<?php
/**
 * message.php - Message controller
 *
 * This program 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 2 of
 * the License, or (at your option) any later version.
 *
 * @author Stud.IP developers
 * @author Moritz Strohm <strohm@data-quest.de> (only code related to the new file area)
 */

require_once 'lib/statusgruppe.inc.php';

class MessagesController extends AuthenticatedController {

    protected $number_of_displayed_messages = 50;

    public function before_filter(&$action, &$args)
    {
        parent::before_filter($action, $args);

        PageLayout::setTitle(_('Nachrichten'));
        PageLayout::setHelpKeyword('Basis.InteraktionNachrichten');

        if (in_array($action, ['overview', 'sent'])) {
            $this->tags = Message::getUserTags();
        }
        $this->setupSidebar($action);
    }

    public function overview_action($message_id = null)
    {
        Navigation::activateItem('/messaging/messages/inbox');

        if (Request::get("read_all")) {
            Message::markAllAs($GLOBALS['user']->id, 1);
            PageLayout::postSuccess(_("Alle Nachrichten wurden als gelesen markiert."));
            $this->redirect('messages/overview');
            return;
        }

        if (Request::isPost()) {
            $mbox = Request::option('mbox');
            foreach (Request::optionArray('bulk') as $message_id) {
                $this->deleteMessage($message_id, $mbox);
            }
            PageLayout::postSuccess(sprintf(
                _('%u Nachrichten wurden gelöscht'),
                count(Request::optionArray('bulk'))
            ));

            $this->redirect($this->overviewURL());
            return;
        }

        $this->messages = $this->getMessages(
            true,
            Request::int('limit', $this->number_of_displayed_messages),
            Request::int('offset', 0),
            Request::get('tag'),
            Request::get('search')
        );
        $this->received   = true;
        $this->message_id = $message_id;
        $this->settings   = UserConfig::get($GLOBALS['user']->id)->MESSAGING_SETTINGS;
    }

    public function sent_action($message_id = null)
    {
        Navigation::activateItem('/messaging/messages/sent');

        if (Request::isPost()) {
            $mbox = Request::option('mbox');
            foreach (Request::optionArray('bulk') as $message_id) {
                $this->deleteMessage($message_id, $mbox);
            }
            PageLayout::postSuccess(sprintf(
                _('%u Nachrichten wurden gelöscht'),
                count(Request::optionArray('bulk'))
            ));

            $this->redirect($this->sentURL());
            return;
        }

        $this->messages = $this->getMessages(
            false,
            Request::int('limit', $this->number_of_displayed_messages),
            Request::int('offset', 0),
            Request::get('tag'),
            Request::get('search')
        );
        $this->received   = false;
        $this->message_id = $message_id;
        $this->settings   = UserConfig::get($GLOBALS['user']->id)->MESSAGING_SETTINGS;

        $this->render_action('overview');

        return $this->messages;
    }

    public function more_action()
    {
        $messages = $this->getMessages(
            Request::int("received") ? true : false,
            Request::int("limit", $this->number_of_displayed_messages) + 1,
            Request::int("offset", 0),
            Request::get("tag"),
            Request::get("search")
        );
        $this->output = ['messages' => [], "more" => 0];
        if (count($messages) > Request::int("limit")) {
            $this->output["more"] = 1;
            array_pop($messages);
        }
        $this->settings   = UserConfig::get($GLOBALS['user']->id)->MESSAGING_SETTINGS;
        $template_factory = $this->get_template_factory();
        foreach ($messages as $message) {
            $this->output['messages'][] = $template_factory
                ->open("messages/_message_row.php")
                ->render(['message'    => $message,
                    'controller' => $this,
                    'received'   => (bool) Request::int("received"),
                    'settings'   => $this->settings
                ]);
        }

        $this->render_json($this->output);
    }

    public function read_action($message_id, $mbox = 'rec')
    {
        $this->message = new Message($message_id);
        if (!$this->message->permissionToRead()) {
            throw new AccessDeniedException();
        }

        //load the message's top folder (if any):
        $attachment_folder = Folder::findOneByRange_id($this->message->id);
        if ($attachment_folder) {
            $this->attachment_folder = $attachment_folder->getTypedFolder();
        }


        PageLayout::setTitle(_('Betreff') . ': ' . $this->message['subject']);

        if ($this->message['autor_id'] === $GLOBALS['user']->id) {
            Navigation::activateItem('/messaging/messages/sent');
        } else {
            Navigation::activateItem('/messaging/messages/inbox');
        }
        if (Request::isXhr()) {
            $this->response->add_header('X-Tags', json_encode($this->message->getTags()));
            $this->response->add_header('X-All-Tags', json_encode(Message::getUserTags()));
        } else {
            // Try to redirect to overview of recevied/sent messages if
            // controller is not called via ajax to ensure message is loaded
            // in dialog.
            $target = $this->message->autor_id === $GLOBALS['user']->id
                ? $this->url_for('messages/sent/' . $message_id)
                : $this->url_for('messages/overview/' . $message_id);

