<?php
namespace RESTAPI\Routes;

/**
 * @author      Till Glöggler <tgloeggl@uos.de>
 * @author      André Klaßen <klassen@elan-ev.de>
 * @license     GPL 2 or later
 * @deprecated  Since Stud.IP 5.0. Will be removed in Stud.IP 6.0.
 *
 * @condition user_id ^[a-f0-9]{1,32}$
 */
class Activity extends \RESTAPI\RouteMap
{
    /**
     * List activities for an user
     *
     * @get /user/:user_id/activitystream
     *
     * @param string  $user_id   the user to get the activities for
     *
     * @return array   the activities as array('collection' => array(...), 'pagination' => array())
     */
    public function getActivities($user_id)
    {
        // only root can retrieve arbitrary streams
        if (!$GLOBALS['perm']->have_perm('root') && $GLOBALS['user']->id != $user_id) {
            $this->error(401);
        }

        // failsafe einbauen - falls es keine älteren Aktivitäten mehr im System gibt, Abbruch!

        $oldest_activity = \Studip\Activity\Activity::getOldestActivity();
        $max_age = $oldest_activity ? $oldest_activity->mkdate : time();


        $contexts = [];

        $user = \User::find($user_id);

        // create system context
        $system_context = new \Studip\Activity\SystemContext($user);
        $contexts[] = $system_context;

        $contexts[] = new \Studip\Activity\UserContext($user, $user);
        $user->contacts->each(function($another_user) use (&$contexts, $user) {
            $contexts[] = new \Studip\Activity\UserContext($another_user, $user);
        });

        if (!in_array($user->perms, ['admin','root'])) {
            // create courses and institutes context
            foreach (\Course::findMany($user->course_memberships->pluck('seminar_id')) as $course) {
                    $contexts[] = new \Studip\Activity\CourseContext($course, $user);
            }
            foreach (\Institute::findMany($user->institute_memberships->pluck('institut_id')) as $institute) {
                $contexts[] = new \Studip\Activity\InstituteContext($institute, $user);
            }
        }


        // add filters
        $filter = new \Studip\Activity\Filter();

        $start = \Request::int('start', strtotime('-1 days'));
        $end   = \Request::int('end',   time());


        $scrollfrom = \Request::int('scrollfrom', false);
        $filtertype = \Request::get('filtertype', '');

        $objectType = \Request::get('object_type');
        $filter->setObjectType($objectType);

        $objectId = \Request::get('object_id');
        $filter->setObjectId($objectId);

        $context = \Request::get('context_type');
        $filter->setContext($context);

        $contextId = \Request::get('context_id');
        $filter->setContextId($contextId);

        if (!empty($filtertype)) {
            $filter->setType(json_decode($filtertype));
        }

        if ($scrollfrom) {
            // shorten "watch-window" by one second to prevent duplication of activities
            $scrollfrom -= 1;

            if ($scrollfrom > $max_age){
                $end = $scrollfrom;
                $start = strtotime('-1 day', $end);
                $data = [];

                $backtrack = 1;

                while (empty($data)) {
                    $filter->setStartDate($start);
                    $filter->setEndDate($end);

                    $data = $this->getStreamData($contexts, $filter);

                    if ($start < $max_age) {
                        break;
                    }

                    // move "watch-window" back one day at a time
                    $end = $start - 1;
                    $start = strtotime('-'. $backtrack . ' days', $start);

                    // enforce maximum "watch-window", currently 2 weeks
                    $backtrack = min (14, $backtrack + 1);
                }
            } else {
                $data = false;
            }
        } else {

            $filter->setStartDate($start);
            $filter->setEndDate($end);
            $data = $this->getStreamData($contexts, $filter);

        }

        // set etag for preventing resending the same stuff over and over again
        $this->etag(md5(serialize($data)));

        return $data;
    }

    /**
     *  private helper function to get stream data for given contexts and filter
     *
     * @param $contexts
     * @param $filter
     * @return array
     */

    private function getStreamData($contexts, $filter)
    {
        $stream = new \Studip\Activity\Stream($contexts, $filter);
        $data = $stream->toArray();

        foreach ($data as $key => $act) {
            $actor = [
                'type' => $data[$key]['actor_type'],
                'id'   => $data[$key]['actor_id']
            ];

            if ($data[$key]['actor_type'] == 'user') {
                $a_user = \User::findFull($data[$key]['actor_id']);
                $actor['details'] = User::getMiniUser($this, $a_user ?: new \User());
            } elseif ($data[$key]['actor_type'] === 'anonymous') {
                $actor['details'] = [
                    'name' => _('Anonym'),
                ];
            }

            unset($data[$key]['actor_type']);
            unset($data[$key]['actor_id']);

            $data[$key]['actor'] = $actor;
        }

        return $data;

    }
}