<?php
// This file is part of the Studyplan plugin for Moodle
//
// 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 <https://www.gnu.org/licenses/>.

/**
 * Moodle hook functions and some internally used functions
 * @package    local_treestudyplan
 * @copyright  2023 P.M. Kuipers
 * @license    https://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 */

 defined('MOODLE_INTERNAL') || die();
 require_once($CFG->dirroot.'/course/modlib.php');

use local_treestudyplan\local\helpers\webservicehelper;
use local_treestudyplan\studyplan;
use local_treestudyplan\studyplanpage;

/**
 * Describe editor options
 * @param context $context Context for options
 * @return array Editor options
 */
function local_treestudyplan_unit_get_editor_options(context $context) {
    global $CFG;
    return ['subdirs' => 1,
            'maxbytes' => $CFG->maxbytes,
            'maxfiles' => -1,
            'changeformat' => 1,
            'context' => $context,
            'noclean' => 1,
            'trusttext' => 0];
}

/**
 * Create primary navigation links for studyplan if needed
 */
function local_treestudyplan_autofill_customusermenuitems() {
    if (get_config("local_treestudyplan", "primary_nav_autofill")) {
        $lang = current_language();
        $navitems = [
            "/local/treestudyplan/myreport.php" => ["included" => false, "strkey" => "link_myreport"],
            "/local/treestudyplan/view-plan.php" => ["included" => false, "strkey" => "link_viewplan"],
            "/local/treestudyplan/edit-plan.php" => ["included" => false, "strkey" => "link_editplan"],
        ];
        if (\get_config("local_treestudyplan", "enablecoach")) {
            // Also include the coach role if enabled.
            $navitems["/local/treestudyplan/coach.php"] = ["included" => false, "strkey" => "link_coach"];
        }

        // Load the custom menu items from config.
        $custommenuitems = get_config("core", "custommenuitems");

        // Scan through all the lines to see if it is a link to one of our nav items in the current language.
        $lines = explode("\n", $custommenuitems);

        $links = array_keys($navitems);
        foreach ($lines as $line) {
            $parms = explode('|', $line);
            if (count($parms) > 3) {
                $link = trim($parms[1]);
                if (trim($parms[3]) == $lang && in_array($link, $links)) {
                    // Register the link as already included if it is found.
                    $navitems[$link]["included"] = true;
                }
            }
        }

        // List through all the links to see if we need to add one or more.
        foreach ($navitems as $link => $details) {
            if (!$details["included"]) {
                $line = implode("|", [
                    get_string($details["strkey"], "local_treestudyplan"), // Menu text.
                    $link, // Link.
                    '', // Tooltip.
                    $lang, // Language code.
                    " #Automatically added by studyplan plugin. See setting 'primary_nav_autofill' to disable this",
                ]);
                $custommenuitems = trim($custommenuitems)."\n".$line;
            }
        }

        // Store the modified custom menu items.
        set_config("custommenuitems", $custommenuitems);
    }
}

/**
 * Hook to extend navigation
 * @param global_navigation $navigation Navigation object
 */
function local_treestudyplan_extend_navigation(global_navigation $navigation) {
    global $CFG, $PAGE, $COURSE, $USER, $DB;

    $systemcontext = context_system::instance();

    /* Moodle 4.0-4.2 do not yet support customizing the primary navigation bar (it is a planned feature though).
       For now, go to theme settings and add the following into "Custom menu items".
          [your name for my studyplan]|/local/treestudyplan/myreport.php.
          [your name for studyplan viewing]|/local/treestudyplan/view-plan.php.
          [your name for studyplan managing]|/local/treestudyplan/edit-plan.php.
       For example:.
          Mijn studieplan|/local/treestudyplan/myreport.php.
          Studieplannen|/local/treestudyplan/view-plan.php.
          Studieplannen beheren|/local/treestudyplan/edit-plan.php.

       Using some javascript magic we'll hide the links that are not accessible.
       (Since the Output API does not easily support inline style tags, adding one through Javascript is easier, .
        and not much more complex than loading a separate stylesheet for each link we want to hide).
       We will add all the hrefs that should be hidden to this variable below.
    */

    /*
        In addition, the function local_treestudyplan_autofill_customusermenuitems() called below will
        automatically generate the required lines if they are missing...
    */
    local_treestudyplan_autofill_customusermenuitems();

    $hideprimaryhrefs = [];

    if ($USER->id > 1) {
        // Don't show if user is not logged in (id == 0) or is guest user (id == 1).

