[moodle.git] / mod / feedback / lib.php

<?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 functions and constants for module feedback
 * includes the main-part of feedback-functions
 *
 * @package mod-feedback
 * @copyright Andreas Grabs
 * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
 */

/** Include eventslib.php */
require_once($CFG->libdir.'/eventslib.php');
/** Include calendar/lib.php */
require_once($CFG->dirroot.'/calendar/lib.php');


define('FEEDBACK_ANONYMOUS_YES', 1);
define('FEEDBACK_ANONYMOUS_NO', 2);
define('FEEDBACK_MIN_ANONYMOUS_COUNT_IN_GROUP', 2);
define('FEEDBACK_DECIMAL', '.');
define('FEEDBACK_THOUSAND', ',');
define('FEEDBACK_RESETFORM_RESET', 'feedback_reset_data_');
define('FEEDBACK_RESETFORM_DROP', 'feedback_drop_feedback_');
define('FEEDBACK_MAX_PIX_LENGTH', '400'); //max. Breite des grafischen Balkens in der Auswertung
define('FEEDBACK_DEFAULT_PAGE_COUNT', 20);

/**
 * @uses FEATURE_GROUPS
 * @uses FEATURE_GROUPINGS
 * @uses FEATURE_GROUPMEMBERSONLY
 * @uses FEATURE_MOD_INTRO
 * @uses FEATURE_COMPLETION_TRACKS_VIEWS
 * @uses FEATURE_GRADE_HAS_GRADE
 * @uses FEATURE_GRADE_OUTCOMES
 * @param string $feature FEATURE_xx constant for requested feature
 * @return mixed True if module supports feature, null if doesn't know
 */
function feedback_supports($feature) {
    switch($feature) {
        case FEATURE_GROUPS:                  return true;
        case FEATURE_GROUPINGS:               return true;
        case FEATURE_GROUPMEMBERSONLY:        return true;
        case FEATURE_MOD_INTRO:               return true;
        case FEATURE_COMPLETION_TRACKS_VIEWS: return true;
        case FEATURE_GRADE_HAS_GRADE:         return false;
        case FEATURE_GRADE_OUTCOMES:          return false;
        case FEATURE_BACKUP_MOODLE2:          return true;

        default: return null;
    }
}

/**
 * this will create a new instance and return the id number
 * of the new instance.
 *
 * @global object
 * @param object $feedback the object given by mod_feedback_mod_form
 * @return int
 */
function feedback_add_instance($feedback) {
    global $DB;

    $feedback->timemodified = time();
    $feedback->id = '';

    //check if openenable and/or closeenable is set and set correctly to save in db
    if(empty($feedback->openenable)) {
        $feedback->timeopen = 0;
    }
    if(empty($feedback->closeenable)) {
        $feedback->timeclose = 0;
    }
    if(empty($feedback->site_after_submit)) {
        $feedback->site_after_submit = '';
    }

    //saving the feedback in db
    $feedbackid = $DB->insert_record("feedback", $feedback);

    $feedback->id = $feedbackid;

    feedback_set_events($feedback);

    return $feedbackid;
}

/**
 * this will update a given instance
 *
 * @global object
 * @param object $feedback the object given by mod_feedback_mod_form
 * @return boolean
 */
function feedback_update_instance($feedback) {
    global $DB;

    $feedback->timemodified = time();
    $feedback->id = $feedback->instance;

    //check if openenable and/or closeenable is set and set correctly to save in db
    if(empty($feedback->openenable)) {
        $feedback->timeopen = 0;
    }
    if(empty($feedback->closeenable)) {
        $feedback->timeclose = 0;
    }
    if(empty($feedback->site_after_submit)) {
        $feedback->site_after_submit = '';
    }

    //save the feedback into the db
    $DB->update_record("feedback", $feedback);

    //create or update the new events
    feedback_set_events($feedback);

    return true;
}

/**
 * Serves the files included in feedback items like label. Implements needed access control ;-)
 *
 * @param object $course
 * @param object $cminfo
 * @param object $context
 * @param string $filearea
 * @param array $args
 * @param bool $forcedownload
 * @return bool false if file not found, does not return if found - justsend the file
 */
function feedback_pluginfile($course, $cminfo, $context, $filearea, $args, $forcedownload) {
    global $CFG, $DB;

    if (!$cminfo->uservisible) {
        return false;
    }
    
    if($filearea === 'feedback_template') {
        $usedcontext = get_context_instance(CONTEXT_COURSE, $course->id);
    }else {
        $usedcontext = $context;
    }

    if ($filearea === 'feedback_item' OR $filearea === 'feedback_template') {
        $itemid = (int)array_shift($args);

        if (!$cm = get_coursemodule_from_instance('feedback', $cminfo->instance, $course->id)) {
            return false;
        }

        require_course_login($course, true, $cm);

        if (!$item = $DB->get_record('feedback_item', array('id'=>$itemid))) {
            return false;
        }

        if (!$feedback = $DB->get_record('feedback', array('id'=>$cminfo->instance))) {
            return false;
        }

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

        if ($item->feedback == $cminfo->instance) {
            $filecontext = $usedcontext;
        } else {
            return false;
        }

        $relativepath = '/'.implode('/', $args);
        $fullpath = $filecontext->id.$filearea.$itemid.$relativepath;

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

        // finally send the file
        send_stored_file($file, 0, 0, true); // download MUST be forced - security!
    }

    return false;
}


/**
 * this will delete a given instance.
 * all referenced data also will be deleted
 *
 * @global object
 * @param int $id the instanceid of feedback
 * @return boolean
 */
function feedback_delete_instance($id) {
    global $DB;

    //get all referenced items
    $feedbackitems = $DB->get_records('feedback_item', array('feedback'=>$id));

    //deleting all referenced items and values
    if (is_array($feedbackitems)){
        foreach($feedbackitems as $feedbackitem){
            $DB->delete_records("feedback_value", array("item"=>$feedbackitem->id));
            $DB->delete_records("feedback_valuetmp", array("item"=>$feedbackitem->id));
        }
        if($delitems = $DB->get_records("feedback_item", array("feedback"=>$id))) {
            foreach($delitems as $delitem) {
                feedback_delete_item($delitem->id, false);
            }
        }
    }

    //deleting the referenced tracking data
    $DB->delete_records('feedback_tracking', array('feedback'=>$id));

    //deleting the completeds
    $DB->delete_records("feedback_completed", array("feedback"=>$id));

    //deleting the unfinished completeds
    $DB->delete_records("feedback_completedtmp", array("feedback"=>$id));

    //deleting old events
    $DB->delete_records('event', array('modulename'=>'feedback', 'instance'=>$id));
    return $DB->delete_records("feedback", array("id"=>$id));
}

/**
 * this is called after deleting all instances if the course will be deleted.
 * only templates have to be deleted
 *
 * @global object
 * @param object $course
 * @return boolean
 */
function feedback_delete_course($course) {
    global $DB;

    //delete all templates of given course
    return $DB->delete_records('feedback_template', array('course'=>$course->id));
}

/**
 * Return 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
 *
 * @param object $course
 * @param object $user
 * @param object $mod
 * @param object $feedback
 * @return object
 */
function feedback_user_outline($course, $user, $mod, $feedback) {
    return null;
}

/**
 * Returns all users who has completed a specified feedback since a given time
 * many thanks to Manolescu Dorel, who contributed these two functions
 *
 * @global object
 * @global object
 * @global object
 * @global object
 * @uses CONTEXT_MODULE
 * @param array $activities Passed by reference
 * @param int $index Passed by reference
 * @param int $timemodified Timestamp
 * @param int $courseid
 * @param int $cmid
 * @param int $userid
 * @param int $groupid
 * @return void
 */
function feedback_get_recent_mod_activity(&$activities, &$index, $timemodified, $courseid, $cmid, $userid="", $groupid="")  {
    global $CFG, $COURSE, $USER, $DB;

    if ($COURSE->id == $courseid) {
        $course = $COURSE;
    } else {
        $course = $DB->get_record('course', array('id'=>$courseid));
    }

    $modinfo =& get_fast_modinfo($course);

    $cm = $modinfo->cms[$cmid];
    
    $sqlargs = array();

    $sql = " SELECT fk . * , fc . * , u.firstname, u.lastname, u.email, u.picture
                                            FROM {feedback_completed} fc
                                                JOIN {feedback} fk ON fk.id = fc.feedback
                                                JOIN {user} u ON u.id = fc.userid ";

    if ($groupid) {
        $sql .= " JOIN {groups_members} gm ON  gm.userid=u.id ";
    }
    
    $sql .= " WHERE fc.timemodified > ? AND fk.id = ? ";
    $sqlargs[] = $timemodified;
    $sqlargs[] = $cm->instace;

    if ($userid) {
        $sql .= " AND u.id = ? ";
        $sqlargs[] = $userid;
    }

    if ($groupid) {
        $sql .= " AND gm.groupid = ? ";
        $sqlargs[] = $groupid;
    }
    
    if (!$feedbackitems = $DB->get_records_sql($sql, $sqlargs)) {
        return;
    }

    $cm_context      = get_context_instance(CONTEXT_MODULE, $cm->id);
    $accessallgroups = has_capability('moodle/site:accessallgroups', $cm_context);
    $viewfullnames   = has_capability('moodle/site:viewfullnames', $cm_context);
    $groupmode       = groups_get_activity_groupmode($cm, $course);

    if (is_null($modinfo->groups)) {
        $modinfo->groups = groups_get_user_groups($course->id); // load all my groups and cache it in modinfo
    }

    $aname = format_string($cm->name,true);
    foreach ($feedbackitems as $feedbackitem) {
        if ($feedbackitem->userid != $USER->id) {

            if ($groupmode == SEPARATEGROUPS and !$accessallgroups) {
                $usersgroups = groups_get_all_groups($course->id, $feedbackitem->userid, $cm->groupingid);
                if (!is_array($usersgroups)) {
                    continue;
                }
                $usersgroups = array_keys($usersgroups);
                $interset = array_intersect($usersgroups, $modinfo->groups[$cm->id]);
                if (empty($intersect)) {
                    continue;
                }
            }
       }

