<?php
// This file is part of Moodle - http://moodle.org/
//
// Moodle is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// Moodle is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.

/**
 * Behat hooks steps definitions.
 *
 * This methods are used by Behat CLI command.
 *
 * @package    core
 * @category   test
 * @copyright  2012 David Monllaó
 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 */

// NOTE: no MOODLE_INTERNAL test here, this file may be required by behat before including /config.php.

require_once(__DIR__ . '/../../behat/behat_base.php');

use Behat\Behat\Event\SuiteEvent as SuiteEvent,
    Behat\Behat\Event\ScenarioEvent as ScenarioEvent,
    Behat\Behat\Event\StepEvent as StepEvent,
    Behat\Mink\Exception\DriverException as DriverException,
    WebDriver\Exception\NoSuchWindow as NoSuchWindow,
    WebDriver\Exception\UnexpectedAlertOpen as UnexpectedAlertOpen,
    WebDriver\Exception\UnknownError as UnknownError,
    WebDriver\Exception\CurlExec as CurlExec,
    WebDriver\Exception\NoAlertOpenError as NoAlertOpenError;

/**
 * Hooks to the behat process.
 *
 * Behat accepts hooks after and before each
 * suite, feature, scenario and step.
 *
 * They can not call other steps as part of their process
 * like regular steps definitions does.
 *
 * Throws generic Exception because they are captured by Behat.
 *
 * @package   core
 * @category  test
 * @copyright 2012 David Monllaó
 * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 */
class behat_hooks extends behat_base {

    /**
     * @var Last browser session start time.
     */
    protected static $lastbrowsersessionstart = 0;

    /**
     * @var For actions that should only run once.
     */
    protected static $initprocessesfinished = false;

    /**
     * Some exceptions can only be caught in a before or after step hook,
     * they can not be thrown there as they will provoke a framework level
     * failure, but we can store them here to fail the step in i_look_for_exceptions()
     * which result will be parsed by the framework as the last step result.
     *
     * @var Null or the exception last step throw in the before or after hook.
     */
    protected static $currentstepexception = null;

    /**
     * If we are saving any kind of dump on failure we should use the same parent dir during a run.
     *
     * @var The parent dir name
     */
    protected static $faildumpdirname = false;

    /**
     * Gives access to moodle codebase, ensures all is ready and sets up the test lock.
     *
     * Includes config.php to use moodle codebase with $CFG->behat_*
     * instead of $CFG->prefix and $CFG->dataroot, called once per suite.
     *
     * @static
     * @throws Exception
     * @BeforeSuite
     */
    public static function before_suite($event) {
        global $CFG;

        // Defined only when the behat CLI command is running, the moodle init setup process will
        // read this value and switch to $CFG->behat_dataroot and $CFG->behat_prefix instead of
        // the normal site.
        define('BEHAT_TEST', 1);

        define('CLI_SCRIPT', 1);

        // With BEHAT_TEST we will be using $CFG->behat_* instead of $CFG->dataroot, $CFG->prefix and $CFG->wwwroot.
        require_once(__DIR__ . '/../../../config.php');

        // Now that we are MOODLE_INTERNAL.
        require_once(__DIR__ . '/../../behat/classes/behat_command.php');
        require_once(__DIR__ . '/../../behat/classes/behat_selectors.php');
        require_once(__DIR__ . '/../../behat/classes/behat_context_helper.php');
        require_once(__DIR__ . '/../../behat/classes/util.php');
        require_once(__DIR__ . '/../../testing/classes/test_lock.php');
        require_once(__DIR__ . '/../../testing/classes/nasty_strings.php');

        // Avoids vendor/bin/behat to be executed directly without test environment enabled
        // to prevent undesired db & dataroot modifications, this is also checked
        // before each scenario (accidental user deletes) in the BeforeScenario hook.

        if (!behat_util::is_test_mode_enabled()) {
            throw new Exception('Behat only can run if test mode is enabled. More info in ' . behat_command::DOCS_URL . '#Running_tests');
        }

        if (!behat_util::is_server_running()) {
            throw new Exception($CFG->behat_wwwroot .
                ' is not available, ensure you specified correct url and that the server is set up and started.' .
                ' More info in ' . behat_command::DOCS_URL . '#Running_tests');
        }

