package com.github.binarywang.utils.qrcode;

import com.google.zxing.LuminanceSource;

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

/**
 * <pre>
 * Created by Binary Wang on 2017-01-05.
 * @author <a href="https://github.com/binarywang">binarywang(Binary Wang)</a>
 * </pre>
 */
public final 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;
  }

  @Override
  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];
    }
    this.image.getRaster().getDataElements(this.left, this.top + y, width,
      1, row);
    return row;
  }

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

  @Override
  public boolean isCropSupported() {
    return true;
  }

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

  @Override
  public boolean isRotateSupported() {
    return true;
  }

  @Override
  public LuminanceSource rotateCounterClockwise() {

    int sourceWidth = this.image.getWidth();
    int sourceHeight = this.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(this.image, transform, null);
    g.dispose();

    int width = getWidth();
    return new BufferedImageLuminanceSource(rotatedImage, this.top,
      sourceWidth - (this.left + width), getHeight(), width);
  }

}