        $tmpactivity = new object();

        $tmpactivity->type      = 'feedback';
        $tmpactivity->cmid      = $cm->id;
        $tmpactivity->name      = $aname;
        $tmpactivity->sectionnum= $cm->sectionnum;
        $tmpactivity->timestamp = $feedbackitem->timemodified;

        $tmpactivity->content->feedbackid = $feedbackitem->id;
        $tmpactivity->content->feedbackuserid = $feedbackitem->userid;

        $tmpactivity->user->userid   = $feedbackitem->userid;
        $tmpactivity->user->fullname = fullname($feedbackitem, $viewfullnames);
        $tmpactivity->user->picture  = $feedbackitem->picture;

        $activities[$index++] = $tmpactivity;
    }

  return;
}

/**
 * Prints all users who has completed a specified feedback since a given time
 * many thanks to Manolescu Dorel, who contributed these two functions
 *
 * @global object
 * @param object $activity
 * @param int $courseid
 * @param string $detail
 * @param array $modnames
 * @return void Output is echo'd
 */
function feedback_print_recent_mod_activity($activity, $courseid, $detail, $modnames) {
    global $CFG, $OUTPUT;

    echo '<table border="0" cellpadding="3" cellspacing="0" class="forum-recent">';

    echo "<tr><td class=\"userpicture\" valign=\"top\">";
    echo $OUTPUT->user_picture($activity->user, array('courseid'=>$courseid));
    echo "</td><td>";

    if ($detail) {
        $modname = $modnames[$activity->type];
        echo '<div class="title">';
        echo "<img src=\"" . $OUTPUT->pix_url('icon', $activity->type) . "\" ".
             "class=\"icon\" alt=\"$modname\" />";
        echo "<a href=\"$CFG->wwwroot/mod/feedback/view.php?id={$activity->cmid}\">{$activity->name}</a>";
        echo '</div>';
    }

    echo '<div class="title">';
    echo '</div>';

    echo '<div class="user">';
    echo "<a href=\"$CFG->wwwroot/user/view.php?id={$activity->user->userid}&amp;course=$courseid\">"
         ."{$activity->user->fullname}</a> - ".userdate($activity->timestamp);
    echo '</div>';

    echo "</td></tr></table>";

    return;
}


/**
 * Print a detailed representation of what a  user has done with
 * a given particular instance of this module, for user activity reports.
 *
 * @param object $course
 * @param object $user
 * @param object $mod
 * @param object $feedback
 * @return bool
 */
function feedback_user_complete($course, $user, $mod, $feedback) {
    return true;
}

/**
 * @return bool true
 */
function feedback_cron () {
    return true;
}

/**
 * @return bool false
 */
function feedback_get_participants($feedbackid) {
    return false;
}


/**
 * @return bool false
 */
function feedback_scale_used ($feedbackid,$scaleid) {
    return false;
}

/**
 * This function is used by the reset_course_userdata function in moodlelib.
 * This function will remove all responses from the specified feedback
 * and clean up any related data.
 *
 * @global object
 * @global object
 * @uses FEEDBACK_RESETFORM_RESET
 * @uses FEEDBACK_RESETFORM_DROP
 * @param object $data the data submitted from the reset course.
 * @return array status array
 */
function feedback_reset_userdata($data) {
    global $CFG, $DB;

    $resetfeedbacks = array();
    $dropfeedbacks = array();
    $status = array();
    $componentstr = get_string('modulenameplural', 'feedback');

    //get the relevant entries from $data
    foreach($data as $key => $value) {
        switch(true) {
            case substr($key, 0, strlen(FEEDBACK_RESETFORM_RESET)) == FEEDBACK_RESETFORM_RESET:
                if($value == 1) {
                    $templist = explode('_', $key);
                    if(isset($templist[3]))$resetfeedbacks[] = intval($templist[3]);
                }
            break;
            case substr($key, 0, strlen(FEEDBACK_RESETFORM_DROP)) == FEEDBACK_RESETFORM_DROP:
                if($value == 1) {
                    $templist = explode('_', $key);
                    if(isset($templist[3]))$dropfeedbacks[] = intval($templist[3]);
                }
            break;
        }
    }

    //reset the selected feedbacks
    foreach($resetfeedbacks as $id) {
        $feedback = $DB->get_record('feedback', array('id'=>$id));
        feedback_delete_all_completeds($id);
        $status[] = array('component'=>$componentstr.':'.$feedback->name, 'item'=>get_string('resetting_data','feedback'), 'error'=>false);
    }

    //drop the selected feedbacks
    // foreach($dropfeedbacks as $id) {
        // $cm = get_coursemodule_from_instance('feedback', $id);
        // feedback_delete_instance($id);
        // feedback_delete_course_module($cm->id);
        // $status[] = array('component'=>$componentstr, 'item'=>get_string('drop_feedback','feedback'), 'error'=>false);
    // }
    return $status;
}

/**
 * Called by course/reset.php
 *
 * @global object
 * @uses FEEDBACK_RESETFORM_RESET
 * @param object $mform form passed by reference
 */
function feedback_reset_course_form_definition(&$mform) {
    global $COURSE, $DB;

    $mform->addElement('header', 'feedbackheader', get_string('modulenameplural', 'feedback'));

    if(!$feedbacks = $DB->get_records('feedback', array('course'=>$COURSE->id), 'name')){
        return;
    }

    $mform->addElement('static', 'hint', get_string('resetting_data','feedback'));
    foreach($feedbacks as $feedback) {
        $mform->addElement('checkbox', FEEDBACK_RESETFORM_RESET.$feedback->id, $feedback->name);
        // $mform->addElement('checkbox', FEEDBACK_RESETFORM_DROP.$feedback->id, get_string('drop_feedback','feedback'));
    }
}

/**
 * Course reset form defaults.
 *
 * @global object
 * @uses FEEDBACK_RESETFORM_RESET
 * @param object $course
 */
function feedback_reset_course_form_defaults($course) {
    global $DB;

    $return = array();
    if(!$feedbacks = $DB->get_records('feedback', array('course'=>$course->id), 'name')){
        return;
    }
    foreach($feedbacks as $feedback) {
        $return[FEEDBACK_RESETFORM_RESET.$feedback->id] = true;
        // $return[FEEDBACK_RESETFORM_DROP.$feedback->id] = false;
    }
    return $return;
}

/**
 * Called by course/reset.php and shows the formdata by coursereset.
 * it prints checkboxes for each feedback available at the given course
 * there are two checkboxes: 1) delete userdata and keep the feedback 2) delete userdata and drop the feedback
 *
 * @global object
 * @uses FEEDBACK_RESETFORM_RESET
 * @uses FEEDBACK_RESETFORM_DROP
 * @param object $course
 * @return void
 */
function feedback_reset_course_form($course) {
    global $DB, $OUTPUT;

    echo get_string('resetting_feedbacks', 'feedback'); echo ':<br />';
    if (!$feedbacks = $DB->get_records('feedback', array('course'=>$course->id), 'name')) {
        return;
    }

    foreach($feedbacks as $feedback) {
        echo '<p>';
        echo get_string('name','feedback').': '.$feedback->name.'<br />';
        echo html_writer::checkbox(FEEDBACK_RESETFORM_RESET.$feedback->id, 1, true, get_string('resetting_data','feedback'));
        echo '<br />';
        echo html_writer::checkbox(FEEDBACK_RESETFORM_DROP.$feedback->id, 1, false, get_string('drop_feedback','feedback'));
        echo '</p>';
    }
}

/**
 * This creates new events given as timeopen and closeopen by $feedback.
 *
 * @global object
 * @param object $feedback
 * @return void
 */
function feedback_set_events($feedback) {
    global $DB;

    // adding the feedback to the eventtable (I have seen this at quiz-module)
    $DB->delete_records('event', array('modulename'=>'feedback', 'instance'=>$feedback->id));

    if (!isset($feedback->coursemodule)) {
        $cm = get_coursemodule_from_id('feedback', $feedback->id);
        $feedback->coursemodule = $cm->id;
    }

    // the open-event
    if($feedback->timeopen > 0) {
        $event = NULL;
        $event->name         = get_string('start', 'feedback').' '.$feedback->name;
        $event->description  = format_module_intro('feedback', $feedback, $feedback->coursemodule);
        $event->courseid     = $feedback->course;
        $event->groupid      = 0;
        $event->userid       = 0;
        $event->modulename   = 'feedback';
        $event->instance     = $feedback->id;
        $event->eventtype    = 'open';
        $event->timestart    = $feedback->timeopen;
        $event->visible      = instance_is_visible('feedback', $feedback);
        if($feedback->timeclose > 0) {
            $event->timeduration = ($feedback->timeclose - $feedback->timeopen);
        } else {
            $event->timeduration = 0;
        }

        calendar_event::create($event);
    }

    // the close-event
    if($feedback->timeclose > 0) {
        $event = NULL;
        $event->name         = get_string('stop', 'feedback').' '.$feedback->name;
        $event->description  = format_module_intro('feedback', $feedback, $feedback->coursemodule);
        $event->courseid     = $feedback->course;
        $event->groupid      = 0;
        $event->userid       = 0;
        $event->modulename   = 'feedback';
        $event->instance     = $feedback->id;
        $event->eventtype    = 'close';
        $event->timestart    = $feedback->timeclose;
        $event->visible      = instance_is_visible('feedback', $feedback);
        $event->timeduration = 0;

        calendar_event::create($event);
    }
}

/**
 *  this function is called by {@link feedback_delete_userdata()}
 *  it drops the feedback-instance from the course_module table
 *
 * @global object
 *  @param int $id the id from the coursemodule
 *  @return boolean
 */
function feedback_delete_course_module($id) {
    global $DB;

    if (!$cm = $DB->get_record('course_modules', array('id'=>$id))) {
        return true;
    }
    return $DB->delete_records('course_modules', array('id'=>$cm->id));
}


