<?php

namespace Mvc\Model\Behavior;

use \Phalcon\Mvc\Model\Behavior;
use \Phalcon\Mvc\Model\BehaviorInterface;
use \Phalcon\Exception;

/**
 * Generates a unique base64 url-safe id for the field specified.
 *
 * Class RandomId
 * @package Mvc\Model\Behavior
 */
class RandomId extends Behavior implements BehaviorInterface
{
    public function __construct($options = null)
    {
        $field = null;
        if (isset($options['field'])) {
            $field = $options['field'];
        }

        if (isset($options['length'])) {
            if (!is_numeric($options['length'])) {
                throw new Exception("'length' must be a number.");
            }
        } else {
            $options['length'] = 32;
        }

        if (strlen($field) < 1) {
            throw new Exception("'field' must be set in the option array.");
        }
        parent::__construct($options);
    }

    public function notify($type, \Phalcon\Mvc\ModelInterface $model)
    {
        switch($type) {
        case 'beforeValidationOnCreate' :
            $this->generateId($model);
            break;
        }
    }

    public function generateId(\Phalcon\Mvc\ModelInterface $model)
    {
        $field = $this->_options['field'];

        if ($model->$field === null) {

            $random = new \Phalcon\Security\Random();
            for($i = 0; $i < 3; $i++) {
                $id = $random->base64Safe();
                $id = substr($id, 0, $this->_options['length']);

                $count = $model->count(array(
                    "$field = ?0",
                    'bind' => array($id)
                ));

                if ($count < 1) {
                    $model->$field = $id;
                    break;
                }
            }
        }
    }
}