<?php
/**
 * Zend Framework (http://framework.zend.com/)
 *
 * @link      http://github.com/zendframework/zf2 for the canonical source repository
 * @copyright Copyright (c) 2005-2014 Zend Technologies USA Inc. (http://www.zend.com)
 * @license   http://framework.zend.com/license/new-bsd New BSD License
 */

namespace Zend\Validator;

class Callback extends AbstractValidator
{
    /**
     * Invalid callback
     */
    const INVALID_CALLBACK = 'callbackInvalid';

    /**
     * Invalid value
     */
    const INVALID_VALUE = 'callbackValue';

    /**
     * Validation failure message template definitions
     *
     * @var array
     */
    protected $messageTemplates = array(
        self::INVALID_VALUE    => "The input is not valid",
        self::INVALID_CALLBACK => "An exception has been raised within the callback",
    );

    /**
     * Default options to set for the validator
     *
     * @var mixed
     */
    protected $options = array(
        'callback'         => null,     // Callback in a call_user_func format, string || array
        'callbackOptions'  => array(),  // Options for the callback
    );

    /**
     * Constructor
     *
     * @param array|callable $options
     */
    public function __construct($options = null)
    {
        if (is_callable($options)) {
            $options = array('callback' => $options);
        }

        parent::__construct($options);
    }

    /**
     * Returns the set callback
     *
     * @return mixed
     */
    public function getCallback()
    {
        return $this->options['callback'];
    }

    /**
     * Sets the callback
     *
     * @param  string|array|callable $callback
     * @return Callback Provides a fluent interface
     * @throws Exception\InvalidArgumentException
     */
    public function setCallback($callback)
    {
        if (!is_callable($callback)) {
            throw new Exception\InvalidArgumentException('Invalid callback given');
        }

        $this->options['callback'] = $callback;
        return $this;
    }

    /**
     * Returns the set options for the callback
     *
     * @return mixed
     */
    public function getCallbackOptions()
    {
        return $this->options['callbackOptions'];
    }

    /**
     * Sets options for the callback
     *
     * @param  mixed $options
     * @return Callback Provides a fluent interface
     */
    public function setCallbackOptions($options)
    {
        $this->options['callbackOptions'] = (array) $options;
        return $this;
    }

    /**
     * Returns true if and only if the set callback returns
     * for the provided $value
     *
     * @param  mixed $value
     * @param  mixed $context Additional context to provide to the callback
     * @return bool
     * @throws Exception\InvalidArgumentException
     */
    public function isValid($value, $context = null)
    {
        $this->setValue($value);

        $options  = $this->getCallbackOptions();
        $callback = $this->getCallback();
        if (empty($callback)) {
            throw new Exception\InvalidArgumentException('No callback given');
        }

        $args = array($value);
        if (empty($options) && !empty($context)) {
            $args[] = $context;
        }
        if (!empty($options) && empty($context)) {
            $args = array_merge($args, $options);
        }
        if (!empty($options) && !empty($context)) {
            $args[] = $context;
            $args   = array_merge($args, $options);
        }

        try {
            if (!call_user_func_array($callback, $args)) {
                $this->error(self::INVALID_VALUE);
                return false;
            }
        } catch (\Exception $e) {
            $this->error(self::INVALID_CALLBACK);
            return false;
        }

        return true;
    }
}