Merge branch 'main' into issue-3911issue-3911

1 files changed, 810 insertions, 0 deletions

diff --git a/lib/classes/InstituteCalendarHelper.php b/lib/classes/InstituteCalendarHelper.php
new file mode 100644
index 0000000..6c934b4
--- /dev/null
+++ b/lib/classes/InstituteCalendarHelper.php
@@ -0,0 +1,810 @@
+<?php
+
+/**
+ * InstituteCalendarHelper.php - class for institute calendar convenience functions
+ *
+ * @author      Timo Hartge <hartge@data-quest>
+ * @license     http://www.gnu.org/licenses/gpl-2.0.html GPL version 2
+ * @category    Stud.IP
+ *
+ */
+
+class InstituteCalendarHelper
+{
+    const COLUMN_DATAFIELD_ID = '69f6485f3c937766866a03d9d642ecbb';
+    const COLOR_DATAFIELD_ID = '41cda2be71fe9efd6e28b853fc0681f3';
+    const INST_DEFAULT_COLOR_DATAFIELD_ID = '0c63321a8e93b3ccc927611709248e07';
+    const DEFAULT_EVENT_COLOR = '#899ab9';
+
+    /**
+     * Returns the default calendar columns.
+     *
+     * @return array   default column names
+     */
+    private static function getDefaultColumns()
+    {
+        return [
+            1 => ['Spalte 1', 1],
+            2 => ['Spalte 2', 1],
+            3 => ['Spalte 3', 1],
+            4 => ['Spalte 4', 1],
+            5 => ['Spalte 5', 1],
+            6 => ['Spalte 6', 1]
+        ];
+    }
+
+    /**
+     * Fetches the stores columns merged with defaults.
+     *
+     * @param string $institut_id
+     * @param boolean $only_visible only return visible columns
+     *
+     * @return array column array in a fullcalender expected format
+     */
+    public static function getResourceColumns($institut_id, $only_visible = false)
+    {
+        $columns = [];
+        $inst_columns = [
+            0 => ['Sammelspalte', 1]
+        ];
+
+        $db_inst_columns = InstitutePlanColumn::findByInstitute($institut_id);
+
+        if ($db_inst_columns) {
+            foreach ($db_inst_columns as $col_info) {
+                $inst_columns[$col_info['column']] = [$col_info['name'], $col_info['visible']];
+            }
+        } else {
+            $inst_columns = array_merge($inst_columns, self::getDefaultColumns());
+        }
+        foreach ($inst_columns as $id => $info) {
+            if ($only_visible && !$info[1]) continue;
+            $columns[] = ['id' => $id, 'title' => $info[0], 'visible' => $info[1]];
+        }
+        return $columns;
+    }
+
+    /**
+     * Adds the default resource columns
+     *
+     * @param string $institut_id
+     *
+     * @return int last resource column number
+     */
+    public static function addDefaultResourceColumns($institut_id)
+    {
+        $max_col = 0;
+        foreach (self::getDefaultColumns() as $col_id => $col_info) {
+            $new_col = new InstitutePlanColumn([$institut_id, $col_id]);
+            $new_col->name = $col_info[0];
+            $new_col->visible = $col_info[1];
+            if ($new_col->store()) {
+                $max_col = $col_id;
+            }
+        }
+        return $max_col;
+    }
+
+    /**
+     * Adds a resource column
+     *
+     * @param string $institut_id
+     * @param string $name
+     * @param int $specific_column_number
+     *
+     * @return int number of affected rows
+     */
+    public static function addResourceColumn($institut_id, $name, $specific_column_number = 0)
+    {
+        $last_col = InstitutePlanColumn::getLastColumnOfInstitute($institut_id);
+        if ($last_col !== null) {
+            $max_col = $last_col->column;
+        } else {
+            $max_col = self::addDefaultResourceColumns($institut_id);
+        }
+        $column_number = $specific_column_number>0?$specific_column_number:intval($max_col)+1;
+        $new_col = new InstitutePlanColumn([$institut_id, $column_number]);
+        $new_col->name = $name;
+        $new_col->visible = 1;
+        return $new_col->store();
+    }
+
+    /**
+     * Looks up column id for course events
+     *
+     * @param Course $course
+     *
+     * @return array course events with column id
+     */
+    public static function getCourseEventcolumns(Course $course)
+    {
+        $df = DatafieldEntryModel::findByModel($course, self::COLUMN_DATAFIELD_ID);
+        if ($df[0] && $df[0]->content) {
+            $event_columns = unserialize($df[0]->content);
+        } else {
+            $event_columns = [];
+        }
+        return $event_columns;
+    }
+
+    /**
+     * Sets the column id for course events
+     *
+     * @param Course $course
+     * @param string $event_id SeminarCycleDate id
+     * @param string $institut_id