            PageLayout::addHeadElement('script', [], sprintf(
                'jQuery(function () { %s });',
                "location.href = '{$target}';"
            ));
        }
        $this->message->markAsRead($GLOBALS['user']->id);

        $this->mbox = $mbox;
    }

    /**
     * Lets the user compose a message and send it.
     */
    public function write_action()
    {
        if ($GLOBALS['user']->perms === 'user' && !Request::option('answer_to')) {
            throw new AccessDeniedException();
        }

        PageLayout::setTitle(_('Neue Nachricht schreiben'));

        $this->to = [];
        $this->default_message = new Message();
        $this->default_attachments = [];

        //the message-ID for the new message:
        $this->default_message->setId(Request::option('message_id', $this->default_message->getNewId()));

        if (Request::option('message_id')) {
            //add default attachments if there are any:
            if ($this->default_message->attachment_folder) {
                foreach ($this->default_message->attachment_folder->getTypedFolder()->getFiles() as $filetype) {
                    $this->default_attachments[] = [
                        'icon'        => $filetype->getIcon('info')->asImg(['class' => 'text-bottom']),
                        'name'        => $filetype->getFilename(),
                        'document_id' => $filetype->getId(),
                        'size'        => $filetype->getSize()
                    ];
                }
            }
        }

        //flag to determine if the message is forwarded or not:
        $forward_message = false;
        $quoted_message = false;


        //check if a receiver is given:
        if (Request::username('rec_uname')) {
            $user = User::findByUsername(Request::username('rec_uname'));
            if ($user) {
                $this->default_message->receivers[] = MessageUser::build([
                    'user_id' => $user->id,
                    'snd_rec' => 'rec',
                ]);
            }
        }

        //check if a list of receivers is given:
        if (Request::getArray('rec_uname')) {
            User::findEachByUsername(
                function ($user) {
                    $this->default_message->receivers[] = MessageUser::build([
                        'user_id' => $user->id,
                        'snd_rec' => 'rec',
                    ]);
                },
                Request::usernameArray('rec_uname')
            );
        }

        //check if the message shall be sent to all members of a status group:
        $group_ids = [];
        if (Request::option('group_id')) {
            $group_ids[] = Request::option('group_id');
        } elseif (Request::submitted('group_ids')) {
            $group_ids = Request::getArray('group_ids');
        }
        if ($group_ids) {
            $this->default_message->receivers = [];
            $groups = Statusgruppen::findMany($group_ids);

            foreach ($groups as $group) {
                // Exclude hidden course members from mails if not at least tutor
                $hidden = [];
                $course = Course::find($group->range_id);
                if ($course && !$GLOBALS['perm']->have_studip_perm('tutor', $course->id)) {
                    $hidden = $course->members->findBy('visible', 'no')->pluck('user_id');
                }

                if ($group['range_id'] === $GLOBALS['user']->id
                    || $GLOBALS['perm']->have_studip_perm('autor', $group['range_id']))
                {
                    foreach ($group->members as $member) {
                        if (in_array($member->user_id, $hidden)) {
                            continue;
                        }

                        $user = new MessageUser();
                        $user->setData(['user_id' => $member['user_id'], 'snd_rec' => 'rec']);
                        $this->default_message->receivers->append($user);
                    }
                }
            }
        }

        //check if the message shall be sent to all members of an institute:
        if (Request::get('inst_id') && $GLOBALS['perm']->have_studip_perm('admin', Request::get('inst_id'))) {
            if (Request::get('filter') === 'inst_status') {
                $query = "SELECT user_id, 'rec' AS snd_rec
                          FROM user_inst
                          JOIN auth_user_md5 USING (user_id)
                          WHERE Institut_id = ? AND inst_perms = ?
                          ORDER BY Nachname, Vorname";
            } else {
                $query = "SELECT user_id, 'rec' AS snd_rec
                            FROM user_inst
                            JOIN auth_user_md5 USING (user_id)
                            WHERE Institut_id = ? AND inst_perms != 'user'
                            ORDER BY Nachname, Vorname";
            }
            $this->default_message->receivers = DBManager::get()->fetchAll($query, [Request::option('inst_id'), Request::option('who')], 'MessageUser::build');
        }