////////////////////////////////////////////////
//functions to handle capabilities
////////////////////////////////////////////////

/**
 *  returns the context-id related to the given coursemodule-id
 *
 * @staticvar object $context
 *  @param int $cmid the coursemodule-id
 *  @return object $context
 */
function feedback_get_context($cmid) {
    static $context;

    if(isset($context)) return $context;

    if (!$context = get_context_instance(CONTEXT_MODULE, $cmid)) {
            print_error('badcontext');
    }
    return $context;
}

/**
 *  returns true if the current role is faked by switching role feature
 *
 * @global object
 *  @return boolean
 */
function feedback_check_is_switchrole(){
    global $USER;
    if(isset($USER->switchrole) AND is_array($USER->switchrole) AND count($USER->switchrole) > 0) {
        return true;
    }
    return false;
}

/**
 * count users which have the completed a feedback
 *
 * @global object
 * @uses CONTEXT_MODULE
 * @param object $cm
 * @param int $group single groupid
 * @return object the userrecords
 */
function feedback_count_complete_users($cm, $group = false) {
    global $DB;

    $params = array(FEEDBACK_ANONYMOUS_NO, $cm->instance);

    $fromgroup = '';
    $wheregroup = '';
    if($group) {
        $fromgroup = ', {groups_members} g';
        $wheregroup = ' AND g.groupid = ? AND g.userid = c.userid';
        $params[] = $group;
    }
    
    $sql = 'SELECT COUNT(u.id) FROM {user} u, {feedback_completed} c'.$fromgroup.'
              WHERE anonymous_response = ? AND u.id = c.userid AND c.feedback = ?
              '.$wheregroup;
              ;
              
    return $DB->count_records_sql($sql, $params);

}

/**
 * get users which have the completed a feedback
 *
 * @global object
 * @uses CONTEXT_MODULE
 * @param object $cm
 * @param int $group single groupid
 * @param string $sort a table field
 * @return object the userrecords
 */
function feedback_get_complete_users($cm, $group = false, $where, $sort = '', $startpage = false, $pagecount = false) {
    global $DB;

    if (!$context = get_context_instance(CONTEXT_MODULE, $cm->id)) {
            print_error('badcontext');
    }

    $params = array(FEEDBACK_ANONYMOUS_NO, $cm->instance);

    $fromgroup = '';
    $wheregroup = '';
    if($group) {
        $fromgroup = ', {groups_members} g';
        $wheregroup = ' AND g.groupid = ? AND g.userid = c.userid';
        $params[] = $group;
    }
    
    if($sort) {
        $sortsql = ' ORDER BY '.$sort;
    }else {
        $sortsql = '';
    }
    
    $sql = 'SELECT DISTINCT u.* FROM {user} u, {feedback_completed} c'.$fromgroup.'
              WHERE '.$where.' anonymous_response = ? AND u.id = c.userid AND c.feedback = ?
              '.$wheregroup.$sortsql;
              ;
              
    if($startpage === false OR $pagecount === false) {
        $startpage = false;
        $pagecount = false;
    }
    return $DB->get_records_sql($sql, $params, $startpage, $pagecount);
}

/**
 * get users which have the viewreports-capability
 *
 * @uses CONTEXT_MODULE
 * @param int $cmid
 * @param mixed $groups single groupid or array of groupids - group(s) user is in
 * @return object the userrecords
 */
function feedback_get_viewreports_users($cmid, $groups = false) {

    if (!$context = get_context_instance(CONTEXT_MODULE, $cmid)) {
            print_error('badcontext');
    }

    //description of the call below: get_users_by_capability($context, $capability, $fields='', $sort='', $limitfrom='', $limitnum='', $groups='', $exceptions='', $doanything=true)
    return get_users_by_capability($context, 'mod/feedback:viewreports', '', 'lastname', '', '', $groups, '', false);
}

/**
 * get users which have the receivemail-capability
 *
 * @uses CONTEXT_MODULE
 * @param int $cmid
 * @param mixed $groups single groupid or array of groupids - group(s) user is in
 * @return object the userrecords
 */
function feedback_get_receivemail_users($cmid, $groups = false) {

    if (!$context = get_context_instance(CONTEXT_MODULE, $cmid)) {
            print_error('badcontext');
    }

    //description of the call below: get_users_by_capability($context, $capability, $fields='', $sort='', $limitfrom='', $limitnum='', $groups='', $exceptions='', $doanything=true)
    return get_users_by_capability($context, 'mod/feedback:receivemail', '', 'lastname', '', '', $groups, '', false);
}

////////////////////////////////////////////////
//functions to handle the templates
////////////////////////////////////////////////
////////////////////////////////////////////////

/**
 * creates a new template-record.
 *
 * @global object
 * @param int $courseid
 * @param string $name the name of template shown in the templatelist
 * @param int $ispublic 0:privat 1:public
 * @return int the new templateid
 */
function feedback_create_template($courseid, $name, $ispublic = 0) {
    global $DB;

    $templ = new object();
    $templ->course   = $courseid;
    $templ->name     = $name;
    $templ->ispublic = $ispublic;

    $templid = $DB->insert_record('feedback_template', $templ);
    return $DB->get_record('feedback_template', array('id'=>$templid));
}

/**
 * creates new template items.
 * all items will be copied and the attribute feedback will be set to 0
 * and the attribute template will be set to the new templateid
 *
 * @global object
 * @param object $feedback
 * @param string $name the name of template shown in the templatelist
 * @param int $ispublic 0:privat 1:public
 * @return boolean
 */
function feedback_save_as_template($feedback, $name, $ispublic = 0) {
    global $DB;
    $fs = get_file_storage();

    if (!$feedbackitems = $DB->get_records('feedback_item', array('feedback'=>$feedback->id))) {
        return false;
    }

    if (!$newtempl = feedback_create_template($feedback->course, $name, $ispublic)) {
        return false;
    }
    
    //files in the template_item are in the context of the current course
    //files in the feedback_item are in the feedback_context of the feedback
    $c_context = get_context_instance(CONTEXT_COURSE, $newtempl->course);
    $cm = get_coursemodule_from_instance('feedback', $feedback->id);
    $f_context = get_context_instance(CONTEXT_MODULE, $cm->id);
    
    //create items of this new template
    foreach($feedbackitems as $item) {
        $t_item = clone($item);
        
        unset($t_item->id);
        $t_item->feedback = 0;
        $t_item->template     = $newtempl->id;
        $t_item->id = $DB->insert_record('feedback_item', $t_item);
        //copy all included files to the feedback_template filearea
        if ($itemfiles = $fs->get_area_files($f_context->id, 'feedback_item', $item->id, "id", false)) {
            foreach($itemfiles as $ifile) {
                $file_record = new object();
                $file_record->contextid = $c_context->id;
                $file_record->filearea = 'course_summary';
                $file_record->itemid = $t_item->id;
                $fs->create_file_from_storedfile($file_record, $ifile);
            }
        }
    }
    return true;
}

/**
 * deletes all feedback_items related to the given template id
 *
 * @global object
 * @param int $id the templateid
 * @return void
 */
function feedback_delete_template($id) {
    global $DB;

    $template = $DB->get_record("feedback_template", array("id"=>$id));

    //deleting the files from the item
    $fs = get_file_storage();
    $context = get_context_instance(CONTEXT_COURSE, $template->course);
    

    if($t_items = $DB->get_records("feedback_item", array("template"=>$id))) {
        foreach($t_items as $t_item) {
            if ($templatefiles = $fs->get_area_files($context->id, 'course_summary', $t_item->id, "id", false)) {
                $fs->delete_area_files($context->id, 'course_summary', $t_item->id);
            }
        }
    }
    $DB->delete_records("feedback_template", array("id"=>$id));
}

/**
 * creates new feedback_item-records from template.
 * if $deleteold is set true so the existing items of the given feedback will be deleted
 * if $deleteold is set false so the new items will be appanded to the old items
 *
 * @global object
 * @param object $feedback
 * @param int $templateid
 * @param boolean $deleteold
 */
function feedback_items_from_template($feedback, $templateid, $deleteold = false) {
    global $DB;
    $fs = get_file_storage();

    //get all templateitems
    if(!$templitems = $DB->get_records('feedback_item', array('template'=>$templateid))) {
        return false;
    }

    //files in the template_item are in the context of the current course
    //files in the feedback_item are in the feedback_context of the feedback
    $c_context = get_context_instance(CONTEXT_COURSE, $feedback->course);
    $cm = get_coursemodule_from_instance('feedback', $feedback->id);
    $f_context = get_context_instance(CONTEXT_MODULE, $cm->id);

    //if deleteold then delete all old items before
    //get all items
    if($deleteold) {
        if($feedbackitems = $DB->get_records('feedback_item', array('feedback'=>$feedback->id))) {
            //delete all items of this feedback
            foreach($feedbackitems as $item) {
                feedback_delete_item($item->id, false);
            }
            //delete tracking-data
            $DB->delete_records('feedback_tracking', array('feedback'=>$feedback->id));
            $DB->delete_records('feedback_completed', array('feedback'=>$feedback->id));
            $DB->delete_records('feedback_completedtmp', array('feedback'=>$feedback->id));
        }
        $positionoffset = 0;
    } else {
        //if the old items are kept the new items will be appended
        //therefor the new position has an offset
        $positionoffset = $DB->count_records('feedback_item', array('feedback'=>$feedback->id));
    }

    foreach($templitems as $t_item) {
        $item = clone($t_item);
        unset($item->id);
        $item->feedback = $feedback->id;
        $item->template = 0;
        $item->position = $item->position + $positionoffset;

        $item->id = $DB->insert_record('feedback_item', $item);
        
        //TODO: moving the files to the new items
        if ($templatefiles = $fs->get_area_files($c_context->id, 'course_summary', $t_item->id, "id", false)) {
            foreach($templatefiles as $tfile) {
                $file_record = new object();
                $file_record->contextid = $f_context->id;
                $file_record->filearea = 'feedback_item';
                $file_record->itemid = $item->id;
                $fs->create_file_from_storedfile($file_record, $tfile);
            }
        }
    }
}

