package com.walker.support.kaptcha;

import com.walker.infrastructure.utils.StringUtils;
import com.walker.web.CaptchaProvider;
import com.walker.web.CaptchaResult;
import com.walker.web.CaptchaType;

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.util.Random;

/**
 * 只有文字的验证码，数字或者字母。
 * @author 时克英
 * @date 2023-05-12
 */
public class WordCaptchaProvider implements CaptchaProvider<CaptchaResult> {

    private static final Random random = new Random();

    private final int width = 80;     //图片宽度
    private final int height = 34;    //图片高度
    private final int stringNum = 4;  //字符的数量
    private final int lineSize = 40;  //干扰线数量

    @Override
    public CaptchaResult generateCaptcha(Object param) {
        CaptchaResult captchaResult = new CaptchaResult();
        BufferedImage image = this.createImage(captchaResult);
//        captchaResult.setCode(code);
        captchaResult.setImage(image);
        return captchaResult;
    }

    @Override
    public boolean validateCaptcha(CaptchaResult data) {
        // 由业务子类继承并重写该方法完成校验，一般会把生成结果放入缓存，然后与给定的结果做对比。
        return false;
    }

    @Override
    public CaptchaType getCaptchaType() {
        return CaptchaType.InputCode;
    }

    private BufferedImage createImage(CaptchaResult captchaResult){
        Graphics Graphics = null;
        try {
            BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_INT_BGR);
            Graphics = image.getGraphics();// 获得BufferedImage对象的Graphics对象
            Graphics.fillRect(0, 0, width, height);//填充矩形
            Graphics.setFont(new Font("Times New Roman", Font.ROMAN_BASELINE, 18));//设置字体
            Graphics.setColor(getRandColor(110, 133));//设置颜色
            //绘制干扰线
            for(int i = 0; i <= lineSize; i++) {
                drawLine(Graphics);
            }
            //绘制字符
            String randomString = "";
            for(int i = 1; i <= stringNum; i++) {
                randomString = drawString(Graphics, randomString, i);
                captchaResult.setCode(randomString);
            }
            return image;

        } catch (Exception ex){
            ex.printStackTrace();
            return null;

        } finally {
            if(Graphics != null){
                Graphics.dispose();//释放绘图资源
            }
        }
    }

    /**
     * 绘制字符串,返回绘制的字符串
     * @param graphics 获得BufferedImage对象的Graphics对象
     * @param randomString 随机字符串
     * @param i 坐标倍数

     * @since 2020-04-16
     * @return string
     */
    private String drawString(Graphics graphics, String randomString, int i) {
        Graphics2D g2d = (Graphics2D) graphics;
        g2d.setFont(getFont());   //设置字体
        g2d.setColor(new Color(random.nextFloat(), random.nextFloat(), random.nextFloat()));//设置颜色
        String randChar = getRandomChar(random.nextInt(StringUtils.STRING_RANDOM_CHAR.length()));
        randomString += randChar;   //组装
//        int rot = getRandomNum(1,10);
        int rot = Integer.parseInt(StringUtils.generateRandomNumber(1));
//        System.out.println(".......... rot = " + rot);
        g2d.translate(random.nextInt(3), random.nextInt(3));
        g2d.rotate(rot * Math.PI / 180);
        g2d.drawString(randChar, 13*i, 20);
        g2d.rotate(-rot * Math.PI / 180);
        return randomString;
    }

    private void drawLine(Graphics graphics) {
        //起点(x,y)  偏移量x1、y1
        int x = random.nextInt(width);
        int y = random.nextInt(height);
        int xl = random.nextInt(13);
        int yl = random.nextInt(15);
        graphics.setColor(new Color(random.nextFloat(), random.nextFloat(), random.nextFloat()));
        graphics.drawLine(x, y, x + xl, y + yl);
    }

    private Font getFont() {
        return new Font("Fixedsys", Font.CENTER_BASELINE, 25);  //名称、样式、磅值
    }

    private String getRandomChar(int index) {
        //获取指定位置index的字符，并转换成字符串表示形式
        return String.valueOf(StringUtils.STRING_RANDOM_CHAR.charAt(index));
    }

    private Color getRandColor(int frontColor, int backColor) {
        if(frontColor > 255)
            frontColor = 255;
        if(backColor > 255)
            backColor = 255;

        int red = frontColor + random.nextInt(backColor - frontColor - 16);
        int green = frontColor + random.nextInt(backColor - frontColor -14);
        int blue = frontColor + random.nextInt(backColor - frontColor -18);
        return new Color(red, green, blue);
    }
}