<?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/>.

/**
 * Library of interface functions and constants for module minilesson
 *
 * All the core Moodle functions, neeeded to allow the module to work
 * integrated in Moodle should be placed here.
 * All the minilesson specific functions, needed to implement all the module
 * logic, should go to locallib.php. This will help to save some memory when
 * Moodle is performing actions across all modules.
 *
 * @package    mod_minilesson
 * @copyright  2015 Justin Hunt (poodllsupport@gmail.com)
 * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 */

use mod_minilesson\aigen_contextform;
use mod_minilesson\constants;
use mod_minilesson\local\formelement\ttsaudio;
use mod_minilesson\local\itemtype\item_audiochat;
use mod_minilesson\translate_form;
use mod_minilesson\utils;

/**
 * Returns the information on whether the module supports a feature
 *
 * @see plugin_supports() in lib/moodlelib.php
 * @param string $feature FEATURE_xx constant for requested feature
 * @return mixed true if the feature is supported, null if unknown
 */
function minilesson_supports($feature) {
    switch ($feature) {
        case FEATURE_MOD_INTRO:
            return true;
        case FEATURE_SHOW_DESCRIPTION:
            return true;
        case FEATURE_COMPLETION_HAS_RULES:
            return true;
        case FEATURE_COMPLETION_TRACKS_VIEWS:
            return true;
        case FEATURE_GRADE_HAS_GRADE:
            return true;
        case FEATURE_GRADE_OUTCOMES:
            return true;
        case FEATURE_BACKUP_MOODLE2:
            return true;
        case FEATURE_GROUPINGS:
            return false;
        case FEATURE_GROUPS:
            return true;

        // FEATURE_MOD_PURPOSE  - wont be defined for < 4.0. so we hard code it.
        case "mod_purpose":
            if (defined('MOD_PURPOSE_INTERACTIVECONTENT')) {
                return "interactivecontent";
            } else if (defined('MOD_PURPOSE_ASSESSMENT')) {
                return "assessment";
            } else {
                return null;
            }
            // FEATURE_MOD_OTHERPURPOSE  - wont be defined for < 5.1. so we hard code it.
            // If it is defined then interactivecontent  and assessment will also be  defined.
        case "mod_otherpurpose":
            return "assessment";

        default:
            return null;
    }
}

/**
 * Implementation of the function for printing the form elements that control
 * whether the course reset functionality affects the minilesson.
 *
 * @param $mform form passed by reference
 */
function minilesson_reset_course_form_definition(&$mform) {
    $mform->addElement('header', constants::M_MODNAME . 'header', get_string('modulenameplural', constants::M_COMPONENT));
    $mform->addElement('advcheckbox', 'reset_' . constants::M_MODNAME, get_string('deletealluserdata', constants::M_COMPONENT));
}

/**
 * Course reset form defaults.
 * @param object $course
 * @return array
 */
function minilesson_reset_course_form_defaults($course) {
    return ['reset_' . constants::M_MODNAME => 1];
}
/**
 * Editor options allowing files.
 *
 * @param context $context
 * @return array
 */
function minilesson_editor_with_files_options($context) {
    return [
        'maxfiles' => EDITOR_UNLIMITED_FILES,
        'noclean' => true,
        'context' => $context,
        'subdirs' => true,
    ];
}
/**
 * Editor file options disallowing files
 *
 * @param context $context
 * @return array
 */
function minilesson_editor_no_files_options($context) {
    return ['maxfiles' => 0, 'noclean' => true, 'context' => $context];
}
/**
 * Picture file options
 *
 * @param context $context
 * @return array
 */
function minilesson_picturefile_options($context) {
    return [
        'maxfiles' => EDITOR_UNLIMITED_FILES,
        'noclean' => true,
        'context' => $context,
        'subdirs' => true,
        'accepted_types' => ['image'],
    ];
}

/**
 * Removes all grades from gradebook
 *
 * @param int $courseid
 * @param string $type optional type
 */
function minilesson_reset_gradebook($courseid, $type = '') {
    global $CFG, $DB;

    $sql = "SELECT l.*, cm.idnumber as cmidnumber, l.course as courseid
              FROM {" . constants::M_TABLE . "} l, {course_modules} cm, {modules} m
             WHERE m.name='" . constants::M_MODNAME . "' AND m.id=cm.module AND cm.instance=l.id AND l.course=:course";
    $params = ["course" => $courseid];
    if ($moduleinstances = $DB->get_records_sql($sql, $params)) {
        foreach ($moduleinstances as $moduleinstance) {
            minilesson_grade_item_update($moduleinstance, 'reset');
        }
    }
}

/**
 * Actual implementation of the reset course functionality, delete all the
 * minilesson attempts for course $data->courseid.
 *
 * @param object $data the data submitted from the reset course.
 * @return array status array
 */
function minilesson_reset_userdata($data) {
    global $CFG, $DB;

    $componentstr = get_string('modulenameplural', constants::M_COMPONENT);
    $status = [];

    if (!empty($data->{'reset_' . constants::M_MODNAME})) {
        $sql = "SELECT l.id
                         FROM {" . constants::M_TABLE . "} l
                        WHERE l.course=:course";

