package com.ruoyi.other.util;

import com.google.zxing.BarcodeFormat;
import com.google.zxing.EncodeHintType;
import com.google.zxing.MultiFormatWriter;
import com.google.zxing.common.BitMatrix;
import com.google.zxing.qrcode.decoder.ErrorCorrectionLevel;

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

public class QRCodeUtils {

    private static final String CHARSET = "utf-8";
    private static final String FORMAT_NAME = "JPG";
    private static final int QRCODE_SIZE = 300;

    private QRCodeUtils() {
    }

    public static void encode(String content, OutputStream output) throws Exception {
        Hashtable<EncodeHintType, Object> hints = new Hashtable<>();
        hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.H);
        hints.put(EncodeHintType.CHARACTER_SET, CHARSET);
        hints.put(EncodeHintType.MARGIN, 1);
        BitMatrix bitMatrix = new MultiFormatWriter().encode(
                content,
                BarcodeFormat.QR_CODE,
                QRCODE_SIZE,
                QRCODE_SIZE,
                hints
        );
        BufferedImage image = new BufferedImage(QRCODE_SIZE, QRCODE_SIZE, BufferedImage.TYPE_INT_RGB);
        for (int x = 0; x < QRCODE_SIZE; x++) {
            for (int y = 0; y < QRCODE_SIZE; y++) {
                image.setRGB(x, y, bitMatrix.get(x, y) ? 0xFF000000 : 0xFFFFFFFF);
            }
        }
        ImageIO.write(image, FORMAT_NAME, output);
    }
}