using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using JWT;
using JWT.Algorithms;
using JWT.Serializers;
using Newtonsoft.Json;

namespace Services.Tool
{
    /// <summary>
    /// Token辅助类
    /// 需要引用jwt包
    /// </summary>
    public class TokenHelper
    {
        //私钥
        static string Private_key = "CWLCJLWQZYY";
        //创建一个世界协调时间提供对象 utc时间协调时间
       static IDateTimeProvider provider = new UtcDateTimeProvider();
        //时间戳起点时间 
        static DateTime timeEpoch = new DateTime(1970,1,1,0,0,0,DateTimeKind.Utc);
        //序列化对象
       static IJsonSerializer serializer = new JsonNetSerializer();
        //编码序列化对象
        static IBase64UrlEncoder encoder = new JwtBase64UrlEncoder();
        //编码算法
        static IJwtAlgorithm algorithm = new HMACSHA384Algorithm();
        //jwt编码
        static JwtEncoder jwtEncoder= new JwtEncoder(algorithm,serializer,encoder);
        //验证对象
        static IJwtValidator validator = new JwtValidator(serializer,provider);
        //jwt解码
        static JwtDecoder decoder = new JwtDecoder(serializer, validator, encoder, algorithm);
        /// <summary>
        /// 加密的数据键值对传入
        /// </summary>
        /// <param name="keys"></param>
        /// <returns></returns>
        public static string GetToken(Dictionary<string,object> keys,float day)
        {
            //荷载，负载,最重要的信息,token中保存的信息 keys
            var now = provider.GetNow();
            //获取当前时间距离时间戳的差秒
            var epochSecons = Math.Round((now-timeEpoch).TotalSeconds);
            keys.Add("exp",(epochSecons+3600)*24*day);//设置过期时间
            //jwt同一加密
            var token = jwtEncoder.Encode(keys,Private_key);
            return token;
        }
        public static string CheckToken(string token)
        {
            try
            {
                //解码 tonken 私钥 验证是否过期 
                //过期时间验证  系统默认起始时间为1970,1,1,0,0,0 如果验证过期需要保证起始时间一致
                //要么手动验证过期,现在时间与起始时间的差值如果大于设置exp则过期
                return   JsonConvert.DeserializeObject<Datainfo>(decoder.Decode(token, Private_key,verify: true)).data.ToString();//str数据转成Dictionary<string,object>类型即可
            }
            catch (Exception)
            {
                return null;
            }
           
        }
        public class Datainfo {
           public dynamic data { get; set; }
            public dynamic exp { get; set; }
        }
    }
}