        //check if the message shall be sent to all (or some) members of a course:
        $filters = explode(',', Request::get('filter', ''));
        $course = Course::find(Request::option('course_id'));
        if ($filters && $course) {
            $additional = '';
            if ($GLOBALS['perm']->have_studip_perm('tutor', $course->id)) {
                $allow_tutor_filters = true;
            } elseif ($GLOBALS['perm']->have_studip_perm('user', $course->id)
                && ($course->getSemClass()['studygroup_mode'] || CourseConfig::get($course->id)->COURSE_STUDENT_MAILING)) {
                $additional = " AND seminar_user.visible != 'no'";
                $allow_tutor_filters = false;
            } else {
                throw new AccessDeniedException();
            }
            $this->default_message->receivers = [];
            $all_recipients = [];
            foreach ($filters as $filter) {
                $query = '';
                $params = ['course_id' => $course->id];
                if (Request::get('who')) {
                    $params['status'] = explode(',', Request::get('who', ''));
                }
                if ($filter === 'all' || $filter === 'send_sms_to_all') {
                    if ($params['status']) {
                        $additional .= ' AND seminar_user.status IN ( :status )';
                    }
                    $query = "SELECT user_id, 'rec' AS snd_rec
                                      FROM seminar_user
                                      JOIN auth_user_md5 USING (user_id)
                                      WHERE Seminar_id = :course_id {$additional}
                                      ORDER BY Nachname, Vorname";
                } elseif ($filter === 'prelim' && $allow_tutor_filters) {
                    $query = "SELECT user_id, 'rec' AS snd_rec
                                      FROM admission_seminar_user
                                      JOIN auth_user_md5 USING (user_id)
                                      WHERE  Seminar_id = :course_id AND status = 'accepted'
                                      ORDER BY Nachname, Vorname";
                } elseif ($filter === 'awaiting' && $allow_tutor_filters) {
                    $query = "SELECT user_id, 'rec' AS snd_rec
                                      FROM admission_seminar_user
                                      JOIN auth_user_md5 USING (user_id)
                                      WHERE  Seminar_id = :course_id AND status = 'awaiting'
                                      ORDER BY Nachname, Vorname";
                } elseif ($filter === 'not_grouped' && $allow_tutor_filters) {
                    $query = "SELECT seminar_user.user_id, 'rec' as snd_rec
                                      FROM seminar_user
                                      JOIN auth_user_md5 USING (user_id)
                                      LEFT JOIN statusgruppen ON range_id = seminar_id
                                      LEFT JOIN statusgruppe_user ON statusgruppen.statusgruppe_id = statusgruppe_user.statusgruppe_id
                                      AND seminar_user.user_id = statusgruppe_user.user_id
                                      WHERE seminar_id = :course_id
                                      GROUP BY seminar_user.user_id
                                      HAVING COUNT(statusgruppe_user.statusgruppe_id) = 0
                                      ORDER BY Nachname, Vorname";
                } elseif ($filter === 'claiming' && $allow_tutor_filters) {
                    $cs = CourseSet::getSetForCourse($course->id);
                    if (is_object($cs) && !$cs->hasAlgorithmRun()) {
                        foreach (AdmissionPriority::getPrioritiesByCourse($cs->getId(), $course->id) as $user_id => $p) {
                            $all_recipients[] = MessageUser::build(['user_id' => $user_id, 'snd_rec' => 'rec']);
                        }
                    }
                }
                if ($query) {
                    $all_recipients = array_merge(
                        $all_recipients,
                        DBManager::get()->fetchAll($query, $params, 'MessageUser::build')
                    );
                }
            }
            $this->default_message->receivers = $all_recipients;
        }


        if (Request::option('prof_id') && Request::option('deg_id') && $GLOBALS['perm']->have_perm('root')) {
            $query = "SELECT DISTINCT user_id,'rec' as snd_rec
            FROM user_studiengang
            WHERE fach_id = ? AND abschluss_id = ?";
            $this->default_message->receivers = DBManager::get()->fetchAll($query, [
                Request::option('prof_id'),
                Request::option('deg_id')
            ], 'MessageUser::build');
        }

        if (Request::option('sd_id') && $GLOBALS['perm']->have_perm('root')) {
            $query = "SELECT DISTINCT user_id, 'rec' AS snd_rec
                      FROM user_studiengang
                      WHERE abschluss_id = ?";
            $this->default_message->receivers = DBManager::get()->fetchAll($query, [
                Request::option('sd_id')
            ], 'MessageUser::build');
        }

        if (Request::option('sp_id') && $GLOBALS['perm']->have_perm('root')) {
            $query = "SELECT DISTINCT user_id,'rec' as snd_rec
            FROM user_studiengang
            WHERE fach_id = ?";
            $this->default_message->receivers = DBManager::get()->fetchAll($query, [
                Request::option('sp_id')
            ], 'MessageUser::build');
        }

        if (!$this->default_message->receivers->count() && is_array($_SESSION['sms_data']['p_rec'])) {
            $this->default_message->receivers = DBManager::get()->fetchAll("SELECT user_id,'rec' as snd_rec FROM auth_user_md5 WHERE username IN(?) ORDER BY Nachname,Vorname", [$_SESSION['sms_data']['p_rec']], 'MessageUser::build');
            unset($_SESSION['sms_data']);
        }

