<?php 
/**
 * The Feeler framework, licensed under LGPL license
 * Author: Rick Guo
 */

defined("HEAD") or define("HEAD", 1);
defined("END") or define("END", 2);

class File{
	public $segLength = 524288; //to read and write slice in segments, this set every segment's length
	public $state = true;
	public $position = 0;
	
	protected $handle;
	protected $fileSize;
	protected $file;

	function __construct($file, $mode = "r", $pointer = null, $override = false){
		$this->init($file, $mode, $pointer, $override);
	}
	
	function __destruct(){
		if(is_resource($this->handle))
			fclose($this->handle);
	}
	
	public function init($file, $mode = "r", $pointer = null, $override = false){
		if(!is_file($file)){
			$this->state = false;
			return false;
		}
		
		$lockMode = LOCK_SH;
		
		if($mode == "r"){
			$modeParam = "r";
		}
		else if($mode == "w"){
			if(!$pointer)
				$pointer = END;
			
			if($override)
				$modeParam = "w";
			else{
				if($pointer == HEAD){
					$modeParam = "c";
				}
				else if($pointer == END){
					$modeParam = "a";
				}
			}
		}
		else if($mode == "rw"){
			if(!$pointer)
				$pointer = HEAD;
			
			if($override)
				$modeParam = "w+";
			else{
				if($pointer == HEAD){
					$modeParam = "r+";
				}
				else if($pointer == END){
					$modeParam = "a+";
				}
			}
		}
		else{
			$this->state = false;
			return false;
		}
		
		if($modeParam != "r")
			$lockMode = LOCK_EX;
		
		$this->handle = fopen($file, $modeParam);
		
		if(!$this->lock($lockMode)){
			$this->state = false;
			return false;
		}
		
		$this->file = $file;
		$this->fileSize = filesize($this->file);
	}
	
	public function getContent($length = -1, $position = null){
		if(!$this->state)
			return null;
		
		if($position === null)
			$position = $this->position;
		
		if($position < 0)
			return null;
		
		if($length === -1)
			$length = $this->fileSize;
		
		$this->seek($position);
		if($length <= $this->segLength || ($this->fileSize - $position) < $this->segLength){
			return fread($this->handle, $length);
		}
		
		$data = null;
		$round = ceil($length / $this->segLength);
		
		for($i = 0; $i < $round; $i++){
			$data .= fread($this->handle, $this->segLength);
			
			if($position == 0){
				$this->seek(($position += $this->segLength + 1));
			}
			else{
				$this->seek(($position += $this->segLength));
			}
		}
		
		return $data;
	}
	
	public function seek($position = 0){
		return fseek($this->handle, $position);
	}
	
	public function write($data, $length = -1){
		if(!$this->state || !$data)
			return false;
		
		if($length === -1)
			return fwrite($this->handle, $data);
		
		if($length > 0)
			return fwrite($this->handle, $data, $length);
		
		return false;
	}
	
	public function lock($mode = LOCK_EX){
		return flock($this->handle, $mode);
	}
	
	public function unlock(){
		return flock($this->handle, LOCK_UN);
	}
	
	public static function create($file){
		return fopen($file, "w") !== false ? true : false;
	}
	
	public static function save($file, $content, $length = -1){
		$fileObj = new self($file, "w", null, true);
		return $fileObj->write($content, $length);
	}

	//make new dirs, will create all unexist dirs on the path
	public static function mkdir($path, $chmod = 0755){
		return is_dir($path) || (self::mkdir(dirname($path), $chmod) && mkdir($path, $chmod));
	}
	
	public static function rm($target, $recursive = false){
		if(file_exists($target)){
			if($recursive){
				if(is_dir($target)){
					$handle = opendir($target);
					
					while($subTarget = readdir($handle)){
						if($subTarget !== "." && $subTarget !== ".."){
							$position = "{$target}/{$subTarget}";
							
							if(is_dir($position)){
								self::rm($position);
							}
							else{
								unlink($position);
							}
						}
					}
					
					closedir($handle);
					
					if(rmdir($target)){
						return true;
					}
				}
			}
			
			if(is_file($target)){
				return unlink($target);
			}
		}
		
		return false;
	}
	
	public static function rmdir($dir){
		return self::rm($dir, true);
	}
	
	//read the first and last 512byte data and convert to hex then check it whether have trojans signature code or not
	public static function checkHex($file){
		$handle = fopen($file, "rb");
		$fileSize = filesize($file);
		fseek($handle, 0);
		
		if($fileSize > 512){
			$hexCode = bin2hex(fread($handle, 512));
			fseek($handle, $fileSize - 512);
			$hexCode .= bin2hex(fread($handle, 512));
		}
		else{
			$hexCode = bin2hex(fread($handle, $fileSize));
		}
		fclose($handle);
		/**
		 * match <% (  ) %> 
		 * 		 <? (  ) ?> 
		 * 		 <script  /script> 
		 */
		if(preg_match("/(3c25.*?28.*?29.*?253e)|(3c3f.*?28.*?29.*?3f3e)|(3C534352495054.*?2F5343524950543E)|(3C736372697074.*?2F7363726970743E)/is", $hexCode))
			return false;
		else
			return true;
	}
	
	//get the extension of the file
	public static function getExt($fileName){
		if(is_file($fileName)){
			$fileInfo = pathinfo($fileName);
			return isset($fileInfo["extension"]) ? $fileInfo["extension"] : null;
		}
		else{
			return strtolower(substr(strrchr($fileName, "."), 1));
		}
	}
	
	public static function getName($fileName){
		if(preg_match("/^.*\/(.*)(?:\..*)$/", $fileName, $matches)){
			return $matches[1];
		}
		
		return null;
	}
	
	public static function getFullName($file){
		if(preg_match("/^.*\/(.*\..*)$/", $file, $matches)){
			return $matches[1];
		}
		
		return null;
	}
	
	public static function getPath($file){
		if(preg_match("/^(.*\/)(.*\..*)$/", $file, $matches)){
			return $matches[1];
		}
	
		return null;
	}
	
	//get file size
	public static function getSize($file){
		return is_file($file) ? filesize($file) : null;
	}
	
    public static function getTypeList(){
    	return array(
	    	"255216" => "jpg",
			"13780" => "png",
			"7173" => "gif",
			"6677" => "bmp",
			"6063" => "xml",
			"60104" => "html",
			"208207" => array("xls", "doc"),
			"8075" => array("zip", "docx", "xlsx"),
			"8297" => "rar",
    	);
    }
	
	//get file's type according to start of 2bytes binary data
	public static function getType($file){
		if(!is_file($file)){
			return null;
		}
		
		$handle = fopen($file, "rb");
	    if(!$handle){
			return null;
		}
        $bin = fread($handle, 2);
        fclose($handle);
		
        if($bin){
        	$strs = unpack("C2str", $bin);
        	
	        $typeCode = $strs["str1"].$strs["str2"];
			$types = self::getTypeList();
			
			foreach($types as $key => $type){
				if((string)$key === $typeCode){
					return $type;
				}
			}
        }
        
		return null;
	}
}