<?

/**********************************************************************************************************\
* This function takes a reference to a variable in the calling scope which will be set as the file  	   *
* name of the uploaded file.  It's purpose is to process the information in the $_FILES array to 		   *
* determine if an upload successfully occurred and, if so, to take the necessary steps to save that	       *
* file and to prepare information for the database.  It returns an array whose first index is a boolean    *
* and second index is either the new file name, if no errors occured, or an error code.  The boolean is    *
* true on an error case and false otherwise.                                                               *
\**********************************************************************************************************/

function process_upload($file_field_name, $destination) {
	global $FILE_ROOT;
	list($fname, $ftype, $ftemp, $ferror, $fsize) = array_values($_FILES[$file_field_name]);
	if($ferror != 0) return array(true, get_error_code($ferror));							
		
	$destination = strlen($destination)>0 ? $destination . "/" : "";	// adds a file seperator if the destination isn't blank
	$fname = strtolower(ereg_replace("[ #%&?]", "_", $fname));			// change spaces to underscores and make lower case

	// to avoid file name collisions with older files, we're going to split the file name into its component 
	// parts: the name and the extension.  Then, we'll use the uniqid() function to create a random element
	// prefixed by the date in YYYYMMDD format in between those two sections so that this file will never be
	// named the same as another file.  Because file names could include periods within them, we'll have to
	// split up the entire name into its component, period delimited sections and assume the extention is the
	// last one and the rest make up the name.
	
	$file_name_parts = explode(".", $fname);		
	$extension = $file_name_parts[sizeof($file_name_parts)-1];							// extract the extension
	$name = join(array_slice($file_name_parts, 0, sizeof($file_name_parts)-1), ".");;	// rejoin the rest as the name
	$filename = $name . "." . uniqid(date("Ymd").".", true) . "." . $extension;			// and create the unique name
	
	// now we'll try to move the file.  remember, we want to return false if ther are no errors, so if the
	// move function works, then we'll return false and if not, then we'll return an error code.
	
	$abs_filename = "$FILE_ROOT/media/uploads/" . $destination . $filename;
	if(move_uploaded_file($ftemp, $abs_filename)) return array(false, $filename);
	else return array(true, "cannot_move");	
}

function get_error_code($ferror) {
	$error = "";
	switch($ferror) {
		case 1:	
		case 2: $error = "too_large";		break;
		case 3: $error = "partial";			break;
		case 4: $error = "no_file";			break;
		case 6: $error = "no_temp_dir";		break;
	} return $error;
}
?>