package com.doumee.service.common;

import com.doumee.core.exception.BusinessException;
import com.doumee.core.constants.ResponseStatus;
import com.doumee.core.utils.redis.RedisUtil;
import com.fasterxml.jackson.annotation.JsonIgnore;
import io.swagger.annotations.ApiModel;
import io.swagger.annotations.ApiModelProperty;
import lombok.Data;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.stereotype.Service;

import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.util.Base64;
import java.util.Random;
import java.util.UUID;

/**
 * 图片验证码
 * @author Eva.Caesar Liu
 * @date 2022/03/15 09:54
 */
@Service
public class CaptchaService {

    @Value("${cache.captcha.expire}")
    private int expire;

    // 验证码字符集
    private static final char[] CODES = { 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'J',
            'K', 'L', 'M', 'N', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W',
            'X', 'Y', 'a', 'b', 'c', 'd', 'e', 'f', 'h', 'j',
            'k', 'l', 'm', 'n', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w',
            'x', 'y', '3', '4', '5', '6', '7', '8' };

    // 验证码图片宽度
    private static final Integer WIDTH = 90;

    // 验证码图片高度
    private static final Integer HEIGHT = 30;

    @Autowired
    private RedisTemplate<String, Object> redisTemplate;
    /**
     * 生成验证码图片
     * @author Eva.Caesar Liu
     * @date 2022/03/15 09:54
     */
    public Captcha genCaptcha () {
        // 定义图像buffer
        BufferedImage buffImg = new BufferedImage(WIDTH, HEIGHT, BufferedImage.TYPE_INT_RGB);
        Graphics gd = buffImg.getGraphics();
        // 创建一个随机数生成器类
        Random random = new Random();
        // 将图像填充为白色
        gd.setColor(Color.decode("#FFFFFF"));
        gd.fillRect(0, 0, WIDTH, HEIGHT);
        // 创建字体，字体的大小应该根据图片的高度来定。
        Font font = new Font("Dialog", 1, 23);
        // 设置字体
        gd.setFont(font);
        // 画边框
        // gd.setColor(Color.decode("#E6BA09"));
        gd.drawRect(0, 0, WIDTH, HEIGHT);
        // 随机产生40条干扰线，使图象中的认证码不易被其它程序探测到。
        gd.setColor(Color.decode("#990000"));
        for (int i = 0; i < 30; i++) {
            int x = random.nextInt(WIDTH);
            int y = random.nextInt(HEIGHT);
            int xl = random.nextInt(12);
            int yl = random.nextInt(12);
            gd.drawLine(x, y, x + xl, y + yl);
        }
        // randomCode用于保存随机产生的验证码，以便用户登录后进行验证。
        StringBuffer randomCode = new StringBuffer();
        int red, green, blue;
        // 随机产生codeCount数字的验证码。
        for (int i = 0; i < 4; i++) {
            // 得到随机产生的验证码数字。
            String code = String.valueOf(CODES[random.nextInt(CODES.length)]);
            // 产生随机的颜色分量来构造颜色值，这样输出的每位数字的颜色值都将不同。
            red = random.nextInt(255);
            green = random.nextInt(255);
            blue = random.nextInt(255);

            // 用随机产生的颜色将验证码绘制到图像中。
            gd.setColor(new Color(red, green, blue));
            gd.drawString(code, (i + 1) * 15, 24);

            // 将产生的四个随机数组合在一起。
            randomCode.append(code);
        }
        // 存入缓存
        Captcha captcha = new Captcha(randomCode.toString(), buffImg);
        RedisUtil.addObject(redisTemplate, captcha.getUuid(),captcha.getText(),expire);
        return captcha;
    }

    /**
     * 校验验证码
     * @author Eva.Caesar Liu
     * @date 2022/03/15 09:54
     */
    public void check(String uuid, String code) {
       ;
        String cacheCode =  RedisUtil.getObject(redisTemplate, uuid,String.class);
        if (cacheCode == null) {
            throw new BusinessException(ResponseStatus.VERIFICATION_CODE_INCORRECT);
        }

        RedisUtil.deleteObject(redisTemplate, uuid);

//        redisTemplate.opsForValue().de(cacheCode);
        if (!code.equalsIgnoreCase(cacheCode)) {
            throw new BusinessException(ResponseStatus.VERIFICATION_CODE_INCORRECT);
        }
    }

    /**
     * @author Eva.Caesar Liu
     * @date 2022/03/15 09:54
     */
    @Data
    @ApiModel("验证码对象")
    public static class Captcha {

        @ApiModelProperty(value = "验证码UUID")
        private String uuid;

        @JsonIgnore
        @ApiModelProperty(value = "验证码", hidden = true)
        private String text;

        @ApiModelProperty(value = "验证码Base64")
        private String image;

        Captcha (String text, BufferedImage image) {
            this.uuid = UUID.randomUUID().toString();
            this.text = text;
            ByteArrayOutputStream stream = new ByteArrayOutputStream();
            try {
                ImageIO.write(image, "png", stream);
            } catch (IOException e) {
                throw new RuntimeException("生成验证码失败");
            }
            this.image = "data:image/png;base64," + Base64.getEncoder().encodeToString(stream.toByteArray());
        }
    }
}