<?php

namespace Box\Spout\Common\Helper;

use Box\Spout\Common\Exception\IOException;

/**
* Class FileSystemHelper
* This class provides helper functions to help with the file system operations
* like files/folders creation & deletion
*
* @package Box\Spout\Common\Helper
*/
class FileSystemHelper
{
/** @var string Real path of the base folder where all the I/O can occur */
protected $baseFolderRealPath;

/**
* @param string $baseFolderPath The path of the base folder where all the I/O can occur
*/
public function __construct($baseFolderPath)
{
$this->baseFolderRealPath = realpath($baseFolderPath);
}

/**
* Creates an empty folder with the given name under the given parent folder.
*
* @param string $parentFolderPath The parent folder path under which the folder is going to be created
* @param string $folderName The name of the folder to create
* @return string Path of the created folder
* @throws \Box\Spout\Common\Exception\IOException If unable to create the folder or if the folder path is not inside of the base folder
*/
public function createFolder($parentFolderPath, $folderName)
{
$this->throwIfOperationNotInBaseFolder($parentFolderPath);

$folderPath = $parentFolderPath . '/' . $folderName;

$wasCreationSuccessful = mkdir($folderPath, 0777, true);
if (!$wasCreationSuccessful) {
throw new IOException("Unable to create folder: $folderPath");
}

return $folderPath;
}

/**
* Creates a file with the given name and content in the given folder.
* The parent folder must exist.
*
* @param string $parentFolderPath The parent folder path where the file is going to be created
* @param string $fileName The name of the file to create
* @param string $fileContents The contents of the file to create
* @return string Path of the created file
* @throws \Box\Spout\Common\Exception\IOException If unable to create the file or if the file path is not inside of the base folder
*/
public function createFileWithContents($parentFolderPath, $fileName, $fileContents)
{
$this->throwIfOperationNotInBaseFolder($parentFolderPath);

$filePath = $parentFolderPath . '/' . $fileName;

$wasCreationSuccessful = file_put_contents($filePath, $fileContents);
if ($wasCreationSuccessful === false) {
throw new IOException("Unable to create file: $filePath");
}

return $filePath;
}

/**
* Delete the file at the given path
*
* @param string $filePath Path of the file to delete
* @return void
* @throws \Box\Spout\Common\Exception\IOException If the file path is not inside of the base folder
*/
public function deleteFile($filePath)
{
$this->throwIfOperationNotInBaseFolder($filePath);

if (file_exists($filePath) && is_file($filePath)) {
unlink($filePath);
}
}

/**
* Delete the folder at the given path as well as all its contents
*
* @param string $folderPath Path of the folder to delete
* @return void
* @throws \Box\Spout\Common\Exception\IOException If the folder path is not inside of the base folder
*/
public function deleteFolderRecursively($folderPath)
{
$this->throwIfOperationNotInBaseFolder($folderPath);

$itemIterator = new \RecursiveIteratorIterator(
new \RecursiveDirectoryIterator($folderPath, \RecursiveDirectoryIterator::SKIP_DOTS),
\RecursiveIteratorIterator::CHILD_FIRST
);

foreach ($itemIterator as $item) {
if ($item->isDir()) {
rmdir($item->getPathname());
} else {
unlink($item->getPathname());
}
}

rmdir($folderPath);
}

/**
* All I/O operations must occur inside the base folder, for security reasons.
* This function will throw an exception if the folder where the I/O operation
* should occur is not inside the base folder.
*
* @param string $operationFolderPath The path of the folder where the I/O operation should occur
* @return void
* @throws \Box\Spout\Common\Exception\IOException If the folder where the I/O operation should occur is not inside the base folder
*/
protected function throwIfOperationNotInBaseFolder($operationFolderPath)
{
$operationFolderRealPath = realpath($operationFolderPath);
$isInBaseFolder = (strpos($operationFolderRealPath, $this->baseFolderRealPath) === 0);
if (!$isInBaseFolder) {
throw new IOException("Cannot perform I/O operation outside of the base folder: {$this->baseFolderRealPath}");
}
}
}