<?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/>.
/**
 * Background task to refresh the list of associaded teachers with studyplans
 * @package    tool_sptoolboxmgr
 * @copyright  2023 P.M. Kuipers
 * @license    https://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 */

namespace tool_sptoolboxmgr\task;

use \local_treestudyplan\associationservice;
use \tool_sptoolboxmgr\profilehelper;
use \mtrace;
use \mtrace_exception;
use \ValueError;

defined('MOODLE_INTERNAL') || die();

require_once($CFG->dirroot.'/user/profile/lib.php');

/**
 * Background task to process changes in 
 */
class profilescannertask extends \core\task\scheduled_task {

    /**
     * Return the task's name as shown in admin screens.
     *
     * @return string
     */
    public function get_name() {
        return get_string('profilescannertask', 'tool_sptoolboxmgr');
    }

    /**
     * Execute the task.
     */
    public function execute() {
        global $DB;
        // We need to test for changes in the profile fields...
        
        // First check the userids eligable for enrolment
        $enrollable = profilehelper::enrollable_user_ids();
        
        // Next, check each of these fields for changes
        mtrace("Checking ".count($enrollable)." enrollable uids for changes ....");
        foreach ($enrollable as $uid) {
            $user = $DB->get_record("user",["id"=>$uid]);
            try {
                $changes = profilehelper::check_changes($uid);
                mtrace("Checking user {$user->username}... ".(($changes->changed)?"Has changes":"No changes"));
            
                /**
                 * @var studyplan
                 */
                $toolbox = null;
                if ($changes->trackchanged) {
                    if ($changes->toolbox) {
                        mtrace("  User changed track - removing coaches from old toolbox '{$changes->toolbox->name()}' ");
                        // Remove coach from old toolbox.
                        $coaches = associationservice::associated_coaches($changes->toolbox->id());
                        foreach ($coaches as $coach) {
                            $coach = (object)$coach; // Convert from array to object.
                            associationservice::disconnect_coach($changes->toolbox->id(),$coach->id);
                        }
                    }

                    try {
                        // Create new toolbox based on new track and add coach.
                        $template = profilehelper::get_track_plan($changes->track);
                        
                        mtrace("  Created new toolbox");
                        $toolbox = $template->duplicate(
                            "{$user->firstname} {$user->lastname} - {$template->name()}",
                            "{$user->username}-{$template->shortname()}",
                            $template->context()->id,
                            null,
                            null
                        );
                        mtrace("  Creating new toolbox - Created {$toolbox->id()} - {$toolbox->name()}");

                        // Add user to toolbox.
                        associationservice::connect_user($toolbox->id(),$uid);
                        mtrace("  Creating new toolbox - Added user '{$user->username}' to toolbox");
                        // Add new coach to toolbox.
                        $coach = $DB->get_record("user", ["id"=> $changes->coach]);
                        mtrace("  Creating new toolbox - adding coach '{$coach->username}' to toolbox");
                        associationservice::connect_coach($toolbox->id(), $changes->coach);
                    } catch (ValueError $x) {
                        mtrace("Cannot find track template '{$changes->track}' for user '{$user->username}'");
                        mtrace_exception($x);
                    }
                } elseif ($changes->coachchanged || $changes->enrolchanged) {
                    if ($changes->toolbox) { // If there is an associated toolbox. Otherwise, it should have been created above.
                        $toolbox = $changes->toolbox;

                        if ($changes->coachchanged) {
                            // Remove coach from old toolbox.
                            $coaches = associationservice::associated_coaches($changes->toolbox->id());
                            foreach ($coaches as $coach) {
                                $coach = (object)$coach; // Convert from array to object.
                                mtrace("  Coach changed - removing coach {$coach->username} from toolbox");
                                associationservice::disconnect_coach($changes->toolbox->id(),$coach->id);
                            }
                        }
                        // Add new coach to toolbox.
                        $coach = $DB->get_record("user", ["id"=> $changes->coach]);
                        mtrace("  Coach or enrol changed - (re)adding coach {$coach->username} to toolbox");
                        $result = (object)associationservice::connect_coach($toolbox->id(), $changes->coach);
                        if (! $result->success) {
                            $ci = new \local_treestudyplan\contextinfo($toolbox->context());
                            mtrace("  Error: {$result->msg} - Toolbox '".$toolbox->name()."' context: ". $ci->pathstr());
                        }
                    }
                }
                
                
                mtrace("Registering new status");
                profilehelper::register_changes($uid,$toolbox);
                
            } catch (\ValueError $x) {
                // This is thrown if any of the fields are invalid.
                
                mtrace("Error retrieving fields for user {$user->username}");
                mtrace_exception($x);
            }
        }

        // Next process the previously enrollable uids
        $prevenrollable = profilehelper::previously_enrollable_user_ids();
        
        // Next, check each of these fields for changes
        mtrace("Processing ".count($prevenrollable)." previously enrollable uids for the change in enrollability");
        foreach ($enrollable as $uid) {
            try {
                $changes = profilehelper::check_changes($uid);
                mtrace("Checking user {$user->username}... ".(($changes->changed)?"Has changes":"No changes"));
                // There should be changes in the enrol now, since all of these uids are no longer eligable for an active toolbox.
                // Do not remove the old toolbox, but do remove the coach access - if 
                if ($changes->enrolchanged) {
                    // Remove coach from old toolbox.
                    $coaches = associationservice::associated_coaches($changes->toolbox->id());
                    foreach ($coaches as $coach) {
                        $coach = (object)$coach; // Convert from array to object.
                        mtrace("  User enrol changed - removing coach {$coach->username} from toolbox");
                        associationservice::disconnect_coach($changes->toolbox->id(),$coach->id);
                    }
                }

                mtrace("Registering new status");
                profilehelper::register_changes($uid,$changes->toolbox);
                
            } catch (\ValueError $x) {
                // This is thrown if any of the fields are invalid.
                
                mtrace("Error retrieving fields for user {$user->username}");
                mtrace_exception($x);
            }
        }
    }
}