using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Net.Http;
using System.Security.Cryptography;
using System.Text;
using System.Web.Http;
using AIAHTML5.WebAPI.Models;
using AIAHTML5.WebAPI.ViewModels;
using JWT;


namespace AIAHTML5.WebAPI.Controllers
{
    public class AccountController : ApiController
    {
        
        [AllowAnonymous]
        [Route("api/signin")]
        [HttpPost]
        public HttpResponseMessage Login(LoginViewModel model)
        {
            var loginSuccess = false;
            User userObj = new User();
            userObj.Email = "amrita.vishnoi@ebix.com";
            userObj.Id = 1;

            HttpResponseMessage response = null;
            if (ModelState.IsValid)
            {
                if (model.Email == userObj.Email && model.Password == "education")
                {
                    loginSuccess = true;
                }
                else
                {
                    loginSuccess = false;
                }

                    if (loginSuccess)
                    {
                        object dbUser;
                        var token = CreateToken(userObj, out dbUser);
                        response = Request.CreateResponse(new { dbUser, token });
                    }
                }
            
            else
            {
                response = Request.CreateErrorResponse(HttpStatusCode.BadRequest, ModelState);
            }
            return response;
        }

        //[AllowAnonymous]
        //[Route("signup")]
        //[HttpPost]
        //public HttpResponseMessage Register(RegisterViewModel model)
        //{
        //    HttpResponseMessage response;
        //    if (ModelState.IsValid)
        //    {
        //        var existingUser = db.Users.FirstOrDefault(u => u.Email == model.Email);
        //        if (existingUser != null)
        //        {
        //            return Request.CreateResponse(HttpStatusCode.BadRequest, "User already exist.");
        //        }

        //        //Create user and save to database
        //        //var user = CreateUser(model);

        //        object dbUser;

        //        //Create token
        //        var token = CreateToken(user, out dbUser);

        //        response = Request.CreateResponse(new { dbUser, token });
        //    }
        //    else
        //    {
        //        response = Request.CreateResponse(HttpStatusCode.BadRequest, new { success = false });
        //    }

        //    return response;
        //}

        /// <summary>
        /// Create a Jwt with user information
        /// </summary>
        /// <param name="user"></param>
        /// <param name="dbUser"></param>
        /// <returns></returns>
        private static string CreateToken(User user, out object dbUser)
        {
            var unixEpoch = new DateTime(1970, 1, 1, 0, 0, 0, DateTimeKind.Utc);
            var expiry = Math.Round((DateTime.UtcNow.AddHours(2) - unixEpoch).TotalSeconds);
            var issuedAt = Math.Round((DateTime.UtcNow - unixEpoch).TotalSeconds);
            var notBefore = Math.Round((DateTime.UtcNow.AddMonths(6) - unixEpoch).TotalSeconds);


            var payload = new Dictionary<string, object>
            {
                {"email", user.Email},
                {"userId", user.Id},
                {"role", "Admin"  },
                {"sub", user.Id},
                {"nbf", notBefore},
                {"iat", issuedAt},
                {"exp", expiry}
            };

            //var secret = ConfigurationManager.AppSettings.Get("jwtKey");
            const string apikey = "secretKey";

            var token = JsonWebToken.Encode(payload, apikey, JwtHashAlgorithm.HS256);

            dbUser = new { user.Email, user.Id };
            return token;
        }

        /// <summary>
        /// Create a new user and saves it to the database
        /// </summary>
        /// <param name="registerDetails"></param>
        /// <returns></returns>
        //private User CreateUser(RegisterViewModel registerDetails)
        //{
        //    var passwordSalt = CreateSalt();
        //    var user = new User
        //    {
        //        Salt = passwordSalt,
        //        Email = registerDetails.Email,
        //        PasswordHash = EncryptPassword(registerDetails.Password, passwordSalt)
        //    };

        //    var adminRole = db.Roles.FirstOrDefault(d => d.Name == "Admin");

        //    user.Roles.Add(new UserRole
        //    {
        //        User = user,
        //        Role = adminRole
        //    });

        //    db.Users.Add(user);
        //    db.SaveChanges();

        //    return user;
        //}


        /// <summary>
        ///     Creates a random salt to be used for encrypting a password
        /// </summary>
        /// <returns></returns>
        public static string CreateSalt()
        {
            var data = new byte[0x10];
            using (var cryptoServiceProvider = new RNGCryptoServiceProvider())
            {
                cryptoServiceProvider.GetBytes(data);
                return Convert.ToBase64String(data);
            }
        }

        /// <summary>
        ///     Encrypts a password using the given salt
        /// </summary>
        /// <param name="password"></param>
        /// <param name="salt"></param>
        /// <returns></returns>
        public static string EncryptPassword(string password, string salt)
        {
            using (var sha256 = SHA256.Create())
            {
                var saltedPassword = string.Format("{0}{1}", salt, password);
                var saltedPasswordAsBytes = Encoding.UTF8.GetBytes(saltedPassword);
                return Convert.ToBase64String(sha256.ComputeHash(saltedPasswordAsBytes));
            }
        }

        //protected override void Dispose(bool disposing)
        //{
        //    if (disposing)
        //    {
        //        db.Dispose();
        //    }
        //    base.Dispose(disposing);
        //}
    }
}