package com.util;

import com.google.zxing.LuminanceSource;

import java.awt.*;
import java.awt.geom.AffineTransform;
import java.awt.image.BufferedImage;

/**
* Created by yanghl on 2016/11/15.
*/
public class BufferedImageLuminanceSource extends LuminanceSource {

   private final BufferedImage image;
   private final int left;
   private final int top;

   public BufferedImageLuminanceSource(BufferedImage image) {
       this(image, 0, 0, image.getWidth(), image.getHeight());
   }

   public BufferedImageLuminanceSource(BufferedImage image, int left,
                                       int top, int width, int height) {
       super(width, height);

       int sourceWidth = image.getWidth();
       int sourceHeight = image.getHeight();
       if (left + width > sourceWidth || top + height > sourceHeight) {
           throw new IllegalArgumentException(
                   "Crop rectangle does not fit within image data.");
       }

       for (int y = top; y < top + height; y++) {
           for (int x = left; x < left + width; x++) {
               if ((image.getRGB(x, y) & 0xFF000000) == 0) {
                   image.setRGB(x, y, 0xFFFFFFFF); // = white
               }
           }
       }

       this.image = new BufferedImage(sourceWidth, sourceHeight,
               BufferedImage.TYPE_BYTE_GRAY);
       this.image.getGraphics().drawImage(image, 0, 0, null);
       this.left = left;
       this.top = top;
   }


   public byte[] getRow(int y, byte[] row) {
       if (y < 0 || y >= getHeight()) {
           throw new IllegalArgumentException(
                   "Requested row is outside the image: " + y);
       }
       int width = getWidth();
       if (row == null || row.length < width) {
           row = new byte[width];
       }
       image.getRaster().getDataElements(left, top + y, width, 1, row);
       return row;
   }


   public byte[] getMatrix() {
       int width = getWidth();
       int height = getHeight();
       int area = width * height;
       byte[] matrix = new byte[area];
       image.getRaster().getDataElements(left, top, width, height, matrix);
       return matrix;
   }


   public boolean isCropSupported() {
       return true;
   }


   public LuminanceSource crop(int left, int top, int width, int height) {
       return new BufferedImageLuminanceSource(image, this.left + left,
               this.top + top, width, height);
   }


   public boolean isRotateSupported() {
       return true;
   }


   public LuminanceSource rotateCounterClockwise() {
       int sourceWidth = image.getWidth();
       int sourceHeight = image.getHeight();
       AffineTransform transform = new AffineTransform(0.0, -1.0, 1.0,
               0.0, 0.0, sourceWidth);
       BufferedImage rotatedImage = new BufferedImage(sourceHeight,
               sourceWidth, BufferedImage.TYPE_BYTE_GRAY);
       Graphics2D g = rotatedImage.createGraphics();
       g.drawImage(image, transform, null);
       g.dispose();
       int width = getWidth();
       return new BufferedImageLuminanceSource(rotatedImage, top,
               sourceWidth - (left + width), getHeight(), width);
   }
}