        //check if the message is a reply or if it shall be forwarded:
        if (Request::option("answer_to")) {
            $this->default_message->receivers = [];
            $old_message = new Message(Request::option("answer_to"));
            $this->default_tags = Request::get("default_tags", "");
            $oldtags = $old_message->getTags($GLOBALS['user']->id);
            if (count($oldtags)) {
                $this->default_tags .= " ".implode(" ", $oldtags);
            }
            if (!$old_message->permissionToRead()) {
                throw new AccessDeniedException("Message is not for you.");
            }
            if (!Request::get('forward')) {
                //message is a reply message
                if (Request::option("quote") === $old_message->getId()) {
                    $quoted_message = true;
                    $message = _(". . . ursprüngliche Nachricht . . .");
                    $message .= "\n" . _("Betreff") . ": " . $old_message['subject'];
                    $message .= "\n" . _("Datum") . ": " . strftime('%x %X', $old_message['mkdate']);
                    $message .= "\n" . _("Von") . ": " . get_fullname($old_message['autor_id']);
                    $num_recipients = $old_message->getNumRecipients();
                    if ($GLOBALS['user']->id == $old_message->autor_id) {
                        $message .= "\n" . ($num_recipients == 1 ? _('An: Eine Person') : sprintf(_('An: %d Personen'), $num_recipients));
                    } else {
                        $message .= "\n";
                        if($num_recipients > 1) {
                            $message .= sprintf(
                                ngettext(
                                    'An: %1$s (und %2$d weitere/n)',
                                    'An: %1$s (und %2$d weitere)',
                                    $num_recipients
                                ),
                                $GLOBALS['user']->getFullName(),
                                $num_recipients
                            );
                        } else {
                            $message .= sprintf(
                                _('An: %s'),
                                $GLOBALS['user']->getFullName()
                            );
                        }
                    }
                    $message .= "\n\n";
                    if (Studip\Markup::editorEnabled()) {
                        $message = Studip\Markup::markupToHtml($message, false) . Studip\Markup::markupToHtml($old_message['message']);
                    } else if (Studip\Markup::isHtml($old_message['message'])) {
                        $message .= Studip\Markup::removeHtml($old_message['message']);
                    } else {
                        $message .= $old_message['message'];
                    }
                    $this->default_message['message'] = $message;
                }
                $this->default_message['subject'] = mb_substr($old_message['subject'], 0, 4) === "RE: " ? $old_message['subject'] : "RE: ".$old_message['subject'];
                if ($old_message['autor_id'] !== $GLOBALS['user']->id) {
                    $user = new MessageUser();
                    $user->setData(['user_id' => $old_message['autor_id'], 'snd_rec' => "rec"]);
                    $this->default_message->receivers[] = $user;
                } else {
                    foreach ($old_message->receivers as $old_receivers) {
                        $user = new MessageUser();
                        $user->setData(['user_id' => $old_receivers['user_id'], 'snd_rec' => "rec"]);
                        $this->default_message->receivers[] = $user;
                    }
                }
                $this->answer_to = $old_message->id;
            } else {
                //message shall be forwarded
                $forward_message = true;

                $messagesubject = 'FWD: ' . $old_message['subject'];
                $message = _(". . . weitergeleitete Nachricht . . .");
                $message .= "\n" . _("Betreff") . ": " . $old_message['subject'];
                $message .= "\n" . _("Datum") . ": " . strftime('%x %X', $old_message['mkdate']);
                $message .= "\n" . _("Von") . ": " . get_fullname($old_message['autor_id']);
                $num_recipients = $old_message->getNumRecipients();
                if ($GLOBALS['user']->id == $old_message->autor_id) {
                    $message .= "\n" . ($num_recipients == 1 ? _('An: Eine Person') : sprintf(_('An: %d Personen'), $num_recipients));
                } else {
                    $message .= "\n";
                    if($num_recipients > 1) {
                        $message .= sprintf(
                            ngettext(
                                'An: %1$s (und %2$d weitere/n)',
                                'An: %1$s (und %2$d weitere)',
                                $num_recipients
                            ),
                            $GLOBALS['user']->getFullName(),
                            $num_recipients
                        );
                    } else {
                        $message .= sprintf(
                            _('An: %s'),
                            $GLOBALS['user']->getFullName()
                        );
                    }
                }
                $message .= "\n\n";
                if (Studip\Markup::editorEnabled()) {
                    $message = Studip\Markup::markupToHtml($message, false) . Studip\Markup::markupToHtml($old_message['message']);
                } else if (Studip\Markup::isHtml($old_message['message'])) {
                    $message .= Studip\Markup::removeHtml($old_message['message']);
                } else {
                    $message .= $old_message['message'];
                }
                if ($old_message->getNumAttachments()) {
                    //there is at least one attachment: we must copy it
                    $old_attachment_folder = MessageFolder::findTopFolder($old_message->id);

                    if ($old_attachment_folder) {
                        $new_attachment_folder = MessageFolder::createTopFolder($this->default_message->id);
                        if ($new_attachment_folder) {
                            foreach ($old_attachment_folder->getFiles() as $old_attachment) {
                                $old_attachment_file_ref = $old_attachment->getFileRef();
                                $new_attachment_file_ref = new FileRef();
                                $new_attachment_file_ref->file_id = $old_attachment_file_ref->file_id;
                                $new_attachment_file_ref->name = $old_attachment_file_ref->name;
                                $new_attachment_file_ref->folder_id = $new_attachment_folder->getId();
                                $new_attachment_file_ref->description = $old_attachment_file_ref->description;
                                $new_attachment_file_ref->content_terms_of_use_id = $old_attachment_file_ref->content_terms_of_use_id;
                                $new_attachment_file_ref->user_id = $GLOBALS['user']->id;