+     * @param string $column number of the column
+     *
+     * @return bool stored
+     */
+    public static function setCourseEventcolumn($course, $event_id, $institut_id, $column)
+    {
+        $df = DatafieldEntryModel::findByModel($course, self::COLUMN_DATAFIELD_ID);
+        if ($df[0]) {
+            $event_columns = self::getCourseEventcolumns($course);
+            if (!is_array($event_columns[$event_id])) {
+                unset($event_columns[$event_id]);
+            }
+            $event_columns[$event_id][$institut_id] = $column;
+            $df[0]->content = serialize($event_columns);
+            return $df[0]->store();
+        }
+        return false;
+    }
+
+    /**
+     * Looks up color value for course events
+     *
+     * @param Course $course
+     *
+     * @return array course events with color value
+     */
+    public static function getCourseEventcolors($course)
+    {
+        $df = DatafieldEntryModel::findByModel($course, self::COLOR_DATAFIELD_ID);
+        if ($df[0] && $df[0]->content) {
+            $event_colors = unserialize($df[0]->content);
+        } else {
+            $event_colors = [];
+        }
+        return $event_colors;
+    }
+
+    /**
+     * Sets color value for course events
+     *
+     * @param Course $course
+     * @param string $event_id SeminarCycleDate id
+     * @param string $institut_id
+     * @param string $color colorcode
+     *
+     * @return bool stored
+     */
+    public static function setCourseEventcolor($course, $event_id, $institut_id, $color)
+    {
+        $df = DatafieldEntryModel::findByModel($course, self::COLOR_DATAFIELD_ID);
+        if ($df[0]) {
+            $event_colors = self::getCourseEventcolors($course);
+            if (!is_array($event_colors[$event_id])) {
+                unset($event_colors[$event_id]);
+            }
+            $event_colors[$event_id][$institut_id] = $color;
+            $df[0]->content = serialize($event_colors);
+            return $df[0]->store();
+        }
+        return false;
+    }
+
+    /**
+     * Looks up default color value for institute course events
+     *
+     * @param SimpleORMap $context
+     *
+     * @return array course events with color value
+     */
+    public static function getInstituteDefaultEventcolors($context)
+    {
+        $df = DatafieldEntryModel::findByModel($context, self::INST_DEFAULT_COLOR_DATAFIELD_ID);
+        if ($df && $df[0]->content) {
+            $event_colors = unserialize($df[0]->content);
+        } else {
+            $event_colors = [];
+        }
+        return $event_colors;
+    }
+
+    /**
+     * Sets default institute course events color value for semtypes
+     *
+     * @param SimpleORMap $context
+     * @param string $semtype
+     * @param string $color colorcode
+     *
+     * @return bool stored
+     */
+    public static function setInstituteDefaultEventcolor($context, $semtype, $color)
+    {
+        $df = DatafieldEntryModel::findByModel($context, self::INST_DEFAULT_COLOR_DATAFIELD_ID);
+        if ($df[0]) {
+            $event_colors = self::getInstituteDefaultEventcolors($context);
+            $event_colors[$semtype['name']] = $color;
+            $df[0]->content = serialize($event_colors);
+            return $df[0]->store();
+        }
+        return false;
+    }
+
+    /**
+     * Sets color value for every course events of given courses semtype
+     *
+     * @param Course $course
+     * @param string $institut_id
+     * @param string $color colorcode
+     *
+     * @return bool stored
+     */
+    public static function setSemtypeEventcolor($course, $institut_id, $color)
+    {
+        $semtype = $course->getSemType();
+        $institut = Institute::find($institut_id);
+        if ($institut) {
+            self::setInstituteDefaultEventcolor($institut, $semtype, $color);
+        }
+        $courses = Course::findBySQL('status =? AND Institut_id=?', [$semtype['id'], $course->institut_id]);
+        if ($courses) {
+            foreach ($courses as $semtype_course) {
+                foreach (SeminarCycleDate::findBySeminar($semtype_course->seminar_id) as $cycle_date) {
+                    self::setCourseEventcolor($semtype_course, $cycle_date->id, $institut_id, $color);
+                }
+            }
+            return true;
+        }
+        return false;
+    }
+
+    /**
+     * Prepares an array of course id and names for creation of dropable calendar events
+     *
+     * @param array $courses Array of courses
+     * @param array $semester Semester
