/*
 * PhoneGap is available under *either* the terms of the modified BSD license *or* the
 * MIT License (2008). See http://opensource.org/licenses/alphabetical for full text.
 * 
 * Copyright (c) 2005-2010, Nitobi Software Inc.
 * Copyright (c) 2010, IBM Corporation
 */

package com.phonegap.plugins.ftpclient;

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.IOException;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.StringTokenizer;

import org.apache.commons.net.ftp.FTP;
import org.apache.commons.net.ftp.FTPClient;
import org.json.JSONArray;
import org.json.JSONException;

import android.util.Log;

import com.phonegap.api.Plugin;
import com.phonegap.api.PluginResult;

public class FtpClient extends Plugin {

    private static final String LOG_TAG = "FtpClient";

	/**
     * Executes the request and returns PluginResult.
     *
     * @param action        The action to execute.
     * @param args          JSONArry of arguments for the plugin.
     * @param callbackId    The callback id used when calling back into JavaScript.
     * @return              A PluginResult object with a status and message.
     */
	@Override
	public PluginResult execute(String action, JSONArray args, String callbackId) {
		PluginResult.Status status = PluginResult.Status.OK;
        JSONArray result = new JSONArray();

        try {
        	String filename = args.getString(0);
        	URL url = new URL(args.getString(1));
        	
        	
            if (action.equals("get")) {
            	get(filename, url);
            }
            else if (action.equals("put")) {
            	put(filename, url);
            }
            return new PluginResult(status, result);
        } catch (JSONException e) {
            return new PluginResult(PluginResult.Status.JSON_EXCEPTION);
        } catch (MalformedURLException e) {
        	return new PluginResult(PluginResult.Status.MALFORMED_URL_EXCEPTION);
		} catch (IOException e) {
        	return new PluginResult(PluginResult.Status.IO_EXCEPTION);
		}
	}

	/**
	 * Uploads a file to a ftp server.
	 * @param filename the name of the local file to send to the server
	 * @param url the url of the server
	 * @throws IOException
	 */
	private void put(String filename, URL url) throws IOException {
		FTPClient f = setup(url);
		
		BufferedInputStream buffIn=null;
		buffIn=new BufferedInputStream(new FileInputStream(filename));
		f.storeFile(extractFileName(url), buffIn);
		buffIn.close();
		
		teardown(f);
	}

	/**
	 * Downloads a file from a ftp server.
	 * @param filename the name to store the file locally
	 * @param url the url of the server
	 * @throws IOException
	 */
	private void get(String filename, URL url) throws IOException {
		FTPClient f = setup(url);
		
		BufferedOutputStream buffOut=null;
		buffOut=new BufferedOutputStream(new FileOutputStream(filename));
		f.retrieveFile(extractFileName(url), buffOut);
		buffOut.flush();
		buffOut.close();
		
		teardown(f);
	}

	/**
	 * Tears down the FTP connection
	 * @param f the FTPClient
	 * @throws IOException
	 */
	private void teardown(FTPClient f) throws IOException {
		f.logout();
		f.disconnect();
	}

	/**
	 * Creates, connects and logs into a FTP server
	 * @param url of the FTP server
	 * @return an instance of FTPClient
	 * @throws IOException
	 */
	private FTPClient setup(URL url) throws IOException {
	    FTPClient f = new FTPClient();
		f.connect(url.getHost(), extractPort(url));
		
		StringTokenizer tok = new StringTokenizer(url.getUserInfo(), ":");
		f.login(tok.nextToken(), tok.nextToken());
		
		f.enterLocalPassiveMode();
		f.setFileType(FTP.BINARY_FILE_TYPE);
		
		return f;
	}

	/**
	 * Extracts the port of the FTP server. Returns 21 by default.
	 * @param url
	 * @return
	 */
	private int extractPort(URL url) {
	    if (url.getPort() == -1) {
			return url.getDefaultPort();
		}
		else {
			return url.getPort();
		}
	}

	/**
	 * Extracts the file name from the URL.
	 * @param url of the ftp server, includes the file to upload/download
	 * @return the filename to upload/download
	 */
	private String extractFileName(URL url) {
		String filename = url.getFile();
		if (filename.endsWith(";type=i") || filename.endsWith(";type=a")) {
			filename = filename.substring(0, filename.length() - 7);			
		}
		return filename;
	}

}