package ftp;

import java.io.File;
import java.io.FileInputStream;

import javax.swing.JOptionPane;
import javax.swing.SwingWorker;

import org.apache.log4j.Logger;

import models.Image;

/**
 * Executes the file upload in a background thread and updates progress to
 * listeners that implement the java.beans.PropertyChangeListener interface.
 * 
 * @author www.codejava.net
 * 
 */
public class UploadTask extends SwingWorker<Void, Void> {

	/**
	 * Logger instance for this class.
	 */
	private final static Logger LOGGER = Logger.getLogger(UploadTask.class);

	private static final int BUFFER_SIZE = 1024 * 1024;
	private static final double UPDATE_INTERVAL_SECONDS = 0.6;
	private static final double UPDATE_INTERVAL_MS = UPDATE_INTERVAL_SECONDS * 1000;
	private static final double BYTES_PER_MIB = 1024 * 1024;

	private String host;
	private int port;
	private String username;
	private String password;
	private String destDir;
	private File uploadFile;
	private int percentCompleted;

	public UploadTask(String host, int port, String username, String password,
			String destDir, File uploadFile) {
		this.host = host;
		this.port = port;
		this.username = username;
		this.password = password;
		this.destDir = destDir;
		this.uploadFile = uploadFile;

	}

	/**
	 * Executed in background thread
	 */
	@Override
	protected Void doInBackground() throws Exception {
		FTPUtility util = new FTPUtility(host, port, username, password);
		try {
			util.connect();
			util.uploadFile(uploadFile, destDir);

			// show filesize in the GUI
			long fileSize = uploadFile.length();
			Image.Filesize = fileSize;
			firePropertyChange("filesize", 0, fileSize);

			// prepare input stream
			FileInputStream inputStream = new FileInputStream(uploadFile);

			// initialize the counters needed for speed calculations
			percentCompleted = 0;
			byte[] buffer = new byte[BUFFER_SIZE];
			int bytesRead = -1;
			long totalBytesRead = 0;
			long lastUpdate = 0;
			long lastBytes = 0;
			long currentBytes = 0;
			while ((bytesRead = inputStream.read(buffer)) != -1 && !isCancelled()) {
				util.writeFileBytes(buffer, 0, bytesRead);
				currentBytes += bytesRead;
				totalBytesRead += bytesRead;
				long now = System.currentTimeMillis();
				if (lastUpdate + UPDATE_INTERVAL_MS < now) {
					percentCompleted = (int) ((totalBytesRead * 100) / fileSize);
					setProgress(percentCompleted);
					lastBytes = (lastBytes * 2 + currentBytes) / 3;
					final double speed = lastBytes / UPDATE_INTERVAL_SECONDS;
					firePropertyChange("speed", 0, speed / BYTES_PER_MIB);
					firePropertyChange("bytesread", 0, totalBytesRead);
					lastUpdate = now;
					currentBytes = 0;
				}
			}
			// finalize the upload by updating the progress bar one last time
			// (in case we didn't get to do it because of the time interval)
			percentCompleted = (int) ((totalBytesRead * 100) / fileSize);
			setProgress(percentCompleted);
			firePropertyChange("bytesread", 0, totalBytesRead);
			inputStream.close();
			util.finish();
		} catch (FTPException ex) {
			JOptionPane.showMessageDialog(null,
					"Error uploading file: " + ex.getMessage(), "Error",
					JOptionPane.ERROR_MESSAGE);
			ex.printStackTrace();
			setProgress(0);
			cancel(true);
		} finally {
			util.disconnect();
		}

		return null;
	}

	/**
	 * Executed in Swing's event dispatching thread
	 */
	@Override
	protected void done() {
		if (!isCancelled() && percentCompleted == 100) {
			LOGGER.info("Datei erfolgreich hochgeladen.");
			JOptionPane.showMessageDialog(null, "Datei erfolgreich hochgeladen.",
					"Message", JOptionPane.INFORMATION_MESSAGE);
		} else if (!isCancelled() && percentCompleted != 100) {
			LOGGER.error("Datei wurde unvollständig hochgeladen.");
			JOptionPane.showMessageDialog(null,
					"Datei wurde unvollständig hochgeladen. Bitte wiederholen.",
					"Message", JOptionPane.INFORMATION_MESSAGE);
		}
	}
}