage();
        $node = $container->find('named', [
            'select',
            $select,
        ]);
        if ($node === NULL) {
            throw new ElementNotFoundException($this->session
                ->getDriver(), 'select', 'id|name|label|value', $select);
        }
        return $node;
    }
    
    /**
     * Checks that specific option in a select field exists on the current page.
     *
     * @param string $select
     *   One of id|name|label|value for the select field.
     * @param string $option
     *   The option value.
     * @param \Behat\Mink\Element\TraversableElement $container
     *   (optional) The document to check against. Defaults to the current page.
     *
     * @return \Behat\Mink\Element\NodeElement
     *   The matching option element
     *
     * @throws \Behat\Mink\Exception\ElementNotFoundException
     *   When the element doesn't exist.
     */
    public function optionExists($select, $option, TraversableElement $container = NULL) {
        $container = $container ?: $this->session
            ->getPage();
        $select_field = $container->find('named', [
            'select',
            $select,
        ]);
        if ($select_field === NULL) {
            throw new ElementNotFoundException($this->session
                ->getDriver(), 'select', 'id|name|label|value', $select);
        }
        $option_field = $select_field->find('named', [
            'option',
            $option,
        ]);
        if ($option_field === NULL) {
            throw new ElementNotFoundException($this->session
                ->getDriver(), 'select', 'id|name|label|value', $option);
        }
        return $option_field;
    }
    
    /**
     * Checks that an option in a select field does NOT exist on the current page.
     *
     * @param string $select
     *   One of id|name|label|value for the select field.
     * @param string $option
     *   The option value that should not exist.
     * @param \Behat\Mink\Element\TraversableElement $container
     *   (optional) The document to check against. Defaults to the current page.
     *
     * @throws \Behat\Mink\Exception\ElementNotFoundException
     *   When the select element doesn't exist.
     */
    public function optionNotExists($select, $option, TraversableElement $container = NULL) {
        $container = $container ?: $this->session
            ->getPage();
        $select_field = $container->find('named', [
            'select',
            $select,
        ]);
        if ($select_field === NULL) {
            throw new ElementNotFoundException($this->session
                ->getDriver(), 'select', 'id|name|label|value', $select);
        }
        $option_field = $select_field->find('named', [
            'option',
            $option,
        ]);
        $this->assert($option_field === NULL, sprintf('An option "%s" exists in select "%s", but it should not.', $option, $select));
    }
    
    /**
     * Pass if the page title is the given string.
     *
     * @param string $expected_title
     *   The string the page title should be.
     *
     * @throws \Behat\Mink\Exception\ExpectationException
     *   Thrown when element doesn't exist, or the title is a different one.
     */
    public function titleEquals($expected_title) {
        $title_element = $this->session
            ->getPage()
            ->find('css', 'title');
        if (!$title_element) {
            throw new ExpectationException('No title element found on the page', $this->session
                ->getDriver());
        }
        $actual_title = $title_element->getText();
        $this->assert($expected_title === $actual_title, 'Title found');
    }
    
    /**
     * Passes if a link with the specified label is found.
     *
     * An optional link index may be passed.
     *
     * @param string $label
     *   Text between the anchor tags.
     * @param int $index
     *   Link position counting from zero.
     * @param string $message
     *   (optional) A message to display with the assertion. Do not translate
     *   messages: use strtr() to embed variables in the message text, not
     *   t(). If left blank, a default message will be displayed.
     *
     * @throws \Behat\Mink\Exception\ExpectationException
     *   Thrown when element doesn't exist, or the link label is a different one.
     */
    public function linkExists($label, $index = 0, $message = '') {
        $message = $message ? $message : strtr('Link with label %label found.', [
            '%label' => $label,
        ]);
        $links = $this->session
            ->getPage()
            ->findAll('named', [
            'link',
            $label,
        ]);
        $this->assert(!empty($links[$index]), $message);
    }
    
    /**
     * Passes if a link with the exactly specified label is found.
     *
     * An optional link index may be passed.
     *
     * @param string $label
     *   Text between the anchor tags.
     * @param int $index
     *   Link position counting from zero.
     * @param string $message
     *   (optional) A message to display with the assertion. Do not translate
     *   messages: use strtr() to embed variables in the message text, not
     *   t(). If left blank, a default message will be displayed.
     *
     * @throws \Behat\Mink\Exception\ExpectationException
     *   Thrown when element doesn't exist, or the link label is a different one.
     */
    public function linkExistsExact($label, $index = 0, $message = '') {
        $message = $message ? $message : strtr('Link with label %label found.', [
            '%label' => $label,
        ]);
        $links = $this->session
            ->getPage()
            ->findAll('named_exact', [
            'link',
            $label,
        ]);
        $this->assert(!empty($links[$index]), $message);
    }
    
