#!/usr/bin/env php
<?php
/**
* This file is part of PDepend.
*
* PHP Version 5
*
* Copyright (c) 2008-2013, Manuel Pichler <mapi@pdepend.org>.
* 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 Manuel Pichler 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.
*
* @copyright 2008-2013 Manuel Pichler. All rights reserved.
* @license http://www.opensource.org/licenses/bsd-license.php BSD License
*/

namespace PDepend;

/**
* Utility class that we use to recalculate the cache hash/version.
*
* @copyright 2008-2013 Manuel Pichler. All rights reserved.
* @license http://www.opensource.org/licenses/bsd-license.php BSD License
*/
class CacheVersionUpdater
{
/**
* The source directory.
*
* @var string
*/
private $rootDirectory = null;

/**
* The source sub directories that we will process.
*
* @var array(string)
*/
private $localPaths = array(
'/Source',
'/Metrics',
);

/**
* The target file, where this script will persist the new cache version.
*
* @var string
*/
private $targetFile = '/Util/Cache/CacheDriver.php';

/**
* Regular expression used to replace a previous cache version.
*
* @var string
*/
private $targetRegexp = '(@version:[a-f0-9]{32}:@)';

/**
* Constructs a new cache version updater instance.
*/
public function __construct()
{
$this->rootDirectory = realpath(dirname(__FILE__) . '/../src/main/php/PDepend');
}

/**
* Processes all source files and generates a combined version for all files.
* The it replaces the old version key within the project source with the
* newly calculated value.
*
* @return void
*/
public function run()
{
$checksum = '';

foreach ($this->localPaths as $localPath) {
$path = $this->rootDirectory . $localPath;
foreach ($this->readFiles($path) as $file) {
$checksum = $this->hash($file, $checksum);
}
}

$file = $this->rootDirectory . $this->targetFile;

$code = file_get_contents($file);
$code = preg_replace($this->targetRegexp, "@version:{$checksum}:@", $code);
file_put_contents($file, $code);
}

/**
* Generates a hash value for the given <b>$path</b> in combination with a
* previous calculated <b>$checksum</b>.
*
* @param string $path Path to the current context file.
* @param string $checksum Hash/Checksum for all previously parsed files.
* @return string
*/
protected function hash($path, $checksum)
{
return md5($checksum . md5_file($path));
}

/**
* Reads all files below the given <b>$path</b>.
*
* @param string $path The parent directory or a file.
* @return array(string)
*/
protected function readFiles($path)
{
if ($this->accept($path)) {
return array($path);
}
$files = array();
foreach ($this->createFileIterator($path) as $file) {
if ($this->accept($file)) {
$files[] = (string) $file;
}
}
return $files;
}

/**
* Does the given path represent a file that has the expected file extension?
*
* @param string $path Path to a file or directory.
* @return boolean
*/
protected function accept($path)
{
return (is_file($path) && '.php' === substr($path, -4, 4));
}

/**
* Creates an iterator with all files below the given directory.
*
* @param string $path Path to a directory.
* @return \Iterator
*/
protected function createFileIterator($path)
{
return new \RecursiveIteratorIterator(
new \RecursiveDirectoryIterator($path)
);
}

/**
* The main method starts the cache version updater.
*
* @param array $args Cli arguments.
* @return void
*/
public static function main(array $args)
{
$updater = new CacheVersionUpdater();
$updater->run();
}
}

CacheVersionUpdater::main($_SERVER['argv']);