<?php
class Loan extends Event {
    private $user = 0;
    private $endtime = 0;

    public static function create_loan($user, $product, $endtime) {
        begin_trans();
        $event = parent::create_event($product, 'loan');
        $event_id = $event->get_id();
        $insert = prepare('insert into `loan`(`event`, `user`, `endtime`)
                               values (?, ?, ?)');
        $endtime .= '13:00';
        bind($insert, 'iii', $event_id, $user->get_id(), strtotime($endtime));
        execute($insert);
        $loan = new Loan($event_id);
        $loan->queue_receipt($user);
        commit_trans();
        return $loan;
    }

    public function __construct($id) {
        parent::__construct($id);
        $search = prepare('select * from `loan` where `event`=?');
        bind($search, 'i', $id);
        execute($search);
        $result = result_single($search);
        if($result === null) {
            throw new Exception('Loan does not exist.');
        }
        $this->update_fields();
    }

    protected function update_fields() {
        parent::update_fields();
        $get = prepare('select * from `loan` where `event`=?');
        bind($get, 'i', $this->get_id());
        execute($get);
        $loan = result_single($get);
        $this->user = $loan['user'];
        $this->endtime = $loan['endtime'];
    }

    protected function queue_receipt($user) {
        $now = time();
        $sendtime = $now + 3600;
        $pending = prepare('select * from `pending_receipt` where `user` = ?
                                and `since_time` < ? and `send_time` > ?');
        bind($pending, 'iii', $user->get_id(), $now, $now);
        execute($pending);
        $result = result_single($pending);
        if($result === null) {
            $add = prepare('insert into `pending_receipt`
                                (`user`, `since_time`, `send_time`)
                                values(?, ?, ?)');
            bind($add, 'iii', $user->get_id(), $now, $sendtime);
            execute($add);
        } else {
            $update = prepare('update `pending_receipt` set `send_time` = ?
                               where `user` = ? and `since_time` < ?
                                   and `send_time` > ?');
            bind($update, 'iiii', $sendtime, $user->get_id(), $now, $now);
            execute($update);
        }
    }

    public function get_user() {
        return new User($this->user);
    }

    public function get_endtime() {
        return $this->endtime;
    }

    public function extend($time) {
        $oldend = $this->get_endtime();
        $now = time();
        $ts = strtotime($time . ' 13:00');

        begin_trans();
        $extend = prepare('update `loan` set `endtime`=? where `event`=?');
        bind($extend, 'ii', $ts, $this->get_id());
        execute($extend);

        $log = prepare('insert into `loan_extension`
                            (`loan`, `extend_time`, `old_end`, `new_end`)
                            values (?, ?, ?, ?)');
        bind($log, 'iiii', $this->get_id(), $now, $oldend, $ts);
        execute($log);

        $this->queue_receipt($this->get_user());

        $this->endtime = $ts;
        commit_trans();
        return true;
    }

    public function get_last_extension() {
        $select = prepare('select max(`extend_time`) as `extend_time`
                           from `loan_extension` where `loan`=?');
        bind($select, 'i', $this->get_id());
        execute($select);
        return result_single($select)['extend_time'];
    }

    public function end() {
        $now = time();
        $query = prepare('update `event` set `returntime`=? where `id`=?');
        bind($query, 'ii', $now, $this->get_id());
        execute($query);
        $this->returntime = $now;
        return true;
    }

    public function is_overdue() {
        if($this->returntime !== null) {
            return false;
        }
        $now = time();
        if($now > $this->endtime) {
            return true;
        }
        return false;
    }

    public function expires_before($datetime) {
        if($this->returntime !== null) {
            return false;
        }
        $endtime = new DateTime();
        $endtime->setTimestamp($this->endtime);
        if(!$this->is_overdue() && $endtime < $datetime) {
            return true;
        }
        return false;
    }

    public function get_status() {
        if($this->is_overdue()) {
            return 'overdue_loan';
        }
        if($this->is_active()) {
            return 'active_loan';
        }
        return 'inactive_loan';
    }
}
?>