                                if ($new_attachment_file_ref->store()) {
                                    $icon = FileManager::getIconForFileRef($new_attachment_file_ref);
                                    $this->default_attachments[] = [
                                        'icon'        => $icon->asImg(['class' => 'text-bottom']),
                                        'name'        => $new_attachment_file_ref->name,
                                        'document_id' => $new_attachment_file_ref->id,
                                        'size'        => relsize($new_attachment_file_ref->size, false)
                                    ];
                                }
                            }
                        }
                    }
                }
                $this->default_message['subject'] = $messagesubject;
                $this->default_message['message'] = $message;
            }
        }
        if (Request::get('default_body')) {
            if (Studip\Markup::editorEnabled()) {
                $this->default_message['message'] = Studip\Markup::markupToHtml(Request::get("default_body"));
            } else {
                $this->default_message['message'] = Studip\Markup::removeHtml(Request::get("default_body"));
            }
        }
        if (Request::get('default_subject')) {
            $this->default_message['subject'] = Request::get("default_subject");
        }
        $settings = UserConfig::get($GLOBALS['user']->id)->MESSAGING_SETTINGS;
        $this->mailforwarding = Request::get('emailrequest') ? true : $settings['request_mail_forward'];
        $this->show_adressees = Request::get('show_adressees') ? true : $settings['show_adressees'];;
        if (Request::get('inst_id') || Request::get('course_id') || Request::option('group_id') || !Config::get()->SHOW_ADRESSEES_LIMIT) {
            $this->show_adressees = null;
        }
        if (trim($settings['sms_sig'])) {
            if (Studip\Markup::editorEnabled()) {
                $sms_sig = Studip\Markup::markAsHtml('<br><br><hr>' . Studip\Markup::markupToHtml($settings['sms_sig']) . '<br><br>');
            } else {
                $sms_sig =  "\n\n--\n" . $settings['sms_sig'] . "\n\n";
            }
            if ($forward_message || $quoted_message) {
                $this->default_message['message'] = $sms_sig . $this->default_message['message'];
            } else {
                $this->default_message['message'] .= $sms_sig;
            }
        }

        // Create search object for multi person search
        $vis_query = get_vis_query();
        $query = "SELECT DISTINCT
                    auth_user_md5.user_id,
                    {$GLOBALS['_fullname_sql']['full_rev']} AS fullname,
                    username,
                    perms
                  FROM auth_user_md5
                  LEFT JOIN user_info USING (user_id)
                  WHERE (
                      username LIKE :input
                      OR CONCAT(Vorname, ' ', Nachname) LIKE :input
                      OR CONCAT(Nachname, ' ', Vorname) LIKE :input
                      OR CONCAT(Nachname, ', ', Vorname) LIKE :input
                    )
                    AND {$vis_query}
                  ORDER BY Nachname ASC, Vorname ASC";
        $this->mp_search_object = new SQLSearch($query, _('Nutzer suchen'), 'user_id');

        NotificationCenter::postNotification('DefaultMessageForComposerCreated', $this->default_message);
    }

    /**
     * Sends a message and redirects the user.
     */
    public function send_action()
    {
        CSRFProtection::verifyUnsafeRequest();

        PageLayout::setTitle(_('Nachricht verschicken'));

        $recipients = array_filter(Request::getArray('message_to'));

        if (count($recipients) === 0) {
            PageLayout::postError(_('Sie haben nicht angegeben, wer die Nachricht empfangen soll!'));
        } elseif (Request::submitted('message_id') && Message::exists(Request::option('message_id'))) {
            PageLayout::postInfo(_('Diese Nachricht wurde bereits verschickt.'));
        } elseif (Request::submitted('message_body')) {
            $messaging = new messaging();
            $rec_uname = User::findAndMapMany(function ($user) {
                return $user->username;
            }, $recipients);
            $messaging->send_as_email = Request::int('message_mail');
            $messaging->insert_message(
                Studip\Markup::purifyHtml(Request::get('message_body')),
                $rec_uname,
                $GLOBALS['user']->id,
                '',
                Request::option('message_id'),
                '',
                null,
                Request::get('message_subject'),
                '',
                'normal',
                trim(Request::get('message_tags')) ?: null,
                Request::int('show_adressees', 0)
            );
            if (Request::option('answer_to')) {
                $old_message = Message::find(Request::option('answer_to'));
                if ($old_message) {
                    $old_message->markAsAnswered($GLOBALS['user']->id);
                }
            }
            PageLayout::postSuccess(_('Nachricht wurde verschickt.'));
        }

        if (!Request::isXhr()) {
            $this->redirect('messages/overview');
        }
    }

    public function tag_action($message_id)
    {
        if (Request::isPost()) {
            $message = Message::find($message_id);
            if (!$message->permissionToRead()) {
                throw new AccessDeniedException();
            }
            if (Request::get('add_tag')) {
                $message->addTag(Request::get('add_tag'));
            } elseif (Request::get('remove_tag')) {
                $message->removeTag(Request::get('remove_tag'));
            }
        }
        $this->redirect('messages/read/' . $message_id);
    }