        // Prevents using outdated data, upgrade script would start and tests would fail.
        if (!behat_util::is_test_data_updated()) {
            $commandpath = 'php admin/tool/behat/cli/init.php';
            throw new Exception("Your behat test site is outdated, please run\n\n    " .
                    $commandpath . "\n\nfrom your moodle dirroot to drop and install the behat test site again.");
        }
        // Avoid parallel tests execution, it continues when the previous lock is released.
        test_lock::acquire('behat');

        // Store the browser reset time if reset after N seconds is specified in config.php.
        if (!empty($CFG->behat_restart_browser_after)) {
            // Store the initial browser session opening.
            self::$lastbrowsersessionstart = time();
        }

        if (!empty($CFG->behat_faildump_path) && !is_writable($CFG->behat_faildump_path)) {
            throw new Exception('You set $CFG->behat_faildump_path to a non-writable directory');
        }
    }

    /**
     * Resets the test environment.
     *
     * @throws coding_exception If here we are not using the test database it should be because of a coding error
     * @BeforeScenario
     */
    public function before_scenario($event) {
        global $DB, $SESSION, $CFG;

        // As many checks as we can.
        if (!defined('BEHAT_TEST') ||
               !defined('BEHAT_SITE_RUNNING') ||
               php_sapi_name() != 'cli' ||
               !behat_util::is_test_mode_enabled() ||
               !behat_util::is_test_site()) {
            throw new coding_exception('Behat only can modify the test database and the test dataroot!');
        }

        $moreinfo = 'More info in ' . behat_command::DOCS_URL . '#Running_tests';
        $driverexceptionmsg = 'Selenium server is not running, you need to start it to run tests that involve Javascript. ' . $moreinfo;
        try {
            $session = $this->getSession();
        } catch (CurlExec $e) {
            // Exception thrown by WebDriver, so only @javascript tests will be caugth; in
            // behat_util::is_server_running() we already checked that the server is running.
            throw new Exception($driverexceptionmsg);
        } catch (DriverException $e) {
            throw new Exception($driverexceptionmsg);
        } catch (UnknownError $e) {
            // Generic 'I have no idea' Selenium error. Custom exception to provide more feedback about possible solutions.
            $this->throw_unknown_exception($e);
        }


        // We need the Mink session to do it and we do it only before the first scenario.
        if (self::is_first_scenario()) {
            behat_selectors::register_moodle_selectors($session);
            behat_context_helper::set_session($session);
        }

        // Reset $SESSION.
        \core\session\manager::init_empty_session();

        behat_util::reset_database();
        behat_util::reset_dataroot();

        accesslib_clear_all_caches(true);

        // Reset the nasty strings list used during the last test.
        nasty_strings::reset_used_strings();

        // Assign valid data to admin user (some generator-related code needs a valid user).
        $user = $DB->get_record('user', array('username' => 'admin'));
        \core\session\manager::set_user($user);

        // Reset the browser if specified in config.php.
        if (!empty($CFG->behat_restart_browser_after) && $this->running_javascript()) {
            $now = time();
            if (self::$lastbrowsersessionstart + $CFG->behat_restart_browser_after < $now) {
                $session->restart();
                self::$lastbrowsersessionstart = $now;
            }
        }

        // Start always in the the homepage.
        try {
            // Let's be conservative as we never know when new upstream issues will affect us.
            $session->visit($this->locate_path('/'));
        } catch (UnknownError $e) {
            $this->throw_unknown_exception($e);
        }


        // Checking that the root path is a Moodle test site.
        if (self::is_first_scenario()) {
            $notestsiteexception = new Exception('The base URL (' . $CFG->wwwroot . ') is not a behat test site, ' .
                'ensure you started the built-in web server in the correct directory or your web server is correctly started and set up');
            $this->find("xpath", "//head/child::title[normalize-space(.)='" . behat_util::BEHATSITENAME . "']", $notestsiteexception);

            self::$initprocessesfinished = true;
        }
        // Run all test with medium (1024x768) screen size, to avoid responsive problems.
        $this->resize_window('medium');
    }

