BookingBackend/Myshipping.Core/Captcha/ClickWord/ClickWordCaptcha.cs

using Furion;
using Furion.DependencyInjection;
using Furion.JsonSerialization;
using Microsoft.Extensions.Caching.Memory;
using System;
using System.Collections.Generic;
using System.Drawing;
using System.Drawing.Imaging;
using System.IO;
using System.Linq;
using Yitter.IdGenerator;

namespace Myshipping.Core;

/// <summary>
/// 点选验证码
/// </summary>
public class ClickWordCaptcha : IClickWordCaptcha, ITransient
{
    private readonly IMemoryCache _memoryCache;

    public ClickWordCaptcha(IMemoryCache memoryCache)
    {
        _memoryCache = memoryCache;
    }

    /// <summary>
    /// 生成验证码图片
    /// </summary>
    /// <param name="code"></param>
    /// <param name="width"></param>
    /// <param name="height"></param>
    /// <returns></returns>
    public ClickWordCaptchaResult CreateCaptchaImage(string code, int width, int height)
    {
        var rtnResult = new ClickWordCaptchaResult();

        // 变化点: 3个字
        int rightCodeLength = 3;

        Bitmap bitmap = null;
        Graphics g = null;
        MemoryStream ms = null;
        Random random = new();

        Color[] colorArray = { Color.Black, Color.DarkBlue, Color.Green, Color.Orange, Color.Brown, Color.DarkCyan, Color.Purple };

        string bgImagesDir = Path.Combine(App.WebHostEnvironment.WebRootPath, "Captcha/Image");
        string[] bgImagesFiles = Directory.GetFiles(bgImagesDir);

        // 字体来自：https://www.zcool.com.cn/special/zcoolfonts/
        string fontsDir = Path.Combine(App.WebHostEnvironment.WebRootPath, "Captcha/Font");
        string[] fontFiles = new DirectoryInfo(fontsDir)?.GetFiles()
            ?.Where(m => m.Extension.ToLower() == ".ttf")
            ?.Select(m => m.FullName).ToArray();

        int imgIndex = random.Next(bgImagesFiles.Length);
        string randomImgFile = bgImagesFiles[imgIndex];
        var imageStream = Image.FromFile(randomImgFile);

        bitmap = new Bitmap(imageStream, width, height);
        imageStream.Dispose();
        g = Graphics.FromImage(bitmap);
        Color[] penColor = { Color.Red, Color.Green, Color.Blue };
        int code_length = code.Length;
        var words = new List<string>();
        for (int i = 0; i < code_length; i++)
        {
            int colorIndex = random.Next(colorArray.Length);
            int fontIndex = random.Next(fontFiles.Length);
            Font f = LoadFont(fontFiles[fontIndex], 15, FontStyle.Regular);
            Brush b = new SolidBrush(colorArray[colorIndex]);
            int _y = random.Next(height);
            if (_y > (height - 30))
                _y -= 60;

            int _x = width / (i + 1);
            if ((width - _x) < 50)
            {
                _x = width - 60;
            }
            string word = code.Substring(i, 1);
            if (rtnResult.repData.point.Count < rightCodeLength)
            {
                // (int, int) percentPos = ToPercentPos((width, height), (_x, _y));
                // 添加正确答案 位置数据
                if (random.Next(0, 3).Equals(1) || (code_length - i).Equals(rightCodeLength - rtnResult.repData.point.Count))
                {
                    rtnResult.repData.point.Add(new PointPosModel()
                    {
                        X = _x, //percentPos.Item1,
                        Y = _y  //percentPos.Item2,
                    });
                    words.Add(word);
                }
            }
            g.DrawString(word, f, b, _x, _y);
        }
        rtnResult.repData.wordList = words;

        ms = new MemoryStream();
        bitmap.Save(ms, ImageFormat.Jpeg);
        g.Dispose();
        bitmap.Dispose();
        ms.Dispose();
        rtnResult.repData.originalImageBase64 = Convert.ToBase64String(ms.GetBuffer()); //"data:image/jpg;base64," +
        rtnResult.repData.token = YitIdHelper.NextId().ToString();

