package com.zhjq.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.QRCodeWriter;
import com.google.zxing.qrcode.decoder.ErrorCorrectionLevel;

import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;

public class QRCodeUtils {


    /**
     * 生成二维码
     *
     * @param content 二维码的内容
     * @return BitMatrix对象
     */
    public static BitMatrix createCode(String content) throws IOException {
        //二维码的宽高
        int width = 200;
        int height = 200;

        //其他参数，如字符集编码
        Map<EncodeHintType, Object> hints = new HashMap<EncodeHintType, Object>();
        hints.put(EncodeHintType.CHARACTER_SET, "UTF-8");
        //容错级别为H
        hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.H);
        //白边的宽度，可取0~4
        hints.put(EncodeHintType.MARGIN, 0);

        BitMatrix bitMatrix = null;
        try {
            //生成矩阵，因为我的业务场景传来的是编码之后的URL，所以先解码
            bitMatrix = new MultiFormatWriter().encode(content,
                    BarcodeFormat.QR_CODE, width, height, hints);

            //bitMatrix = deleteWhite(bitMatrix);
        } catch (WriterException e) {
            e.printStackTrace();
        }

        return bitMatrix;
    }

    /**
     * 生成带有底部文字的二维码
     *
     * @param content 二维码的内容
     * @param text    底部文字
     * @throws IOException
     */
    public static byte[] createCodeWithText(String content, String text) throws IOException {
        // 二维码的宽高
        int width = 300;
        int height = 300;

        // 其他参数，如字符集编码
        Map<EncodeHintType, Object> hints = new HashMap<>();
        hints.put(EncodeHintType.CHARACTER_SET, "UTF-8");
        hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.H);
        hints.put(EncodeHintType.MARGIN, 0);

        BitMatrix bitMatrix = null;
        try {
            // 生成二维码矩阵
            QRCodeWriter writer = new QRCodeWriter();
            bitMatrix = writer.encode(content, BarcodeFormat.QR_CODE, width, height, hints);
        } catch (WriterException e) {
            e.printStackTrace();
        }

        // 创建图像并绘制二维码
        int imgWidth = width;
        int imgHeight = height + 30; // 增加额外空间用于文本
        BufferedImage image = new BufferedImage(imgWidth, imgHeight, BufferedImage.TYPE_INT_RGB);
        Graphics2D graphics = image.createGraphics();

        // 设置背景色
        graphics.setColor(Color.WHITE);
        graphics.fillRect(0, 0, imgWidth, imgHeight);

        // 绘制二维码
        graphics.setColor(Color.BLACK);
        for (int x = 0; x < width; x++) {
            for (int y = 0; y < height; y++) {
                if (bitMatrix.get(x, y)) {
                    graphics.fillRect(x, y, 1, 1);
                }
            }
        }

        // 添加底部文字，使用合适的字体
        graphics.setColor(Color.BLACK);
        // 使用支持中文的字体
        Font font = new Font("Microsoft YaHei", Font.BOLD, 16);
        graphics.setFont(font);
        FontMetrics metrics = graphics.getFontMetrics(font);
        int textWidth = metrics.stringWidth(text);
        // 在底部居中绘制文本
        graphics.drawString(text, (imgWidth - textWidth) / 2, height + 20);

        graphics.dispose();

        // 保存图像
        try {
            ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
//            ImageIO.write(image, "png", new File(filePath));
            ImageIO.write(image, "png", outputStream);
            return outputStream.toByteArray();
        } catch (IOException e) {
            e.printStackTrace();
        }
        return null;
    }

    /**
     * 删除生成的二维码周围的白边，根据审美决定是否删除
     *
     * @param matrix BitMatrix对象
     * @return BitMatrix对象
     */
    private static BitMatrix deleteWhite(BitMatrix matrix) {
        int[] rec = matrix.getEnclosingRectangle();
        int resWidth = rec[2] + 1;
        int resHeight = rec[3] + 1;

        BitMatrix resMatrix = new BitMatrix(resWidth, resHeight);
        resMatrix.clear();
        for (int i = 0; i < resWidth; i++) {
            for (int j = 0; j < resHeight; j++) {
                if (matrix.get(i + rec[0], j + rec[1]))
                    resMatrix.set(i, j);
            }
        }
        return resMatrix;
    }
}