package class9_3_VirtualProxy_inClass_start;

import javax.imageio.ImageIO;
import javax.swing.*;
import java.awt.*;
import java.io.File;
import java.io.IOException;
import java.net.URL;

// This class implements a virtual proxy, which temporarily substitutes
// a "cheap" resource in place of one that takes longer to create
public class ImageProxy implements Icon {

    // TODO: Coding
    private Icon realImage;
//	private Image tempImage; // the cheap resource
    private final int realImageWidth = 13500;
    private final int realImageHeight = 6750;
	private URL imageURL; // the location of the real resource
	private boolean isRetrieving = false; // indicates whether the thread is getting the real resource
    private JFrame parent;
	private Thread thread; // thread to load the image on

	// constructor
	// @throws IOException if an error occurs
	public ImageProxy(URL url, JFrame parent) throws IOException {
        this.imageURL = url;
        this.parent = parent;
        // TODO: Stuff
//		tempImage = ImageIO.read(getClass().getResource("dnb_land_ocean_ice.2012.13500x6750.small.jpg"));// load the temporary resource
    }
	
	@Override
	// required accessor
	public int getIconHeight() {
        // TODO: Note that we can make the image change size if desired.
//		int height = tempImage.getHeight(null);
//		if(realImage!=null) {
//			height = realImage.getIconHeight();
//		}
		return realImageHeight;
	}
	
	@Override
	// required accessor
	public int getIconWidth() {
//		int width = tempImage.getWidth(null);
//		if(realImage!=null) {
//			width = realImage.getIconWidth();
//		}
		return realImageWidth;
	}
	
	@Override
	// Called by the Swing framework whenever this icon needs to paint itself
	public void paintIcon(final Component c, Graphics g, int x, int y) {
		if(realImage!=null) { // we already have the real image loaded
			realImage.paintIcon(c, g, x, y);
		} else { // the real image has not been loaded yet
			// display the temporary image for now...
//			g.drawImage(tempImage, 0, 0, realImageWidth, realImageHeight, null);
			g.setColor(Color.BLACK);
			g.setFont(Font.decode("Arial 30"));
			g.drawString("Loading image, please wait...", x+50, y+50);
            System.out.println("DEBUG: Loading image....");

            //...and load the real image
            // TODO: How to not load the image every time we call this?
			System.out.println("Debug: starting to load remote image");

			Thread thread = new Thread(()-> {
					// the following may take some time to execute
					// if the imageURL is on a slow remote server
					realImage = new ImageIcon(imageURL);
			//			try {
			//				Thread.sleep(4000); // sleep a little longer for good measure.
			//			} catch (InterruptedException e) {
			//				System.out.println("Our sleep was cut short.");
			//			}
					System.out.println("Done loading icon.");
					// TODO: Why doesn't it paint?
					SwingUtilities.invokeLater(
						new Runnable(){
							public void run() {
								realImage.paintIcon(c, g, x, y);
								parent.repaint();
							}
						});
				});
			thread.start();
		}
	}
}

















































//private ImageIcon image;
//private URL imageURL;
//private Thread retrievalThread;
//private boolean retrieving = false;
//
//public ImageProxy(URL url) {
//	imageURL = url;
//}
//
//@Override
//public int getIconHeight() {
//	int height = ImageComponent.MAX_HEIGHT;
//	if(image!=null) {
//		height = image.getIconHeight();
//	}
//	return height;
//}
//
//@Override
//public int getIconWidth() {
//	int width = ImageComponent.MAX_WIDTH;
//	if(image!=null) {
//		width = image.getIconWidth();
//	}
//	return width;
//}
//
//@Override
//public void paintIcon(final Component component, Graphics graphics, int x, int y) {
//	if(image!=null) {
//		image.paintIcon(component, graphics, x, y);
//	} else {
//		graphics.drawString("Loading image, please wait...", x+50, y+100);
//		if(!retrieving) {
//			retrieving = true;
//			retrievalThread = new Thread(new Runnable() {
//				public void run() {
//					try {
//						Thread.sleep(200);
//						image = new ImageIcon(imageURL, "Image");
//						component.repaint();
//					} catch(Exception e) {
//						e.printStackTrace();
//					}
//				}
//			});
//			retrievalThread.start();
//		}
//	}
//}