        $params = ["course" => $data->courseid];
        $DB->delete_records_select(constants::M_ATTEMPTSTABLE, "moduleid IN ($sql)", $params);

        // Remove all grades from gradebook.
        if (empty($data->reset_gradebook_grades)) {
            minilesson_reset_gradebook($data->courseid);
        }

        $status[] = ['component' => $componentstr,
        'item' => get_string('deletealluserdata', constants::M_COMPONENT), 'error' => false];
    }

    // Updating dates - shift may be negative too.
    if ($data->timeshift) {
        shift_course_mod_dates(constants::M_MODNAME, ['available', 'deadline'], $data->timeshift, $data->courseid);
        $status[] = ['component' => $componentstr, 'item' => get_string('datechanged'), 'error' => false];
    }

    return $status;
}


/**
 * Create grade item for activity instance
 *
 * @category grade
 * @uses GRADE_TYPE_VALUE
 * @uses GRADE_TYPE_NONE
 * @param object $moduleinstance object with extra cmidnumber
 * @param array|object $grades optional array/object of grade(s); 'reset' means reset grades in gradebook
 * @return int 0 if ok, error code otherwise
 */
function minilesson_grade_item_update($moduleinstance, $grades = null) {
    global $CFG;
    if (!function_exists('grade_update')) { // Workaround for buggy PHP versions.
        require_once($CFG->libdir . '/gradelib.php');
    }

    if (array_key_exists('cmidnumber', (array) $moduleinstance)) { // It may not be always present.
        $params = ['itemname' => $moduleinstance->name, 'idnumber' => $moduleinstance->cmidnumber];
    } else {
        $params = ['itemname' => $moduleinstance->name];
    }

    if ($moduleinstance->grade > 0) {
        $params['gradetype'] = GRADE_TYPE_VALUE;
        $params['grademax'] = $moduleinstance->grade;
        $params['grademin'] = 0;
    } else if ($moduleinstance->grade < 0) {
        $params['gradetype'] = GRADE_TYPE_SCALE;
        $params['scaleid'] = -$moduleinstance->grade;

        // Make sure current grade fetched correctly from $grades.
        $currentgrade = null;
        if (!empty($grades)) {
            if (is_array($grades)) {
                $currentgrade = reset($grades);
            } else {
                $currentgrade = $grades;
            }
        }

        // When converting a score to a scale, use scale's grade maximum to calculate it.
        if (!empty($currentgrade) && $currentgrade->rawgrade !== null) {
            $grade = grade_get_grades(
                $moduleinstance->course,
                'mod',
                constants::M_MODNAME,
                $moduleinstance->id,
                $currentgrade->userid
            );
            $params['grademax'] = reset($grade->items)->grademax;
        }
    } else {
        $params['gradetype'] = GRADE_TYPE_NONE;
    }

    if ($grades === 'reset') {
        $params['reset'] = true;
        $grades = null;
    } else if (!empty($grades)) {
        // Need to calculate raw grade (Note: $grades has many forms).
        if (is_object($grades)) {
            $grades = [$grades->userid => $grades];
        } else if (array_key_exists('userid', $grades)) {
            $grades = [$grades['userid'] => $grades];
        }
        foreach ($grades as $key => $grade) {
            if (!is_array($grade)) {
                $grades[$key] = $grade = (array) $grade;
            }
            // Check raw grade isnt null otherwise we insert a grade of 0.
            if ($grade['rawgrade'] !== null) {
                $grades[$key]['rawgrade'] = ($grade['rawgrade'] * $params['grademax'] / 100);
            } else {
                // Setting rawgrade to null just in case user is deleting a grade.
                $grades[$key]['rawgrade'] = null;
            }
        }
    }

    return grade_update(
        'mod/' . constants::M_MODNAME,
        $moduleinstance->course,
        'mod',
        constants::M_MODNAME,
        $moduleinstance->id,
        0,
        $grades,
        $params
    );
}

/**
 * Update grades in central gradebook
 *
 * @category grade
 * @param object $moduleinstance
 * @param int $userid specific user only, 0 means all
 * @param bool $nullifnone
 */
function minilesson_update_grades($moduleinstance, $userid = 0, $nullifnone = true) {
    global $CFG, $DB;
    require_once($CFG->libdir . '/gradelib.php');

    if ($moduleinstance->grade == 0) {
        minilesson_grade_item_update($moduleinstance);
    } else if ($grades = minilesson_get_user_grades($moduleinstance, $userid)) {
        minilesson_grade_item_update($moduleinstance, $grades);
    } else if ($userid && $nullifnone) {
        $grade = new stdClass();
        $grade->userid = $userid;
        $grade->rawgrade = null;
        minilesson_grade_item_update($moduleinstance, $grade);
    } else {
        minilesson_grade_item_update($moduleinstance);
    }
}

/**
 * Return grade for given user or all users.
 *
 * @param int $moduleinstance
 * @param int $userid optional user id, 0 means all users
 * @return array array of grades, false if none
 */
function minilesson_get_user_grades($moduleinstance, $userid = 0) {
    global $CFG, $DB;

