Proyectos de Subversion Moodle

<?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/>.

/**

 * Represents a Zoom invitation.

 *

 * @package    mod_zoom

 * @author     Andrew Madden <andrewmadden@catalyst-au.net>

 * @copyright  2021 Catalyst IT

 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later

 */

namespace mod_zoom;

use coding_exception;

use context_module;

use moodle_exception;

/**

 * Invitation class.

 */

class invitation {

    /**

     * Invitation settings prefix.

     * @var string

     */

    public const PREFIX = 'invitation_';

    /** @var string|null $invitation The unaltered zoom invitation text. */

    private $invitation;

    /** @var array $configregex Array of regex patterns defined in plugin settings. */

    private $configregex;

    /**

     * invitation constructor.

     *

     * @param string|null $invitation Zoom invitation returned from

     * https://marketplace.zoom.us/docs/api-reference/zoom-api/meetings/meetinginvitation.

     */

    public function __construct($invitation) {

        $this->invitation = $invitation;

    }

    /**

     * Get the display string to show on the module page.

     *

     * @param int $coursemoduleid Course module where the user will view the invitation.

     * @param int|null $userid Optionally supply the intended user to view the string. Defaults to global $USER.

     * @return ?string

     */

    public function get_display_string(int $coursemoduleid, ?int $userid = null) {

        if (empty($this->invitation)) {

            return null;

        }

        // If regex patterns are disabled, return the raw zoom meeting invitation.

        if (!get_config('zoom', 'invitationregexenabled')) {

            return $this->invitation;

        }

        $displaystring = $this->invitation;

        try {

            // If setting enabled, strip the invite message.

            if (get_config('zoom', 'invitationremoveinvite')) {

                $displaystring = $this->remove_element($displaystring, 'invite');

            }

            // If setting enabled, strip the iCal link.

            if (get_config('zoom', 'invitationremoveicallink')) {

                $displaystring = $this->remove_element($displaystring, 'icallink');

            }

            // Check user capabilities, and remove parts of the invitation they don't have permission to view.

            if (!has_capability('mod/zoom:viewjoinurl', context_module::instance($coursemoduleid), $userid)) {

                $displaystring = $this->remove_element($displaystring, 'joinurl');

            }

            if (!has_capability('mod/zoom:viewdialin', context_module::instance($coursemoduleid), $userid)) {

                $displaystring = $this->remove_element($displaystring, 'onetapmobile');

                $displaystring = $this->remove_element($displaystring, 'dialin');

                $displaystring = $this->remove_element($displaystring, 'sip');

                $displaystring = $this->remove_element($displaystring, 'h323');

            } else {

                // Fix the formatting of the onetapmobile section if it exists.

                $displaystring = $this->add_paragraph_break_above_element($displaystring, 'onetapmobile');

            }

        } catch (moodle_exception $e) {

            // If the regex parsing fails, log a debugging message and return the whole invitation.

            debugging($e->getMessage(), DEBUG_DEVELOPER);

            return $this->invitation;

        }

        $displaystring = trim($this->clean_paragraphs($displaystring));

        return $displaystring;

    }

    /**

     * Remove instances of a zoom invitation element using a regex pattern.

     *

     * @param string $invitation

     * @param string $element

     * @return string

     *

     * @throws \coding_exception

     * @throws \dml_exception

     * @throws \moodle_exception

     */

    private function remove_element(string $invitation, string $element): string {

        global $PAGE;

        $configregex = $this->get_config_invitation_regex();

        if (!array_key_exists($element, $configregex)) {

            throw new coding_exception('Cannot remove element: ' . $element

                    . '. See mod/zoom/classes/invitation.php:get_default_invitation_regex for valid elements.');

        }

        // If the element pattern is intentionally empty, return the invitation string unaltered.

        if (empty($configregex[$element])) {

            return $invitation;

        }

        $count = 0;

        $invitation = @preg_replace($configregex[$element], "", $invitation, -1, $count);

