<?php
/**
 * GlobalState
 *
 * Copyright (c) 2001-2014, 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.
 *
 * @author     Sebastian Bergmann <sebastian@phpunit.de>
 * @copyright  2001-2014 Sebastian Bergmann <sebastian@phpunit.de>
 * @license    http://www.opensource.org/licenses/BSD-3-Clause  The BSD 3-Clause License
 * @link       http://www.github.com/sebastianbergmann/global-state
 */

namespace SebastianBergmann\GlobalState;

use ReflectionProperty;

/**
 * Restorer of snapshots of global state.
 *
 * @author     Sebastian Bergmann <sebastian@phpunit.de>
 * @copyright  2001-2014 Sebastian Bergmann <sebastian@phpunit.de>
 * @license    http://www.opensource.org/licenses/BSD-3-Clause  The BSD 3-Clause License
 * @link       http://www.github.com/sebastianbergmann/global-state
 */
class Restorer
{
    /**
     * Deletes function definitions that are not defined in a snapshot.
     *
     * @param  Snapshot $snapshot
     * @throws RuntimeException when the uopz_delete() function is not available
     * @see    https://github.com/krakjoe/uopz
     */
    public function restoreFunctions(Snapshot $snapshot)
    {
        if (!function_exists('uopz_delete')) {
            throw new RuntimeException('The uopz_delete() function is required for this operation');
        }

        $functions = get_defined_functions();

        foreach (array_diff($functions['user'], $snapshot->functions()) as $function) {
            uopz_delete($function);
        }
    }

    /**
     * Restores all global and super-global variables from a snapshot.
     *
     * @param Snapshot $snapshot
     */
    public function restoreGlobalVariables(Snapshot $snapshot)
    {
        $superGlobalArrays = $snapshot->superGlobalArrays();

        foreach ($superGlobalArrays as $superGlobalArray) {
            $this->restoreSuperGlobalArray($snapshot, $superGlobalArray);
        }

        $globalVariables = $snapshot->globalVariables();

        foreach (array_keys($GLOBALS) as $key) {
            if ($key != 'GLOBALS' &&
                !in_array($key, $superGlobalArrays) &&
                !$snapshot->blacklist()->isGlobalVariableBlacklisted($key)) {
                if (isset($globalVariables[$key])) {
                    $GLOBALS[$key] = $globalVariables[$key];
                } else {
                    unset($GLOBALS[$key]);
                }
            }
        }
    }

    /**
     * Restores all static attributes in user-defined classes from this snapshot.
     *
     * @param Snapshot $snapshot
     */
    public function restoreStaticAttributes(Snapshot $snapshot)
    {
        foreach ($snapshot->staticAttributes() as $className => $staticAttributes) {
            foreach ($staticAttributes as $name => $value) {
                $reflector = new ReflectionProperty($className, $name);
                $reflector->setAccessible(true);
                $reflector->setValue($value);
            }
        }
    }

    /**
     * Restores a super-global variable array from this snapshot.
     *
     * @param Snapshot $snapshot
     * @param $superGlobalArray
     */
    private function restoreSuperGlobalArray(Snapshot $snapshot, $superGlobalArray)
    {
        $superGlobalVariables = $snapshot->superGlobalVariables();

        if (isset($GLOBALS[$superGlobalArray]) &&
            is_array($GLOBALS[$superGlobalArray]) &&
            isset($superGlobalVariables[$superGlobalArray])) {
            $keys = array_keys(
                array_merge(
                    $GLOBALS[$superGlobalArray],
                    $superGlobalVariables[$superGlobalArray]
                )
            );

            foreach ($keys as $key) {
                if (isset($superGlobalVariables[$superGlobalArray][$key])) {
                    $GLOBALS[$superGlobalArray][$key] = $superGlobalVariables[$superGlobalArray][$key];
                } else {
                    unset($GLOBALS[$superGlobalArray][$key]);
                }
            }
        }
    }
}