/**
 * get the list of available templates.
 * if the $onlyown param is set true so only templates from own course will be served
 * this is important for droping templates
 *
 * @global object
 * @param object $course
 * @param boolean $onlyown
 * @return array the template recordsets
 */
function feedback_get_template_list($course, $onlyown = false) {
    global $DB;

    if ($onlyown) {
        $templates = $DB->get_records('feedback_template', array('course'=>$course->id));
    } else {
        $templates = $DB->get_records_select('feedback_template', 'course = ? OR ispublic = 1', array($course->id));
    }
    return $templates;
}

////////////////////////////////////////////////
//Handling der Items
////////////////////////////////////////////////
////////////////////////////////////////////////

/**
 * load the available item plugins from given subdirectory of $CFG->dirroot
 * the default is "mod/feedback/item"
 *
 * @global object
 * @param string $dir the subdir
 * @return array pluginnames as string
 */
function feedback_load_feedback_items($dir = 'mod/feedback/item') {
    global $CFG;
    $names =get_list_of_plugins($dir);
    $ret_names = array();

    foreach($names as $name) {
        require_once($CFG->dirroot.'/'.$dir.'/'.$name.'/lib.php');
        if(class_exists('feedback_item_'.$name)) {
          $ret_names[] = $name;
        }
    }
    return $ret_names;
}

/**
 * load the available item plugins to use as dropdown-options
 *
 * @global object
 * @return array pluginnames as string
 */
function feedback_load_feedback_items_options() {
    global $CFG;

    $feedback_options = array("pagebreak" => get_string('add_pagebreak', 'feedback'));

    if (!$feedback_names = feedback_load_feedback_items('mod/feedback/item')) {
        return array();
    }

    foreach($feedback_names as $fn) {
        $feedback_options[$fn] = get_string($fn,'feedback');
    }
    asort($feedback_options);
    $feedback_options = array_merge( array(' ' => get_string('select')), $feedback_options );
    return $feedback_options;
}

/**
 * creates a new item-record
 *
 * @global object
 * @param object $data the data from edit_item_form
 * @return int the new itemid
 */
function feedback_create_item($data) {
    global $DB;

    $item = new object;
    $item->feedback = $data->feedbackid;

    $item->template=0;
    if (isset($data->templateid)) {
            $item->template = intval($data->templateid);
    }

    $itemname = trim($data->itemname);
    $item->name = ($itemname ? $data->itemname : get_string('no_itemname', 'feedback'));

    if (!empty($data->itemlabel)) {
        $item->label = trim($data->itemlabel);
    } else {
        $item->label = get_string('no_itemlabel', 'feedback');
    }

    //get the used class from item-typ
    $itemclass = 'feedback_item_'.$data->typ;
    //get the instance of the item class
    $itemobj = new $itemclass();
    // $item->presentation = $itemobj->get_presentation($data);
    $item->presentation = ''; //the date comes from postupdate() of the itemobj

    $item->hasvalue = $itemobj->get_hasvalue();

    $item->typ = $data->typ;
    $item->position = $data->position;

    $item->required=0;
    if (!empty($data->required)) {
        $item->required = $data->required;
    }

    $item->id = $DB->insert_record('feedback_item', $item);

    //move all itemdata to the data
    $data->id = $item->id;
    $data->feedback = $item->feedback;
    $data->name = $item->name;
    $data->label = $item->label;
    $data->required = $item->required;
    return $itemobj->postupdate($data);
}

/**
 * save the changes of a given item.
 *
 * @global object
 * @param object $item
 * @return boolean
 */
function feedback_update_item($item){
    global $DB;
    return $DB->update_record("feedback_item", $item);
}

/**
 * deletes a item and also deletes all related values
 *
 * @global object
 * @param int $itemid
 * @param boolean $renumber should the kept items renumbered Yes/No
 * @return void
 */
function feedback_delete_item($itemid, $renumber = true){
    global $DB;
    
    
    $item = $DB->get_record('feedback_item', array('id'=>$itemid));
    
    //deleting the files from the item
    $fs = get_file_storage();
    if (!$cm = get_coursemodule_from_instance('feedback', $item->feedback)) {
        return false;
    }
    $context = get_context_instance(CONTEXT_MODULE, $cm->id);
    
    if ($itemfiles = $fs->get_area_files($context->id, 'feedback_item', $item->id, "id", false)) {
        $fs->delete_area_files($context->id, 'feedback_item', $item->id);
    }
    
    $DB->delete_records("feedback_value", array("item"=>$itemid));
    $DB->delete_records("feedback_valuetmp", array("item"=>$itemid));
    $DB->delete_records("feedback_item", array("id"=>$itemid));
    if($renumber) {
        feedback_renumber_items($item->feedback);
    }
}

/**
 * deletes all items of the given feedbackid
 *
 * @global object
 * @param int $feedbackid
 * @return void
 */
function feedback_delete_all_items($feedbackid){
    global $DB;

    if(!$items = $DB->get_records('feedback_item', array('feedback'=>$feedbackid))) {
        return;
    }
    foreach($items as $item) {
        feedback_delete_item($item->id, false);
    }
    $DB->delete_records('feedback_completedtmp', array('feedback'=>$feedbackid));
    $DB->delete_records('feedback_completed', array('feedback'=>$feedbackid));
}

/**
 * this function toggled the item-attribute required (yes/no)
 *
 * @global object
 * @param object $item
 * @return boolean
 */
function feedback_switch_item_required($item) {
    global $DB;

    if($item->required == 1) {
        $item->required = 0;
    } else {
        $item->required = 1;
    }
    $item->name = $item->name;
    $item->presentation = $item->presentation;
    return $DB->update_record('feedback_item', $item);
}

/**
 * renumbers all items of the given feedbackid
 *
 * @global object
 * @param int $feedbackid
 * @return void
 */
function feedback_renumber_items($feedbackid){
    global $DB;

    $items = $DB->get_records('feedback_item', array('feedback'=>$feedbackid), 'position');
    $pos = 1;
    if($items) {
        foreach($items as $item){
            $item->position = $pos;
            $pos++;
            feedback_update_item($item);
        }
    }
}

/**
 * this decreases the position of the given item
 *
 * @global object
 * @param object $item
 * @return void
 */
function feedback_moveup_item($item){
    global $DB;

    if($item->position == 1) {
        return true;
    }
    
    if(!$items = $DB->get_records('feedback_item', array('feedback'=>$item->feedback), 'position')) {
        return false;
    }
    
    $itembefore = null;
    foreach($items as $i) {
        if($i->id == $item->id) {
            if(is_null($itembefore)) {
                return true;
            }
            $itembefore->position = $item->position;
            $item->position--;
            feedback_update_item($itembefore);
            feedback_update_item($item);
            feedback_renumber_items($item->feedback);
            return true;
        }
        $itembefore = $i;
    }
    return false;
}

/**
 * this increased the position of the given item
 *
 * @global object
 * @param object $item
 * @return void
 */
function feedback_movedown_item($item){
    global $DB;

    if(!$items = $DB->get_records('feedback_item', array('feedback'=>$item->feedback), 'position')) {
        return false;
    }
    
    $movedownitem = null;
    foreach($items as $i) {
        if(!is_null($movedownitem) AND $movedownitem->id == $item->id) {
            $movedownitem->position = $i->position;
            $i->position--;
            feedback_update_item($movedownitem);
            feedback_update_item($i);
            feedback_renumber_items($item->feedback);
            return true;
        }
        $movedownitem = $i;
    }
    return false;
}

/**
 * here the position of the given item will be set to the value in $pos
 *
 * @global object
 * @param object $moveitem
 * @param int $pos
 * @return boolean
 */
function feedback_move_item($moveitem, $pos){
    global $DB;

    if (!$allitems = $DB->get_records('feedback_item', array('feedback'=>$moveitem->feedback), 'position')) {
        return false;
    }
    if (is_array($allitems)) {
        $index = 1;
        foreach($allitems as $item) {
            if($index == $pos) {
                $index++;
            }
            if($item->id == $moveitem->id) {
                $moveitem->position = $pos;
                feedback_update_item($moveitem);
                continue;
            }
            $item->position = $index;
            feedback_update_item($item);
            $index++;
        }
        return true;
    }
    return false;
}

/**
 * prints the given item.
 * if $readonly is set true so the ouput only is for showing responses and not for editing or completing.
 * each item-class has an own print_item function implemented.
 *
 * @param object $item the item what we want to print out
 * @return void
 */
function feedback_print_item_preview($item){
    global $CFG;
    if($item->typ == 'pagebreak') {
        return;
    }
    //get the class of the given item-typ
    $itemclass = 'feedback_item_'.$item->typ;
    if (!class_exists($itemclass)) {
        require_once($CFG->dirroot.'/mod/feedback/item/'.$item->typ.'/lib.php');
    }
    //get the instance of the item-class
    $itemobj = new $itemclass();
    $itemobj->print_item_preview($item);
}

/**
 * prints the given item.
 * if $readonly is set true so the ouput only is for showing responses and not for editing or completing.
 * each item-class has an own print_item function implemented.
 *
 * @param object $item the item what we want to print out
 * @param mixed $value the value if $readonly is set true and we showing responses
 * @param boolean $highlightrequire if this set true and the value are false on completing so the item will be highlighted
 * @return void
 */
function feedback_print_item_complete($item, $value = false, $highlightrequire = false){
    global $CFG;
    if($item->typ == 'pagebreak') {
        return;
    }

    //get the class of the given item-typ
    $itemclass = 'feedback_item_'.$item->typ;
    if (!class_exists($itemclass)) {
        require_once($CFG->dirroot.'/mod/feedback/item/'.$item->typ.'/lib.php');
    }
    //get the instance of the item-class
    $itemobj = new $itemclass();
    $itemobj->print_item_complete($item, $value, $highlightrequire);
}

