/*
 * Created on Jul 20, 2004
 */
package imageprocessing;

import java.awt.Color;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.File;

import javax.swing.BoxLayout;
import javax.swing.JButton;
import javax.swing.JFileChooser;
import javax.swing.JPanel;

/** A panel with buttons to control an image viewer frame.
 Code is provided only for reference.  You don't need to modify it,
 and won't be able to hand in a modified version.  You don't need to
 understand how it works, either -- but you might learn something by
 studying it.
 * @author dickey
 */
public class ImageButtonPanel extends JPanel {
	
	private final IImageProcessor iprocessor;
	
	private final IImageFilter[] filters;
	
	private final AbstractImagePanel leftPanel, rightPanel;
	
	private final Color buttonColor = new Color(255, 255, 200);
	
	private final Color backgroundColor = new Color(120, 0, 0);
	
	/** Create a panel with buttons to control image operations.  Typically,
	 * pressing a button causes an operation to occur, followed by the result
	 * of the operation being displayed.  Some operations (LOAD, SAVE, SWAP)
	 * are built-in, and others are supplied as image filters.
	 * @param iprocessor a non-null image processor object.
	 * @param filters an array of non-null filters, which may be zero-length but should
	 * not be null.
	 * @param leftPanel a non-null image panel
	 * @param rightPanel a non-null image panel
	 */
	public ImageButtonPanel(IImageProcessor iprocessor,
						IImageFilter[] filters,
						AbstractImagePanel leftPanel, AbstractImagePanel rightPanel) {
		
		if (iprocessor == null) {
			throw new IllegalArgumentException("Image processor for button panel" +
					" must not be null");
		}
		this.iprocessor = iprocessor;
		if (filters == null) {
			throw new IllegalArgumentException("filter array for button panel" +
			" must not be null");			
		}
		this.filters = new IImageFilter[filters.length];
		for (int f = 0; f < filters.length; f++) {
			if (filters[f] == null) {
				throw new IllegalArgumentException("filter " + f + 
						" for button panel" + " must not be null");			
			}
			this.filters[f] = filters[f];
		}
		if (leftPanel == null) {
			throw new IllegalArgumentException("left image panel for button panel" +
					" must not be null");
		}
		this.leftPanel = leftPanel;
		// Arguments have been saved.
		if (rightPanel == null) {
			throw new IllegalArgumentException("right image panel for button panel" +
					" must not be null");
		}
		this.rightPanel = rightPanel;
		//arguments have been saved
		this.setLayout(new BoxLayout(this, BoxLayout.Y_AXIS));
		//this.setBackground(backgroundColor);
		
		// Start building buttons.
		
		;
		this.add(new ReadFileButton());
		
		this.add(new SaveFileButton());		
		
		//add a button for each filter
		for (int b = 0; b < this.filters.length; b++) {
			JButton aButton = new FilterButton(this.filters[b]);
			this.add(aButton);
		}
		
		this.add(new SwapPanelsButton());
	}
	
	/** A button, which when pressed, causes a file to be chosen, loaded,
	 * and shown.
	 * @author dickey
	 */
	private class ReadFileButton extends JButton {
		ReadFileButton() {
			super("Read File");	
			setToolTipText("Prompt for a file and attempt to load and display it." +
					"  Only .pgm and .ppm file formats are supported.");
			addActionListener(new ActionListener () {
				public void actionPerformed(ActionEvent e) {
					JFileChooser chooser = new JFileChooser("choose an image file");
					int result = chooser.showOpenDialog(ImageButtonPanel.this);
					if (result == JFileChooser.APPROVE_OPTION) {
						//a file was selected
						File f = chooser.getSelectedFile();
						String fname = f.getAbsolutePath();
						IImage image = ImageButtonPanel.this.iprocessor.produceImage(fname);
						if (image != null) {
							ImageButtonPanel.this.leftPanel.setImage(image);
							ImageButtonPanel.this.leftPanel.repaint();
						}
					}			
				}
			});
		}
	}

	/** A button, which when pressed, causes a file to be chosen, and the image
	 * in the right panel to be saved to the file.   The user must give the
	 * full file name, including extension.
	 * @author dickey
	 */
	private class SaveFileButton extends JButton {
		SaveFileButton() {
			super("Save File");	
			setToolTipText("Prompt for a file, and save the right-hand image" +
					" in that file.  Be sure to enter the full filename," +
					" including the extension, since no extension is added" +
					" automatically.");
			addActionListener(new ActionListener () {
				public void actionPerformed(ActionEvent e) {
					IImage imageToSave = ImageButtonPanel.this.rightPanel.getImage();
					if (imageToSave != null) {
					JFileChooser chooser = new JFileChooser("choose a file to write in");
					int result = chooser.showSaveDialog(ImageButtonPanel.this);
					if (result == JFileChooser.APPROVE_OPTION) {
						//a file was selected
						File f = chooser.getSelectedFile();
						String fname = f.getAbsolutePath();
						boolean saved = 
							ImageButtonPanel.this.iprocessor.writeImage(
									imageToSave, fname);
						if (saved) {
							System.out.println("Image saved to " + fname);
						} else {
							System.out.println("Image not successfully saved to " +
									fname);
						}
					}
					}
				}
			});
		}
	}

	/** A button, which when pressed, causes the images in the two panels
	 * to be swapped.
	 * @author dickey
	 */
	private class SwapPanelsButton extends JButton {
		SwapPanelsButton() {
			super("Swap");
			setToolTipText("Swap the images in the left and right panels.");
			addActionListener(new ActionListener () {
				public void actionPerformed(ActionEvent e) {
					IImage oldleft = ImageButtonPanel.this.leftPanel.getImage();
					IImage oldright = ImageButtonPanel.this.rightPanel.getImage();
					
					ImageButtonPanel.this.leftPanel.setImage(oldright);
					ImageButtonPanel.this.leftPanel.repaint();
					
					
					ImageButtonPanel.this.rightPanel.setImage(oldleft);
					ImageButtonPanel.this.rightPanel.repaint();
					
				}				
			});
		}
	}
	
	/** A button which, when pressed, causes the image in the left-hand window
	 * to be given to an image filter, after which the resulting image is
	 * displayed in the right-hand window.
	 * @author dickey
	 */
	private class FilterButton extends JButton {
		
		private final IImageFilter filter;
		
		FilterButton (IImageFilter filter) {
			assert filter != null;
			this.filter = filter;
			this.setText(filter.shortName());
			this.setToolTipText(filter.description());
			this.setBackground(buttonColor);
			this.addActionListener(new ActionListener() {
				
				public void actionPerformed(ActionEvent e) {
					IImage inputImage = ImageButtonPanel.this.leftPanel.getImage();
					if (inputImage != null) {
						IImage outputImage = FilterButton.this.filter.filter(inputImage);
						if (outputImage != null) {
							ImageButtonPanel.this.rightPanel.setImage(outputImage);
							ImageButtonPanel.this.rightPanel.repaint();
						}
					}
				}				
			});
			
		}
	}

}