        $userstudyplans = studyplan::find_for_user($USER->id);
        if (!empty($userstudyplans)) {

            // Create studyplan node.
            $node = navigation_node::create(
                get_string("link_myreport", "local_treestudyplan"),
                new moodle_url($CFG->wwwroot . "/local/treestudyplan/myreport.php", []),
                global_navigation::TYPE_SYSTEM,
                null,
                "local_treestudyplan_myreport",
                new pix_icon("myreport", '', 'local_treestudyplan')
                );
            $node->showinflatnavigation = true;
            $node->showinsecondarynavigation = true;

            // Create invitenode node.
            $invitenode = navigation_node::create(
                get_string("manage_invites", "local_treestudyplan"),
                new moodle_url($CFG->wwwroot . "/local/treestudyplan/invitations.php", []),
                global_navigation::TYPE_CUSTOM ,
                null,
                "local_treestudyplan_invitemgmt",
                new pix_icon("invitemgmt", '', 'local_treestudyplan')
                );
            $invitenode->showinflatnavigation = false;
            $node->add_node($invitenode);

            $navigation->add_node($node, 'mycourses');
        } else {
            $hideprimaryhrefs[] = "/local/treestudyplan/myreport.php";
        }
        if (has_capability('local/treestudyplan:viewuserreports', context_system::instance())
            || webservicehelper::has_capability_in_any_category('local/treestudyplan:viewuserreports')) {
            $node = navigation_node::create(
                get_string("link_viewplan", "local_treestudyplan"),
                new moodle_url($CFG->wwwroot . "/local/treestudyplan/view-plan.php", []),
                global_navigation::TYPE_SYSTEM ,
                null,
                "local_treestudyplan_viewplan",
                new pix_icon("viewplans", '', 'local_treestudyplan')
                );
            $node->showinflatnavigation = true;
            $node->showinsecondarynavigation = true;
            $navigation->add_node($node, 'mycourses');
        } else {
            $hideprimaryhrefs[] = "/local/treestudyplan/view-plan.php";
        }
        if (has_capability('local/treestudyplan:editstudyplan', context_system::instance())
              || webservicehelper::has_capability_in_any_category('local/treestudyplan:editstudyplan')
           ) {
            $node = navigation_node::create(
                get_string("link_editplan", "local_treestudyplan"),
                new moodle_url($CFG->wwwroot . "/local/treestudyplan/edit-plan.php", []),
                global_navigation::TYPE_SYSTEM ,
                null,
                "local_treestudyplan_editplan",
                new pix_icon("viewplans", '', 'local_treestudyplan')
                );
            $node->showinflatnavigation = true;
            $node->showinsecondarynavigation = true;
            $navigation->add_node($node, 'mycourses');
        } else {
            $hideprimaryhrefs[] = "/local/treestudyplan/edit-plan.php";
        }

        $coachsql = "SELECT COUNT('id') FROM {local_treestudyplan_coach} c
                     INNER JOIN {local_treestudyplan} t ON c.studyplan_id = t.id
                     WHERE c.user_id = :user_id";

        if (\get_config("local_treestudyplan", "enablecoach") &&
             (has_capability('local/treestudyplan:coach', context_system::instance())
             || webservicehelper::has_capability_in_any_category('local/treestudyplan:coach')
             ) && $DB->count_records_sql($coachsql, ["user_id" => $USER->id]) > 0
            ) {
            $node = navigation_node::create(
                get_string("link_coach", "local_treestudyplan"),
                new moodle_url($CFG->wwwroot . "/local/treestudyplan/coach.php", []),
                global_navigation::TYPE_SYSTEM ,
                null,
                "local_treestudyplan_coach",
                new pix_icon("viewplans", '', 'local_treestudyplan')
                );
            $node->showinflatnavigation = true;
            $node->showinsecondarynavigation = true;
            $navigation->add_node($node, 'mycourses');
        } else {
            $hideprimaryhrefs[] = "/local/treestudyplan/coach.php";
        }
    } else {
        $hideprimaryhrefs[] = "/local/treestudyplan/myreport.php";
        $hideprimaryhrefs[] = "/local/treestudyplan/edit-plan.php";
        $hideprimaryhrefs[] = "/local/treestudyplan/view-plan.php";
        $hideprimaryhrefs[] = "/local/treestudyplan/coach.php";
    }
    // Create invitenode node.
    $invitenode = navigation_node::create(
        get_string("nav_invited", "local_treestudyplan"),
        new moodle_url($CFG->wwwroot . "/local/treestudyplan/invited.php", []),
        global_navigation::TYPE_USER ,
        null,
        "local_treestudyplan_invitemgmt",
        new pix_icon("nav_invited", '', 'local_treestudyplan')
        );
    $invitenode->showinflatnavigation = false;
    $navigation->add_node($invitenode, 'mycourses');

    // Now using some javascript magic, we'll hide the links that are not accessible.
    $PAGE->requires->js_call_amd('local_treestudyplan/primary-nav-tools', 'hidePrimary', [$hideprimaryhrefs]);

