<?php

/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */

namespace modules\locks\code;

/**
 * Description of Lock
 *
 * @author pegas
 */
class Lock extends \app\classes\MNRelation {

    const LOCK_INTERVAL = 20; // in lock.js too

    private $time;

    public function __construct($element_id, $element_table, $id = 0) {
        $this->time = time();
        parent::__construct($id, "locks", array("element_id" => $element_id, "element_table" => $element_table), "id", false, "SELECT * FROM locks WHERE element_table=:element_table AND element_id=:element_id");
    }

    /**
     * @return Lock
     */
    public static function getLock($element_id, $element_table) {
        return parent::getMNRelationPrototype($element_id, $element_table);
    }

    protected static function addRelation($element_id, $element_table) {
        $db = \app\classes\PDODatabase::getInstance();
        $db->addRecord("locks", array(
            "element_id" => $element_id,
            "element_table" => $element_table,
            "last_lock" => "2000-01-01 00:00:00"
        ));
    }

    public function lock($by = false, $throwEx = true) {
        if ($by === false) {
            try {
                $user = \app\classes\BasicUser::getLoggedUser();
                $by = $user->_get("email");
            } catch (\Exception $ex) {
                if ($throwEx) {
                    throw new \Exception($ex->getMessage(), $ex->getCode(), $ex->getPrevious());
                }
                return false;
            }
        }

        $db = \app\classes\PDODatabase::getInstance();
        $db->sqlCommand("UPDATE locks SET last_lock=:last_lock, last_lock_by=:last_lock_by WHERE element_id=:element_id AND element_table=:element_table "
                . "AND (last_lock_by=:last_lock_by OR last_lock < :last_lock_cond)", array(
            "last_lock" => date("Y-m-d H:i:s", $this->time),
            "last_lock_by" => $by,
            "element_id" => $this->_get("element_id"),
            "element_table" => $this->_get("element_table"),
            "last_lock_cond" => date("Y-m-d H:i:s", time() - 2.5 * self::LOCK_INTERVAL)
        ));

        $success = $db->getValue("SELECT id FROM locks WHERE element_id=:element_id AND element_table=:element_table AND last_lock_by=:last_lock_by AND last_lock=:last_lock", array(
                    "last_lock" => date("Y-m-d H:i:s", $this->time),
                    "last_lock_by" => $by,
                    "element_id" => $this->_get("element_id"),
                    "element_table" => $this->_get("element_table"),
                )) === NULL ? false : true;

        if (!$success && $throwEx) {
            $lock = Lock::getLock($this->_get("element_id"), $this->_get("element_table"));
            throw new \Exception($lock->_get("last_lock_by"), \app\constants\ResponseCodes::LOCKED);
        }
        return $success;
    }

    public function unlock($by = false) {
        if ($by === false) {
            try {
                $user = \app\classes\BasicUser::getLoggedUser();
                $by = $user->_get("email");
            } catch (\Exception $ex) {
                return false;
            }
        }

        $db = \app\classes\PDODatabase::getInstance();
        $db->sqlCommand("UPDATE locks SET last_lock=:last_lock, last_lock_by=:last_lock_by WHERE element_id=:element_id AND element_table=:element_table "
                . "AND (last_lock_by=:last_lock_by OR last_lock < :last_lock_cond)", array(
            "last_lock" => date("Y-m-d H:i:s", $this->time - 5 * self::LOCK_INTERVAL),
            "last_lock_by" => $by,
            "element_id" => $this->_get("element_id"),
            "element_table" => $this->_get("element_table"),
            "last_lock_cond" => date("Y-m-d H:i:s", time() - 2.5 * self::LOCK_INTERVAL)
        ));
    }

}