<?php

#Author: Siddharth Prakash Singh(spsneo)
#Google Summer Of Code Project 2008
# Copyright (C) 2002 CCGIS 
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2, or (at your option)
# any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.

function build_checksum($dir_path) {
	
	#This array holds the file-name and sha1 checksum for the files in the current directory
	$file_arr = array();
	
	//remove slash if it is there at the end of the path
	if(substr($dir_path, -1) == '/') {
		$dir_path = substr($dir_path, 0 , -1);
	}
	
	
	if(!is_dir($dir_path)) {
		echo $dir_path." is not a valid directory\n";
		return FALSE;
	}
	
	if(!is_readable($dir_path)) {
		echo $dir_path." is not readable.\nPlease make sure you have privilege to build.\nAborting...\n";
		exit();
	}
	
	$directory = dir($dir_path);
	while(false !== ($file = $directory->read())) {
		$file_path = $dir_path.'/'.$file;
		if(is_file($file_path) && $file != 'checksum.json' && !preg_match("/~$/", $file) && !preg_match("/^\./", $file)) {
			if(is_readable($file_path)) {
				$file_arr[$file] = sha1_file($file_path);
			} else {
				echo $file_path." is not readable.\nPlease make sure you have privelege to build.\nAborting...\n";
				exit();
			}
		} else if (is_dir($file_path) && !preg_match("/^\./", $file)) {
			if($file != '.' && $file != '..' ) {
				//echo "Scanning directory: ".$file_path."\n";
				build_checksum($file_path);
			}
		} else {
			
		}
	}
	$file_json_string = json_encode($file_arr);
	$file_json_name = $dir_path."/checksum.json";
	$file_json_handle = fopen($file_json_name, "w");
	if(!file_json_handle) {
		echo "Error creating file checksum.json\nPlease execute this script again.\nAborting...\n ";
		exit();
	}
	fwrite($file_json_handle, $file_json_string);
	fclose($file_json_handle);
	//echo "Succesfully created checksums of files in directory: ".$dir_path."\n";
	return TRUE;
}