    /**
     * Wait for JS to complete before beginning interacting with the DOM.
     *
     * Executed only when running against a real browser. We wrap it
     * all in a try & catch to forward the exception to i_look_for_exceptions
     * so the exception will be at scenario level, which causes a failure, by
     * default would be at framework level, which will stop the execution of
     * the run.
     *
     * @BeforeStep @javascript
     */
    public function before_step_javascript($event) {

        try {
            $this->wait_for_pending_js();
            self::$currentstepexception = null;
        } catch (Exception $e) {
            self::$currentstepexception = $e;
        }
    }

    /**
     * Wait for JS to complete after finishing the step.
     *
     * With this we ensure that there are not AJAX calls
     * still in progress.
     *
     * Executed only when running against a real browser. We wrap it
     * all in a try & catch to forward the exception to i_look_for_exceptions
     * so the exception will be at scenario level, which causes a failure, by
     * default would be at framework level, which will stop the execution of
     * the run.
     *
     * @AfterStep @javascript
     */
    public function after_step_javascript($event) {
        global $CFG;

        // Save a screenshot if the step failed.
        if (!empty($CFG->behat_faildump_path) &&
                $event->getResult() === StepEvent::FAILED) {
            $this->take_screenshot($event);
        }

        try {
            $this->wait_for_pending_js();
            self::$currentstepexception = null;
        } catch (UnexpectedAlertOpen $e) {
            self::$currentstepexception = $e;

            // Accepting the alert so the framework can continue properly running
            // the following scenarios. Some browsers already closes the alert, so
            // wrapping in a try & catch.
            try {
                $this->getSession()->getDriver()->getWebDriverSession()->accept_alert();
            } catch (Exception $e) {
                // Catching the generic one as we never know how drivers reacts here.
            }
        } catch (Exception $e) {
            self::$currentstepexception = $e;
        }
    }

    /**
     * Execute any steps required after the step has finished.
     *
     * This includes creating an HTML dump of the content if there was a failure.
     *
     * @AfterStep
     */
    public function after_step($event) {
        global $CFG;

        // Save the page content if the step failed.
        if (!empty($CFG->behat_faildump_path) &&
                $event->getResult() === StepEvent::FAILED) {
            $this->take_contentdump($event);
        }
    }

    /**
     * Getter for self::$faildumpdirname
     *
     * @return string
     */
    protected function get_run_faildump_dir() {
        return self::$faildumpdirname;
    }

    /**
     * Take screenshot when a step fails.
     *
     * @throws Exception
     * @param StepEvent $event
     */
    protected function take_screenshot(StepEvent $event) {
        // Goutte can't save screenshots.
        if (!$this->running_javascript()) {
            return false;
        }

        list ($dir, $filename) = $this->get_faildump_filename($event, 'png');
        $this->saveScreenshot($filename, $dir);
    }

    /**
     * Take a dump of the page content when a step fails.
     *
     * @throws Exception
     * @param StepEvent $event
     */
    protected function take_contentdump(StepEvent $event) {
        list ($dir, $filename) = $this->get_faildump_filename($event, 'html');

        $fh = fopen($dir . DIRECTORY_SEPARATOR . $filename, 'w');
        fwrite($fh, $this->getSession()->getPage()->getContent());
        fclose($fh);
    }

    /**
     * Determine the full pathname to store a failure-related dump.
     *
     * This is used for content such as the DOM, and screenshots.
     *
     * @param StepEvent $event
     * @param String $filetype The file suffix to use. Limited to 4 chars.
     */
    protected function get_faildump_filename(StepEvent $event, $filetype) {
        global $CFG;

        // All the contentdumps should be in the same parent dir.
        if (!$faildumpdir = self::get_run_faildump_dir()) {
            $faildumpdir = self::$faildumpdirname = date('Ymd_His');