    $params = ["moduleid" => $moduleinstance->id];
    $cantranscribe = utils::can_transcribe($moduleinstance);

    if (!empty($userid)) {
        $params["userid"] = $userid;
        $user = "AND u.id = :userid";
    } else {
        $user = "";
    }

    // Human_sql.
    $humansql = "SELECT u.id, u.id AS userid, a.sessionscore AS rawgrade
                      FROM {user} u, {" . constants::M_ATTEMPTSTABLE . "} a
                     WHERE a.id= (SELECT max(id) FROM {" . constants::M_ATTEMPTSTABLE . "} ia WHERE ia.userid=u.id AND
                      ia.moduleid = a.moduleid AND ia.status = " . constants::M_STATE_COMPLETE . ")
                       " . " AND u.id = a.userid AND a.moduleid = :moduleid  $user
                  GROUP BY u.id, a.sessionscore";

    $results = $DB->get_records_sql($humansql, $params);

    // Return results.
    return $results;
}

/**
 * Get completion state for user
 *
 * @param stdClass $course
 * @param stdClass $cm
 * @param int $userid
 * @param int $type
 * @return int|bool
 * @throws Exception
 */
function minilesson_get_completion_state($course, $cm, $userid, $type) {
    return minilesson_is_complete($course, $cm, $userid, $type);
}


/**
 * Check if activity is complete
 *
 * @param stdClass $course
 * @param stdClass $cm
 * @param int $userid
 * @param int $type
 * @return int|bool
 * @throws Exception
 */
function minilesson_is_complete($course, $cm, $userid, $type) {

    global $DB;

    // Get module object.
    if (!($moduleinstance = $DB->get_record(constants::M_TABLE, ['id' => $cm->instance]))) {
        throw new Exception("Can't find module with cmid: {$cm->instance}");
    }

    // Check if conditional completion is enabled.
    $onfinished = !empty($moduleinstance->completionwhenfinished);
    $onmingrade = !empty($moduleinstance->mingrade);
    $completionenabled = $onfinished || $onmingrade;
    if (!$completionenabled) {
        return $type;
    }

    // Check completion reqs against satisfied conditions.
    switch ($type) {
        case COMPLETION_AND:
            if ($onfinished && $onmingrade) {
                return utils::is_complete('completionwhenfinished', $moduleinstance, $userid) &&
                    utils::is_complete('mingrade', $moduleinstance, $userid);
            } else if ($onfinished) {
                return utils::is_complete('completionwhenfinished', $moduleinstance, $userid);
            } else if ($onmingrade) {
                return utils::is_complete('mingrade', $moduleinstance, $userid);
            }
            break;

        case COMPLETION_OR:
            if ($onfinished || $onmingrade) {
                return utils::is_complete('completionwhenfinished', $moduleinstance, $userid) ||
                    utils::is_complete('mingrade', $moduleinstance, $userid);
            }
    }
    // Completion option is not enabled, we must return $type.
    return $type;
}


/**
 * A task called from scheduled or adhoc
 *
 * @param progress_trace trace object
 *
 */
function minilesson_dotask(progress_trace $trace) {
    $trace->output('executing dotask');
}

/**
 * Returns a list of editor field names
 *
 * @return array
 */
function minilesson_get_editornames() {
    return [];
}

/**
 * Saves a new instance of the minilesson into the database
 *
 * Given an object containing all the necessary data,
 * (defined by the form in mod_form.php) this function
 * will create a new instance and return the id number
 * of the new instance.
 *
 * @param object $minilesson An object from the form in mod_form.php
 * @param mod_minilesson_mod_form $mform
 * @return int The id of the newly inserted minilesson record
 */
function minilesson_add_instance(stdClass $minilesson, ?mod_minilesson_mod_form $mform = null) {
    global $DB;

    $minilesson->timecreated = time();
    $minilesson = minilesson_process_files($minilesson, $mform);
    $minilesson->id = $DB->insert_record(constants::M_TABLE, $minilesson);

    if (!isset($minilesson->cmidnumber)) {
        $minilesson->cmidnumber = null;
    }
    minilesson_grade_item_update($minilesson);

    // Add expected completion date.
    if (class_exists('\core_completion\api')) {
        $completionexpected = (empty($minilesson->completionexpected) ? null : $minilesson->completionexpected);
        \core_completion\api::update_completion_date_event(
            $minilesson->coursemodule,
            'minilesson',
            $minilesson->id,
            $completionexpected
        );
    }
    return $minilesson->id;
}

/**
 * Process the files from the editors
 *
 * @param stdClass $minilesson
 * @param mod_minilesson_mod_form|null $mform
 * @return stdClass
 */
function minilesson_process_files(stdClass $minilesson, ?mod_minilesson_mod_form $mform = null) {
    global $DB;
    $cmid = $minilesson->coursemodule;
    $context = context_module::instance($cmid);
    $editors = minilesson_get_editornames();
    $itemid = 0;
    $edoptions = minilesson_editor_no_files_options($context);
    foreach ($editors as $editor) {
        $minilesson = file_postupdate_standard_editor(
            $minilesson,
            $editor,
            $edoptions,
            $context,
            constants::M_COMPONENT,
            $editor,
            $itemid
        );
    }

    return $minilesson;
}

/**
 * Updates an instance of the minilesson in the database
 *
 * Given an object containing all the necessary data,
 * (defined by the form in mod_form.php) this function
 * will update an existing instance with new data.
 *
 * @param object $minilesson An object from the form in mod_form.php
 * @param mod_minilesson_mod_form $mform
 * @return boolean Success/Fail
 */
function minilesson_update_instance(stdClass $minilesson, ?mod_minilesson_mod_form $mform = null) {

    global $DB;

