trait UiHelperTrait

trait UiHelperTrait {
    use BrowserHtmlDebugTrait;
    use AssertHelperTrait;
    use RefreshVariablesTrait;
    
    /**
     * The current user logged in using the Mink controlled browser.
     *
     * @var \Drupal\user\UserInterface
     */
    protected $loggedInUser = FALSE;
    
    /**
     * The number of meta refresh redirects to follow, or NULL if unlimited.
     *
     * @var null|int
     */
    protected $maximumMetaRefreshCount = NULL;
    
    /**
     * The number of meta refresh redirects followed during ::drupalGet().
     *
     * @var int
     */
    protected $metaRefreshCount = 0;
    
    /**
     * Fills and submits a form.
     *
     * @param array $edit
     *   Field data in an associative array. Changes the current input fields
     *   (where possible) to the values indicated.
     *
     *   A checkbox can be set to TRUE to be checked and should be set to FALSE to
     *   be unchecked.
     * @param string $submit
     *   Value of the submit button whose click is to be emulated. For example,
     *   'Save'. The processing of the request depends on this value. For example,
     *   a form may have one button with the value 'Save' and another button with
     *   the value 'Delete', and execute different code depending on which one is
     *   clicked.
     * @param string $form_html_id
     *   (optional) HTML ID of the form to be submitted. On some pages
     *   there are many identical forms, so just using the value of the submit
     *   button is not enough. For example: 'trigger-node-presave-assign-form'.
     *   Note that this is not the Drupal $form_id, but rather the HTML ID of the
     *   form, which is typically the same thing but with hyphens replacing the
     *   underscores.
     */
    protected function submitForm(array $edit, $submit, $form_html_id = NULL) {
        $assert_session = $this->assertSession();
        // Get the form.
        if (isset($form_html_id)) {
            $form = $assert_session->elementExists('xpath', "//form[@id='{$form_html_id}']");
            $submit_button = $assert_session->buttonExists($submit, $form);
            $action = $form->getAttribute('action');
        }
        else {
            $submit_button = $assert_session->buttonExists($submit);
            $form = $assert_session->elementExists('xpath', './ancestor::form', $submit_button);
            $action = $form->getAttribute('action');
        }
        // Edit the form values.
        foreach ($edit as $name => $value) {
            $field = $assert_session->fieldExists($name, $form);
            // Provide support for the values '1' and '0' for checkboxes instead of
            // TRUE and FALSE.
            // @todo Get rid of supporting 1/0 by converting all tests cases using
            // this to boolean values.
            $field_type = $field->getAttribute('type');
            if ($field_type === 'checkbox') {
                $value = (bool) $value;
            }
            $field->setValue($value);
        }
        // Submit form.
        $this->prepareRequest();
        $submit_button->press();
        // Ensure that any changes to variables in the other thread are picked up.
        $this->refreshVariables();
        // Check if there are any meta refresh redirects (like Batch API pages).
        if ($this->checkForMetaRefresh()) {
            // We are finished with all meta refresh redirects, so reset the counter.
            $this->metaRefreshCount = 0;
        }
        // Log only for JavascriptTestBase tests because for Goutte we log with
        // ::getResponseLogHandler.
        if ($this->htmlOutputEnabled && !$this->getSession()
            ->getDriver() instanceof GoutteDriver) {
            $out = $this->getSession()
                ->getPage()
                ->getContent();
            $html_output = 'POST request to: ' . $action . '<hr />Ending URL: ' . $this->getSession()
                ->getCurrentUrl();
            $html_output .= '<hr />' . $out;
            $html_output .= $this->getHtmlOutputHeaders();
            $this->htmlOutput($html_output);
        }
    }
    
