package com.kidgrow.common.utils;

import com.google.zxing.BarcodeFormat;
import com.google.zxing.EncodeHintType;
import com.google.zxing.MultiFormatWriter;
import com.google.zxing.WriterException;
import com.google.zxing.common.BitMatrix;
import com.google.zxing.qrcode.decoder.ErrorCorrectionLevel;
import sun.misc.BASE64Encoder;

import javax.imageio.ImageIO;
import java.awt.image.BufferedImage;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.util.Hashtable;

/**
 * @Author: dougang
 * @Description:
 * @Date: create in 2020/6/19 10:02
 */
public class QRCodeUtil {

    /**
     * 生成二维码
     * @param contents
     * @param width
     * @param height
     * @param level 0:M,1:L,2:H,3:Q
     * @return
     */
    public static String creatRrCode(String contents, int width, int height,int level) {
        String binary = null;
        Hashtable hints = new Hashtable();
        hints.put(EncodeHintType.CHARACTER_SET, "utf-8");
        switch (level){
            case 0:
                hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.M);
                break;
            case 1:
                hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.L);
                break;
            case 2:
                hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.H);
                break;
            case 3:
                hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.Q);
                break;
            default:
                break;
        }

        try {
            BitMatrix bitMatrix = new MultiFormatWriter().encode(
                    contents, BarcodeFormat.QR_CODE, width, height, hints);
            // 读取文件转换为字节数组
            ByteArrayOutputStream out = new ByteArrayOutputStream();
            BufferedImage image = toBufferedImage(bitMatrix);
            //转换成png格式的IO流
            ImageIO.write(image, "png", out);
            byte[] bytes = out.toByteArray();

            // 将字节数组转为二进制
            BASE64Encoder encoder = new BASE64Encoder();
            binary = "data:image/png;base64," + encoder.encodeBuffer(bytes).trim();
        } catch (WriterException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        return binary;
    }

    /**
     * image流数据处理
     *
     * @author ianly
     */
    private static BufferedImage toBufferedImage(BitMatrix matrix) {
        int width = matrix.getWidth();
        int height = matrix.getHeight();
        BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB);
        for (int x = 0; x < width; x++) {
            for (int y = 0; y < height; y++) {
                image.setRGB(x, y, matrix.get(x, y) ? 0xFF000000 : 0xFFFFFFFF);
            }
        }
        return image;
    }

    public static void main(String[] args) {
        String binary = QRCodeUtil.creatRrCode("https://baidu.com", 200,200,12);
        System.out.println(binary);
    }
}