    public function print_action($message_id)
    {
        $message = Message::find($message_id);
        if (!$message->permissionToRead()) {
            throw new AccessDeniedException();
        }
        if ($message && $message->permissionToRead($GLOBALS['user']->id)) {
            $this->msg = $message->toArray();
            $this->msg['from'] = $message['autor_id'] === '____%system%____'
                ? _('Stud.IP')
                : ($message->getSender()
                    ? $message->getSender()->getFullname()
                    : _('unbekannt'));
            $this->msg['to'] = $GLOBALS['user']->id == $message->autor_id ?
                join(', ', $message->getRecipients()->pluck('fullname')) :
                $GLOBALS['user']->getFullname() . ' ' . sprintf(_('(und %d weitere)'), $message->getNumRecipients()-1);

            if ($attachment_folder = Folder::findOneByRange_id($message->id)) {
                $this->msg['attachments'] = $attachment_folder->file_refs->toArray('name size');
            }

            PageLayout::setTitle($this->msg['subject']);
            $this->set_layout($GLOBALS['template_factory']->open('layouts/base'));
        } else {
            $this->set_status(400);
            $this->render_nothing();
        }
    }

    protected function deleteMessage($message_id, $mbox)
    {
        $message = Message::find($message_id);
        if ($message) {
            $message->markAsRead($GLOBALS['user']->id);
        }

        $messageuser = MessageUser::find([$GLOBALS['user']->id, $message_id, $mbox]);
        if ($messageuser) {
            $messageuser['deleted'] = true;
            $success = $messageuser->store();
        }

        return $success;
    }

    public function delete_action($message_id, $mbox = 'rec')
    {
        $message = Message::find($message_id);

        $ticket = Request::get('studip-ticket');
        if (Request::isPost() && $ticket && check_ticket($ticket)) {
            $success = $this->deleteMessage($message_id, $mbox);
            if ($success) {
                PageLayout::postMessage(MessageBox::success(_('Nachricht gelöscht!')));
            } else {
                PageLayout::postMessage(MessageBox::error(_('Nachricht konnte nicht gelöscht werden.')));
            }
        }

        $redirect = $mbox === 'rec'
            ? $this->url_for('messages/overview')
            : $this->url_for('messages/sent');

        $this->redirect($redirect);
    }

    /* delete all sent or received messages */
    public function purge_action($sndrec)
    {
        CSRFProtection::verifyUnsafeRequest();

        $query = "SELECT message_id
                  FROM message_user
                  WHERE snd_rec = :sndrec
                    AND user_id = :id
                    AND deleted != 1";
        $returnedMessages = DBManager::get()->fetchFirst($query, [
            'sndrec' => $sndrec,
            'id' => $GLOBALS['user']->id,
        ]);
        foreach ($returnedMessages as $returnedMessage) {
            $this->deleteMessage($returnedMessage, $sndrec);
        }
        if ($sndrec === 'rec') {
            PageLayout::postSuccess(_('Alle empfangenen Nachrichten wurden gelöscht.'));
            $this->redirect('messages/overview');
        } else if ($sndrec === 'snd') {
            PageLayout::postSuccess(_('Alle gesendeten Nachrichten wurden gelöscht.'));
            $this->redirect('messages/sent');
        }
    }

    protected function getMessages($received = true, $limit = 50, $offset = 0, $tag = null, $search = null)
    {
        if ($tag) {
            $messages_data = DBManager::get()->prepare("
                SELECT message.*
                FROM message_user
                    INNER JOIN message ON (message_user.message_id = message.message_id)
                    INNER JOIN message_tags ON (message_tags.message_id = message_user.message_id AND message_tags.user_id = message_user.user_id)
                WHERE message_user.user_id = :me
                    AND message_user.deleted = 0
                    AND snd_rec = :sender_receiver
                    AND message_tags.tag = :tag
                ORDER BY message_user.mkdate DESC
                LIMIT ".(int) $offset .", ".(int) $limit ."
            ");
            $messages_data->execute([
                'me' => $GLOBALS['user']->id,
                'tag' => $tag,
                'sender_receiver' => $received ? "rec" : "snd"
            ]);
        } elseif ($search) {

            $suchmuster = '/".*"/U';
            preg_match_all($suchmuster, $search, $treffer);
            array_walk($treffer[0], function(&$value) { $value = trim($value, '"'); });

            // remove the quoted parts from $_searchfor
            $_searchfor = trim(preg_replace($suchmuster, '', $search));

            // split the searchstring $_searchfor at every space
            $parts = explode(' ', $_searchfor);
            foreach ($parts as $key => $val) {
                if ($val == '') {
                    unset($parts[$key]);
                }
            }
            if (!empty($parts)) {
                $_searchfor = array_merge($parts, $treffer[0]);
            } else  {
                $_searchfor = $treffer[0];
            }

            if (!Request::int('search_autor') && !Request::int('search_subject') && !Request::int('search_content')) {
                $message = _('Es wurden keine Bereiche angegeben, in denen gesucht werden soll.');
                PageLayout::postMessage(MessageBox::error($message));

