using JWT;
using JWT.Algorithms;
using JWT.Serializers;
using Newtonsoft.Json;
using Newtonsoft.Json.Linq;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using MyCode.Project.Infrastructure.Exceptions;

namespace MyCode.Project.Infrastructure.Common
{
    public class TokenHelper
    {
        #region CreateToken(创建token)
        public static string CreateToken(string key, string objName, object t, int expireMinute = 300)
        {

            var payload = new Dictionary<string, object>
            {
                { "exp", DateTimeOffset.UtcNow.AddMinutes(expireMinute).ToUnixTimeSeconds() },
                { objName,t}
            };

            //采用HS256加密算法
            IJwtAlgorithm algorithm = new HMACSHA256Algorithm();
            IJsonSerializer serializer = new JsonNetSerializer();
            IBase64UrlEncoder urlEncoder = new JwtBase64UrlEncoder();
            IJwtEncoder encoder = new JwtEncoder(algorithm, serializer, urlEncoder);

            return encoder.Encode(payload, key);
        }
        #endregion

        #region Get(根据token得到登录信息)
        public static object Get(string token, string tokenKey, string jsonKey)
        {
            try
            {
                IJsonSerializer serializer = new JsonNetSerializer();
                IBase64UrlEncoder urlEncoder = new JwtBase64UrlEncoder();
                IDateTimeProvider provider = new UtcDateTimeProvider();
                IJwtValidator validator = new JwtValidator(serializer, provider);
                IJwtDecoder decoder = new JwtDecoder(serializer, validator, urlEncoder);

                string json = decoder.Decode(token, tokenKey, verify: true);

                var dic = decoder.DecodeToObject<Dictionary<string, object>>(token);

                return dic[jsonKey];
            }
            catch (TokenExpiredException ex)
            {
                throw new BaseException("请重新登录，token已失效");
            }
            catch (SignatureVerificationException ex)
            {
                throw new BaseException("请重新登录，签名错误");
            }
        }
        #endregion


        #region Get(根据token得到登录信息)
        public static object GetString(string token, string tokenKey, string jsonKey)
        {
            try
            {
                IJsonSerializer serializer = new JsonNetSerializer();
                IBase64UrlEncoder urlEncoder = new JwtBase64UrlEncoder();
                IDateTimeProvider provider = new UtcDateTimeProvider();
                IJwtValidator validator = new JwtValidator(serializer, provider);
                IJwtDecoder decoder = new JwtDecoder(serializer, validator, urlEncoder);

                string json = decoder.Decode(token, tokenKey, verify: false);

                var dic = decoder.DecodeToObject<Dictionary<string, object>>(token);

                return dic[jsonKey];
            }
            catch (TokenExpiredException ex)
            {
                throw new BaseException("请重新登录，token已失效");
            }
            catch (SignatureVerificationException ex)
            {
                throw new BaseException("请重新登录，签名错误");
            }
        }
        #endregion


        public static string GetJwtString(string token)
        {
            if (string.IsNullOrWhiteSpace(token))
                return "";
            //string token = "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiIxMjM0NTY3ODkwIiwibmFtZSI6IkpvaG4gRG9lIiwiaWF0IjoxNTE2MjM5MDIyfQ.SflKxwRJSMeKKF2QT4fwpMeJf36Po1Qh";
            string[] parts = token.Split('.');
            string headerJson = DecodeBase64(parts[0]);
            string payloadJson = DecodeBase64(parts[1]);
            var payload = JsonConvert.DeserializeObject<Dictionary<string, object>>(payloadJson);
            if (payload["login"] != null)
            {
                var json = payload["login"].ToString();
                return json;
            }
            else
            {
                return "";
            }
        }

        private static string DecodeBase64(string str)
        {
            str = str.Replace('-', '+').Replace('_', '/');
            while (str.Length % 4 != 0)
            {
                str += '=';
            }
            var bytes = Convert.FromBase64String(str);
            return Encoding.UTF8.GetString(bytes);
        }
    }
}