using Newtonsoft.Json;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Security.Cryptography;
using System.Text;

namespace AllBase
{
    public static class SignHelper
    {
        public static string GetSign()
        {
            string url = BaseClass.LoginApiUrl + "?obj=littlecow/sign&act=get_sign";
            string sign = GetHtml.GetUtf8(url, BaseClass.ChromeUserAgent);
            if (!string.IsNullOrEmpty(sign))
            {
                Encoding utf8 = Encoding.UTF8;
                Encoding ascii = Encoding.ASCII;

                string input = sign;
                sign = ascii.GetString(Encoding.Convert(utf8, ascii, utf8.GetBytes(input)));
                sign = sign.Trim('?');
            }
            return sign;
        }

        public static string DESDecrypt(string decrypt, string key = "")
        {
            if (string.IsNullOrEmpty(key))
            {
                key = "20190813";
            }
            try
            {
                DESCryptoServiceProvider oDESCryptoServiceProvider = new DESCryptoServiceProvider();

                byte[] inputByteArray = new byte[decrypt.Length / 2];
                for (int x = 0; x < decrypt.Length / 2; x++)
                {
                    int i = (Convert.ToInt32(decrypt.Substring(x * 2, 2), 16));
                    inputByteArray[x] = (byte)i;
                }
                oDESCryptoServiceProvider.Key = ASCIIEncoding.ASCII.GetBytes(key);
                oDESCryptoServiceProvider.IV = ASCIIEncoding.ASCII.GetBytes(key);
                MemoryStream oMemoryStream = new MemoryStream();
                CryptoStream oCryptoStream = new CryptoStream(oMemoryStream, oDESCryptoServiceProvider.CreateDecryptor(), CryptoStreamMode.Write);
                oCryptoStream.Write(inputByteArray, 0, inputByteArray.Length);
                oCryptoStream.FlushFinalBlock();
                return Encoding.Default.GetString(oMemoryStream.ToArray());
            }
            catch (System.Exception ex)
            {
                LogSave.Add(ex.ToString());
                return string.Empty;
            }
        }

        public static Dictionary<string, object> BuildSign(Dictionary<string, object> dict, string clientSecret)
        {
            var result = new Dictionary<string, object>();
            // 去除空值并排序
            dict = dict.Where(d => d.Value != null)
                .OrderBy(d => d.Key)
                .ToDictionary((d) => d.Key, (d) => d.Value);
            // 拼接
            string signString = "";
            // 反射处理非基本类型字段的json转换
            string[] types = { "String", "DateTime", "Int64", "Boolean", "Float", "Double", "Long", "Int32" };
            foreach (var item in dict.Keys.ToArray())
            {
                if (!types.Contains(dict[item]?.GetType().Name))
                {
                    dict[item] = JsonConvert.SerializeObject(dict[item]);
                }
                object value = null;
                dict.TryGetValue(item, out value);
                // 布尔值大写造成的签名错误
                if (value.ToString().ToLower().Equals("false")) value = "false";
                if (value.ToString().ToLower().Equals("true")) value = "true";
                signString += item + value.ToString();
                result.Add(item, value.ToString());
            }
            signString = clientSecret + signString + clientSecret;
            Console.WriteLine("拼接内容:" + signString);
            // MD5加密
            using (var md5 = MD5.Create())
            {
                signString = GetMd5Hash(md5, signString).ToUpper();
            }
            Console.WriteLine("签名:" + signString);
            result.Add("sign", signString);
            return result;
        }

        static string GetMd5Hash(MD5 md5Hash, string input)
        {
            byte[] data = md5Hash.ComputeHash(Encoding.UTF8.GetBytes(input));
            StringBuilder sBuilder = new StringBuilder();
            for (int i = 0; i < data.Length; i++)
            {
                sBuilder.Append(data[i].ToString("x2"));
            }
            return sBuilder.ToString();
        }

    }
}