<?php
class Fetch {
	static function ftp($url, $file = NULL) {
		$url = parse_url($url);
		if(!isset($url['scheme']) || $url['scheme'] != 'ftp') {
			throw new Exception('Only FTP URLs are supported');
		}
		if(!isset($url['host'])) {
			throw new Exception('Hostname not present in the URL');
		}
		if(!isset($url['path'])) {
			throw new Exception('Path component not present in the URL');
		}
		if(!isset($url['port'])) {
			$url['port'] = 21;
		}
		if(!isset($url['user'])) {
			$url['user'] = 'anonymous';
		}
		if(!isset($url['pass'])) {
			$url['pass'] = 'anonymous@mpk.jacekk.net';
		}
		if($file == NULL) {
			$file = basename($url['path']);
		}
		
		$localTime = -1;
		$localSize = -1;
		if(is_file($file)) {
			$localTime = filemtime($file);
			$localSize = filesize($file);
		}
		
		$ftp = FtpConnection::create($url['host'], $url['port'], $url['user'], $url['pass']);
		$remoteSize = $ftp->size($url['path']);
		$remoteTime = $ftp->mdtm($url['path']);
		
		$updated = FALSE;
		
		if($localTime < $remoteTime || ($localTime == $remoteTime && $localSize != $remoteSize)) {
			if(file_exists($file.'.tmp')) {
				unlink($file.'.tmp');
			}
			$ftp->get($file.'.tmp', $url['path'], FTP_BINARY);
			touch($file.'.tmp', $remoteTime);
			if(!rename($file.'.tmp', $file)) {
				throw new Exception('Temporary file rename failed');
			}
			$updated = TRUE;
		}
		
		return $updated;
	}
	
	static function generic($url, $file = NULL) {
		if($file == NULL) {
			$file = basename($url['url']);
		}
		$data = file_get_contents($url);
		if($data === FALSE) {
			throw new Exception('URL fetch failed');
		}
		if(file_put_contents($file.'.tmp', $data) === FALSE) {
			throw new Exception('Temporary file creation failed');
		}
		if(!rename($file.'.tmp', $file)) {
			throw new Exception('Temporary file rename failed');
		}
	}
}