package Demo;

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.FlowLayout;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.MediaTracker;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;

import javax.imageio.ImageIO;
import javax.swing.JButton;
import javax.swing.JComponent;
import javax.swing.JFileChooser;
import javax.swing.JFrame;
import javax.swing.JPanel;

public class ImageComparerUI extends JComponent implements ActionListener {

	/**
	 * 
	 */
	private static final long serialVersionUID = 1L;
	private JButton browseBtn;
	private JButton histogramBtn;
	private JButton compareBtn;
	private Dimension mySize;
	
	// image operator
	private MediaTracker tracker;
	private BufferedImage sourceImage;
	private BufferedImage candidateImage;
	private double simility; 
	
	// command constants
	public final static String BROWSE_CMD = "Browse...";
	public final static String HISTOGRAM_CMD = "Histogram Bins";
	public final static String COMPARE_CMD = "Compare Result";
	
	public ImageComparerUI() {
		JPanel btnPanel = new JPanel();
		btnPanel.setLayout(new FlowLayout(FlowLayout.LEFT));
		browseBtn = new JButton("Browse...");
		histogramBtn = new JButton("Histogram Bins");
		compareBtn = new JButton("Compare Result");
		
		// buttons
		btnPanel.add(browseBtn);
		btnPanel.add(histogramBtn);
		btnPanel.add(compareBtn);
		
		// setup listener...
		browseBtn.addActionListener(this);
		histogramBtn.addActionListener(this);
		compareBtn.addActionListener(this);
		
		mySize = new Dimension(620, 500);
		JFrame demoUI = new JFrame("Similiar Image Finder");
		demoUI.getContentPane().setLayout(new BorderLayout());
		demoUI.getContentPane().add(this, BorderLayout.CENTER);
		demoUI.getContentPane().add(btnPanel, BorderLayout.SOUTH);
		demoUI.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
		demoUI.pack();
		demoUI.setVisible(true);
	}
	
	public void paint(Graphics g) {
		Graphics2D g2 = (Graphics2D) g;
		if(sourceImage != null) {
			Image scaledImage = sourceImage.getScaledInstance(300, 300, Image.SCALE_FAST);
			g2.drawImage(scaledImage, 0, 0, 300, 300, null);
		}
		
		if(candidateImage != null) {
			Image scaledImage = candidateImage.getScaledInstance(300, 330, Image.SCALE_FAST);
			g2.drawImage(scaledImage, 310, 0, 300, 300, null);
		}
		
		// display compare result info here
		Font myFont = new Font("Serif", Font.BOLD, 16);
		g2.setFont(myFont);
		g2.setPaint(Color.RED);
		g2.drawString("The degree of similarity : " + simility, 50, 350);
	}
	
	public void actionPerformed(ActionEvent e) {
		if(BROWSE_CMD.equals(e.getActionCommand())) {
			JFileChooser chooser = new JFileChooser();
			chooser.showOpenDialog(null);
			File f = chooser.getSelectedFile();
			BufferedImage bImage = null;
			if(f == null) return;
			try {
				bImage = ImageIO.read(f);
				
			} catch (IOException e1) {
				e1.printStackTrace();
			}
			
			tracker = new MediaTracker(this);
			tracker.addImage(bImage, 1);
			
			// blocked 10 seconds to load the image data
			try {
				if (!tracker.waitForID(1, 10000)) {
					System.out.println("Load error.");
					System.exit(1);
				}// end if
			} catch (InterruptedException ine) {
				ine.printStackTrace();
				System.exit(1);
			} // end catch
			
			if(sourceImage == null) {
				sourceImage = bImage;
			}else if(candidateImage == null) {
				candidateImage = bImage;
			} else {
				sourceImage = null;
				candidateImage = null;
			}
			repaint();
		} else if(HISTOGRAM_CMD.equals(e.getActionCommand())) {
			// do something now...
		} else if(COMPARE_CMD.equals(e.getActionCommand())) {
			ImageComparer imageCom = new ImageComparer(sourceImage, candidateImage);
			simility = imageCom.modelMatch();
			repaint();
		}
		
	}
	
	public Dimension getPreferredSize() {
		return mySize;
	}
	
	public Dimension getMinimumSize() {
		return mySize;
	}
	
	public Dimension getMaximumSize() {
		return mySize;
	}
	
	public static void main(String[] args) {
		new ImageComparerUI();
	}

}