            $dir = $CFG->behat_faildump_path . DIRECTORY_SEPARATOR . $faildumpdir;

            if (!is_dir($dir) && !mkdir($dir, $CFG->directorypermissions, true)) {
                // It shouldn't, we already checked that the directory is writable.
                throw new Exception('No directories can be created inside $CFG->behat_faildump_path, check the directory permissions.');
            }
        } else {
            // We will always need to know the full path.
            $dir = $CFG->behat_faildump_path . DIRECTORY_SEPARATOR . $faildumpdir;
        }

        // The scenario title + the failed step text.
        // We want a i-am-the-scenario-title_i-am-the-failed-step.$filetype format.
        $filename = $event->getStep()->getParent()->getTitle() . '_' . $event->getStep()->getText();
        $filename = preg_replace('/([^a-zA-Z0-9\_]+)/', '-', $filename);

        // File name limited to 255 characters. Leaving 4 chars for the file
        // extension as we allow .png for images and .html for DOM contents.
        $filename = substr($filename, 0, 250) . '.' . $filetype;

        return array($dir, $filename);
    }

    /**
     * Waits for all the JS to be loaded.
     *
     * @throws \Exception
     * @throws NoSuchWindow
     * @throws UnknownError
     * @return bool True or false depending whether all the JS is loaded or not.
     */
    protected function wait_for_pending_js() {

        // We don't use behat_base::spin() here as we don't want to end up with an exception
        // if the page & JSs don't finish loading properly.
        for ($i = 0; $i < self::EXTENDED_TIMEOUT * 10; $i++) {
            $pending = '';
            try {
                $jscode = 'return ' . self::PAGE_READY_JS . ' ? "" : M.util.pending_js.join(":");';
                $pending = $this->getSession()->evaluateScript($jscode);
            } catch (NoSuchWindow $nsw) {
                // We catch an exception here, in case we just closed the window we were interacting with.
                // No javascript is running if there is no window right?
                $pending = '';
            } catch (UnknownError $e) {
                // M is not defined when the window or the frame don't exist anymore.
                if (strstr($e->getMessage(), 'M is not defined') != false) {
                    $pending = '';
                }
            }

            // If there are no pending JS we stop waiting.
            if ($pending === '') {
                return true;
            }

            // 0.1 seconds.
            usleep(100000);
        }

        // Timeout waiting for JS to complete. It will be catched and forwarded to behat_hooks::i_look_for_exceptions().
        // It is unlikely that Javascript code of a page or an AJAX request needs more than self::EXTENDED_TIMEOUT seconds
        // to be loaded, although when pages contains Javascript errors M.util.js_complete() can not be executed, so the
        // number of JS pending code and JS completed code will not match and we will reach this point.
        throw new \Exception('Javascript code and/or AJAX requests are not ready after ' . self::EXTENDED_TIMEOUT .
            ' seconds. There is a Javascript error or the code is extremely slow.');
    }

    /**
     * Internal step definition to find exceptions, debugging() messages and PHP debug messages.
     *
     * Part of behat_hooks class as is part of the testing framework, is auto-executed
     * after each step so no features will splicitly use it.
     *
     * @Given /^I look for exceptions$/
     * @throw Exception Unknown type, depending on what we caught in the hook or basic \Exception.
     * @see Moodle\BehatExtension\Tester\MoodleStepTester
     */
    public function i_look_for_exceptions() {

        // If the step already failed in a hook throw the exception.
        if (!is_null(self::$currentstepexception)) {
            throw self::$currentstepexception;
        }

        // Wrap in try in case we were interacting with a closed window.
        try {

            // Exceptions.
            $exceptionsxpath = "//div[@data-rel='fatalerror']";
            // Debugging messages.
            $debuggingxpath = "//div[@data-rel='debugging']";
            // PHP debug messages.
            $phperrorxpath = "//div[@data-rel='phpdebugmessage']";
            // Any other backtrace.
            $othersxpath = "(//*[contains(., ': call to ')])[1]";

