using System;

using Jose;

using System.Collections.Generic;

using System.Text;

using Newtonsoft.Json;

public class Program

{

    public static readonly DateTime UnixEpoch = new DateTime(1970, 1, 1, 0, 0, 0, 0, DateTimeKind.Utc);

    public static void Main()

    {

        var now = DateTime.UtcNow;

        var secretClear = "MzQ0NjdDM0VFMzFBNDc0QzlCMEQ2NEJDMDkyNzY4Q0U4NEU3MjlFMDcwNTk0QzZBQTk3NTQ0QTZCQjEyM0I3RA";

        var encodedSecret = GetSecretKeyAsBytes(secretClear);

        //var secretKey = new byte[]{164,60,194,0,161,189,41,38,130,89,141,164,45,170,159,209,69,137,243,216,191,131,47,250,32,107,231,117,37,158,225,234};

​

        string token=Jose.JWT.Encode(GetPayload(now), encodedSecret, JwsAlgorithm.HS512);

        Console.WriteLine("nbf = " + GetNbf(now));

        Console.WriteLine("exp = " + GetExp(now));

        Console.WriteLine("token = " + token);

    }

    private static Dictionary<string, object> GetPayload(DateTime utcNow)

    {

        //var user = "corp\\lee.western";

        var exten = new {key1 = "value", CustId = "A100003280"} ;

        var payload = new Dictionary<string, object>()

        {

            { "System", "eTrustWeb" },

            { "Product", "CheckMMAUser" }, 

            { "UTCDateTime", "20220613025111" },  /* netwotk user */

            { "AccessToken", null },

            { "UId", "2024d313-6f1f-4ca9-b27b-2d5167f66413"},

            { "Extension", Newtonsoft.Json.JsonConvert.SerializeObject(exten)}          

        };

        return payload;

    }

    private static byte[] GetSecretKeyAsBytes(string secret)

        {

            return Encoding.UTF8.GetBytes(secret);

        }

    public static string SecretAsBase64Encoded(string secret)

        {

            return Convert.ToBase64String(GetSecretKeyAsBytes(secret));

        }

    private static long GetNbf(DateTime utcNow) { return GetEpochDateTimeAsInt(utcNow); /* nbf */ }

    private static long GetExp(DateTime utcNow)

    {       

        var tokenValidFor = TimeSpan.FromDays(200);

        var expiry = utcNow.Add(tokenValidFor);

        return GetEpochDateTimeAsInt(expiry); // exp    

    }

    public static long GetEpochDateTimeAsInt(DateTime datetime)

    {

        DateTime dateTime = datetime;

        if (datetime.Kind != DateTimeKind.Utc)

            dateTime = datetime.ToUniversalTime();

        if (dateTime.ToUniversalTime() <= UnixEpoch)

            return 0;

        return (long)(dateTime - UnixEpoch).TotalSeconds;

    }

}