/**
 * prints the given item.
 * if $readonly is set true so the ouput only is for showing responses and not for editing or completing.
 * each item-class has an own print_item function implemented.
 *
 * @param object $item the item what we want to print out
 * @param mixed $value the value if $readonly is set true and we showing responses
 * @return void
 */
function feedback_print_item_show_value($item, $value = false){
    global $CFG;
    if($item->typ == 'pagebreak') {
        return;
    }
    
    //get the class of the given item-typ
    $itemclass = 'feedback_item_'.$item->typ;
    if (!class_exists($itemclass)) {
        require_once($CFG->dirroot.'/mod/feedback/item/'.$item->typ.'/lib.php');
    }
    //get the instance of the item-class
    $itemobj = new $itemclass();
    $itemobj->print_item_show_value($item, $value);
}

/**
 * if the user completes a feedback and there is a pagebreak so the values are saved temporary.
 * the values are saved permanently not until the user click on save button
 *
 * @global object
 * @param object $feedbackcompleted
 * @return object temporary saved completed-record
 */
function feedback_set_tmp_values($feedbackcompleted) {
    global $DB;

    //first we create a completedtmp
    $tmpcpl = new object();
    foreach($feedbackcompleted as $key => $value) {
        $tmpcpl->{$key} = $value;
    }
    // $tmpcpl = $feedbackcompleted;
    unset($tmpcpl->id);
    $tmpcpl->timemodified = time();
    $tmpcpl->id = $DB->insert_record('feedback_completedtmp', $tmpcpl);
    //get all values of original-completed
    if(!$values = $DB->get_records('feedback_value', array('completed'=>$feedbackcompleted->id))) {
        return;
    }
    foreach($values as $value) {
        unset($value->id);
        $value->completed = $tmpcpl->id;
        $DB->insert_record('feedback_valuetmp', $value);
    }
    return $tmpcpl;
}

/**
 * this saves the temporary saved values permanently
 *
 * @global object
 * @param object $feedbackcompletedtmp the temporary completed
 * @param object $feedbackcompleted the target completed
 * @param int $userid
 * @return int the id of the completed
 */
function feedback_save_tmp_values($feedbackcompletedtmp, $feedbackcompleted, $userid) {
    global $DB;

    $tmpcplid = $feedbackcompletedtmp->id;
    if(!$feedbackcompleted) {

        //first we create a completedtmp
        $newcpl = new object();
        foreach($feedbackcompletedtmp as $key => $value) {
            $newcpl->{$key} = $value;
        }

        unset($newcpl->id);
        $newcpl->userid = $userid;
        $newcpl->timemodified = time();
        $newcpl->id = $DB->insert_record('feedback_completed', $newcpl);
        //get all values of tmp-completed
        if(!$values = $DB->get_records('feedback_valuetmp', array('completed'=>$feedbackcompletedtmp->id))) {
            return false;
        }

        foreach($values as $value) {
            unset($value->id);
            $value->completed = $newcpl->id;
            $DB->insert_record('feedback_value', $value);
        }
        //drop all the tmpvalues
        $DB->delete_records('feedback_valuetmp', array('completed'=>$tmpcplid));
        $DB->delete_records('feedback_completedtmp', array('id'=>$tmpcplid));
        return $newcpl->id;

    } else {
        //first drop all existing values
        $DB->delete_records('feedback_value', array('completed'=>$feedbackcompleted->id));
        //update the current completed
        $feedbackcompleted->timemodified = time();
        $DB->update_record('feedback_completed', $feedbackcompleted);
        //save all the new values from feedback_valuetmp
        //get all values of tmp-completed
        if(!$values = $DB->get_records('feedback_valuetmp', array('completed'=>$feedbackcompletedtmp->id))) {
            return false;
        }
        foreach($values as $value) {
            unset($value->id);
            $value->completed = $feedbackcompleted->id;
            $DB->insert_record('feedback_value', $value);
        }
        //drop all the tmpvalues
        $DB->delete_records('feedback_valuetmp', array('completed'=>$tmpcplid));
        $DB->delete_records('feedback_completedtmp', array('id'=>$tmpcplid));
        return $feedbackcompleted->id;
    }
}

/**
 * deletes the given temporary completed and all related temporary values
 *
 * @global object
 * @param int $tmpcplid
 * @return void
 */
function feedback_delete_completedtmp($tmpcplid) {
    global $DB;

    $DB->delete_records('feedback_valuetmp', array('completed'=>$tmpcplid));
    $DB->delete_records('feedback_completedtmp', array('id'=>$tmpcplid));
}

////////////////////////////////////////////////
////////////////////////////////////////////////
////////////////////////////////////////////////
//functions to handle the pagebreaks
////////////////////////////////////////////////

/**
 * this creates a pagebreak.
 * a pagebreak is a special kind of item
 *
 * @global object
 * @param int $feedbackid
 * @return mixed false if there already is a pagebreak on last position or the id of the pagebreak-item
 */
function feedback_create_pagebreak($feedbackid) {
    global $DB;

    //check if there already is a pagebreak on the last position
    $lastposition = $DB->count_records('feedback_item', array('feedback'=>$feedbackid));
    if($lastposition == feedback_get_last_break_position($feedbackid)) {
        return false;
    }

    $item = new object();
    $item->feedback = $feedbackid;

    $item->template=0;

    $item->name = '';

    $item->presentation = '';
    $item->hasvalue = 0;

    $item->typ = 'pagebreak';
    $item->position = $lastposition + 1;

    $item->required=0;

    return $DB->insert_record('feedback_item', $item);
}

/**
 * get all positions of pagebreaks in the given feedback
 *
 * @global object
 * @param int $feedbackid
 * @return array all ordered pagebreak positions
 */
function feedback_get_all_break_positions($feedbackid) {
    global $DB;

    if(!$allbreaks = $DB->get_records_menu('feedback_item', array('typ'=>'pagebreak', 'feedback'=>$feedbackid), 'position', 'id, position')) return false;
    return array_values($allbreaks);
}

/**
 * get the position of the last pagebreak
 *
 * @param int $feedbackid
 * @return int the position of the last pagebreak
 */
function feedback_get_last_break_position($feedbackid) {
    if(!$allbreaks = feedback_get_all_break_positions($feedbackid)) return false;
    return $allbreaks[count($allbreaks) - 1];
}

/**
 * this returns the position where the user can continue the completing.
 *
 * @global object
 * @global object
 * @global object
 * @param int $feedbackid
 * @param int $courseid
 * @param string $guestid this id will be saved temporary and is unique
 * @return int the position to continue
 */
function feedback_get_page_to_continue($feedbackid, $courseid = false, $guestid) {
    global $CFG, $USER, $DB;

    //is there any break?

    if(!$allbreaks = feedback_get_all_break_positions($feedbackid)) return false;

    $params = array();
    if($courseid) {
        $courseselect = "fv.course_id = :courseid";
        $params['courseid'] = $courseid;
    }else {
        $courseselect = "1";
    }

    if($guestid) {
        $userselect = "AND fc.guestid = :guestid";
        $usergroup = "GROUP BY fc.guestid";
        $params['guestid'] = $guestid;
    }else {
        $userselect = "AND fc.userid = :userid";
        $usergroup = "GROUP BY fc.userid";
        $params['userid'] = $USER->id;
    }

    $sql =  "SELECT MAX(fi.position)
               FROM {feedback_completedtmp} fc, {feedback_valuetmp} fv, {feedback_item} fi
              WHERE fc.id = fv.completed
                    $userselect
                    AND fc.feedback = :feedbackid
                    AND $courseselect
                    AND fi.id = fv.item
         $usergroup";
    $params['feedbackid'] = $feedbackid;

    $lastpos = $DB->get_field_sql($sql, $params);

    //the index of found pagebreak is the searched pagenumber
    foreach($allbreaks as $pagenr => $br) {
        if($lastpos < $br) return $pagenr;
    }
    return count($allbreaks);
}

////////////////////////////////////////////////
////////////////////////////////////////////////
////////////////////////////////////////////////
//functions to handle the values
////////////////////////////////////////////////

/**
 * this saves the values of an completed.
 * if the param $tmp is set true so the values are saved temporary in table feedback_valuetmp
 * if there is already a completed and the userid is set so the values are updated
 * on all other things new value records will be created
 *
 * @global object
 * @param int $userid
 * @param boolean $tmp
 * @return mixed false on error or the completeid
 */
function feedback_save_values($usrid, $tmp = false) {
    global $DB;
    
    $completedid = optional_param('completedid', false, PARAM_INT);

    $tmpstr = $tmp ? 'tmp' : '';
    $time = time();
    $timemodified = mktime(0, 0, 0, date('m', $time),date('d', $time),date('Y', $time));

    if($usrid == 0) {
        return feedback_create_values($usrid, $timemodified, $tmp);
    }
    if(!$completedid or !$completed = $DB->get_record('feedback_completed'.$tmpstr, array('id'=>$completedid))) {
        return feedback_create_values($usrid, $timemodified, $tmp);
    }else{
        $completed->timemodified = $timemodified;
        return feedback_update_values($completed, $tmp);
    }
}

/**
 * this saves the values from anonymous user such as guest on the main-site
 *
 * @global object
 * @param string $guestid the unique guestidentifier
 * @return mixed false on error or the completeid
 */
function feedback_save_guest_values($guestid) {
    global $DB;

    $completedid = optional_param('completedid', false, PARAM_INT);
    
    $timemodified = time();
    if(!$completed = $DB->get_record('feedback_completedtmp', array('id'=>$completedid))) {
        return feedback_create_values(0, $timemodified, true, $guestid);
    }else {
        $completed->timemodified = $timemodified;
        return feedback_update_values($completed, true);
    }
}

/**
 * get the value from the given item related to the given completed.
 * the value can come as temporary or as permanently value. the deciding is done by $tmp
 *
 * @global object
 * @param int $completeid
 * @param int $itemid
 * @param boolean $tmp
 * @return mixed the value, the type depends on plugin-definition
 */
function feedback_get_item_value($completedid, $itemid, $tmp = false) {
    global $DB;