+     *
+     * @return array prepared array
+     */
+    public static function getEventlessCourses($courses, $semester = null)
+    {
+        $eventless = [];
+        foreach (array_keys($courses) as $cid) {
+            $course = Course::find($cid);
+            $cycle_dates = SeminarCycleDate::findBySeminar($course->seminar_id);
+            if (count($cycle_dates) < 1) {
+                $eventless[$cid] = $course->getFullName('number-name');
+            } elseif ($semester) {
+                $has_date_in_semester = false;
+                foreach ($cycle_dates as $cycle_date) {
+                    foreach ($cycle_date->getAllDates() as $course_date) {
+                        if ($course_date->date >= $semester->beginn && $course_date->date <= $semester->ende) {
+                            $has_date_in_semester = true;
+                            break;
+                        }
+                    }
+                    if ($has_date_in_semester) break;
+                }
+                if (!$has_date_in_semester) {
+                    $eventless[$cid] = $course->getFullName('number-name');
+                }
+            }
+        }
+        return $eventless;
+    }
+
+    /**
+     * Creates FullCalendar event date of course events
+     *
+     * @param array $courses Array of courses
+     * @param string $institut_id
+     * @param array $semester Semester
+     * @param array $specific_weekday fetch only events for specific weekday
+     *
+     * @return array fullcalendar events
+     */
+    public static function getEvents($courses, $institut_id, $semester = null, $specific_weekday = null)
+    {
+        $today = date('w');
+
+        $user_insts = array_map(function ($arr) {
+            return $arr['Institut_id'];
+        }, Institute::getMyInstitutes($GLOBALS['user']->id));
+
+        $min_time = explode(':', Config::get()->INSTITUTE_COURSE_PLAN_START_HOUR);
+        $minbigtime = (int) $min_time[0];
+        $max_time = explode(':', Config::get()->INSTITUTE_COURSE_PLAN_END_HOUR);
+        $maxbigtime = (int) $max_time[0];
+
+        $institut = Institute::find($institut_id);
+
+        if (!$institut) {
+            return [];
+        }
+
+        $inst_default_colors = self::getInstituteDefaultEventcolors($institut);
+
+        $events = [];
+        Course::findEachMany(function ($course) use (
+            $courses,
+            &$events,
+            $today,
+            $minbigtime,
+            $maxbigtime,
+            $user_insts,
+            $institut_id,
+            $inst_default_colors,
+            $semester,
+            $specific_weekday
+        ) {
+            $semtype = $course->getSemType();
+
+            $event_columns = self::getCourseEventcolumns($course) ?: [];
+            $event_colors = self::getCourseEventcolors($course) ?: [];
+
+            if (in_array($course->institut_id, $user_insts)) {
+                $is_editable = true;
+                $is_start_editable = !LockRules::Check($course->id, 'room_time');
+                $is_duration_editable = false;
+            } else {
+                $is_editable = false;
+                $is_start_editable = false;
+                $is_duration_editable = false;
+            }
+
+            foreach (SeminarCycleDate::findBySeminar($course->seminar_id) as $cycle_date) {
+                if ($semester) {
+                    $has_date_in_semester = false;
+                    foreach ($cycle_date->getAllDates() as $course_date) {
+                        if ($course_date->date >= $semester->beginn && $course_date->date <= $semester->ende) {
+                            $has_date_in_semester = true;
+                            break;
+                        }
+                    }
+                    if (!$has_date_in_semester) {
+                        continue;
+                    }
+                }
+
+                if (is_numeric($specific_weekday) && $specific_weekday != $cycle_date['weekday']) {
+                    continue;
+                }
+
+                $conform = true;
+
+                if ($cycle_date['weekday'] == 0) {
+                    $day_offset = 7 - $today;
+                } else {
+                    $day_offset = $cycle_date['weekday'] - $today;
+                }
+
+                $start_time = explode(':', $cycle_date['start_time']);
+                $bigtime = (int) $start_time[0];
+                if ($bigtime > $maxbigtime || $bigtime < $minbigtime) {
+                    $conform = false;
+                } elseif ($bigtime % 2) {