    $minilesson->timemodified = time();
    $minilesson->id = $minilesson->instance;
    $minilesson = minilesson_process_files($minilesson, $mform);
    $params = ['id' => $minilesson->instance];
    $oldgradefield = $DB->get_field(constants::M_TABLE, 'grade', $params);

    // If region has changed we will need a new scorer. So lets flag that if necessary.
    $oldrecord = $DB->get_record(constants::M_TABLE, ['id' => $minilesson->id]);
    $needsnewlangmodels = false;
    if ($minilesson->region != $oldrecord->region) {
        $needsnewlangmodels = true;
    }

    // Perform our update.
    $success = $DB->update_record(constants::M_TABLE, $minilesson);

    // Update lang models if required.
    if ($needsnewlangmodels) {
        \mod_minilesson\local\itemform\helper::update_all_langmodels($minilesson);
    }

    if (!isset($minilesson->cmidnumber)) {
        $minilesson->cmidnumber = null;
    }
    minilesson_grade_item_update($minilesson);
    $updategrades = ($minilesson->grade === $oldgradefield ? false : true);
    if ($updategrades) {
        minilesson_update_grades($minilesson, 0, false);
    }

    // Update expected completion date.
    if (class_exists('\core_completion\api')) {
        $completionexpected = (empty($minilesson->completionexpected) ? null : $minilesson->completionexpected);
        \core_completion\api::update_completion_date_event(
            $minilesson->coursemodule,
            'minilesson',
            $minilesson->id,
            $completionexpected
        );
    }

    return $success;
}

/**
 * Removes an instance of the minilesson from the database
 *
 * Given an ID of an instance of this module,
 * this function will permanently delete the instance
 * and any data that depends on it.
 *
 * @param int $id Id of the module instance
 * @return boolean Success/Failure
 */
function minilesson_delete_instance($id) {
    global $DB;

    if (!$minilesson = $DB->get_record(constants::M_TABLE, ['id' => $id])) {
        return false;
    }

    // Delete any dependent records here #.

    $DB->delete_records(constants::M_TABLE, ['id' => $minilesson->id]);

    return true;
}

/**
 * Returns a small object with summary information about what a
 * user has done with a given particular instance of this module
 * Used for user activity reports.
 * $return->time = the time they did it
 * $return->info = a short text description
 *
 * @return stdClass|null
 */
function minilesson_user_outline($course, $user, $mod, $minilesson) {

    $return = new stdClass();
    $return->time = 0;
    $return->info = '';
    return $return;
}

/**
 * Prints a detailed representation of what a user has done with
 * a given particular instance of this module, for user activity reports.
 *
 * @param stdClass $course the current course record
 * @param stdClass $user the record of the user we are generating report for
 * @param cm_info $mod course module info
 * @param stdClass $minilesson the module instance record
 * @return void, is supposed to echp directly
 */
function minilesson_user_complete($course, $user, $mod, $minilesson) {
}

/**
 * Given a course and a time, this module should find recent activity
 * that has occurred in minilesson activities and print it out.
 * Return true if there was output, or false is there was none.
 *
 * @return boolean
 */
function minilesson_print_recent_activity($course, $viewfullnames, $timestart) {
    return false;  // True if anything was printed, otherwise false.
}

/**
 * Prepares the recent activity data
 *
 * This callback function is supposed to populate the passed array with
 * custom activity records. These records are then rendered into HTML via
 * {@link minilesson_print_recent_mod_activity()}.
 *
 * @param array $activities sequentially indexed array of objects with the 'cmid' property
 * @param int $index the index in the $activities to use for the next record
 * @param int $timestart append activity since this time
 * @param int $courseid the id of the course we produce the report for
 * @param int $cmid course module id
 * @param int $userid check for a particular user's activity only, defaults to 0 (all users)
 * @param int $groupid check for a particular group's activity only, defaults to 0 (all groups)
 * @return void adds items into $activities and increases $index
 */
function minilesson_get_recent_mod_activity(&$activities, &$index, $timestart, $courseid, $cmid, $userid = 0, $groupid = 0) {
}

/**
 * Prints single activity item prepared by {@see minilesson_get_recent_mod_activity()}

 * @return void
 */
function minilesson_print_recent_mod_activity($activity, $courseid, $detail, $modnames, $viewfullnames) {
}

/**
 * Function to be run periodically according to the moodle cron
 * This function searches for things that need to be done, such
 * as sending out mail, toggling flags etc ...
 *
 * @return boolean
 * @todo Finish documenting this function
 **/
function minilesson_cron() {
    return true;
}

/**
 * Returns all other caps used in the module
 *
 * @return array
 */
function minilesson_get_extra_capabilities() {
    return [];
}

// Gradebook API.

