<?PHP
$conf = array();
$conf['backup_time'] = time();
$conf['backup_limit'] = 7;
$conf['backup_dir'] = "/home/skarecrow/backup";
$conf['backup_fld'] = "/home/skarecrow/www";
$conf['fl_backuplog'] = "/home/skarecrow/backup/log.txt";
$conf['fl_checksum'] = "/home/skarecrow/backup/chksum.txt";
$conf['fl_backup'] = "Leave_Blank";
$conf['backup_sum'] = "Leave_Blank";

logMessage("Starting Backup Generator: ".date("F j, Y, g:i a"));

build();
BuildBackup();
CheckBackup();
cleanup();

function build() {

	global $conf;

	if (!file_exists($conf['fl_checksum'])) {

		$conf['backup_sum'] = "null";

		logMessage("Checksum file does not exist. Setting sum to null.");

	} else {

		$conf['backup_sum'] = file_get_contents($conf['fl_checksum']);
		$conf['backup_sum'] = str_replace("\n", "", $conf['backup_sum']);

		logMessage("Checksum loaded. Last Backup checksum {$conf['backup_sum']}");

	}

}

function BuildBackup() {

	global $conf;

	$conf['fl_backup'] = $conf['backup_dir']."/".$conf['backup_time'].".tar";

	logMessage("Generating backup {$conf['fl_backup']}");

	exec("tar -cf {$conf['fl_backup']} {$conf['backup_fld']}");
	if (!file_exists($conf['fl_backup'])) {

		logMessage("Backup utility failed: ".date("F j, Y, g:i a"));
		logMessage("The backup utility could not generate a backup.");
		logMessage("Please make sure you have the correct permissions set on {$conf['backup_dir']}");
		logMessage("If that does not work you can contact me at http://www.WarpedCoders.org/");
		die();

	}

}

function CheckBackup() {

	global $conf;

	$chksum = exec("md5sum {$conf['fl_backup']}");
	$chksum = explode(" ", $chksum);
	$chksum = $chksum[0];

	if ($conf['backup_sum'] == $chksum) {

		logMessage("{$conf['fl_backup']} has the same checksum as the previous backup.");
		logMessage("Backup will be deleted do to a previous backup of the same checksum.");

		if (unlink($conf['fl_backup'])) {

			logMessage("Backup {$conf['fl_backup']} was deleted successfully!");

		} else {

			logMessage("Could not delete backup {$conf['fl_backup']}");

		}

	} else {

		logMessage("Detected changes in file checksum. Backup will be saved.");
		updateSum($chksum);

	}

}

function cleanup() {

	global $conf;

	$fileArray = array();

	if ($opDir = opendir($conf['backup_dir'])) {

		$count = 0;
		while (($file = readdir($opDir)) != false) {

			$ext = explode(".", $file);
			$file_bk = $ext[0];
			$ext = $ext[1];

			if ($ext == "tar") {

				$fileArray[$count] = $file_bk;
				$count++;

			}

		}

	}

	sort($fileArray);
	if (count($fileArray) > $conf['backup_limit']) {

		if (!unlink($conf['backup_dir']."/{$fileArray[0]}.tar")) {

			logMessage("Could not unlink {$conf['backup_dir']}/{$fileArray[0]}.tar");

		} else {

			logMessage("Meximum backup limit reached: {$conf['backup_limit']} - Last backup on ".date("F j, Y", $fileArray[0])." will be deleted.");
			logMessage("Old Backup file deleted {$conf['backup_dir']}/{$fileArray[0]}.tar");
			cleanup();

		}

	}

}

function updateSum($sum) {

	global $conf;

	$file = fopen($conf['fl_checksum'], "w");
	fputs($file, $sum);
	fclose($file);

}

function logMessage($msg) {

	global $conf;

	$file = fopen($conf['fl_backuplog'], "a+");
	fwrite($file, $msg."\n");
	fclose($file);

}

logMessage("Backup Generator Completed: ".date("F j, Y, g:i a"));
?>