        // If invitation is null, an error occurred in preg_replace.

        if ($invitation === null) {

            throw new moodle_exception(

                'invitationmodificationfailed',

                'mod_zoom',

                $PAGE->url,

                ['element' => $element, 'pattern' => $configregex[$element]]

            );

        }

        // Add debugging message to assist site administrator in testing regex patterns if no match is found.

        if (empty($count)) {

            debugging(

                get_string(

                    'invitationmatchnotfound',

                    'mod_zoom',

                    ['element' => $element, 'pattern' => $configregex[$element]]

                ),

                DEBUG_DEVELOPER

            );

        }

        return $invitation;

    }

    /**

     * Add a paragraph break above an element defined by a regex pattern in a zoom invitation.

     *

     * @param string $invitation

     * @param string $element

     * @return string

     *

     * @throws \coding_exception

     * @throws \dml_exception

     */

    private function add_paragraph_break_above_element(string $invitation, string $element): string {

        $matches = [];

        $configregex = $this->get_config_invitation_regex();

        // If no pattern found for element, return the invitation string unaltered.

        if (empty($configregex[$element])) {

            return $invitation;

        }

        $result = preg_match($configregex[$element], $invitation, $matches, PREG_OFFSET_CAPTURE);

        // If error occurred in preg_match, show debugging message to help site administrator.

        if ($result === false) {

            debugging(

                get_string(

                    'invitationmodificationfailed',

                    'mod_zoom',

                    ['element' => $element, 'pattern' => $configregex[$element]]

                ),

                DEBUG_DEVELOPER

            );

        }

        // No match found, so return invitation string unaltered.

        if (empty($matches)) {

            return $invitation;

        }

        // Get the position of the element in the full invitation string.

        $pos = $matches[0][1];

        // Inject a paragraph break above element. Use $this->clean_paragraphs() to fix uneven breaks between paragraphs.

        return substr_replace($invitation, "\r\n\r\n", $pos, 0);

    }

    /**

     * Ensure that paragraphs in string have correct spacing.

     *

     * @param string $invitation

     * @return string

     */

    private function clean_paragraphs(string $invitation): string {

        // Replace partial paragraph breaks with exactly two line breaks.

        $invitation = preg_replace("/\r\n\n/m", "\r\n\r\n", $invitation);

        // Replace breaks of more than two line breaks with exactly two.

        $invitation = preg_replace("/\r\n\r\n[\r\n]+/m", "\r\n\r\n", $invitation);

        return $invitation;

    }

    /**

     * Get regex patterns from site config to find the different zoom invitation elements.

     *

     * @return array

     * @throws \dml_exception

     */

    private function get_config_invitation_regex(): array {

        if ($this->configregex !== null) {

            return $this->configregex;

        }

        $config = get_config('zoom');

        $this->configregex = [];

        // Get the regex defined in the plugin settings for each element.

        foreach (self::get_default_invitation_regex() as $element => $pattern) {

            $settingname = self::PREFIX . $element;

            $this->configregex[$element] = $config->$settingname;

        }

        return $this->configregex;

    }

    /**

     * Get default regex patterns to find the different zoom invitation elements.

     *

     * @return string[]

     */

    public static function get_default_invitation_regex(): array {

        return [

            'invite' => '/^.+is inviting you to a scheduled zoom meeting.+$/mi',

            'joinurl' => '/^join zoom meeting.*(\n.*)+?(\nmeeting id.+\npasscode.+)$/mi',

            'onetapmobile' => '/^one tap mobile.*(\n\s*\+.+)+$/mi',

            'dialin' => '/^dial by your location.*(\n\s*\+.+)+(\n.*)+find your local number.+$/mi',

            'sip' => '/^join by sip.*\n.+$/mi',

            'h323' => '/^join by h\.323.*(\n.*)+?(\nmeeting id.+\npasscode.+)$/mi',

            'icallink' => '/^.+download and import the following iCalendar.+$\n.+$/mi',

        ];

    }

}