/*
 * Copyright (c) 1997, 2019 Oracle and/or its affiliates. All rights reserved.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Distribution License v. 1.0, which is available at
 * http://www.eclipse.org/org/documents/edl-v10.php.
 *
 * SPDX-License-Identifier: BSD-3-Clause
 */

package mime.client;

import javax.xml.transform.stream.StreamSource;
import javax.imageio.ImageWriter;
import javax.imageio.ImageIO;
import javax.imageio.stream.ImageOutputStream;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.awt.image.ImageObserver;
import java.awt.image.PixelGrabber;
import java.io.IOException;
import java.io.InputStream;
import java.io.ByteArrayOutputStream;
import java.util.ArrayList;
import java.util.Iterator;

public class AttachmentHelper {
    public static boolean compareStreamSource (StreamSource src1, StreamSource src2) throws Exception {
        if (src1 == null || src2 == null) {
            System.out.println ("compareStreamSource - src1 or src2 null!");
            return false;
        }
        InputStream is1 = src1.getInputStream ();
        InputStream is2 = src2.getInputStream ();
        if ((is1 == null) || (is2 == null)) {
            System.out.println ("InputStream of - src1 or src2 null!");
            return false;
        }
        
        return true;
    }

    public static byte[] getImageBytes(Image image, String type) throws IOException {
        ByteArrayOutputStream baos = new ByteArrayOutputStream();

        BufferedImage bufImage = convertToBufferedImage(image);
        ImageWriter writer = null;
        Iterator i = ImageIO.getImageWritersByMIMEType(type);
        if (i.hasNext()) {
            writer = (ImageWriter)i.next();
        }
        if (writer != null) {
            ImageOutputStream stream = ImageIO.createImageOutputStream(baos);
            writer.setOutput(stream);
            writer.write(bufImage);
            stream.close();
            return baos.toByteArray();
        }
        return null;
    }

    private static BufferedImage convertToBufferedImage (Image image) throws IOException {
        if (image instanceof BufferedImage) {
            return (BufferedImage)image;
            
        } else {
            MediaTracker tracker = new MediaTracker (null/*not sure how this is used*/);
            tracker.addImage (image, 0);
            try {
                tracker.waitForAll ();
            } catch (InterruptedException e) {
                throw new IOException (e.getMessage ());
            }
            BufferedImage bufImage = new BufferedImage (
                image.getWidth (null),
                image.getHeight (null),
                BufferedImage.TYPE_INT_RGB);
            
            Graphics g = bufImage.createGraphics ();
            g.drawImage (image, 0, 0, null);
            return bufImage;
        }
    }
    
    public static boolean compareImages (Image image1, Image image2) throws IOException {
        if (image1 == null || image2 == null)
            return false;
        
        boolean matched = false;
        Rectangle rect = new Rectangle (0, 0, convertToBufferedImage (image1).getWidth (), convertToBufferedImage (image1).getHeight ());
        Iterator iter1 = handlePixels (image1, rect);
        Iterator iter2 = handlePixels (image2, rect);
        
        while (iter1.hasNext () && iter2.hasNext ()) {
            Pixel pixel = (Pixel) iter1.next ();
            if (pixel.equals ((Pixel) iter2.next ())) {
                matched = true;
            } else {
                matched = false;
            }
        }
        if (matched)
            return true;
        return false;
    }
    
    private static Iterator handlePixels (Image img, Rectangle rect) {
        int x = rect.x;
        int y = rect.y;
        int w = rect.width;
        int h = rect.height;
        
        int[] pixels = new int[w * h];
        PixelGrabber pg = new PixelGrabber (img, x, y, w, h, pixels, 0, w);
        try {
            pg.grabPixels ();
        } catch (InterruptedException e) {
            System.err.println ("interrupted waiting for pixels!");
            return null;
        }
        if ((pg.getStatus () & ImageObserver.ABORT) != 0) {
            System.err.println ("image fetch aborted or errored");
            return null;
        }
        ArrayList tmpList = new ArrayList ();
        for (int j = 0; j < h; j++) {
            for (int i = 0; i < w; i++) {
                tmpList.add (handleSinglePixel (x + i, y + j, pixels[j * w + i]));
            }
        }
        return tmpList.iterator ();
    }
    
    private static Pixel handleSinglePixel (int x, int y, int pixel) {
        int alpha = (pixel >> 24) & 0xff;
        int red = (pixel >> 16) & 0xff;
        int green = (pixel >> 8) & 0xff;
        int blue = (pixel) & 0xff;
        return new Pixel (alpha, red, green, blue);
    }
    
    private static class Pixel {
        private int a;
        private int r;
        private int g;
        private int b;
        
        Pixel (int a, int r, int g, int b) {
            this.a = a;
            this.r = r;
            this.g = g;
            this.b = b;
        }
        
        protected boolean equals (Pixel p) {
            if (p.a == a && p.r == r && p.g == g && p.b == b)
                return true;
            return false;
        }
    }
}