    /**
     * Passes if a link with the specified label is not found.
     *
     * An optional link index may be passed.
     *
     * @param string $label
     *   Text between the anchor tags.
     * @param string $message
     *   (optional) A message to display with the assertion. Do not translate
     *   messages: use strtr() to embed variables in the message text, not
     *   t(). If left blank, a default message will be displayed.
     *
     * @throws \Behat\Mink\Exception\ExpectationException
     *   Thrown when element doesn't exist, or the link label is a different one.
     */
    public function linkNotExists($label, $message = '') {
        $message = $message ? $message : strtr('Link with label %label not found.', [
            '%label' => $label,
        ]);
        $links = $this->session
            ->getPage()
            ->findAll('named', [
            'link',
            $label,
        ]);
        $this->assert(empty($links), $message);
    }
    
    /**
     * Passes if a link with the exactly specified label is not found.
     *
     * An optional link index may be passed.
     *
     * @param string $label
     *   Text between the anchor tags.
     * @param string $message
     *   (optional) A message to display with the assertion. Do not translate
     *   messages: use strtr() to embed variables in the message text, not
     *   t(). If left blank, a default message will be displayed.
     *
     * @throws \Behat\Mink\Exception\ExpectationException
     *   Thrown when element doesn't exist, or the link label is a different one.
     */
    public function linkNotExistsExact($label, $message = '') {
        $message = $message ? $message : strtr('Link with label %label not found.', [
            '%label' => $label,
        ]);
        $links = $this->session
            ->getPage()
            ->findAll('named_exact', [
            'link',
            $label,
        ]);
        $this->assert(empty($links), $message);
    }
    
    /**
     * Passes if a link containing a given href (part) is found.
     *
     * @param string $href
     *   The full or partial value of the 'href' attribute of the anchor tag.
     * @param int $index
     *   Link position counting from zero.
     * @param string $message
     *   (optional) A message to display with the assertion. Do not translate
     *   messages: use \Drupal\Component\Render\FormattableMarkup to embed
     *   variables in the message text, not t(). If left blank, a default message
     *   will be displayed.
     *
     * @throws \Behat\Mink\Exception\ExpectationException
     *   Thrown when element doesn't exist, or the link label is a different one.
     */
    public function linkByHrefExists($href, $index = 0, $message = '') {
        $xpath = $this->buildXPathQuery('//a[contains(@href, :href)]', [
            ':href' => $href,
        ]);
        $message = $message ? $message : strtr('Link containing href %href found.', [
            '%href' => $href,
        ]);
        $links = $this->session
            ->getPage()
            ->findAll('xpath', $xpath);
        $this->assert(!empty($links[$index]), $message);
    }
    
    /**
     * Passes if a link containing a given href (part) is not found.
     *
     * @param string $href
     *   The full or partial value of the 'href' attribute of the anchor tag.
     * @param string $message
     *   (optional) A message to display with the assertion. Do not translate
     *   messages: use \Drupal\Component\Render\FormattableMarkup to embed
     *   variables in the message text, not t(). If left blank, a default message
     *   will be displayed.
     *
     * @throws \Behat\Mink\Exception\ExpectationException
     *   Thrown when element doesn't exist, or the link label is a different one.
     */
    public function linkByHrefNotExists($href, $message = '') {
        $xpath = $this->buildXPathQuery('//a[contains(@href, :href)]', [
            ':href' => $href,
        ]);
        $message = $message ? $message : strtr('No link containing href %href found.', [
            '%href' => $href,
        ]);
        $links = $this->session
            ->getPage()
            ->findAll('xpath', $xpath);
        $this->assert(empty($links), $message);
    }
    