    /**
     * Executes a form submission.
     *
     * It will be done as usual submit form with Mink.
     *
     * @param \Drupal\Core\Url|string $path
     *   Location of the post form. Either a Drupal path or an absolute path or
     *   NULL to post to the current page. For multi-stage forms you can set the
     *   path to NULL and have it post to the last received page. Example:
     *
     *   @code
     *   // First step in form.
     *   $edit = array(...);
     *   $this->drupalPostForm('some_url', $edit, 'Save');
     *
     *   // Second step in form.
     *   $edit = array(...);
     *   $this->drupalPostForm(NULL, $edit, 'Save');
     *   @endcode
     * @param array $edit
     *   Field data in an associative array. Changes the current input fields
     *   (where possible) to the values indicated.
     *
     *   When working with form tests, the keys for an $edit element should match
     *   the 'name' parameter of the HTML of the form. For example, the 'body'
     *   field for a node has the following HTML:
     *   @code
     *   <textarea id="edit-body-und-0-value" class="text-full form-textarea
     *    resize-vertical" placeholder="" cols="60" rows="9"
     *    name="body[0][value]"></textarea>
     *   @endcode
     *   When testing this field using an $edit parameter, the code becomes:
     *   @code
     *   $edit["body[0][value]"] = 'My test value';
     *   @endcode
     *
     *   A checkbox can be set to TRUE to be checked and should be set to FALSE to
     *   be unchecked. Multiple select fields can be tested using 'name[]' and
     *   setting each of the desired values in an array:
     *   @code
     *   $edit = array();
     *   $edit['name[]'] = array('value1', 'value2');
     *   @endcode
     *   @todo change $edit to disallow NULL as a value for Drupal 9.
     *     https://www.drupal.org/node/2802401
     * @param string $submit
     *   The id, name, label or value of the submit button which is to be clicked.
     *   For example, 'Save'. The first element matched by
     *   \Drupal\Tests\WebAssert::buttonExists() will be used. The processing of
     *   the request depends on this value. For example, a form may have one
     *   button with the value 'Save' and another button with the value 'Delete',
     *   and execute different code depending on which one is clicked.
     * @param array $options
     *   Options to be forwarded to the url generator.
     * @param string|null $form_html_id
     *   (optional) HTML ID of the form to be submitted. On some pages
     *   there are many identical forms, so just using the value of the submit
     *   button is not enough. For example: 'trigger-node-presave-assign-form'.
     *   Note that this is not the Drupal $form_id, but rather the HTML ID of the
     *   form, which is typically the same thing but with hyphens replacing the
     *   underscores.
     *
     * @return string
     *   (deprecated) The response content after submit form. It is necessary for
     *   backwards compatibility and will be removed before Drupal 9.0. You should
     *   just use the webAssert object for your assertions.
     *
     * @see \Drupal\Tests\WebAssert::buttonExists()
     */
    protected function drupalPostForm($path, $edit, $submit, array $options = [], $form_html_id = NULL) {
        if (is_object($submit)) {
            // Cast MarkupInterface objects to string.
            $submit = (string) $submit;
        }
        if ($edit === NULL) {
            $edit = [];
        }
        if (is_array($edit)) {
            $edit = $this->castSafeStrings($edit);
        }
        if (isset($path)) {
            $this->drupalGet($path, $options);
        }
        $this->submitForm($edit, $submit, $form_html_id);
        return $this->getSession()
            ->getPage()
            ->getContent();
    }
    
    /**
     * Logs in a user using the Mink controlled browser.
     *
     * If a user is already logged in, then the current user is logged out before
     * logging in the specified user.
     *
     * Please note that neither the current user nor the passed-in user object is
     * populated with data of the logged in user. If you need full access to the
     * user object after logging in, it must be updated manually. If you also need
     * access to the plain-text password of the user (set by drupalCreateUser()),
     * e.g. to log in the same user again, then it must be re-assigned manually.
     * For example:
     * @code
     *   // Create a user.
     *   $account = $this->drupalCreateUser(array());
     *   $this->drupalLogin($account);
     *   // Load real user object.
     *   $pass_raw = $account->passRaw;
     *   $account = User::load($account->id());
     *   $account->passRaw = $pass_raw;
     * @endcode
     *
     * @param \Drupal\Core\Session\AccountInterface $account
     *   User object representing the user to log in.
     *
     * @see drupalCreateUser()
     */
    protected function drupalLogin(AccountInterface $account) {
        if ($this->loggedInUser) {
            $this->drupalLogout();
        }
        $this->drupalGet(Url::fromRoute('user.login'));
        $this->submitForm([
            'name' => $account->getAccountName(),
            'pass' => $account->passRaw,
        ], t('Log in'));
        // @see ::drupalUserIsLoggedIn()
        $account->sessionId = $this->getSession()
            ->getCookie(\Drupal::service('session_configuration')->getOptions(\Drupal::request())['name']);
        $this->assertTrue($this->drupalUserIsLoggedIn($account), new FormattableMarkup('User %name successfully logged in.', [
            '%name' => $account->getAccountName(),
        ]));
        $this->loggedInUser = $account;
        $this->container
            ->get('current_user')
            ->setAccount($account);
    }
    
    /**
     * Logs a user out of the Mink controlled browser and confirms.
     *
     * Confirms logout by checking the login page.
     */
    protected function drupalLogout() {
        // Make a request to the logout page, and redirect to the user page, the
        // idea being if you were properly logged out you should be seeing a login
        // screen.
        $assert_session = $this->assertSession();
        $destination = Url::fromRoute('user.page')->toString();
        $this->drupalGet(Url::fromRoute('user.logout', [], [
            'query' => [
                'destination' => $destination,
            ],
        ]));
        $assert_session->fieldExists('name');
        $assert_session->fieldExists('pass');
        // @see BrowserTestBase::drupalUserIsLoggedIn()
        unset($this->loggedInUser->sessionId);
        $this->loggedInUser = FALSE;
        \Drupal::currentUser()->setAccount(new AnonymousUserSession());
    }
    
