<?php

namespace Metadata\Cache;

use Metadata\ClassMetadata;

class FileCache implements CacheInterface
{
private $dir;

public function __construct($dir)
{
if (!is_dir($dir)) {
throw new \InvalidArgumentException(sprintf('The directory "%s" does not exist.', $dir));
}

$this->dir = rtrim($dir, '\\/');
}

/**
* {@inheritDoc}
*/
public function loadClassMetadataFromCache(\ReflectionClass $class)
{
$path = $this->dir.'/'.strtr($class->name, '\\', '-').'.cache.php';
if (!file_exists($path)) {
return null;
}

return include $path;
}

/**
* {@inheritDoc}
*/
public function putClassMetadataInCache(ClassMetadata $metadata)
{
if (!is_writable($this->dir)) {
throw new \InvalidArgumentException(sprintf('The directory "%s" is not writable.', $this->dir));
}

$path = $this->dir.'/'.strtr($metadata->name, '\\', '-').'.cache.php';

$tmpFile = tempnam($this->dir, 'metadata-cache');
file_put_contents($tmpFile, '<?php return unserialize('.var_export(serialize($metadata), true).');');

// Let's not break filesystems which do not support chmod.
@chmod($tmpFile, 0666 & ~umask());

$this->renameFile($tmpFile, $path);
}

/**
* Renames a file with fallback for windows
*
* @param string $source
* @param string $target
*/
private function renameFile($source, $target) {
if (false === @rename($source, $target)) {
if (defined('PHP_WINDOWS_VERSION_BUILD')) {
if (false === copy($source, $target)) {
throw new \RuntimeException(sprintf('(WIN) Could not write new cache file to %s.', $target));
}
if (false === unlink($source)) {
throw new \RuntimeException(sprintf('(WIN) Could not delete temp cache file to %s.', $source));
}
} else {
throw new \RuntimeException(sprintf('Could not write new cache file to %s.', $target));
}
}
}

/**
* {@inheritDoc}
*/
public function evictClassMetadataFromCache(\ReflectionClass $class)
{
$path = $this->dir.'/'.strtr($class->name, '\\', '-').'.cache.php';
if (file_exists($path)) {
unlink($path);
}
}
}