    $tmpstr = $tmp ? 'tmp' : '';
    return $DB->get_field('feedback_value'.$tmpstr, 'value', array('completed'=>$completedid, 'item'=>$itemid));
}

/**
 * this function checks the correctness of values.
 * the rules for this are implemented in the class of each item.
 * it can be the required attribute or the value self e.g. numeric.
 * the params first/lastitem are given to determine the visible range between pagebreaks.
 *
 * @global object
 * @param int $firstitem the position of firstitem for checking
 * @param int $lastitem the position of lastitem for checking
 * @return boolean
 */
function feedback_check_values($firstitem, $lastitem) {
    global $DB, $CFG;

    $feedbackid = optional_param('feedbackid', 0, PARAM_INT);

    //get all items between the first- and lastitem
    $select = "feedback = ?
                    AND position >= ?
                    AND position <= ?
                    AND hasvalue = 1";
    $params = array($feedbackid, $firstitem, $lastitem);
    if(!$feedbackitems = $DB->get_records_select('feedback_item', $select, $params)) {
        //if no values are given so no values can be wrong ;-)
        return true;
    }

    foreach($feedbackitems as $item) {
        //the name of the input field of the completeform is given in a special form:
        //<item-typ>_<item-id> eg. numeric_234
        //this is the key to get the value for the correct item
        $formvalname = $item->typ . '_' . $item->id;
    
        $value = optional_param($formvalname, NULL, PARAM_RAW);
        
        //check if the value is set
        if(is_null($value) AND $item->required == 1) {
            return false;
        }

        //get the class of the item-typ
        $itemclass = 'feedback_item_'.$item->typ;

        if (!class_exists($itemclass)) {
            require_once($CFG->dirroot.'/mod/feedback/item/'.$item->typ.'/lib.php');
        }

        //get the instance of the item-class
        $itemobj = new $itemclass();

        //now we let check the value by the item-class
        if(!$itemobj->check_value($value, $item)) {
            return false;
        }
    }
    //if no wrong values so we can return true
    return true;
}

/**
 * this function create a complete-record and the related value-records.
 * depending on the $tmp (true/false) the values are saved temporary or permanently
 *
 * @global object
 * @param int $userid
 * @param int $timemodified
 * @param boolean $tmp
 * @param string $guestid a unique identifier to save temporary data
 * @return mixed false on error or the completedid
 */
function feedback_create_values($usrid, $timemodified, $tmp = false, $guestid = false){
    global $DB;

    $feedbackid = optional_param('feedbackid', false, PARAM_INT);
    $anonymous_response = optional_param('anonymous_response', false, PARAM_INT);
    $courseid = optional_param('courseid', false, PARAM_INT);
    
    $tmpstr = $tmp ? 'tmp' : '';
    //first we create a new completed record
    $completed = new object();
    $completed->feedback           = $feedbackid;
    $completed->userid             = $usrid;
    $completed->guestid            = $guestid;
    $completed->timemodified       = $timemodified;
    $completed->anonymous_response = $anonymous_response;

    $completedid = $DB->insert_record('feedback_completed'.$tmpstr, $completed);

    $completed = $DB->get_record('feedback_completed'.$tmpstr, array('id'=>$completedid));

    //the keys are in the form like abc_xxx
    //with explode we make an array with(abc, xxx) and (abc=typ und xxx=itemnr)
    
    //get the items of the feedback
    if(!$allitems = $DB->get_records('feedback_item', array('feedback'=>$completed->feedback))) {
        return false;
    }
    foreach($allitems as $item) {
        $keyname = $item->typ.'_'.$item->id;
        $itemvalue = optional_param($keyname, NULL, PARAM_RAW);
        if(is_null($itemvalue)) {
            continue;
        }
        $value = new object();
        $value->item = $item->id;
        $value->completed = $completed->id;
        $value->course_id = $courseid;
        
        //get the class of item-typ
        $itemclass = 'feedback_item_'.$item->typ;
        
        //get the instance of item-class
        if (!class_exists($itemclass)) {
            require_once($CFG->dirroot.'/mod/feedback/item/'.$item->typ.'/lib.php');
        }
        $itemobj = new $itemclass();
        
        //the kind of values can be absolutely different so we run create_value directly by the item-class
        $value->value = $itemobj->create_value($itemvalue);
        $DB->insert_record('feedback_value'.$tmpstr, $value);
    }
    return $completed->id;
}

/**
 * this function updates a complete-record and the related value-records.
 * depending on the $tmp (true/false) the values are saved temporary or permanently
 *
 * @global object
 * @param object $completed
 * @param boolean $tmp
 * @return int the completedid
 */
function feedback_update_values($completed, $tmp = false) {
    global $DB;
    $courseid = optional_param('courseid', false, PARAM_INT);

    $tmpstr = $tmp ? 'tmp' : '';

    $DB->update_record('feedback_completed'.$tmpstr, $completed);
    //get the values of this completed
    $values = $DB->get_records('feedback_value'.$tmpstr, array('completed'=>$completed->id));

    //get the items of the feedback
    if(!$allitems = $DB->get_records('feedback_item', array('feedback'=>$completed->feedback))) {
        return false;
    }
    foreach($allitems as $item) {
        $keyname = $item->typ.'_'.$item->id;
        $itemvalue = optional_param($keyname, NULL, PARAM_RAW);
        //is the itemvalue set (could be a subset of items because pagebreak)?
        if(is_null($itemvalue)) {
            continue;
        }
        
        $newvalue = new object();
        $newvalue->item = $item->id;
        $newvalue->completed = $completed->id;
        $newvalue->course_id = $courseid;

        //get the class of item-typ
        $itemclass = 'feedback_item_'.$item->typ;
        
        //get the instance of item-class
        if (!class_exists($itemclass)) {
            require_once($CFG->dirroot.'/mod/feedback/item/'.$item->typ.'/lib.php');
        }
        $itemobj = new $itemclass();
        //the kind of values can be absolutely different so we run create_value directly by the item-class
        $newvalue->value = $itemobj->create_value($itemvalue);
        
        //check, if we have to create or update the value
        $exist = false;
        foreach($values as $value){
            if($value->item == $newvalue->item){
                $newvalue->id = $value->id;
                $exist = true;
                break;
            }
        }
        if($exist){
            $DB->update_record('feedback_value'.$tmpstr, $newvalue);
        }else {
            $DB->insert_record('feedback_value'.$tmpstr, $newvalue);
        }
    }

    return $completed->id;
}

/**
 * get the values of an item depending on the given groupid.
 * if the feedback is anonymous so the values are shuffled
 *
 * @global object
 * @global object
 * @param object $item
 * @param int $groupid
 * @param int $courseid
 * @return array the value-records
 */
function feedback_get_group_values($item, $groupid = false, $courseid = false, $ignore_empty = false){
    global $CFG, $DB;

    //if the groupid is given?
    if (intval($groupid) > 0) {
        if($ignore_empty) {
            $ignore_empty_select = "AND fbc.value != ''";
        }
        else {
            $ignore_empty_select = "";
        }
        
        $query = 'SELECT fbv .  *
                    FROM {feedback_value} fbv, {feedback_completed} fbc, {groups_members} gm
                   WHERE fbv.item = ?
                         AND fbv.completed = fbc.id
                         AND fbc.userid = gm.userid
                         '.$ignore_empty_select.'
                         AND gm.groupid = ?
                ORDER BY fbc.timemodified';
        $values = $DB->get_records_sql($query, array($item->id, $groupid));

    } else {
        if($ignore_empty) {
            $ignore_empty_select = "AND value != ''";
        }
        else {
            $ignore_empty_select = "";
        }
        
        if ($courseid) {
            $values = $DB->get_records_select('feedback_value', "item = ? AND course_id = ? ".$ignore_empty_select, array($item->id, $courseid));
        } else {
            $values = $DB->get_records_select('feedback_value', "item = ? ".$ignore_empty_select, array($item->id));
        }
    }
    if ($DB->get_field('feedback', 'anonymous', array('id'=>$item->feedback)) == FEEDBACK_ANONYMOUS_YES) {
        if(is_array($values))
            shuffle($values);
    }
    return $values;
}

/**
 * check for multiple_submit = false.
 * if the feedback is global so the courseid must be given
 *
 * @global object
 * @global object
 * @param int $feedbackid
 * @param int $courseid
 * @return boolean true if the feedback already is submitted otherwise false
 */
function feedback_is_already_submitted($feedbackid, $courseid = false) {
    global $USER, $DB;

    if (!$trackings = $DB->get_records_menu('feedback_tracking', array('userid'=>$USER->id, 'feedback'=>$feedbackid), '', 'id, completed')) {
        return false;
    }

    if($courseid) {
        $select = 'completed IN ('.implode(',',$trackings).') AND course_id = ?';
        if(!$values = $DB->get_records_select('feedback_value', $select, array($courseid))) {
            return false;
        }
    }

    return true;
}

/**
 * if the completion of a feedback will be continued eg. by pagebreak or by multiple submit so the complete must be found.
 * if the param $tmp is set true so all things are related to temporary completeds
 *
 * @global object
 * @global object
 * @global object
 * @param int $feedbackid
 * @param boolean $tmp
 * @param int $courseid
 * @param string $guestid
 * @return int the id of the found completed
 */
function feedback_get_current_completed($feedbackid, $tmp = false, $courseid = false, $guestid = false) {
    global $USER, $CFG, $DB;

    $tmpstr = $tmp ? 'tmp' : '';

    if(!$courseid) {
        if($guestid) {
            return $DB->get_record('feedback_completed'.$tmpstr, array('feedback'=>$feedbackid, 'guestid'=>$guestid));
        }else {
            return $DB->get_record('feedback_completed'.$tmpstr, array('feedback'=>$feedbackid, 'userid'=>$USER->id));
        }
    }