        // 缓存验证码正确位置集合
        var cacheOptions = new MemoryCacheEntryOptions().SetSlidingExpiration(TimeSpan.FromSeconds(30));
        _memoryCache.Set(CommonConst.CACHE_KEY_CODE + rtnResult.repData.token, rtnResult.repData.point, cacheOptions);

        rtnResult.repData.point = null; // 清空位置信息
        return rtnResult;
    }

    /// <summary>
    /// 转换为相对于图片的百分比单位
    /// </summary>
    /// <param name="widthAndHeight">图片宽高</param>
    /// <param name="xAndy">相对于图片的绝对尺寸</param>
    /// <returns>(int:xPercent, int:yPercent)</returns>
    private (int, int) ToPercentPos((int, int) widthAndHeight, (int, int) xAndy)
    {
        (int, int) rtnResult = (0, 0);
        // 注意: int / int = int (小数部分会被截断)
        rtnResult.Item1 = (int)(((double)xAndy.Item1) / ((double)widthAndHeight.Item1) * 100);
        rtnResult.Item2 = (int)(((double)xAndy.Item2) / ((double)widthAndHeight.Item2) * 100);

        return rtnResult;
    }

    /// <summary>
    /// 加载字体
    /// </summary>
    /// <param name="path">字体文件路径,包含字体文件名和后缀名</param>
    /// <param name="size">大小</param>
    /// <param name="fontStyle">字形(常规/粗体/斜体/粗斜体)</param>
    private Font LoadFont(string path, int size, FontStyle fontStyle)
    {
        var pfc = new System.Drawing.Text.PrivateFontCollection();
        pfc.AddFontFile(path);// 字体文件路径
        return new Font(pfc.Families[0], size, fontStyle);
    }

    /// <summary>
    /// 随机绘制字符串
    /// </summary>
    /// <param name="number"></param>
    /// <returns></returns>
    public string RandomCode(int number)
    {
        char[] str_char_arrary = new char[] { '赵', '钱', '孙', '李', '周', '吴', '郑', '王', '冯', '陈', '卫', '蒋', '沈', '韩', '杨', '朱', '秦', '尤', '许', '何', '吕', '施', '张', '孔', '曹', '严', '华', '金', '魏', '陶', '姜', '戚', '谢', '喻', '柏', '水', '章', '云', '苏', '潘', '葛', '范', '彭', '郎', '鲁', '昌', '马', '苗', '凤', '花', '方', '任', '袁', '柳', '史', '唐', '费', '薛', '雷', '贺', '汤', '殷', '罗', '毕', '安', '常', '傅', '齐', '元', '顾', '孟', '平', '黄', '穆', '萧', '姚', '汪', '毛', '米', '伏', '成', '戴', '谈', '宋', '茅', '庞', '熊', '纪', '舒', '屈', '项', '祝', '董', '梁', '杜', '蓝', '季', '贾', '路', '娄', '江', '童', '颜', '郭', '梅', '盛', '林', '钟', '徐', '骆', '高', '夏', '田', '樊', '胡', '凌', '霍', '万', '支', '管', '卢', '莫', '房', '解', '应', '宗', '丁', '宣', '邓', '单', '杭', '洪', '包', '诸', '左', '石', '崔', '吉', '程', '邢', '陆', '荣', '翁', '于', '惠', '曲', '封', '储', '仲', '伊', '宁', '仇', '甘', '武', '符', '刘', '景', '龙', '叶', '幸', '司', '黎', '印', '怀', '蒲', '从', '索', '赖', '卓', '屠', '池', '乔', '闻', '党', '谭', '贡', '劳', '申', '扶', '堵', '宰', '桑', '寿', '通', '燕', '浦', '尚', '农', '温', '别', '庄', '柴', '阎', '连', '习', '容', '向', '古', '易', '终', '步', '都', '耿', '满', '国', '文', '寇', '广', '东', '欧', '利', '师', '巩', '聂', '关', '荆', '伟', '刚', '勇', '毅', '俊', '峰', '强', '军', '平', '保', '东', '文', '辉', '力', '明', '永', '健', '世', '广', '志', '义', '兴', '良', '海', '山', '仁', '波', '宁', '贵', '福', '生', '龙', '元', '全', '国', '胜', '学', '祥', '才', '发', '武', '新', '利', '清', '飞', '彬', '富', '顺', '信', '子', '杰', '涛', '昌', '成', '康', '星', '光', '天', '达', '安', '岩', '中', '茂', '进', '林', '有', '坚', '和', '彪', '博', '诚', '先', '敬', '震', '振', '壮', '会', '思', '群', '豪', '心', '邦', '承', '乐', '绍', '功', '松', '善', '厚', '庆', '民', '友', '裕', '河', '哲', '江', '超', '浩', '亮', '政', '谦', '奇', '固', '之', '轮', '翰', '朗', '伯', '宏', '言', '若', '鸣', '朋', '梁', '栋', '维', '启', '克', '伦', '翔', '旭', '鹏', '泽', '晨', '辰', '士', '以', '建', '家', '致', '树', '炎', '德', '行', '时', '泰', '盛', '雄', '钧', '冠', '策', '腾', '榕', '风', '航', '秀', '英', '华', '慧', '巧', '美', '娜', '静', '淑', '惠', '珠', '翠', '雅', '芝', '玉', '萍', '红', '玲', '芬', '芳', '燕', '彩', '春', '菊', '兰', '凤', '洁', '梅', '琳', '素', '云', '莲', '真', '环', '雪', '荣', '爱', '妹', '霞', '香', '月', '莺', '艳', '瑞', '凡', '佳', '嘉', '琼', '勤', '珍', '贞', '莉', '桂', '叶', '璧', '晶', '秋', '珊', '锦', '青', '婉', '颖', '露', '雁', '仪', '荷', '丹', '蓉', '眉', '君', '琴', '蕊', '薇', '梦', '韵', '融', '园', '艺', '咏', '卿', '聪', '澜', '纯', '悦', '昭', '冰', '爽', '羽', '希', '欣', '飘', '育', '柔', '竹', '凝', '晓', '欢', '枫', '菲', '寒', '伊', '亚', '宜', '可', '舒', '影', '荔', '枝', '丽', '阳', '宝', '贝', '初', '程', '恒', '鸿', '桦', '剑', '娇', '纪', '宽', '苛', '灵', '玛', '媚', '晴', '容', '烁', '堂', '唯', '威', '苇', '阅', '宇', '雨', '洋', '忠', '宗', '曼', '紫', '逸', '贤', '蝶', '绿', '蓝', '儿', '翠', '烟' };
        var rand = new Random();
        var hs = new HashSet<char>();
        var randomBool = true;
        while (randomBool)
        {
            if (hs.Count == number)
                break;
            var rand_number = rand.Next(str_char_arrary.Length);
            hs.Add(str_char_arrary[rand_number]);
        }
        return string.Join("", hs);
    }