    /**
     * Builds an XPath query.
     *
     * Builds an XPath query by replacing placeholders in the query by the value
     * of the arguments.
     *
     * XPath 1.0 (the version supported by libxml2, the underlying XML library
     * used by PHP) doesn't support any form of quotation. This function
     * simplifies the building of XPath expression.
     *
     * @param string $xpath
     *   An XPath query, possibly with placeholders in the form ':name'.
     * @param array $args
     *   An array of arguments with keys in the form ':name' matching the
     *   placeholders in the query. The values may be either strings or numeric
     *   values.
     *
     * @return string
     *   An XPath query with arguments replaced.
     */
    public function buildXPathQuery($xpath, array $args = []) {
        // Replace placeholders.
        foreach ($args as $placeholder => $value) {
            if (is_object($value)) {
                throw new \InvalidArgumentException('Just pass in scalar values for $args and remove all t() calls from your test.');
            }
            // XPath 1.0 doesn't support a way to escape single or double quotes in a
            // string literal. We split double quotes out of the string, and encode
            // them separately.
            if (is_string($value)) {
                // Explode the text at the quote characters.
                $parts = explode('"', $value);
                // Quote the parts.
                foreach ($parts as &$part) {
                    $part = '"' . $part . '"';
                }
                // Return the string.
                $value = count($parts) > 1 ? 'concat(' . implode(', \'"\', ', $parts) . ')' : $parts[0];
            }
            // Use preg_replace_callback() instead of preg_replace() to prevent the
            // regular expression engine from trying to substitute backreferences.
            $replacement = function ($matches) use ($value) {
                return $value;
            };
            $xpath = preg_replace_callback('/' . preg_quote($placeholder) . '\\b/', $replacement, $xpath);
        }
        return $xpath;
    }
    
    /**
     * 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) {
        $this->responseNotContains(Html::escape($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) {
        $this->responseContains(Html::escape($raw));
    }
    
    /**
     * Checks that page HTML (response content) contains text.
     *
     * @param string|object $text
     *   Text value. Any non-string value will be cast to string.
     *
     * @throws \Behat\Mink\Exception\ExpectationException
     */
    public function responseContains($text) {
        parent::responseContains((string) $text);
    }
    
    /**
     * Checks that page HTML (response content) does not contains text.
     *
     * @param string|object $text
     *   Text value. Any non-string value will be cast to string.
     *
     * @throws \Behat\Mink\Exception\ExpectationException
     */
    public function responseNotContains($text) {
        parent::responseNotContains((string) $text);
    }
    
    /**
     * Asserts a condition.
     *
     * The parent method is overridden because it is a private method.
     *
     * @param bool $condition
     *   The condition.
     * @param string $message
     *   The success message.
     *
     * @throws \Behat\Mink\Exception\ExpectationException
     *   When the condition is not fulfilled.
     */
    public function assert($condition, $message) {
        if ($condition) {
            return;
        }
        throw new ExpectationException($message, $this->session
            ->getDriver());
    }
    
    /**
     * Checks that a given form field element is disabled.
     *
     * @param string $field
     *   One of id|name|label|value for the field.
     * @param \Behat\Mink\Element\TraversableElement $container
     *   (optional) The document to check against. Defaults to the current page.
     *
     * @return \Behat\Mink\Element\NodeElement
     *   The matching element.
     *
     * @throws \Behat\Mink\Exception\ElementNotFoundException
     * @throws \Behat\Mink\Exception\ExpectationException
     */
    public function fieldDisabled($field, TraversableElement $container = NULL) {
        $container = $container ?: $this->session
            ->getPage();
        $node = $container->findField($field);
        if ($node === NULL) {
            throw new ElementNotFoundException($this->session
                ->getDriver(), 'field', 'id|name|label|value', $field);
        }
        if (!$node->hasAttribute('disabled')) {
            throw new ExpectationException("Field {$field} is disabled", $this->session
                ->getDriver());
        }
        return $node;
    }
    
    /**
     * Checks that a given form field element is enabled.
     *
     * @param string $field
     *   One of id|name|label|value for the field.
     * @param \Behat\Mink\Element\TraversableElement $container
     *   (optional) The document to check against. Defaults to the current page.
     *
     * @return \Behat\Mink\Element\NodeElement
     *   The matching element.
     *
     * @throws \Behat\Mink\Exception\ElementNotFoundException
     * @throws \Behat\Mink\Exception\ExpectationException
     */
    public function fieldEnabled($field, TraversableElement $container = NULL) {
        $container = $container ?: $this->session
            ->getPage();
        $node = $container->findField($field);
        if ($node === NULL) {
            throw new ElementNotFoundException($this->session
                ->getDriver(), 'field', 'id|name|label|value', $field);
        }
        if ($node->hasAttribute('disabled')) {
            throw new ExpectationException("Field {$field} is not enabled", $this->session
                ->getDriver());
        }
        return $node;
    }
    