}

/**
 * Hook to extend navigation in category view
 * @param mixed $navigation
 * @param context_coursecat $coursecategorycontext
 */
function local_treestudyplan_extend_navigation_category_settings($navigation, context_coursecat $coursecategorycontext) {
    global $CFG, $PAGE;
    $categoryid = $coursecategorycontext->instanceid;
    if (has_capability('local/treestudyplan:editstudyplan', $coursecategorycontext)) {
        $node = $navigation->add(
            get_string('treestudyplan:editstudyplan', "local_treestudyplan"),
            new moodle_url($CFG->wwwroot . "/local/treestudyplan/edit-plan.php", ["categoryid" => $categoryid]),
            global_navigation::TYPE_CATEGORY,
            null,
            "local_treestudyplan_editplan",
            new pix_icon("editplans", '', 'local_treestudyplan')
        );

    }
    if (has_capability('local/treestudyplan:viewuserreports', $coursecategorycontext)) {
        $node = $navigation->add(
            get_string('link_viewplan', "local_treestudyplan"),
            new moodle_url($CFG->wwwroot . "/local/treestudyplan/view-plan.php", ["categoryid" => $categoryid]),
            global_navigation::TYPE_CATEGORY,
            null,
            "local_treestudyplan_viewplan",
            new pix_icon("viewplans", '', 'local_treestudyplan')
        );

    }

}

/**
 * Map fontawesome icons for use in flat navigation
 * @return array Icon mapping
 *
 */
function local_treestudyplan_get_fontawesome_icon_map() {

    // Create the icon map with the icons which are used in any case.
    $iconmapping = [
            'local_treestudyplan:myreport' => 'fa-vcard',
            'local_treestudyplan:editplans' => 'fa-share-alt',
            'local_treestudyplan:viewplans' => 'fa-share-alt',
    ];
    return $iconmapping;
}

/**
 * Helper function to reset the icon system used as updatecallback function when saving some of the plugin's settings.
 */
function local_treestudyplan_reset_fontawesome_icon_map() {
    // Reset the icon system cache.
    // There is the function \core\output\icon_system::reset_caches() which does seem to be only usable in unit tests.
    // Thus, we clear the icon system cache brutally.
    $cache = \cache::make('core', 'fontawesomeiconmapping');
    $cache->delete('mapping');
    // And rebuild it brutally.
    $instance = \core\output\icon_system::instance(\core\output\icon_system::FONTAWESOME);
    $instance->get_icon_name_map();
}

/**
 * Send invitation to invited person
 * @param mixed $inviteid Database id of the invitation
 *
 */
function local_treestudyplan_send_invite($inviteid) {
    global $DB, $USER, $CFG;
    $invite = $DB->get_record("local_treestudyplan_invit", ['id' => $inviteid]);

    $noreply = 'noreply@' . get_host_from_url($CFG->wwwroot);
    $mailer = get_mailer();
    $mailer->setFrom($noreply, "{$USER->firstname} {$USER->lastname}");
    $mailer->addAddress($invite->email, $invite->name);
    $mailer->addReplyTo($USER->email, "{$USER->firstname} {$USER->lastname}");

    $invitehref = $CFG->wwwroot."/local/treestudyplan/invited.php?key={$invite->invitekey}";

    $data = [    'permissions' => '',
                'invitee' => $invite->name,
                'sender' => "{$USER->firstname} {$USER->lastname}",
                'link' => $invitehref];

    if ($invite->allow_details || $invite->allow_calendar || $invite->allow_badges) {
        $data['permissions'] = get_string('invite_mail_permissions', 'local_treestudyplan');
        $data['permissions'] .= "<ul>\n";
        if ($invite->allow_details) {
            $data['permissions'] .= "<li>".get_string('invite_allow_details', 'local_treestudyplan')."</li>\n";
        }
        if ($invite->allow_calendar) {
            $data['permissions'] .= "<li>".get_string('invite_allow_calendar', 'local_treestudyplan')."</li>\n";
        }
        if ($invite->allow_badges) {
            $data['permissions'] .= "<li>".get_string('invite_allow_badges', 'local_treestudyplan')."</li>\n";
        }

        $data['permissions'] .= "</ul></p>\n";
    }

    $body = get_string('invite_mail_text', 'local_treestudyplan', $data);
    $subject = get_string('invite_mail_subject', 'local_treestudyplan', $data);

    $html = "
    <!DOCTYPE html PUBLIC '-//W3C//DTD XHTML 1.0 Transitional//EN' 'http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd'>.
    <html xmlns='http://www.w3.org/1999/xhtml'>.
     <head>
      <meta http-equiv='Content-Type' content='text/html; charset=UTF-8' />
      <title>{$subject}</title>
      <meta name='viewport' content='width=device-width, initial-scale=1.0'/>
    </head>
    <body>
    {$body}
    </body>
    </html>";