    /**
     * Returns WebAssert object.
     *
     * @param string $name
     *   (optional) Name of the session. Defaults to the active session.
     *
     * @return \Drupal\Tests\WebAssert
     *   A new web-assert option for asserting the presence of elements with.
     */
    public function assertSession($name = NULL) {
        $this->addToAssertionCount(1);
        return new WebAssert($this->getSession($name), $this->baseUrl);
    }
    
    /**
     * Retrieves a Drupal path or an absolute path.
     *
     * @param string|\Drupal\Core\Url $path
     *   Drupal path or URL to load into Mink controlled browser.
     * @param array $options
     *   (optional) Options to be forwarded to the url generator.
     * @param string[] $headers
     *   An array containing additional HTTP request headers, the array keys are
     *   the header names and the array values the header values. This is useful
     *   to set for example the "Accept-Language" header for requesting the page
     *   in a different language. Note that not all headers are supported, for
     *   example the "Accept" header is always overridden by the browser. For
     *   testing REST APIs it is recommended to obtain a separate HTTP client
     *   using getHttpClient() and performing requests that way.
     *
     * @return string
     *   The retrieved HTML string, also available as $this->getRawContent()
     *
     * @see \Drupal\Tests\BrowserTestBase::getHttpClient()
     */
    protected function drupalGet($path, array $options = [], array $headers = []) {
        $options['absolute'] = TRUE;
        $url = $this->buildUrl($path, $options);
        $session = $this->getSession();
        $this->prepareRequest();
        foreach ($headers as $header_name => $header_value) {
            $session->setRequestHeader($header_name, $header_value);
        }
        $session->visit($url);
        $out = $session->getPage()
            ->getContent();
        // Ensure that any changes to variables in the other thread are picked up.
        $this->refreshVariables();
        // Replace original page output with new output from redirected page(s).
        if ($new = $this->checkForMetaRefresh()) {
            $out = $new;
            // We are finished with all meta refresh redirects, so reset the counter.
            $this->metaRefreshCount = 0;
        }
        // Log only for JavascriptTestBase tests because for Goutte we log with
        // ::getResponseLogHandler.
        if ($this->htmlOutputEnabled && !$this->getSession()
            ->getDriver() instanceof GoutteDriver) {
            $html_output = 'GET request to: ' . $url . '<hr />Ending URL: ' . $this->getSession()
                ->getCurrentUrl();
            $html_output .= '<hr />' . $out;
            $html_output .= $this->getHtmlOutputHeaders();
            $this->htmlOutput($html_output);
        }
        return $out;
    }
    
    /**
     * Builds an a absolute URL from a system path or a URL object.
     *
     * @param string|\Drupal\Core\Url $path
     *   A system path or a URL.
     * @param array $options
     *   Options to be passed to Url::fromUri().
     *
     * @return string
     *   An absolute URL string.
     */
    protected function buildUrl($path, array $options = []) {
        if ($path instanceof Url) {
            $url_options = $path->getOptions();
            $options = $url_options + $options;
            $path->setOptions($options);
            return $path->setAbsolute()
                ->toString();
        }
        elseif (\Drupal::hasService('url_generator')) {
            $force_internal = isset($options['external']) && $options['external'] == FALSE;
            if (!$force_internal && UrlHelper::isExternal($path)) {
                return Url::fromUri($path, $options)->toString();
            }
            else {
                $uri = $path === '<front>' ? 'base:/' : 'base:/' . $path;
                // Path processing is needed for language prefixing.  Skip it when a
                // path that may look like an external URL is being used as internal.
                $options['path_processing'] = !$force_internal;
                return Url::fromUri($uri, $options)->setAbsolute()
                    ->toString();
            }
        }
        else {
            return $this->getAbsoluteUrl($path);
        }
    }
    
    /**
     * Takes a path and returns an absolute path.
     *
     * @param string $path
     *   A path from the Mink controlled browser content.
     *
     * @return string
     *   The $path with $base_url prepended, if necessary.
     */
    protected function getAbsoluteUrl($path) {
        global $base_url, $base_path;
        $parts = parse_url($path);
        if (empty($parts['host'])) {
            // Ensure that we have a string (and no xpath object).
            $path = (string) $path;
            // Strip $base_path, if existent.
            $length = strlen($base_path);
            if (substr($path, 0, $length) === $base_path) {
                $path = substr($path, $length);
            }
            // Ensure that we have an absolute path.
            if (empty($path) || $path[0] !== '/') {
                $path = '/' . $path;
            }
            // Finally, prepend the $base_url.
            $path = $base_url . $path;
        }
        return $path;
    }
    
