<?php 
class files{
	
	/**
	* upload
	*
	* 文件上传
	*
	* @param String $path   e.g. could be the relative path of web htdocs directory
	* @param Array  $files  e.g. $_FILES['Filedata']
	* @param String $dir    e.g. $_POST['dir']
	*
	* return Array $msg  e.g. if($msg['error']) 
	*/
	static function upload($path,$files,$dir)
	{
		$msg=array();
		
		//文件保存目录路径
		$save_path = $path;
		//文件保存目录URL
		$save_url = $path;
		//定义允许上传的文件扩展名
		$ext_arr = array(
			'image' => array('gif', 'jpg', 'jpeg', 'png', 'bmp'),
			'flash' => array('swf', 'flv'),
			'media' => array('swf', 'flv', 'mp3', 'wav', 'wma', 'wmv', 'mid', 'avi', 'mpg', 'asf', 'rm', 'rmvb'),
			'file' => array('doc', 'docx', 'xls', 'xlsx', 'ppt', 'htm', 'html', 'txt', 'zip', 'rar', 'gz', 'bz2'),
			'reviewatt'=>array('doc', 'docx', 'xls', 'xlsx', 'ppt', 'htm', 'html', 'txt', 'zip', 'rar', 'gz', 'bz2','gif', 'jpg', 'jpeg', 'png', 'bmp','pdf','odt'),
			'md'=>array('doc', 'docx', 'xls', 'xlsx', 'ppt', 'htm', 'html', 'txt', 'zip', 'rar', 'gz', 'bz2','gif', 'jpg', 'jpeg', 'png', 'bmp','pdf','odt')
		);
		//最大文件大小
		$max_size = 10485760;
		
		//$save_path = realpath($save_path). '/';
		
		//有上传文件时
		if (empty($files) === false) {
			//原文件名
			$file_name = $files['name'];
			//服务器上临时文件名
			$tmp_name = $files['tmp_name'];
			//文件大小
			$file_size = $files['size'];
			//目录名
			$dir_name = empty($dir) ? 'image' : trim($dir);
			//检查文件名
			if (!$file_name) {
				$msg['error'] = "请选择文件。";
			}
			//检查目录
			else if (@is_dir($save_path) === false) {
				$msg['error'] = "上传目录不存在。请联系管理员";
			}
			//检查目录写权限
			else if (@is_writable($save_path) === false) {
				$msg['error'] = "上传目录没有写权限。请联系管理员";
			}
			//检查是否已上传
			else if (@is_uploaded_file($tmp_name) === false) {
				$msg['error'] = "临时文件可能不是上传文件。或者文件类型不在允许的范围内，请重新上传";
			}
			//检查文件大小
			else if ($file_size > $max_size) {
				$msg['error'] = "上传文件大小超过限制。";
			}
			//检查目录名
			else if (empty($ext_arr[$dir_name])) {
				$msg['error'] = "目录名不正确。";
			}
			else
			{
				//获得文件扩展名
				$temp_arr = explode(".", $file_name);
				$file_ext = array_pop($temp_arr);
				$file_ext = trim($file_ext);
				$file_ext = strtolower($file_ext);
				//检查扩展名
				if (in_array($file_ext, $ext_arr[$dir_name]) === false) {
					$msg['error'] = "上传文件扩展名是不允许的扩展名。\n只允许" . implode(",", $ext_arr[$dir_name]) . "格式。";
				}
				else
				{
					//创建文件夹
					
					$dbsave = ""; //数据库中存放的路径
					
					if ($dir_name !== '') {
						$save_path .= $dir_name . "/";
						$save_url .= $dir_name . "/";
						$dbsave = $dir_name.'/';
						if (!file_exists($save_path)) {
							mkdir($save_path);
						}
					}
					
					$y = date("Y");
					$m = date("m");
					$d = date("d");
								
					$save_path .= $y . "/";
					$save_url .= $y . "/";
					$dbsave .= $y.'/';
					if (!file_exists($save_path)) {
						mkdir($save_path);
					}
					
					$save_path .= $m . "/";
					$save_url .= $m . "/";
					$dbsave .= $m.'/';
					if (!file_exists($save_path)) {
						mkdir($save_path);
					}
					
					$save_path .= $d . "/";
					$save_url .= $d . "/";
					$dbsave .= $d.'/';
					if (!file_exists($save_path)) {
						mkdir($save_path);
					}
					
					//新文件名
					$new_file_name = date("YmdHis") . '_' . rand(10000, 99999) . '.' . $file_ext;
					//移动文件
					$file_path = $save_path . $new_file_name;
					
					if (move_uploaded_file($tmp_name, $file_path) === false) {
						$msg['error'] = "上传文件失败。";
					}
					//数据库最终存储的文件
					$dbsave .= $new_file_name; 
					@chmod($file_path, 0644);
					$file_url = $save_url . $new_file_name;
					$msg['file_url'] = $file_url;
					$msg['file_size'] = $file_size;
					$msg['db_path'] = $dbsave;
					$msg['realname'] = $file_name;
					$msg['file_type'] = $dir_name;
				}//检查扩展名
			}//目录正确性
			return $msg;
		}
	}//文件上传
	
	
	
	/**
	* downloadFile
	*
	* 文件下载
	*
	* @param String $fullPath   e.g. Zend_Registry::get('upload').$fileurl
	*
	* return file
	*/
	static function downloadFile( $fullPath ){
			
		  //判断是否已经输出头部
		  if( headers_sent() )
		  {
			  return false;
		  }
		  else{
			
			  // Required for some browsers
			  @apache_setenv('no-gzip', 1);
			  @ini_set('zlib.output_compression', 0); 
			
			  // File Exists?
			  if( file_exists($fullPath) ){
			   
				// Parse Info / Get Extension
				$fsize = filesize($fullPath);
				$path_parts = pathinfo($fullPath);
				$ext = strtolower($path_parts["extension"]);
			   
				// Determine Content Type
				switch ($ext) {
				  case "pdf": $ctype="application/pdf"; break;
				  case "exe": $ctype="application/octet-stream"; break;
				  case "zip": $ctype="application/zip"; break;
				  case "doc": $ctype="application/msword"; break;
				  case "xls": $ctype="application/vnd.ms-excel"; break;
				  case "ppt": $ctype="application/vnd.ms-powerpoint"; break;
				  case "gif": $ctype="image/gif"; break;
				  case "png": $ctype="image/png"; break;
				  case "jpeg":
				  case "jpg": $ctype="image/jpg"; break;
				  default: $ctype="application/force-download";
				}
				
				header('Content-Description: File Transfer');
				header("Cache-Control: private",false);
				header("Content-Type: $ctype");
				header("Content-Disposition: attachment; filename=\"".basename($fullPath)."\";" );
				header("Content-Transfer-Encoding: binary\n");
				header("Expires: 0");
				header("Cache-Control: must-revalidate, post-check=0, pre-check=0");
				header("Pragma: public");
				header("Content-Length: ".$fsize);
				ob_clean();
				flush();
				if(readfile($fullPath))
				return true;
				else
				return false;
			} else				
				{return false;}
			}
		} //文件下载
		
}