            $xpaths = array($exceptionsxpath, $debuggingxpath, $phperrorxpath, $othersxpath);
            $joinedxpath = implode(' | ', $xpaths);

            // Joined xpath expression. Most of the time there will be no exceptions, so this pre-check
            // is faster than to send the 4 xpath queries for each step.
            if (!$this->getSession()->getDriver()->find($joinedxpath)) {
                return;
            }

            // Exceptions.
            if ($errormsg = $this->getSession()->getPage()->find('xpath', $exceptionsxpath)) {

                // Getting the debugging info and the backtrace.
                $errorinfoboxes = $this->getSession()->getPage()->findAll('css', 'div.alert-error');
                // If errorinfoboxes is empty, try find notifytiny (original) class.
                if (empty($errorinfoboxes)) {
                    $errorinfoboxes = $this->getSession()->getPage()->findAll('css', 'div.notifytiny');
                }
                $errorinfo = $this->get_debug_text($errorinfoboxes[0]->getHtml()) . "\n" .
                    $this->get_debug_text($errorinfoboxes[1]->getHtml());

                $msg = "Moodle exception: " . $errormsg->getText() . "\n" . $errorinfo;
                throw new \Exception(html_entity_decode($msg));
            }

            // Debugging messages.
            if ($debuggingmessages = $this->getSession()->getPage()->findAll('xpath', $debuggingxpath)) {
                $msgs = array();
                foreach ($debuggingmessages as $debuggingmessage) {
                    $msgs[] = $this->get_debug_text($debuggingmessage->getHtml());
                }
                $msg = "debugging() message/s found:\n" . implode("\n", $msgs);
                throw new \Exception(html_entity_decode($msg));
            }

            // PHP debug messages.
            if ($phpmessages = $this->getSession()->getPage()->findAll('xpath', $phperrorxpath)) {

                $msgs = array();
                foreach ($phpmessages as $phpmessage) {
                    $msgs[] = $this->get_debug_text($phpmessage->getHtml());
                }
                $msg = "PHP debug message/s found:\n" . implode("\n", $msgs);
                throw new \Exception(html_entity_decode($msg));
            }

            // Any other backtrace.
            // First looking through xpath as it is faster than get and parse the whole page contents,
            // we get the contents and look for matches once we found something to suspect that there is a backtrace.
            if ($this->getSession()->getDriver()->find($othersxpath)) {
                $backtracespattern = '/(line [0-9]* of [^:]*: call to [\->&;:a-zA-Z_\x7f-\xff][\->&;:a-zA-Z0-9_\x7f-\xff]*)/';
                if (preg_match_all($backtracespattern, $this->getSession()->getPage()->getContent(), $backtraces)) {
                    $msgs = array();
                    foreach ($backtraces[0] as $backtrace) {
                        $msgs[] = $backtrace . '()';
                    }
                    $msg = "Other backtraces found:\n" . implode("\n", $msgs);
                    throw new \Exception(htmlentities($msg));
                }
            }

        } catch (NoSuchWindow $e) {
            // If we were interacting with a popup window it will not exists after closing it.
        }
    }

    /**
     * Converts HTML tags to line breaks to display the info in CLI
     *
     * @param string $html
     * @return string
     */
    protected function get_debug_text($html) {

        // Replacing HTML tags for new lines and keeping only the text.
        $notags = preg_replace('/<+\s*\/*\s*([A-Z][A-Z0-9]*)\b[^>]*\/*\s*>*/i', "\n", $html);
        return preg_replace("/(\n)+/s", "\n", $notags);
    }

    /**
     * Returns whether the first scenario of the suite is running
     *
     * @return bool
     */
    protected static function is_first_scenario() {
        return !(self::$initprocessesfinished);
    }

    /**
     * Throws an exception after appending an extra info text.
     *
     * @throws Exception
     * @param UnknownError $exception
     * @return void
     */
    protected function throw_unknown_exception(UnknownError $exception) {
        $text = get_string('unknownexceptioninfo', 'tool_behat');
        throw new Exception($text . PHP_EOL . $exception->getMessage());
    }

}

