using System;
using System.Collections.Generic;
using System.Configuration;
using System.IdentityModel.Tokens.Jwt;
using System.Linq;
using System.Security.Claims;
using System.Web;

namespace JsonRx.Helper
{
    /// <summary>
    /// </summary>
    public class JwtTokenizer
    {
        private string username;
        private string guid;
        private string customerId;
        private string fcmId;
        private string deviceType;
        /// <summary>
        /// </summary>
        public JwtTokenizer(string username, string guid, string customerId, string FCMId, string deviceTpe="")
        {
            this.username = username;
            this.guid = guid;
            this.customerId = customerId;
            this.fcmId = FCMId;
            this.deviceType = deviceTpe;
        }

        /// <summary>
        /// </summary>
        /// <returns></returns>
        public string CreateToken()
        {
            //Set issued at date
            DateTime issuedAt = DateTime.UtcNow;
            //set the time when it expires

            var time = ConfigurationManager.AppSettings["TokenExpiryInMinute"].ToString();

            DateTime expires = DateTime.UtcNow.AddMinutes(Convert.ToDouble(time));

            //http://stackoverflow.com/questions/18223868/how-to-encrypt-jwt-security-token
            var tokenHandler = new JwtSecurityTokenHandler();

            IList<Claim> claims = new List<Claim>();
            if (!string.IsNullOrEmpty(username))
            {
                claims.Add(new Claim(ClaimTypes.Name, username));
            }

            if (!string.IsNullOrEmpty(guid))
            {
                claims.Add(new Claim("Guid", guid));
            }

            if (!string.IsNullOrEmpty(customerId))
            {
                claims.Add(new Claim("CustomerNo", customerId));
            }

            if (!string.IsNullOrEmpty(fcmId))
            {
                claims.Add(new Claim("ClientFcmId", fcmId));
            }

            if (!string.IsNullOrEmpty(deviceType))
            {
                claims.Add(new Claim("DeviceType", deviceType));
            }

            //create a identity and add claims to the user which we want to log in
            ClaimsIdentity claimsIdentity = new ClaimsIdentity(claims);

            string sec = ConfigurationManager.AppSettings["JwtSecret"].ToString();
            //var now = DateTime.UtcNow;
            var securityKey = new Microsoft.IdentityModel.Tokens.SymmetricSecurityKey(System.Text.Encoding.Default.GetBytes(sec));
            var signingCredentials = new Microsoft.IdentityModel.Tokens.SigningCredentials(securityKey, Microsoft.IdentityModel.Tokens.SecurityAlgorithms.HmacSha256Signature);

            //create the jwt
            var token =
                (JwtSecurityToken)
                    tokenHandler.CreateJwtSecurityToken(issuer: ConfigurationManager.AppSettings["JwtAudience"].ToString(), audience: ConfigurationManager.AppSettings["JwtIssuer"].ToString(),
                        subject: claimsIdentity, notBefore: issuedAt, expires: expires, signingCredentials: signingCredentials);
            var tokenString = tokenHandler.WriteToken(token);

            return tokenString;
        }
    }
}