+                    $bigtime--;
+                }
+                $start_time = $bigtime . ':00:00';
+
+                $end_time = explode(':', $start_time);
+                $end_time[0] += 2;
+                $end_time = implode(':', $end_time);
+
+                $move_url = URLHelper::getURL('dispatch.php/admin/courseplanning/move_event');
+                $name = $course->getFullName('number-name');
+
+                if ($start_time != $cycle_date['start_time'] && $end_time != $cycle_date['end_time']) {
+                    $start = self::iso8601date(strtotime($day_offset . ' days'), $cycle_date['start_time']);
+                    $end = self::iso8601date(strtotime($day_offset . ' days'), $cycle_date['end_time']);
+                    $backgroundcolor = '#6c737a';
+                    $textcolor = '#ffffff';
+                } else {
+                    $start = self::iso8601date(strtotime($day_offset . ' days'), $start_time);
+                    $end = self::iso8601date(strtotime($day_offset . ' days'), $end_time);
+
+                    $backgroundcolor = null;
+                    if (array_key_exists($cycle_date->id, $event_colors)) {
+                        if (is_array($event_colors[$cycle_date->id]) && array_key_exists($institut_id, $event_colors[$cycle_date->id])) {
+                            $backgroundcolor = $event_colors[$cycle_date->id][$institut_id];
+                        }
+                    }
+                    if (!$backgroundcolor) {
+                        $backgroundcolor = array_key_exists($semtype['name'], $inst_default_colors)
+                            ? $inst_default_colors[$semtype['name']]
+                            : self::DEFAULT_EVENT_COLOR;
+                    }
+
+                    $textcolor = '#ffffff';
+                    if (self::calculateLuminosityRatio($backgroundcolor, $textcolor) < 3) {
+                        $textcolor = '#000000';
+                    }
+                }
+                if (!$is_editable) {
+                    $backgroundcolor = '#c4c7c9';
+                    $textcolor = '#000000';
+                }
+
+                $resource_column = '0';
+                if (array_key_exists($cycle_date->id, $event_columns)) {
+                    if (is_array($event_columns[$cycle_date->id]) && array_key_exists($institut_id, $event_columns[$cycle_date->id])) {
+                        $resource_column = $event_columns[$cycle_date->id][$institut_id];
+                    }
+                }
+
+                $events[] = [
+                    'resourceId'       => $resource_column,
+                    'id'               => $cycle_date->id,
+                    'title'            => $name,
+                    'start'            => $start,
+                    'end'              => $end,
+                    'textColor'        => $textcolor,
+                    'backgroundColor'  => $backgroundcolor,
+                    'borderColor'      => '#000',
+                    'editable'         => $is_editable,
+                    'startEditable'    => $is_start_editable,
+                    'durationEditable' => $is_duration_editable,
+                    'resourceEditable' => true,
+                    'studip_api_urls'  => ['move' => $move_url],
+                    'studip_view_urls' => ['edit' => URLHelper::getURL('dispatch.php/course/details/index/' . $cycle_date->seminar_id)],
+                    'metadate_id'      => $cycle_date->metadate_id,
+                    'course_id'        => $cycle_date->seminar_id,
+                    'tooltip'          => self::getCycleInfos($course, $cycle_date),
+                    'icon'             => $is_start_editable ? '' : 'lock-locked',
+                    'conform'          => $conform,
+                ];
+            }
+        }, array_keys($courses));
+
+        return $events;
+    }
+
+    /**
+     * Creates a fullcalendar event of given SeminarCycleDate
+     *
+     * @param SeminarCycleDate $cycle_date
+     * @param string $institut_id
+     *
+     * @return array enriched course info string for tooltip
+     */
+    public static function getCycleEvent($cycle_date, $institut_id)
+    {
+        $course = Course::find($cycle_date->seminar_id);
+        $semtype = $course->getSemType();
+        $institut = Institute::find($institut_id);
+        $inst_default_colors = self::getInstituteDefaultEventcolors($institut);
+
+        $today = date('w');
+        $user_insts = array_map(function ($arr) {
+            return $arr['Institut_id'];