    $params = array();

    if ($guestid) {
        $userselect = "AND fc.guestid = :guestid";
        $params['guestid'] = $guestid;
    }else {
        $userselect = "AND fc.userid = :userid";
        $params['userid'] = $USER->id;
    }
    //if courseid is set the feedback is global. there can be more than one completed on one feedback
    $sql =  "SELECT DISTINCT fc.*
               FROM {feedback_value{$tmpstr}} fv, {feedback_completed{$tmpstr}} fc
              WHERE fv.course_id = :courseid
                    AND fv.completed = fc.id
                    $userselect
                    AND fc.feedback = :feedbackid";
    $params['courseid']   = intval($courseid);
    $params['feedbackid'] = $feedbackid;

    if (!$sqlresult = $DB->get_records_sql($sql, $params)) {
        return false;
    }
    foreach($sqlresult as $r) {
        return $DB->get_record('feedback_completed'.$tmpstr, array('id'=>$r->id));
    }
}

/**
 * get the completeds depending on the given groupid.
 *
 * @global object
 * @global object
 * @param object $feedback
 * @param int $groupid
 * @return mixed array of found completeds otherwise false
 */
function feedback_get_completeds_group($feedback, $groupid = false, $courseid = false) {
    global $CFG, $DB;

    if (intval($groupid) > 0){
        $query = "SELECT fbc.*
                    FROM {feedback_completed} fbc, {groups_members} gm
                   WHERE fbc.feedback = ?
                         AND gm.groupid = ?
                         AND fbc.userid = gm.userid";
        if ($values = $DB->get_records_sql($query, array($feedback->id, $groupid))) {
            return $values;
        } else {
            return false;
        }
    } else {
        if($courseid) {
            $query = "SELECT DISTINCT fbc.*
                        FROM {feedback_completed} fbc, {feedback_value} fbv
                        WHERE fbc.id = fbv.completed
                            AND fbc.feedback = ?
                            AND fbv.course_id = ?
                        ORDER BY random_response";
            if ($values = $DB->get_records_sql($query, array($feedback->id, $courseid))) {
                return $values;
            } else {
                return false;
            }
        }else {
            if ($values = $DB->get_records('feedback_completed', array('feedback'=>$feedback->id))) {
                return $values;
            } else {
                return false;
            }
        }
    }
}

/**
 * get the count of completeds depending on the given groupid.
 *
 * @global object
 * @global object
 * @param object $feedback
 * @param int $groupid
 * @param int $courseid
 * @return mixed count of completeds or false
 */
function feedback_get_completeds_group_count($feedback, $groupid = false, $courseid = false) {
    global $CFG, $DB;

    if ($courseid > 0 AND !$groupid <= 0) {
        $sql = "SELECT id, COUNT(item) AS ci
                  FROM {feedback_value}
                 WHERE course_id  = ?
              GROUP BY item ORDER BY ci DESC";
        if ($foundrecs = $DB->get_records_sql($sql, array($courseid))) {
            $foundrecs = array_values($foundrecs);
            return $foundrecs[0]->ci;
        }
        return false;
    }
    if($values = feedback_get_completeds_group($feedback, $groupid)) {
        return sizeof($values);
    }else {
        return false;
    }
}

/* get the own groupid.
@param object $course
@param object $cm
function feedback_get_groupid($course, $cm) {
    $groupmode = groupmode($course, $cm);

    //get groupid
    if($groupmode > 0 && !has_capability('moodle/site:doanything', get_context_instance(CONTEXT_SYSTEM))) {
        if($mygroupid = mygroupid($course->id)) {
            return $mygroupid[0]; //get the first groupid
        }
    }else {
        return false;
    }
}
 */

/**
 * deletes all completed-recordsets from a feedback.
 * all related data such as values also will be deleted
 *
 * @global object
 * @param int $feedbackid
 * @return void
 */
function feedback_delete_all_completeds($feedbackid) {
    global $DB;

    if (!$completeds = $DB->get_records('feedback_completed', array('feedback'=>$feedbackid))) {
        return;
    }
    foreach($completeds as $completed) {
        feedback_delete_completed($completed->id);
    }
}

/**
 * deletes a completed given by completedid.
 * all related data such values or tracking data also will be deleted
 *
 * @global object
 * @param int $completedid
 * @return boolean
 */
function feedback_delete_completed($completedid) {
    global $DB;

    if (!$completed = $DB->get_record('feedback_completed', array('id'=>$completedid))) {
        return false;
    }
    //first we delete all related values
    $DB->delete_records('feedback_value', array('completed'=>$completed->id));

    //now we delete all tracking data
    if($tracking = $DB->get_record('feedback_tracking', array('completed'=>$completed->id, 'feedback'=>$completed->feedback))) {
        $DB->delete_records('feedback_tracking', array('completed'=>$completed->id));
    }

    //last we delete the completed-record
    return $DB->delete_records('feedback_completed', array('id'=>$completed->id));
}

////////////////////////////////////////////////
////////////////////////////////////////////////
////////////////////////////////////////////////
//functions to handle sitecourse mapping
////////////////////////////////////////////////

/**
 * checks if the course and the feedback is in the table feedback_sitecourse_map.
 *
 * @global object
 * @param int $feedbackid
 * @param int $courseid
 * @return int the count of records
 */
function feedback_is_course_in_sitecourse_map($feedbackid, $courseid) {
    global $DB;
    return $DB->count_records('feedback_sitecourse_map', array('feedbackid'=>$feedbackid, 'courseid'=>$courseid));
}

/**
 * checks if the feedback is in the table feedback_sitecourse_map.
 *
 * @global object
 * @param int $feedbackid
 * @return boolean
 */
function feedback_is_feedback_in_sitecourse_map($feedbackid) {
    global $Db;
    return $DB->record_exists('feedback_sitecourse_map', array('feedbackid'=>$feedbackid));
}

/**
 * gets the feedbacks from table feedback_sitecourse_map.
 * this is used to show the global feedbacks on the feedback block
 * all feedbacks with the following criteria will be selected:<br />
 *
 * 1) all feedbacks which id are listed together with the courseid in sitecoursemap and<br />
 * 2) all feedbacks which not are listed in sitecoursemap
 *
 * @global object
 * @param int $courseid
 * @return array the feedback-records
 */
function feedback_get_feedbacks_from_sitecourse_map($courseid) {
    global $DB;

    //first get all feedbacks listed in sitecourse_map with named courseid
    $sql = "SELECT f.id AS id, cm.id AS cmid, f.name AS name, f.timeopen AS timeopen, f.timeclose AS timeclose
              FROM {feedback} f, {course_modules} cm, {feedback_sitecourse_map} sm, {modules} m
             WHERE f.id = cm.instance
                   AND f.course = '".SITEID."'
                   AND m.id = cm.module
                   AND m.name = 'feedback'
                   AND sm.courseid = ?
                   AND sm.feedbackid = f.id";

    if (!$feedbacks1 = $DB->get_records_sql($sql, array($courseid))) {
        $feedbacks1 = array();
    }

    //second get all feedbacks not listed in sitecourse_map
    $feedbacks2 = array();
    $sql = "SELECT f.id AS id, cm.id AS cmid, f.name AS name, f.timeopen AS timeopen, f.timeclose AS timeclose
              FROM {feedback} f, {course_modules} cm, {modules} m
             WHERE f.id = cm.instance
                   AND f.course = '".SITEID."'
                   AND m.id = cm.module
                   AND m.name = 'feedback'";
    if (!$allfeedbacks = $DB->get_records_sql($sql)) {
        $allfeedbacks = array();
    }
    foreach($allfeedbacks as $a) {
        if(!$DB->record_exists('feedback_sitecourse_map', array('feedbackid'=>$a->id))) {
            $feedbacks2[] = $a;
        }
    }

    return array_merge($feedbacks1, $feedbacks2);

}

/**
 * gets the courses from table feedback_sitecourse_map.
 *
 * @global object
 * @param int $feedbackid
 * @return array the course-records
 */
function feedback_get_courses_from_sitecourse_map($feedbackid) {
    global $DB;

    $sql = "SELECT f.id, f.courseid, c.fullname, c.shortname
              FROM {feedback_sitecourse_map} f, {course} c
             WHERE c.id = f.courseid
                   AND f.feedbackid = ?
          ORDER BY c.fullname";

    return $DB->get_records_sql($sql, array($feedbackid));

}

/**
 * removes non existing courses or feedbacks from sitecourse_map.
 * it shouldn't be called all too often
 * a good place for it could be the mapcourse.php or unmapcourse.php
 *
 * @global object
 * @return void
 */
function feedback_clean_up_sitecourse_map() {
    global $DB;

    $maps = $DB->get_records('feedback_sitecourse_map');
    foreach($maps as $map) {
        if (!$DB->get_record('course', array('id'=>$map->courseid))) {
            $DB->delete_records('feedback_sitecourse_map', array('courseid'=>$map->courseid, 'feedbackid'=>$map->feedbackid));
            continue;
        }
        if (!$DB->get_record('feedback', array('id'=>$map->feedbackid))) {
            $DB->delete_records('feedback_sitecourse_map', array('courseid'=>$map->courseid, 'feedbackid'=>$map->feedbackid));
            continue;
        }

    }
}

////////////////////////////////////////////////
////////////////////////////////////////////////
////////////////////////////////////////////////
//not relatable functions
////////////////////////////////////////////////

/**
 * prints the option items of a selection-input item (dropdownlist).
 * @param int $startval the first value of the list
 * @param int $endval the last value of the list
 * @param int $selectval which item should be selected
 * @param int $interval the stepsize from the first to the last value
 * @return void
 */
function feedback_print_numeric_option_list($startval, $endval, $selectval = '', $interval = 1){
    for($i = $startval; $i <= $endval; $i += $interval){
        if($selectval == ($i)){
            $selected = 'selected="selected"';
        }else{
            $selected = '';
        }
        echo '<option '.$selected.'>'.$i.'</option>';
    }
}