/**
 * Is a given scale used by the instance of minilesson?
 *
 * This function returns if a scale is being used by one minilesson
 * if it has support for grading and scales. Commented code should be
 * modified if necessary. See forum, glossary or journal modules
 * as reference.
 *
 * @param int $moduleid ID of an instance of this module
 * @return bool true if the scale is used by the given minilesson instance
 */
function minilesson_scale_used($moduleid, $scaleid) {
    global $DB;

    // Example @example.
    if ($scaleid && $DB->record_exists(constants::M_TABLE, ['id' => $moduleid, 'grade' => -$scaleid])) {
        return true;
    } else {
        return false;
    }
}

/**
 * Checks if scale is being used by any instance of minilesson.
 *
 * This is used to find out if scale used anywhere.
 *
 * @param $scaleid int
 * @return boolean true if the scale is used by any minilesson instance
 */
function minilesson_scale_used_anywhere($scaleid) {
    global $DB;

    // Example @example.
    if ($scaleid && $DB->record_exists(constants::M_TABLE, ['grade' => -$scaleid])) {
        return true;
    } else {
        return false;
    }
}

// File API.

/**
 * Returns the lists of all browsable file areas within the given module context
 *
 * The file area 'intro' for the activity introduction field is added automatically
 * by {@link file_browser::get_file_info_context_module()}
 *
 * @param stdClass $course
 * @param stdClass $cm
 * @param stdClass $context
 * @return array of [(string)filearea] => (string)description
 */
function minilesson_get_file_areas($course, $cm, $context) {
    return minilesson_get_editornames();
}

/**
 * File browsing support for minilesson file areas
 *
 * @package mod_minilesson
 * @category files
 *
 * @param file_browser $browser
 * @param array $areas
 * @param stdClass $course
 * @param stdClass $cm
 * @param stdClass $context
 * @param string $filearea
 * @param int $itemid
 * @param string $filepath
 * @param string $filename
 * @return file_info instance or null if not found
 */
function minilesson_get_file_info($browser, $areas, $course, $cm, $context, $filearea, $itemid, $filepath, $filename) {
    return null;
}

/**
 * Serves the files from the minilesson file areas
 *
 * @package mod_minilesson
 * @category files
 *
 * @param stdClass $course the course object
 * @param stdClass $cm the course module object
 * @param stdClass $context the minilesson's 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 $options additional options affecting the file serving
 */
function minilesson_pluginfile($course, $cm, $context, $filearea, array $args, $forcedownload, array $options = []) {
    global $DB, $CFG;

    if ($context->contextlevel != CONTEXT_MODULE) {
        send_file_not_found();
    }

    require_login($course, true, $cm);

    $itemid = (int) array_shift($args);

    require_course_login($course, true, $cm);

    if (!has_capability('mod/minilesson:view', $context)) {
        return false;
    }

    $isexport = strpos($filearea, 'export') !== false;
    $istranslate = strpos($filearea, 'translate') !== false;
    if ($isexport || $istranslate) {
        // Exporting the items as JSON.
        require_login($course, false, $cm);
        require_capability('mod/minilesson:export', $context);

        if (!$moduleinstance = $DB->get_record('minilesson', ['id' => $cm->instance], '*', MUST_EXIST)) {
            return false;
        }
        $name = $moduleinstance->name;
        if ($istranslate) {
            $alllangs = utils::get_lang_options();
            if (count($args) > 1) {
                $fromlang = array_key_exists($args[0], $alllangs) ? $args[0] : 'empty';
                $tolang = array_key_exists($args[1], $alllangs) ? $args[1] : 'empty';
            } else {
                $fromlang = "empty";
                $tolang = "empty";
            }
            if ($fromlang == "empty" || $tolang == "empty") {
                return false;
            }
        }
        // Make a nice filename.
        $cleanfilename = strip_tags(format_string($name));
        if ($istranslate) {
            $cleanfilename .= '_' . $tolang;
        }

        $filename = clean_filename($cleanfilename . '.json');
        $filename = preg_replace('/\s+/', '_', $filename);
        $theimport = new \mod_minilesson\import($moduleinstance, $context, $course, $cm);
        if ($istranslate) {
            $jsondata = $theimport->translate_and_export_items($fromlang, $tolang);
        } else {
            $jsondata = $theimport->export_items();
        }

        // Return to the browser that called us.
        send_file($jsondata, $filename, 0, 0, true, true);
    } else {
        // Files uploaded into activity.
        $fs = get_file_storage();
        $relativepath = implode('/', $args);
        $fullpath = "/$context->id/mod_minilesson/$filearea/$itemid/$relativepath";

        if (!$file = $fs->get_file_by_hash(sha1($fullpath)) || $file->is_directory()) {
            return false;
        }

        // Finally send the file.
        send_stored_file($file, null, 0, $forcedownload, $options);
    }
}

/**
 * Whether the activity is branded.
 * This information is used, for instance, to decide if a filter should be applied to the icon or not.
 *
 * @return bool True if the activity is branded, false otherwise.
 */
function minilesson_is_branded() {
    return true;
}