    /// <summary>
    /// 验证码验证
    /// </summary>
    /// <param name="input"></param>
    /// <returns></returns>
    public dynamic CheckCode(ClickWordCaptchaInput input)
    {
        var res = new ClickWordCaptchaResult();

        var rightVCodePos = _memoryCache.Get(CommonConst.CACHE_KEY_CODE + input.Token) as List<PointPosModel>;
        if (rightVCodePos == null)
        {
            res.repCode = "6110";
            res.repMsg = "验证码已失效，请重新获取";
            return res;
        }

        var userVCodePos = JSON.Deserialize<List<PointPosModel>>(input.PointJson);
        if (userVCodePos == null || userVCodePos.Count < rightVCodePos.Count)
        {
            res.repCode = "6111";
            res.repMsg = "验证码无效";
            return res;
        }

        int allowOffset = 25; // 允许的偏移量(点触容错)
        for (int i = 0; i < userVCodePos.Count; i++)
        {
            var xOffset = userVCodePos[i].X - rightVCodePos[i].X;
            var yOffset = userVCodePos[i].Y - rightVCodePos[i].Y;
            xOffset = Math.Abs(xOffset); // x轴偏移量                
            yOffset = Math.Abs(yOffset); // y轴偏移量
            // 只要有一个点的任意一个轴偏移量大于allowOffset，则验证不通过
            if (xOffset > allowOffset || yOffset > allowOffset)
            {
                res.repCode = "6112";
                res.repMsg = "验证码错误";
                return res;
            }
        }

        _memoryCache.Remove(CommonConst.CACHE_KEY_CODE + input.Token);
        res.repCode = "0000";
        res.repMsg = "验证成功";
        return res;
    }
}

/// <summary>
/// 记录正确位置
/// </summary>
public class PointPosModel
{
    public int X { get; set; }

    public int Y { get; set; }
}