    /**
     * Checks that specific hidden field exists.
     *
     * @param string $field
     *   One of id|name|value for the hidden field.
     * @param \Behat\Mink\Element\TraversableElement $container
     *   (optional) The document to check against. Defaults to the current page.
     *
     * @return \Behat\Mink\Element\NodeElement
     *   The matching element.
     *
     * @throws \Behat\Mink\Exception\ElementNotFoundException
     */
    public function hiddenFieldExists($field, TraversableElement $container = NULL) {
        $container = $container ?: $this->session
            ->getPage();
        if ($node = $container->find('hidden_field_selector', [
            'hidden_field',
            $field,
        ])) {
            return $node;
        }
        throw new ElementNotFoundException($this->session
            ->getDriver(), 'form hidden field', 'id|name|value', $field);
    }
    
    /**
     * Checks that specific hidden field does not exist.
     *
     * @param string $field
     *   One of id|name|value for the hidden field.
     * @param \Behat\Mink\Element\TraversableElement $container
     *   (optional) The document to check against. Defaults to the current page.
     *
     * @throws \Behat\Mink\Exception\ExpectationException
     */
    public function hiddenFieldNotExists($field, TraversableElement $container = NULL) {
        $container = $container ?: $this->session
            ->getPage();
        $node = $container->find('hidden_field_selector', [
            'hidden_field',
            $field,
        ]);
        $this->assert($node === NULL, "A hidden field '{$field}' exists on this page, but it should not.");
    }
    
    /**
     * Checks that specific hidden field have provided value.
     *
     * @param string $field
     *   One of id|name|value for the hidden field.
     * @param string $value
     *   The hidden field value that needs to be checked.
     * @param \Behat\Mink\Element\TraversableElement $container
     *   (optional) The document to check against. Defaults to the current page.
     *
     * @throws \Behat\Mink\Exception\ElementNotFoundException
     * @throws \Behat\Mink\Exception\ExpectationException
     */
    public function hiddenFieldValueEquals($field, $value, TraversableElement $container = NULL) {
        $node = $this->hiddenFieldExists($field, $container);
        $actual = $node->getValue();
        $regex = '/^' . preg_quote($value, '/') . '$/ui';
        $message = "The hidden field '{$field}' value is '{$actual}', but '{$value}' expected.";
        $this->assert((bool) preg_match($regex, $actual), $message);
    }
    
    /**
     * Checks that specific hidden field doesn't have the provided value.
     *
     * @param string $field
     *   One of id|name|value for the hidden field.
     * @param string $value
     *   The hidden field value that needs to be checked.
     * @param \Behat\Mink\Element\TraversableElement $container
     *   (optional) The document to check against. Defaults to the current page.
     *
     * @throws \Behat\Mink\Exception\ElementNotFoundException
     * @throws \Behat\Mink\Exception\ExpectationException
     */
    public function hiddenFieldValueNotEquals($field, $value, TraversableElement $container = NULL) {
        $node = $this->hiddenFieldExists($field, $container);
        $actual = $node->getValue();
        $regex = '/^' . preg_quote($value, '/') . '$/ui';
        $message = "The hidden field '{$field}' value is '{$actual}', but it should not be.";
        $this->assert(!preg_match($regex, $actual), $message);
    }
    
    /**
     * Checks that current page contains text only once.
     *
     * @param string $text
     *   The string to look for.
     *
     * @see \Behat\Mink\WebAssert::pageTextContains()
     */
    public function pageTextContainsOnce($text) {
        $actual = $this->session
            ->getPage()
            ->getText();
        $actual = preg_replace('/\\s+/u', ' ', $actual);
        $regex = '/' . preg_quote($text, '/') . '/ui';
        $count = preg_match_all($regex, $actual);
        if ($count === 1) {
            return;
        }
        if ($count > 1) {
            $message = sprintf('The text "%s" appears in the text of this page more than once, but it should not.', $text);
        }
        else {
            $message = sprintf('The text "%s" was not found anywhere in the text of the current page.', $text);
        }
        throw new ResponseTextException($message, $this->session
            ->getDriver());
    }

}