/**
 * Outputs the fragment for the preview.
 *
 * @param array $args
 * @return string
 */
function minilesson_output_fragment_preview($args) {
    global $DB, $PAGE;
    $args = (object) $args;
    $context = $args->context;

    $cm = get_coursemodule_from_id('minilesson', $context->instanceid, 0, false, MUST_EXIST);
    $course = $DB->get_record('course', ['id' => $cm->course], '*', MUST_EXIST);
    $moduleinstance = $DB->get_record('minilesson', ['id' => $cm->instance], '*', MUST_EXIST);

    $renderer = $PAGE->get_renderer('mod_minilesson');
    $comptest = new \mod_minilesson\comprehensiontest($cm);
    $ret = $renderer->show_quiz_preview($comptest, $args->itemid);
    $ret .= $renderer->fetch_activity_amd($comptest, $cm, $moduleinstance, $args->itemid);
    return $ret;
}

/**
 * Outputs the fragment for the item form.
 *
 * @param array $args
 * @return string
 */
function minilesson_output_fragment_mform($args) {
    global $CFG, $PAGE, $DB;

    $args = (object) $args;
    $context = $args->context;
    $formname = $args->formname;
    $mform = null;
    $o = '';

    [$ignored, $course] = get_context_info_array($context->id);

    // Get filechooser and html editor options.
    $editoroptions = \mod_minilesson\local\itemtype\item::fetch_editor_options($course, $context);
    $filemanageroptions = \mod_minilesson\local\itemtype\item::fetch_filemanager_options($course, 3);

    // Get the objects we need.
    $cm = get_coursemodule_from_id('', $context->instanceid, 0, false, MUST_EXIST);
    $course = $DB->get_record('course', ['id' => $cm->course], '*', MUST_EXIST);
    $moduleinstance = $DB->get_record(constants::M_TABLE, ['id' => $cm->instance], '*', MUST_EXIST);

    $item = false;
    if ($args->itemid) {
        $item = $DB->get_record(
            constants::M_QTABLE,
            ['id' => $args->itemid, constants::M_MODNAME => $cm->instance],
            '*',
            MUST_EXIST
        );
        if ($item) {
            $data = $item;
            $data->itemid = $item->id;
            $data->id = $cm->id;

            // If rich text, use editor otherwise use filepicker.
            if ($moduleinstance->richtextprompt == constants::M_PROMPT_RICHTEXT) {
                // Init our editor field.
                $data = file_prepare_standard_editor(
                    $data,
                    constants::TEXTQUESTION,
                    $editoroptions,
                    $context,
                    constants::M_COMPONENT,
                    constants::TEXTQUESTION_FILEAREA,
                    $data->itemid
                );
            } else {
                // Make sure the media upload fields are in the correct state.
                $fs = get_file_storage();
                $files = $fs->get_area_files($context->id, constants::M_COMPONENT, constants::MEDIAQUESTION, $data->itemid);
                if ($files) {
                    $data->addmedia = 1;
                } else {
                    $data->addmedia = 0;
                }
                if (!empty($data->{constants::TTSQUESTION})) {
                    $data->addttsaudio = 1;
                } else {
                    $data->addttsaudio = 0;
                }
                if (!empty($data->{constants::MEDIAIFRAME})) {
                    $data->addiframe = 1;
                } else {
                    $data->addiframe = 0;
                }
                if (!empty($data->{constants::YTVIDEOID})) {
                    $data->addyoutubeclip = 1;
                } else {
                    $data->addyoutubeclip = 0;
                }
                if (!empty($data->{constants::QUESTIONTEXTAREA})) {
                    $edoptions = constants::ITEMTEXTAREA_EDOPTIONS;
                    $edoptions['context'] = $context;
                    $data->{constants::QUESTIONTEXTAREA . 'format'} = FORMAT_HTML;
                    $data = file_prepare_standard_editor(
                        $data,
                        constants::QUESTIONTEXTAREA,
                        $edoptions,
                        $context,
                        constants::M_COMPONENT,
                        constants::TEXTQUESTION_FILEAREA,
                        $data->itemid
                    );
                    $data->addtextarea = 1;
                } else {
                    $data->addtextarea = 0;
                }
                if (!empty($data->{constants::TTSDIALOG})) {
                    $data->addttsdialog = 1;
                    // Expand opts.
                    $data = utils::unpack_ttsdialogopts($data);
                } else {
                    $data->addttsdialog = 0;
                }
                if (!empty($data->{constants::TTSPASSAGE})) {
                    $data->addttspassage = 1;
                    // Expand opts.
                    $data = utils::unpack_ttspassageopts($data);
                } else {
                    $data->addttspassage = 0;
                }

                // Init our itemmedia field.
                $draftitemid = file_get_submitted_draft_itemid(constants::MEDIAQUESTION);
                file_prepare_draft_area(
                    $draftitemid,
                    $context->id,
                    constants::M_COMPONENT,
                    constants::MEDIAQUESTION,
                    $data->itemid,
                    $filemanageroptions
                );
                $data->{constants::MEDIAQUESTION} = $draftitemid;