    $mailer->isHTML(true);
    $mailer->Subject = $subject;
    $mailer->Body = $html;
    $mailer->AltBody = strip_tags($body);

    $mailer->send();

}

/**
 * Hook to display fragment of activity/mod settings editor. Used in feature to edit name and description of activity
 * @param mixed $args
 * @return string Rendered form output HTML
 */
function local_treestudyplan_output_fragment_mod_edit_form($args) {
    global $CFG;
    global $DB;
    $args = (object)$args;
    $context = $args->context;

    if (empty($args->cmid)) {
        return "RANDOM!";
    }

    // Check the course module exists.
    $cm = \get_coursemodule_from_id('', $args->cmid, 0, false, MUST_EXIST);

    // Check the course exists.
    $course = \get_course($cm->course);

    // Require_login.
    require_login($course, false, $cm); // Needed to setup proper $COURSE.

    list($cm, $context, $module, $data, $cw) = \get_moduleinfo_data($cm, $course);

    $modmoodleform = "$CFG->dirroot/mod/$module->name/mod_form.php";
    if (file_exists($modmoodleform)) {
        require_once($modmoodleform);
    } else {
        throw new \moodle_exception('noformdesc', 'local_treestudyplan');;
    }

    $mformclassname = 'mod_'.$module->name.'_mod_form';
    $mform = new $mformclassname($data, $cw->section, $cm, $course);
    $mform->set_data($data);

    return $mform->render();

}

/**
 * Serve the files from the myplugin file areas.
 *
 * @param stdClass $course the course object
 * @param stdClass $cm the course module object
 * @param stdClass $context the context
 * @param string $filearea the name of the file area
 * @param array $args extra arguments (itemid, path)
 * @param bool $forcedownload whether or not force download
 * @param array $options additional options affecting the file serving
 * @return bool false if the file not found, just send the file otherwise and do not return anything
 */
function local_treestudyplan_pluginfile(
    $course,
    $cm,
    $context,
    string $filearea,
    array $args,
    bool $forcedownload,
    array $options = []
): bool {
    global $DB, $USER;

    $studyplanfilecaps = ["local/treestudyplan:editstudyplan", "local/treestudyplan:viewuserreports"];

    // Check the contextlevel is as expected - the studyplan plugin only uses system context for storing files.
    // This avoids headaches when moving studyplans between contexts, while the security impact is minimal...
    if ($context->contextlevel != CONTEXT_SYSTEM) {
        return false;
    }

    // Make sure the filearea is one of those used by the plugin.
    if (in_array($filearea, ["studyplan", "icon", "studyplanpage"])) {
        // The args is an array containing [itemid, path].
        // Fetch the itemid from the path.
        $itemid = array_shift($args);

        // Studyplan icons and description images are not secret, so don't overdo it on access control...
        if (true) {
            // Extract the filename / filepath from the $args array.
            $filename = array_pop($args); // The last item in the $args array.
            if (empty($args)) {
                // Var $args is empty => the path is '/'.
                $filepath = '/';
            } else {
                // Var $args contains the remaining elements of the filepath.
                $filepath = '/' . implode('/', $args) . '/';
            }

            // Retrieve the file from the Files API.
            $fs = get_file_storage();
            $file = $fs->get_file(\context_system::instance()->id, 'local_treestudyplan', $filearea, $itemid, $filepath, $filename);
            if (!$file) {
                // The file does not exist.
                return false;
            }
            // We can now send the file back to the browser - in this case with a cache lifetime of 1 day and no filtering.
            send_stored_file($file, 24 * 60 * 60, 0, $forcedownload, $options);
        } else {
            return false;
        }

    } else if (in_array($filearea, ['defaulticon'])) {
        // The args is an array containing [itemid, path].
        // Fetch the itemid from the path.
        $itemid = array_shift($args);

        // Extract the filename / filepath from the $args array.
        $filename = array_pop($args); // The last item in the $args array.
        if (empty($args)) {
            // Var $args is empty => the path is '/'.
            $filepath = '/';
        } else {
            // Var $args contains the remaining elements of the filepath.
            $filepath = '/' . implode('/', $args) . '/';
        }

        // Retrieve the file from the Files API.
        $fs = get_file_storage();
        $file = $fs->get_file(\context_system::instance()->id, 'local_treestudyplan', $filearea, $itemid, $filepath, $filename);
        if (!$file) {
            // The file does not exist.
            return false;
        }
        // We can now send the file back to the browser - in this case with a cache lifetime of 1 day and no filtering.
        send_stored_file($file, 24 * 60 * 60, 0, $forcedownload, $options);
    } else {
        return false;
    }

}