/**
 * sends an email to the teachers of the course where the given feedback is placed.
 *
 * @global object
 * @global object
 * @uses FEEDBACK_ANONYMOUS_NO
 * @uses FORMAT_PLAIN
 * @param object $cm the coursemodule-record
 * @param object $feedback
 * @param object $course
 * @param int $userid
 * @return void
 */
function feedback_send_email($cm, $feedback, $course, $userid) {
    global $CFG, $DB;

    if ($feedback->email_notification == 0) {  // No need to do anything
        return;
    }

    $user = $DB->get_record('user', array('id'=>$userid));

    if (isset($cm->groupmode) && empty($course->groupmodeforce)) {
        $groupmode =  $cm->groupmode;
    } else {
        $groupmode = $course->groupmode;
    }

    if ($groupmode == SEPARATEGROUPS) {
        $groups = $DB->get_records_sql_menu("SELECT g.name, g.id
                                               FROM {groups} g, {groups_members} m
                                              WHERE g.courseid = ?
                                                    AND g.id = m.groupid
                                                    AND m.userid = ?
                                           ORDER BY name ASC", array($course->id, $userid));
        $groups = array_values($groups);

        $teachers = feedback_get_receivemail_users($cm->id, $groups);
    } else {
        $teachers = feedback_get_receivemail_users($cm->id);
    }

    if ($teachers) {

        $strfeedbacks = get_string('modulenameplural', 'feedback');
        $strfeedback  = get_string('modulename', 'feedback');
        $strcompleted  = get_string('completed', 'feedback');
        $printusername = $feedback->anonymous == FEEDBACK_ANONYMOUS_NO ? fullname($user) : get_string('anonymous_user', 'feedback');

        foreach ($teachers as $teacher) {
            $info = new object();
            $info->username = $printusername;
            $info->feedback = format_string($feedback->name,true);
            $info->url = $CFG->wwwroot.'/mod/feedback/show_entries.php?id='.$cm->id.'&userid='.$userid.'&do_show=showentries';

            $postsubject = $strcompleted.': '.$info->username.' -> '.$feedback->name;
            $posttext = feedback_send_email_text($info, $course);
            $posthtml = ($teacher->mailformat == 1) ? feedback_send_email_html($info, $course, $cm) : '';

            if($feedback->anonymous == FEEDBACK_ANONYMOUS_NO) {
                $eventdata = new object();
                $eventdata->modulename       = 'feedback';
                $eventdata->userfrom         = $user;
                $eventdata->userto           = $teacher;
                $eventdata->subject          = $postsubject;
                $eventdata->fullmessage      = $posttext;
                $eventdata->fullmessageformat = FORMAT_PLAIN;
                $eventdata->fullmessagehtml  = $posthtml;
                $eventdata->smallmessage     = '';
                message_send($eventdata);
            }else {
                $eventdata = new object();
                $eventdata->modulename       = 'feedback';
                $eventdata->userfrom         = $teacher;
                $eventdata->userto           = $teacher;
                $eventdata->subject          = $postsubject;
                $eventdata->fullmessage      = $posttext;
                $eventdata->fullmessageformat = FORMAT_PLAIN;
                $eventdata->fullmessagehtml  = $posthtml;
                $eventdata->smallmessage     = '';
                message_send($eventdata);
            }
        }
    }
}

/**
 * sends an email to the teachers of the course where the given feedback is placed.
 *
 * @global object
 * @uses FORMAT_PLAIN
 * @param object $cm the coursemodule-record
 * @param object $feedback
 * @param object $course
 * @return void
 */
function feedback_send_email_anonym($cm, $feedback, $course) {
    global $CFG;

    if ($feedback->email_notification == 0) {             // No need to do anything
        return;
    }

    $teachers = feedback_get_receivemail_users($cm->id);

    if ($teachers) {

        $strfeedbacks = get_string('modulenameplural', 'feedback');
        $strfeedback  = get_string('modulename', 'feedback');
        $strcompleted  = get_string('completed', 'feedback');
        $printusername = get_string('anonymous_user', 'feedback');

        foreach ($teachers as $teacher) {
            $info = new object();
            $info->username = $printusername;
            $info->feedback = format_string($feedback->name,true);
            $info->url = $CFG->wwwroot.'/mod/feedback/show_entries_anonym.php?id='.$cm->id;

            $postsubject = $strcompleted.': '.$info->username.' -> '.$feedback->name;
            $posttext = feedback_send_email_text($info, $course);
            $posthtml = ($teacher->mailformat == 1) ? feedback_send_email_html($info, $course, $cm) : '';

            $eventdata = new object();
            $eventdata->modulename       = 'feedback';
            $eventdata->userfrom         = $teacher;
            $eventdata->userto           = $teacher;
            $eventdata->subject          = $postsubject;
            $eventdata->fullmessage      = $posttext;
            $eventdata->fullmessageformat = FORMAT_PLAIN;
            $eventdata->fullmessagehtml  = $posthtml;
            $eventdata->smallmessage     = '';
            message_send($eventdata);
        }
    }
}

/**
 * send the text-part of the email
 *
 * @param object $info includes some infos about the feedback you want to send
 * @param object $course
 * @return string the text you want to post
 */
function feedback_send_email_text($info, $course) {
    $posttext  = $course->shortname.' -> '.get_string('modulenameplural', 'feedback').' -> '.
                    $info->feedback."\n";
    $posttext .= '---------------------------------------------------------------------'."\n";
    $posttext .= get_string("emailteachermail", "feedback", $info)."\n";
    $posttext .= '---------------------------------------------------------------------'."\n";
    return $posttext;
}


/**
 * send the html-part of the email
 *
 * @global object
 * @param object $info includes some infos about the feedback you want to send
 * @param object $course
 * @return string the text you want to post
 */
function feedback_send_email_html($info, $course, $cm) {
    global $CFG;
    $posthtml  = '<p><font face="sans-serif">'.
                '<a href="'.$CFG->wwwroot.'/course/view.php?id='.$course->id.'">'.$course->shortname.'</a> ->'.
                '<a href="'.$CFG->wwwroot.'/mod/feedback/index.php?id='.$course->id.'">'.get_string('modulenameplural', 'feedback').'</a> ->'.
                '<a href="'.$CFG->wwwroot.'/mod/feedback/view.php?id='.$cm->id.'">'.$info->feedback.'</a></font></p>';
    $posthtml .= '<hr /><font face="sans-serif">';
    $posthtml .= '<p>'.get_string('emailteachermailhtml', 'feedback', $info).'</p>';
    $posthtml .= '</font><hr />';
    return $posthtml;
}

/**
 * print some errors to inform users about this.
 *
 * @global object
 * @return void
 */
function feedback_print_errors() {

    global $SESSION, $OUTPUT;

    feedback_init_feedback_session();

    if(empty($SESSION->feedback->errors)) {
        return;
    }

    echo $OUTPUT->box_start('generalbox errorboxcontent boxaligncenter boxwidthnormal');
    echo $OUTPUT->heading(get_string('handling_error', 'feedback'));

    echo '<p align="center"><b><font color="black"><pre>';
    print_r($SESSION->feedback->errors) . "\n";
    echo '</pre></font></b></p>';

    echo $OUTPUT->box_end();
    echo '<br /><br />';
    $SESSION->feedback->errors = array(); //remove errors
}

/**
 * @param string $url
 * @return string
 */
function feedback_encode_target_url($url) {
    if (strpos($url, '?')) {
        list($part1, $part2) = explode('?', $url, 2); //maximal 2 parts
        return $part1 . '?' . htmlentities($part2);
    } else {
        return $url;
    }
}

/**
 * Adds module specific settings to the settings block
 *
 * @param settings_navigation $settings The settings navigation object
 * @param navigation_node $feedbacknode The node to add module settings to
 */
function feedback_extend_settings_navigation(settings_navigation $settings, navigation_node $feedbacknode) {
    global $PAGE, $DB;

    if (!$context = get_context_instance(CONTEXT_MODULE, $PAGE->cm->id)) {
        print_error('badcontext');
    }

    if (has_capability('mod/feedback:edititems', $context)) {
        $questionnode = $feedbacknode->add(get_string('questions', 'feedback'));
        $questionnode->add(get_string('edit_items', 'feedback'), new moodle_url('/mod/feedback/edit.php', array('id'=>$PAGE->cm->id, 'do_show'=>'edit')));
        $questionnode->add(get_string('export_questions', 'feedback'), new moodle_url('/mod/feedback/export.php', array('id'=>$PAGE->cm->id, 'action'=>'exportfile')));
        $questionnode->add(get_string('import_questions', 'feedback'), new moodle_url('/mod/feedback/import.php', array('id'=>$PAGE->cm->id)));
        $questionnode->add(get_string('templates', 'feedback'), new moodle_url('/mod/feedback/edit.php', array('id'=>$PAGE->cm->id, 'do_show'=>'templates')));
    }

    if (has_capability('mod/feedback:viewreports', $context)) {
        $feedback = $DB->get_record('feedback', array('id'=>$PAGE->cm->instance));
        if($feedback->course == SITEID){
            $feedbacknode->add(get_string('analysis', 'feedback'), new moodle_url('/mod/feedback/analysis_course.php', array('id'=>$PAGE->cm->id, 'course'=>$PAGE->course->id,'do_show'=>'analysis')));
        }else {
            $feedbacknode->add(get_string('analysis', 'feedback'), new moodle_url('/mod/feedback/analysis.php', array('id'=>$PAGE->cm->id, 'course'=>$PAGE->course->id,'do_show'=>'analysis')));
        }

        $feedbacknode->add(get_string('show_entries', 'feedback'), new moodle_url('/mod/feedback/show_entries.php', array('id'=>$PAGE->cm->id, 'do_show'=>'showentries')));
    }
}

function feedback_init_feedback_session() {
    //initialize the feedback-Session - not nice at all!!
    global $SESSION;
    if (!empty($SESSION)) {
        if (!isset($SESSION->feedback) OR !is_object($SESSION->feedback)) {
            $SESSION->feedback = new object();
        }
    }
}