                // Show the fields by default if they have some content.
                $visibility = [
                    'addmedia' => $data->addmedia,
                    'addiframe' => $data->addiframe,
                    'addttsaudio' => $data->addttsaudio,
                    'addtextarea' => $data->addtextarea,
                    'addyoutubeclip' => $data->addyoutubeclip,
                    'addttsdialog' => $data->addttsdialog,
                    'addttspassage' => $data->addttspassage,
                ];
                $PAGE->requires->js_call_amd(constants::M_COMPONENT . '/mediaprompts', 'init', [$visibility]);
            }
        }
    }

    $itemformclass = utils::fetch_itemform_classname($formname);
    if (!$itemformclass) {
        print_error('No item type specified');
        return 0;
    }
    $mform = new $itemformclass(
        null,
        [
            'editoroptions' => $editoroptions,
            'filemanageroptions' => $filemanageroptions,
            'moduleinstance' => $moduleinstance,
        ]
    );

    // If we have item data set it.
    if ($item) {
        $mform->set_data($data);
    }

    if (!empty($mform)) {
        ob_start();
        $mform->display();
        $o .= ob_get_contents();
        ob_end_clean();
    }

    return $o;
}
// Navigation API.

/**
 * Extends the global navigation tree by adding minilesson nodes if there is a relevant content
 *
 * This can be called by an AJAX request so do not rely on $PAGE as it might not be set up properly.
 *
 * @param navigation_node $navref An object representing the navigation tree node of the minilesson module instance
 * @param stdClass $course
 * @param stdClass $module
 * @param cm_info $cm
 */
function minilesson_extend_navigation(navigation_node $navref, stdclass $course, stdclass $module, cm_info $cm) {
}

/**
 * Extends the settings navigation with the minilesson settings
 *
 * This function is called when the context for the page is a minilesson module. This is not called by AJAX
 * so it is safe to rely on the $PAGE.
 *
 * @param settings_navigation $settingsnav {@link settings_navigation}
 * @param navigation_node $minilessonnode {@link navigation_node}
 */
function minilesson_extend_settings_navigation(settings_navigation $settingsnav, ?navigation_node $minilessonnode = null) {
}

/**
 * Returns the mapping between Moodle icon identifiers and FontAwesome icon classes.
 *
 * @return array Associative array mapping Moodle icon identifiers to FontAwesome icon classes.
 */
function mod_minilesson_get_fontawesome_icon_map() {
    return [
        'mod_minilesson:print' => 'fa-print',
        'mod_minilesson:volume-up' => 'fa-volume-up',
        'mod_minilesson:close' => 'fa-close',
    ];
}

/**
 * Alters the cm_info object for the given minilesson activity
 * to support dynamic duedate and allowsubmissionsfromdate
 *
 * @param cm_info $cm
 */
function mod_minilesson_cm_info_dynamic(cm_info $cm) {
    global $USER, $DB;

    $moduleinstance = $DB->get_record('minilesson', ['id' => $cm->instance], '*', MUST_EXIST);
    if (method_exists($cm, 'override_customdata')) {
        $cm->override_customdata('duedate', $moduleinstance->viewend);
        $cm->override_customdata('allowsubmissionsfromdate', $moduleinstance->viewstart);
    }
}
/**
 * Returns the information about the module instance needed to show in
 * course and activity listings.
 *
 * @param cm_info $coursemodule
 * @return cached_cm_info|false
 */
function minilesson_get_coursemodule_info($coursemodule) {
    global $DB;

    if (!$moduleinstance = $DB->get_record('minilesson', ['id' => $coursemodule->instance], '*')) {
        return false;
    }
    $result = new cached_cm_info();
    if ($coursemodule->showdescription) {
        if (time() > $moduleinstance->viewstart) {
            $result->content = format_module_intro('minilesson', $moduleinstance, $coursemodule->id, false);
        }
    }
    $result->name = $moduleinstance->name;

    // Populate the custom completion rules as key => value pairs, but only if the completion mode is 'automatic'.
    if ($coursemodule->completion == COMPLETION_TRACKING_AUTOMATIC) {
        $result->customdata['customcompletionrules']['completionwhenfinished'] = $moduleinstance->completionwhenfinished;
        $result->customdata['customcompletionrules']['mingrade'] = $moduleinstance->mingrade;
    }

    $result->customdata['duedate'] = $moduleinstance->viewend;
    $result->customdata['allowsubmissionsfromdate'] = $moduleinstance->viewstart;
    return $result;
}

/**
 * Outputs the TTS Audio form element
 *
 * @param array $args
 * @return string HTML fragment
 */
function minilesson_output_fragment_ttsaudioelement($args) {
    $formdata = [];
    $args = (object) $args;
    parse_str($args->formdata, $formdata);
    $options = json_decode($args->options, true);

    ttsaudio::register();
    $form = new MoodleQuickForm('dummy', 'POST', '');
    $formelement = $form->addElement(ttsaudio::ELNAME, $args->groupname, $options['label'], $options);

    $formrenderer = $form->defaultRenderer();
    $form->updateSubmission($formdata, []);
    $formelement->accept($formrenderer);

    return $formrenderer->toHtml();
}

/**
 * Outputs the AI Gen context form
 *
 * @param array $args
 * @return string JSON encoded response
 */
function minilesson_output_fragment_aigen_contextform($args) {
    global $CFG;
    require_once($CFG->libdir . '/externallib.php');