    /**
     * Prepare for a request to testing site.
     *
     * The testing site is protected via a SIMPLETEST_USER_AGENT cookie that is
     * checked by drupal_valid_test_ua().
     *
     * @see drupal_valid_test_ua()
     */
    protected function prepareRequest() {
        $session = $this->getSession();
        $session->setCookie('SIMPLETEST_USER_AGENT', drupal_generate_test_ua($this->databasePrefix));
    }
    
    /**
     * Returns whether a given user account is logged in.
     *
     * @param \Drupal\Core\Session\AccountInterface $account
     *   The user account object to check.
     *
     * @return bool
     *   Return TRUE if the user is logged in, FALSE otherwise.
     */
    protected function drupalUserIsLoggedIn(AccountInterface $account) {
        $logged_in = FALSE;
        if (isset($account->sessionId)) {
            $session_handler = \Drupal::service('session_handler.storage');
            $logged_in = (bool) $session_handler->read($account->sessionId);
        }
        return $logged_in;
    }
    
    /**
     * Clicks the element with the given CSS selector.
     *
     * @param string $css_selector
     *   The CSS selector identifying the element to click.
     */
    protected function click($css_selector) {
        $starting_url = $this->getSession()
            ->getCurrentUrl();
        $this->getSession()
            ->getDriver()
            ->click($this->cssSelectToXpath($css_selector));
        // Log only for JavascriptTestBase tests because for Goutte we log with
        // ::getResponseLogHandler.
        if ($this->htmlOutputEnabled && !$this->getSession()
            ->getDriver() instanceof GoutteDriver) {
            $out = $this->getSession()
                ->getPage()
                ->getContent();
            $html_output = 'Clicked element with CSS selector: ' . $css_selector . '<hr />Starting URL: ' . $starting_url . '<hr />Ending URL: ' . $this->getSession()
                ->getCurrentUrl();
            $html_output .= '<hr />' . $out;
            $html_output .= $this->getHtmlOutputHeaders();
            $this->htmlOutput($html_output);
        }
    }
    
    /**
     * Follows a link by complete name.
     *
     * Will click the first link found with this link text.
     *
     * If the link is discovered and clicked, the test passes. Fail otherwise.
     *
     * @param string|\Drupal\Component\Render\MarkupInterface $label
     *   Text between the anchor tags.
     * @param int $index
     *   (optional) The index number for cases where multiple links have the same
     *   text. Defaults to 0.
     */
    protected function clickLink($label, $index = 0) {
        $label = (string) $label;
        $links = $this->getSession()
            ->getPage()
            ->findAll('named', [
            'link',
            $label,
        ]);
        $this->assertArrayHasKey($index, $links, 'The link ' . $label . ' was not found on the page.');
        $links[$index]->click();
    }
    
    /**
     * Retrieves the plain-text content from the current page.
     */
    protected function getTextContent() {
        return $this->getSession()
            ->getPage()
            ->getText();
    }
    
    /**
     * Get the current URL from the browser.
     *
     * @return string
     *   The current URL.
     */
    protected function getUrl() {
        return $this->getSession()
            ->getCurrentUrl();
    }
    
    /**
     * Checks for meta refresh tag and if found call drupalGet() recursively.
     *
     * This function looks for the http-equiv attribute to be set to "Refresh" and
     * is case-insensitive.
     *
     * @return string|false
     *   Either the new page content or FALSE.
     */
    protected function checkForMetaRefresh() {
        $refresh = $this->cssSelect('meta[http-equiv="Refresh"], meta[http-equiv="refresh"]');
        if (!empty($refresh) && (!isset($this->maximumMetaRefreshCount) || $this->metaRefreshCount < $this->maximumMetaRefreshCount)) {
            // Parse the content attribute of the meta tag for the format:
            // "[delay]: URL=[page_to_redirect_to]".
            if (preg_match('/\\d+;\\s*URL=\'?(?<url>[^\']*)/i', $refresh[0]->getAttribute('content'), $match)) {
                $this->metaRefreshCount++;
                return $this->drupalGet($this->getAbsoluteUrl(Html::decodeEntities($match['url'])));
            }
        }
        return FALSE;
    }
    
    /**
     * Searches elements using a CSS selector in the raw content.
     *
     * The search is relative to the root element (HTML tag normally) of the page.
     *
     * @param string $selector
     *   CSS selector to use in the search.
     *
     * @return \Behat\Mink\Element\NodeElement[]
     *   The list of elements on the page that match the selector.
     */
    protected function cssSelect($selector) {
        return $this->getSession()
            ->getPage()
            ->findAll('css', $selector);
    }

}