                $search_sql = "AND 0";
            } else {
                $search_sql = "";
                foreach ($_searchfor as $val) {
                    $tmp_sql = [];
                    if (Request::get("search_autor")) {
                        $tmp_sql[] = "CONCAT(auth_user_md5.Vorname, ' ', auth_user_md5.Nachname) LIKE ".DBManager::get()->quote("%".$val."%")." ";
                    }
                    if (Request::get("search_subject")) {
                        $tmp_sql[] = "message.subject LIKE ".DBManager::get()->quote("%".$val."%")." ";
                    }
                    if (Request::get("search_content")) {
                        $tmp_sql[] = "message.message LIKE ".DBManager::get()->quote("%".$val."%")." ";
                    }
                    $search_sql .= "AND (";
                    $search_sql .= implode(" OR ", $tmp_sql);
                    $search_sql .= ") ";
                }
            }

            $messages_data = DBManager::get()->prepare("
                SELECT message.*
                FROM message_user
                    INNER JOIN message ON (message_user.message_id = message.message_id)
                    LEFT JOIN auth_user_md5 ON (auth_user_md5.user_id = message.autor_id)
                WHERE message_user.user_id = :me
                    AND message_user.deleted = 0
                    AND snd_rec = :sender_receiver
                    $search_sql
                ORDER BY message_user.mkdate DESC
                LIMIT ".(int) $offset .", ".(int) $limit ."
            ");
            $messages_data->execute([
                'me' => $GLOBALS['user']->id,
                'sender_receiver' => $received ? "rec" : "snd"
            ]);
        } else {
            $messages_data = DBManager::get()->prepare("
                SELECT message.*
                FROM message_user
                    INNER JOIN message ON (message_user.message_id = message.message_id)
                WHERE message_user.user_id = :me
                    AND message_user.deleted = 0
                    AND snd_rec = :sender_receiver
                ORDER BY message_user.mkdate DESC
                LIMIT ".(int) $offset .", ".(int) $limit ."
            ");
            $messages_data->execute([
                'me' => $GLOBALS['user']->id,
                'sender_receiver' => $received ? "rec" : "snd"
            ]);
        }
        $messages_data->setFetchMode(PDO::FETCH_ASSOC);
        $messages = [];
        foreach ($messages_data as $data) {
            $messages[] = Message::buildExisting($data);
        }
        return $messages;
    }

    public function upload_attachment_action()
    {
        if ($GLOBALS['user']->id === "nobody") {
            throw new AccessDeniedException();
        }
        if (!$GLOBALS['ENABLE_EMAIL_ATTACHMENTS']) {
            throw new AccessDeniedException(_('Mailanhänge sind nicht erlaubt.'));
        }
        $file = $_FILES['file'];
        $output = [
            'name' => $file['name'],
            'size' => $file['size']
        ];

        $message_id = Request::option('message_id');
        $output['message_id'] = $message_id;

        $message_top_folder = MessageFolder::findTopFolder($message_id) ?: MessageFolder::createTopFolder($message_id);

        $uploaded = FileManager::handleFileUpload(
            [
                'tmp_name' => [$file['tmp_name']],
                'name' => [$file['name']],
                'size' => [$file['size']],
                'type' => [$file['type']],
                'error' => [$file['error']]
            ],
            $message_top_folder,
            $GLOBALS['user']->id
        );

        if ($uploaded['error']) {
            $this->response->set_status(400);
            $error = implode("\n", $uploaded['error']);
            $this->render_json(compact('error'));
            return;
        }

        if (!$uploaded['files'][0] instanceof FileType) {
            $error = _('Ein Systemfehler ist beim Upload aufgetreten.');
            $this->response->set_status(400);
            $this->render_json(compact('error'));
            return;
        }

        $output['document_id'] = $uploaded['files'][0]->getId();

        $output['icon'] = $uploaded['files'][0]->getIcon(Icon::ROLE_CLICKABLE)->asImg(['class' => 'text-bottom']);

        $this->render_json($output);
    }

    public function delete_attachment_action()
    {
        CSRFProtection::verifyUnsafeRequest();
        $attachment = FileRef::find(Request::option('document_id'));
        if ($attachment) {
            $attachment->delete();
        }
        $this->render_nothing();
    }

    public function preview_action()
    {
        if (Request::isXhr()) {
            $this->render_text(formatReady(Request::get('text')));
        }
    }

    public function delete_tag_action()
    {
        CSRFProtection::verifyUnsafeRequest();
        DBManager::get()->execute("DELETE FROM message_tags WHERE user_id=? AND tag LIKE ?", [$GLOBALS['user']->id, Request::get('tag')]);
        PageLayout::postMessage(MessageBox::success(_('Schlagwort gelöscht!')));
        $this->redirect('messages/overview');
    }

    public function sendCwMessage_action($course_id, $element_id, $owner_id)
    {
        $body = file_get_contents('php://input');
        $data = json_decode($body, true);
        $text = $data['text'];