+        }, Institute::getMyInstitutes($GLOBALS['user']->id));
+
+        $min_time = explode(':', Config::get()->INSTITUTE_COURSE_PLAN_START_HOUR);
+        $minbigtime = (int) $min_time[0];
+        $max_time = explode(':', Config::get()->INSTITUTE_COURSE_PLAN_END_HOUR);
+        $maxbigtime = (int) $max_time[0];
+
+        $start_time = explode(':', $cycle_date['start_time']);
+        $bigtime = (int) $start_time[0];
+
+        if ($bigtime > $maxbigtime || $bigtime < $minbigtime) {
+            return null;
+        } elseif ($bigtime % 2) {
+            $bigtime--;
+        }
+        $start_time = $bigtime . ':00:00';
+
+        $end_time = explode(':', $start_time);
+        $end_time[0] += 2;
+        $end_time = implode(':', $end_time);
+
+        if (in_array($course->institut_id, $user_insts)) {
+            $is_editable = true;
+            $is_start_editable = !LockRules::Check($cycle_date->seminar_id, 'room_time');
+            $is_duration_editable = false;
+        } else {
+            $is_editable = false;
+            $is_start_editable = false;
+            $is_duration_editable = false;
+        }
+
+        if ($cycle_date['weekday'] == 0) {
+            $day_offset = (7 - $today);
+        } else {
+            $day_offset = ($cycle_date['weekday'] - $today);
+        }
+
+        $event_columns = self::getCourseEventcolumns($course);
+        $event_colors = self::getCourseEventcolors($course);
+
+        $move_url = URLHelper::getURL('dispatch.php/admin/courseplanning/move_event');
+        $name = $course->getFullName('number-name');
+
+        if ($start_time != $cycle_date['start_time'] && $end_time != $cycle_date['end_time']) {
+            $start = self::iso8601date(strtotime($day_offset . ' days'), $cycle_date['start_time']);
+            $end = self::iso8601date(strtotime($day_offset . ' days'), $cycle_date['end_time']);
+            $backgroundcolor = '#6c737a';
+            $textcolor = '#ffffff';
+        } else {
+            $start = self::iso8601date(strtotime($day_offset . ' days'), $start_time);
+            $end = self::iso8601date(strtotime($day_offset . ' days'), $end_time);
+
+            $backgroundcolor = null;
+            if (array_key_exists($cycle_date->id, $event_colors)) {
+                if (is_array($event_colors[$cycle_date->id]) && array_key_exists($institut_id, $event_colors[$cycle_date->id])) {
+                    $backgroundcolor = $event_colors[$cycle_date->id][$institut_id];
+                }
+            }
+            if (!$backgroundcolor) {
+                $backgroundcolor = array_key_exists($semtype['name'], $inst_default_colors)?$inst_default_colors[$semtype['name']]:self::DEFAULT_EVENT_COLOR;
+            }
+
+            $textcolor = '#ffffff';
+            if (self::calculateLuminosityRatio($backgroundcolor, $textcolor) < 3) {
+                $textcolor = '#000000';
+            }
+        }
+        if (!$is_editable) {
+            $backgroundcolor = '#c4c7c9';
+            $textcolor = '#000000';
+        }
+
+        $resource_column = '0';
+        if (array_key_exists($cycle_date->id, $event_columns)) {
+            if (is_array($event_columns[$cycle_date->id]) && array_key_exists($institut_id, $event_columns[$cycle_date->id])) {
+                $resource_column = $event_columns[$cycle_date->id][$institut_id];
+            }
+        }
+
+        return [
+            'resourceId'       => $resource_column,
+            'id'               => $cycle_date->id,
+            'title'            => $name,
+            'start'            => $start,
+            'end'              => $end,
+            'textColor'        => $textcolor,
+            'backgroundColor'  => $backgroundcolor,
+            'borderColor'      => '#000',
+            'editable'         => $is_editable,
+            'startEditable'    => $is_start_editable,
+            'durationEditable' => $is_duration_editable,
+            'resourceEditable' => true,
+            'studip_api_urls'  => ['move' => $move_url],
+            'studip_view_urls' => ['edit' => URLHelper::getURL('dispatch.php/course/details/index/' . $cycle_date->seminar_id)],
+            'metadate_id'      => $cycle_date->metadate_id,
+            'course_id'        => $cycle_date->seminar_id,
+            'tooltip'          => self::getCycleInfos($course, $cycle_date),
+            'icon'             => $is_start_editable ? '' : 'lock-locked'
+        ];
+    }
+
+    /**
+     * Creates a string with course infos to be displayed as a tooltip in calendar events
+     *
