package com.utils;

import com.google.zxing.BarcodeFormat;
import com.google.zxing.EncodeHintType;
import com.google.zxing.client.j2se.MatrixToImageWriter;
import com.google.zxing.common.BitMatrix;
import com.google.zxing.qrcode.QRCodeWriter;
import com.google.zxing.qrcode.decoder.ErrorCorrectionLevel;
import org.apache.commons.codec.binary.Base64;
import org.springframework.stereotype.Component;
import org.springframework.util.StringUtils;

import javax.imageio.ImageIO;
import javax.servlet.ServletOutputStream;
import java.awt.image.BufferedImage;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.util.HashMap;

/**
 * +----------------------------------------------------------------------
 * | CRMEB [ CRMEB赋能开发者，助力企业发展 ]
 * +----------------------------------------------------------------------
 * | Copyright (c) 2016~2020 https://www.crmeb.com All rights reserved.
 * +----------------------------------------------------------------------
 * | Licensed CRMEB并不是自由软件，未经许可不能去掉CRMEB相关版权
 * +----------------------------------------------------------------------
 * | Author: CRMEB Team <admin@crmeb.com>
 * +----------------------------------------------------------------------
 * 二维码工具
 */
@Component
public class QRCodeUtil {

    public static String crateQRCode(String content, int width, int height) throws IOException {

        String resultImage = "";
        if (!StringUtils.isEmpty(content)) {
            ServletOutputStream stream = null;
            ByteArrayOutputStream os = new ByteArrayOutputStream();
            @SuppressWarnings("rawtypes")
            HashMap<EncodeHintType, Comparable> hints = new HashMap<>();
            hints.put(EncodeHintType.CHARACTER_SET, "utf-8"); // 指定字符编码为“utf-8”
            hints.put(EncodeHintType.ERROR_CORRECTION, ErrorCorrectionLevel.H); // 指定二维码的纠错等级为中级
            hints.put(EncodeHintType.MARGIN, 2); // 设置图片的边距

            try {
                QRCodeWriter writer = new QRCodeWriter();
                BitMatrix bitMatrix = writer.encode(content, BarcodeFormat.QR_CODE, width, height, hints);

                BufferedImage bufferedImage = MatrixToImageWriter.toBufferedImage(bitMatrix);
                ImageIO.write(bufferedImage, "png", os);
                /**
                 * 原生转码前面没有 data:image/png;base64 这些字段，返回给前端是无法被解析，可以让前端加，也可以在下面加上
                 */

                return CrmebUtil.getBase64Image(Base64.encodeBase64String(os.toByteArray()));
            } catch (Exception e) {
                e.printStackTrace();
            } finally {
                if (stream != null) {
                    stream.flush();
                    stream.close();
                }
            }
        }
        return null;
    }
}