        $author = User::find($owner_id)->username;

        $this->link_to_share = URLHelper::getURL("dispatch.php/course/courseware/?cid=" . $course_id
            . "#/structural_element/" . $element_id);
        $this->linktext = _('Klicken Sie hier, um zum vorgeschlagenen Courseware-Material zu gelangen.');
        $this->formatted_link = '['. $this->linktext .']' . $this->link_to_share;

        $oer_suggestion_message = sprintf(_("Ihr Courseware-Material wurde zur Veröffentlichung im OER Campus vorgeschlagen:\n\n"
            . "%s \n\n"
            . "Zusätzliche Info: \n %s"),
            $this->formatted_link, $text);

        $messaging = new messaging();

        $messaging->insert_message(
            $oer_suggestion_message,
            $author,
            '____%system%____',
            '',
            Request::option('message_id'),
            '',
            null,
            _('Vorschlag zur Veröffentlichung von Courseware-Material im OER Campus'),
            '',
            'normal',
            '',
            0
        );

        $this->render_nothing();

    }

    public function setupSidebar($action)
    {
        $sidebar = Sidebar::get();

        $actions = new ActionsWidget();

        if ($GLOBALS['user']->perms !== 'user') {
            $actions->addLink(
                _('Neue Nachricht schreiben'),
                $this->url_for('messages/write'),
                Icon::create('mail+add'),
                ['data-dialog' => 'width=700;height=700']
            );
        }
        if ($action !== 'sent' && MessageUser::hasUnreadByUserId($GLOBALS['user']->id)) {
            $actions->addLink(
                _('Alle als gelesen markieren'),
                $this->url_for('messages/overview', ['read_all' => 1]),
                Icon::create('accept', 'clickable')
            );
        }

        $actions->addLink(
            _('Ausgewählte Nachrichten löschen'),
            '#',
            Icon::create('trash'),
            [
                'onclick' => sprintf(
                    'return STUDIP.Dialog.confirm("%s".replace("%%s", $("#bulk tbody :checked").length), function() { $("#bulk").submit(); })',
                    _('Wirklich %s Nachricht(en) löschen?')
                )
            ]
        );

        if ($action === 'overview') {
            if (MessageUser::countBySQL("snd_rec = 'rec' AND user_id = :id AND deleted != 1 LIMIT 1", ['id' => $GLOBALS['user']->id])) {
                $message = sprintf(
                    _("Möchten Sie wirklich alle Nachrichten im Posteingang löschen? Es werden %u Nachrichten endgültig gelöscht."),
                    MessageUser::countBySQL("snd_rec = 'rec' AND user_id = :id AND deleted != 1", ['id' => $GLOBALS['user']->id])
                );
                $actions->addLink(
                    _('Nachrichten im Posteingang löschen'),
                    $this->url_for('messages/purge/rec'),
                    Icon::create('trash'),
                    ['data-confirm' => $message]
                )->asButton();
            }
        } elseif ($action === 'sent') {
            if (MessageUser::countBySQL("snd_rec = 'snd' AND user_id = :id AND deleted != 1 LIMIT 1", ['id' => $GLOBALS['user']->id])) {
                $message = sprintf(
                    _("Möchten Sie wirklich alle Nachrichten im Postausgang löschen? Es werden %u Nachrichten endgültig gelöscht."),
                    MessageUser::countBySQL("snd_rec = 'snd' AND user_id = :id AND deleted != 1", ['id' => $GLOBALS['user']->id])
                );
                $actions->addLink(
                    _('Nachrichten im Postausgang löschen'),
                    $this->url_for('messages/purge/snd'),
                    Icon::create('trash'),
                    ['onclick' => 'return STUDIP.Dialog.confirmAsPost("' . $message . '", this.href);']
                );

            }
        }

        $sidebar->addWidget($actions);

        $search = new SearchWidget(URLHelper::getURL('?'));
        $search->addNeedle(_('Nachrichten durchsuchen'), 'search', true);
        $search->addFilter(_('Betreff'), 'search_subject');
        $search->addFilter(_('Inhalt'), 'search_content');
        $search->addFilter(_('Autor/-in'), 'search_autor');
        $sidebar->addWidget($search);

        $folderwidget = new ViewsWidget();
        $folderwidget->forceRendering();
        $folderwidget->title = _('Schlagworte');
        $folderwidget->id    = 'messages-tags';
        $folderwidget->addLink(
            _('Alle Nachrichten'),
            $this->url_for("messages/{$action}"),
            null,
            ['class' => 'tag all-tags']
        )->setActive(!Request::submitted("tag"));
        if (empty($this->tags)) {
            $folderwidget->style = 'display:none';
        } else {
            foreach ($this->tags as $tag) {
                $folderwidget->addLink(
                    $tag,
                    $this->url_for("messages/{$action}", compact('tag')),
                    null,
                    ['class' => 'tag']
                )->setActive(Request::get('tag') === $tag);
            }
        }

        $sidebar->addWidget($folderwidget);
    }
}