<?php
/**
 * Easy going file access. Obligatory Layer.
 * @author Axel Benz
 * @package file_system_access
 *
 */

//require_once(realpath(dirname(__FILE__)).DIRECTORY_SEPARATOR.
//	"../error_handling/error_handling.php");

class easy_file{

	const invalid_characters = "^°\"§\$%&/()[]{}=?`´ß@€*+~'#<>|,;:äöüÄÖÜ ";

	/**
	 * Write a file, overwrite if it is already there
	 *
	 * @param string $filename
	 * The path to the file to write and the filename.
	 * Must NOT be an URL, but a file system path!
	 * @param string $content
	 * The content to write
	 */
	public static function write($filename, $content){
		error_reporting(E_ERROR);
		$handle=fopen($filename,"wb");
		fwrite($handle,$content);
		fclose($handle);
		error_reporting(E_ALL);
	}

	/**
	 * Test whether a file exists
	 *
	 * @param string $filename
	 * The path to the file and the filename
	 * @return boolean
	 * True, iff file exists.
	 */
	public static function exists($filename){
		clearstatcache();
		return file_exists($filename);
	}


	/**
	 * Test, whether something is a file
	 *
	 * @param string $path
	 * The path to the file to test.
	 * @return boolean
	 * True, if it is a regular file.
	 */
	public static function is_file($path){
		clearstatcache();
		return is_file($path);
	}

	/**
	 * Test, whether something is a directory
	 *
	 * @param string $path
	 * The path to test.
	 * @return boolean
	 * True, if it is a directory.
	 */
	public static function is_dir($path){
		clearstatcache();
		return is_dir($path);
	}

	/**
	 * Read a whole file into a string.
	 *
	 * @param string $filename
	 * The path to the file and the filename
	 * @return string
	 * The content of the file
	 */
	public static function read($filename){
		return file_get_contents($filename);
	}

	/**
	 * Read a whole file into a array of strings (linewise).
	 *
	 * @param string $filename
	 * @return string[]
	 */
	public static function read_lines($filename){
		return explode("\n",self::read($filename));
	}

	/**
	 * Delete a file
	 *
	 * @param string $filename
	 * The path to the file and the filename
	 */
	public static function delete($filename){
		return unlink($filename);
	}

	/**
	 * Copy a file
	 *
	 * @param string $old_file
	 * Filename an path of the file to copy
	 * @param string $new_file
	 * Filename and path of the file to create
	 */
	public static function copy($old_file,$new_file){
		$res = copy($old_file, $new_file);
	}

	/**
	 * Validates a filename
	 *
	 * @param string $file
	 * The filename to validate
	 *
	 * @return boolean
	 * true, if filename is valid
	 */
	public static function is_filename($file){
		foreach (str_split(self::invalid_characters) as $chr){
			if (!(strpos($file,$chr)===false)){
				return false;
			}
		}
		return true;
	}

	/**
	 * Removes ".."  and "." from any given path.
	 * Works also with urls.
	 *
	 * @param string $path
	 */
	public static function clean_path($path){
		$path=str_replace("\\","/",$path);
		$path_ar = explode("/",$path);
		#remove the "."
		foreach ($path_ar as $i=>$pathelement){
			if ($pathelement=="."){
				unset($path_ar[$i]);
			}
		}

		#remove the ".."
		foreach ($path_ar as $i=>$pathelement){
			if ($pathelement==".."){
				unset($path_ar[$i]);
				$j=$i-1;
				while (! isset($path_ar[$j]) and $j>0){
					$j--;
				}
				unset($path_ar[$j]);
			}
		}
		return implode("/",$path_ar);
	}
}
?>