<?php
/**
 * PHPUnit
 *
 * Copyright (c) 2002-2011, Sebastian Bergmann <sebastian@phpunit.de>.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *   * Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *
 *   * Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in
 *     the documentation and/or other materials provided with the
 *     distribution.
 *
 *   * Neither the name of Sebastian Bergmann nor the names of his
 *     contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 * @package    PHPUnit
 * @subpackage Framework_Constraint
 * @author     Sebastian Bergmann <sebastian@phpunit.de>
 * @copyright  2002-2011 Sebastian Bergmann <sebastian@phpunit.de>
 * @license    http://www.opensource.org/licenses/BSD-3-Clause  The BSD 3-Clause License
 * @link       http://www.phpunit.de/
 */

/**
 * Constraint that evaluates against a specified closure.
 *
 * @package    PHPUnit
 * @subpackage Framework_Constraint
 * @author     Sebastian Bergmann <sebastian@phpunit.de>
 * @author     Timon Rapp <timon@zaeda.net>
 * @copyright  2002-2011 Sebastian Bergmann <sebastian@phpunit.de>
 * @license    http://www.opensource.org/licenses/BSD-3-Clause  The BSD 3-Clause License
 * @link       http://www.phpunit.de/
 */
class PHPUnit_Framework_Constraint_Callback extends PHPUnit_Framework_Constraint
{
    private $callback;

    /**
     * @param callable $value
     * @throws InvalidArgumentException
     */
    public function __construct($callback)
    {
        if (!is_callable($callback)) {
            throw new InvalidArgumentException(
              sprintf(
                'Specified callback <%s> is not callable.',
                $this->callbackToString($callback)
              )
            );
        }
        $this->callback = $callback;
    }

    /**
     * Evaluates the constraint for parameter $value. Returns TRUE if the
     * constraint is met, FALSE otherwise.
     *
     * @param mixed $value Value or object to evaluate.
     * @return bool
     */
    protected function matches($other)
    {
        return call_user_func($this->callback, $other);
    }

    /**
     * Returns a string representation of the constraint.
     *
     * @return string
     */
    public function toString()
    {
        return 'is accepted by specified callback';
    }

    private function callbackToString($callback)
    {
        if (!is_array($callback)) {
            return $callback;
        }
        if (empty($callback)) {
            return "empty array";
        }
        if (!isset($callback[0]) || !isset($callback[1])) {
            return "array without indexes 0 and 1 set";
        }
        if (is_object($callback[0])) {
            $callback[0] = get_class($callback[0]);
        }
        return $callback[0] . '::' . $callback[1];
    }

}