+     * @param SeminarCycleDate $cycle_date
+     *
+     * @return string enriched course info string for tooltip
+     */
+    private static function getCycleInfos($course, $cycle_date)
+    {
+
+        $info_string = $course->getFullName('number-name') . "\n";
+
+        $dozenten = [];
+        foreach (CourseMember::findByCourseAndStatus($course->id, 'dozent') as $cmember) {
+            $dozenten[$cmember->user->user_id] = $cmember->user->getFullName();
+        }
+        if ($dozenten) {
+            $info_string .= implode(', ', $dozenten) . "\n";
+        }
+
+        $rooms = [];
+        foreach ($cycle_date->getAllDates() as $course_date) {
+            $room = $course_date->getRoom();
+            if ($room) {
+                $rooms[$room->id] = $room->name;
+            }
+        }
+        if ($rooms) {
+            $info_string .= implode(', ', $rooms) . "\n";
+        }
+
+        if ($course->getSemClass()->offsetGet('module')) {
+            $mvv_pathes = [];
+            $course_start = $course->start_time;
+            $course_end = ($course->end_time < 0 || is_null($course->end_time))
+                        ? PHP_INT_MAX
+                        : $course->end_time;
+            // set filter to show only pathes with valid semester data
+            ModuleManagementModelTreeItem::setObjectFilter('Modul',
+                function ($modul) use ($course_start, $course_end) {
+                    // check for public status
+                    if (!$GLOBALS['MVV_MODUL']['STATUS']['values'][$modul->stat]['public']) {
+                        return false;
+                    }
+                    $modul_start = Semester::find($modul->start)->beginn ?: 0;
+                    $modul_end = Semester::find($modul->end)->ende ?: PHP_INT_MAX;
+                    return ($modul_start <= $course_end && $modul_end >= $course_start);
+                }
+            );
+
+            ModuleManagementModelTreeItem::setObjectFilter('StgteilVersion',
+                function ($version) {
+                    return (bool) $GLOBALS['MVV_STGTEILVERSION']['STATUS']['values'][$version->stat]['public'];
+                }
+            );
+
+            $trail_classes = ['Modulteil', 'StgteilabschnittModul', 'StgteilAbschnitt', 'StgteilVersion'];
+            $mvv_object_pathes = MvvCourse::get($course->getId())->getTrails($trail_classes);
+            if ($mvv_object_pathes) {
+                if (Config::get()->COURSE_SEM_TREE_DISPLAY) {
+                    $mvv_tree = [];
+                    foreach ($mvv_object_pathes as $mvv_object_path) {
+                        // show only complete pathes
+                        if (count($mvv_object_path) == 4) {
+                            // flatten the pathes to a linked list
+                            $stg = reset($mvv_object_path);
+                            $parent_id = 'root';
+                            foreach ($mvv_object_path as $mvv_object) {
+                                $mvv_object_id = $mvv_object instanceof StgteilabschnittModul
+                                        ? $mvv_object->modul_id
+                                        : $mvv_object->id;
+                                $mvv_tree[$parent_id][$mvv_object_id] = [
+                                    'id'    => $mvv_object_id,
+                                    'name'  => $mvv_object->getDisplayName(),
+                                    'class' => get_class($mvv_object),
+                                 ];
+                                $parent_id = $mvv_object_id;
+                            }
+                        }
+                    }
+                    if (count($mvv_tree)) {
+                        // add the root node
+                        $mvv_tree['start'][] = [
+                            'id'    => 'root',
+                            'name'  => Config::get()->UNI_NAME_CLEAN,
+                            'class' => ''
+                        ];
+                    }
+                } else {
+                    foreach ($mvv_object_pathes as $mvv_object_path) {
+                        // show only complete pathes
+                        if (count($mvv_object_path) == 4) {
+                            $mvv_object_names = [];
+                            $modul_id = '';
+                            foreach ($mvv_object_path as $mvv_object) {
+                                if ($mvv_object instanceof StgteilabschnittModul) {
+                                    $modul_id = $mvv_object->modul_id;
+                                }
