<?php
// This file is part of GNU social - https://www.gnu.org/software/social
//
// GNU social is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// GNU social 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 Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with GNU social.  If not, see <http://www.gnu.org/licenses/>.

defined('GNUSOCIAL') || die();

// @todo FIXME: documentation needed.
class SupAction extends Action
{
    public function handle()
    {
        parent::handle();

        $seconds = $this->trimmed('seconds');

        if (!$seconds) {
            $seconds = 15;
        }

        $updates = $this->getUpdates($seconds);

        header('Content-Type: application/json; charset=utf-8');

        print json_encode(array('updated_time' => date('c'),
                                'since_time' => date('c', time() - $seconds),
                                'available_periods' => $this->availablePeriods(),
                                'period' => $seconds,
                                'updates' => $updates));
    }

    public function availablePeriods()
    {
        static $periods = array(86400, 43200, 21600, 7200,
                                3600, 1800, 600, 300, 120,
                                60, 30, 15);
        $available = array();
        foreach ($periods as $period) {
            $available[$period] = common_local_url(
                'sup',
                ['seconds' => $period]
            );
        }

        return $available;
    }

    public function getUpdates($seconds)
    {
        $notice = new Notice();

        // XXX: cache this. Depends on how big this protocol becomes;
        // Re-doing this query every 15 seconds isn't the end of the world.

        $divider = common_sql_date(time() - $seconds);

        $notice->selectAdd();
        $notice->selectAdd('profile_id, MAX(id) AS max_id');
        $notice->whereAdd("created > TIMESTAMP '{$divider}'");
        $notice->groupBy('profile_id');

        $updates = [];

        if ($notice->find()) {
            while ($notice->fetch()) {
                $updates[] = [$notice->profile_id, $notice->max_id];
            }
        }

        return $updates;
    }

    public function isReadOnly($args)
    {
        return true;
    }
}