    $formdata = [];
    $args = (object) $args;
    parse_str($args->params, $formdata);

    require_capability('mod/minilesson:canuseaigen', $args->context);

    $formurl = new moodle_url($args->url, [
        'id' => $formdata['id'],
        'action' => $formdata['action'],
        'templateid' => $formdata['templateid'],
    ]);

    $form = new aigen_contextform($formurl, null, 'post', '', null, true, $formdata);
    if ($response = $form->process_dynamic_submission()) {
        return $response;
    }
    return $form->render();
}

/**
 * Outputs an AI prompt stored in config
 *
 * @param array $args
 * @return string AI prompt text
 */
function mod_minilesson_output_fragment_ai_prompt($args) {
    $args = (object) $args;

    $promptid = (int) $args->promptid;
    $prompttype = (string) $args->prompttype;
    $itemtype = (string) $args->itemtype;
    $configname = $itemtype . '_' . $prompttype . 'prompt_' . $promptid;
    return get_config(constants::M_COMPONENT, $configname);
}

/**
 * Renders preview slides from markdown input
 *
 * @param array $args
 * @return string HTML fragment
 */
function minilesson_output_fragment_preview_slides($args) {
    global $CFG, $OUTPUT;
    require_once($CFG->libdir . '/externallib.php');
    $formdata = [];
    $args = (object) $args;
    parse_str($args->formdata, $formdata);

    $imageserveurl = moodle_url::make_draftfile_url(
        $formdata[constants::FILEANSWER . '1'],
        '/',
        '{filename}'
    );

    $testitem = new stdClass();
    $testitem->inajax = AJAX_SCRIPT;
    $testitem->slidesmarkdown = preg_replace_callback(
        '/!\[[^\]]*\]\((?<filename>.*?)(?=\"|\))(?<optionalpart>\".*\")?\)/',
        function ($matches) use ($imageserveurl) {
            $filename = trim($matches['filename']);

            // Skip if it's already a full URL (http/https).
            if (preg_match('/^https?:\/\//', $filename)) {
                return $matches[0];
            }

            // Add base path (and escape spaces if needed).
            $newsrc = str_replace('{filename}', rawurlencode($filename), urldecode($imageserveurl));

            // Replace only the filename part.
            return str_replace($filename, $newsrc, $matches[0]);
        },
        $formdata[constants::SLIDES_MARKDOWN]
    );

    $testitem->selectedtheme = $formdata[constants::SLIDETHEME];
    $testitem->selectedfontsize = $formdata[constants::SLIDEFONTSIZE];

    return $OUTPUT->render_from_template(constants::M_COMPONENT . '/slidesinner', $testitem);
}

/**
 * Renders AI Gen fragment for selecting output templates
 *
 * @param array $args
 * @return string HTML fragment
 */
function minilesson_output_fragment_templates($args) {
    global $DB, $OUTPUT;
    $args = (object) $args;
    require_capability('mod/minilesson:canuseaigen', $args->context);
    $cm = $DB->get_record('course_modules', ['id' => $args->context->instanceid], '*', MUST_EXIST);
    $filters = !empty($args->filters) ? json_decode($args->filters, true) : [];
    $renderable = new mod_minilesson\output\aigentemplates($cm, $filters);
    return $OUTPUT->render($renderable);
}

/**
 * Fetches a student's submission in a previous freeewriting or freespeaking in the current attempt
 * for passing into an audiochat session. This must be done via AJAX because its not available until
 * after the attempt has started.
 * @param array $args
 * @return stdClass|null
 */
function minilesson_output_fragment_audiochat_fetchstudentsubmission($args) {
    global $DB;
    $args = (object) $args;
    $cm = $DB->get_record('course_modules', ['id' => $args->context->instanceid], '*', MUST_EXIST);
    $minilesson = $DB->get_record(constants::M_TABLE, ['id' => $cm->instance], '*', MUST_EXIST);
    $itemrecord = $DB->get_record(constants::M_QTABLE, ['id' => $args->itemid]);

    $theaudiochat = new item_audiochat($itemrecord, $minilesson, $args->context);
    $studentsubmission = $theaudiochat->fetch_student_submission();
    return $studentsubmission;
}

/**
 * Outputs the translation to import form for AI generated translations
 *
 * @param array $args
 * @return string JSON encoded response
 */
function minilesson_output_fragment_translatetoimport($args) {
    global $CFG;
    require_once($CFG->libdir . '/externallib.php');

    $formdata = [];
    $args = (object) $args;
    parse_str($args->params, $formdata);
    $formdata['id'] = $args->context->instanceid;

    require_capability('mod/minilesson:canuseaigen', $args->context);

    $formurl = new moodle_url('/mod/minilesson/lessonbank.php');

    $form = new translate_form($formurl, null, 'post', '', null, true, $formdata);
    $form->set_data($formdata);
    if ($response = $form->process_dynamic_submission()) {
        return json_encode($response);
    }
    return json_encode(['html' => $form->render()]);
}