+                                $mvv_object_names[] = $mvv_object->getDisplayName();
+                            }
+                            $mvv_pathes[] = [$modul_id => $mvv_object_names];
+                        }
+                    }
+                }
+                // to prevent collisions of object ids in the tree
+                // in the case of same objects listed in more than one part
+                // of the tree
+                $id_sfx = new stdClass();
+                $id_sfx->c = 1;
+            }
+            foreach ($mvv_pathes as $mvv_path) {
+                foreach ($mvv_path as $mvv_path_content) {
+                    $info_string .= implode(' > ', $mvv_path_content) . "\n";
+                }
+            }
+        }
+
+        return $info_string;
+    }
+
+    public static function getBackgroundEvents($start = null)
+    {
+        $datetime = new DateTime();
+        $slot_duration = 1;
+        $start_time = 8;
+        $end_time = 16;
+        $events = [];
+        $day_interval = 1;
+
+        if ($start == null) {
+            $datetime->modify('monday this week');
+            $datetime->add(new DateInterval('PT' . $start_time . 'H'));
+            $day_interval = 7;
+        }
+
+        for ($i = 1; $i <= $day_interval; $i++) {
+            for ($slot = $start_time; $slot < $end_time; $slot += $slot_duration) {
+                if ($slot % 2) {
+                    $datetime->setTime($slot, 0);
+                    $events[] = [
+                        'start'     => self::iso8601date($datetime, $slot),
+                        'end'       => self::iso8601date($datetime, $slot + $slot_duration),
+                        'rendering' => 'background',
+                    ];
+
+                }
+            }
+            $datetime->setTime($start_time, 0);
+            $datetime->add(new DateInterval('P1D'));
+        };
+        return $events;
+    }
+
+    private static function iso8601date($date, $time = '00:00:00', $timezone = '+00:00')
+    {
+        // If only date parameter is passed and is a DateTimeInterface object or
+        // unix timestamp, assume time from date
+        if (func_num_args() === 1 && ($date instanceof DateTimeInterface || ctype_digit($date))) {
+            $time = $date;
+        }
+
+        // Get time
+        if ($time instanceof DateTimeInterface) {
+            $time = $time->format('H:i:s');
+        } elseif (ctype_digit($time)) {
+            $time = date('H:i:s', $time);
+        } elseif (sscanf($time, '%u:%u:%u', $hours, $minutes, $seconds)) {
+            $time = sprintf('%02u:%02u:%02u', $hours, $minutes, $seconds);
+        }
+
+        // Get date
+        if ($date instanceof DateTimeInterface) {
+            $date = $date->format('Y-m-d');
+        } elseif (ctype_digit($date)) {
+            $date = date('Y-m-d', $date);
+        }
+
+        return "{$date}T{$time}{$timezone}";
+    }
+
+
+    // calculates the luminosity of an given RGB color
+    // the color code must be in the format of RRGGBB
+    // the luminosity equations are from the WCAG 2 requirements
+    // http://www.w3.org/TR/WCAG20/#relativeluminancedef
+    private static function calculateLuminosity($color)
+    {
+        $r = hexdec(substr($color, 0, 2)) / 255; // red value
+        $g = hexdec(substr($color, 2, 2)) / 255; // green value
+        $b = hexdec(substr($color, 4, 2)) / 255; // blue value
+        if ($r <= 0.03928) {
+            $r = $r / 12.92;
+        } else {
+            $r = pow(($r + 0.055) / 1.055, 2.4);
+        }
+        if ($g <= 0.03928) {
+            $g = $g / 12.92;
+        } else {
+            $g = pow(($g + 0.055) / 1.055, 2.4);
+        }
+        if ($b <= 0.03928) {
+            $b = $b / 12.92;
+        } else {
+            $b = pow(($b + 0.055) / 1.055, 2.4);
+        }
+        $luminosity = 0.2126 * $r + 0.7152 * $g + 0.0722 * $b;
+        return $luminosity;
+    }
+
+    // calculates the luminosity ratio of two colors
+    // the luminosity ratio equations are from the WCAG 2 requirements
+    // http://www.w3.org/TR/WCAG20/#contrast-ratiodef
+    private static function calculateLuminosityRatio($color1, $color2)
+    {
+        $c1 = ltrim($color1, '#');
+        $c2 = ltrim($color2, '#');
+        $l1 = self::calculateLuminosity($c1);
+        $l2 = self::calculateLuminosity($c2);
+        if ($l1 > $l2) {
+            $ratio = ($l1 + 0.05) / ($l2 + 0.05);
+        } else {
+            $ratio = ($l2 + 0.05) / ($l1 + 0.05);
+        }
+        return $ratio;
+    }
+}