// Copyright (c) Microsoft Open Technologies, Inc. All rights reserved.
// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.

using System;
using System.Collections.Generic;
using System.Globalization;
using System.Linq;
using System.Security.Claims;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using Microsoft.Framework.OptionsModel;

namespace Microsoft.AspNet.Identity
{
    /// <summary>
    ///     Exposes user related api which will automatically save changes to the UserStore
    /// </summary>
    /// <typeparam name="TUser"></typeparam>
    public class UserManager<TUser> : IDisposable where TUser : class
    {
        private readonly Dictionary<string, IUserTokenProvider<TUser>> _tokenProviders =
            new Dictionary<string, IUserTokenProvider<TUser>>();

        private TimeSpan _defaultLockout = TimeSpan.Zero;
        private bool _disposed;
        private IPasswordHasher<TUser> _passwordHasher;
        private IdentityOptions _options;

        /// <summary>
        ///     Constructor which takes a service provider and user store
        /// </summary>
        /// <param name="store"></param>
        /// <param name="optionsAccessor"></param>
        /// <param name="passwordHasher"></param>
        /// <param name="userValidator"></param>
        /// <param name="passwordValidator"></param>
        /// <param name="claimsIdentityFactory"></param>
        public UserManager(IUserStore<TUser> store, IOptions<IdentityOptions> optionsAccessor,
            IPasswordHasher<TUser> passwordHasher, IUserValidator<TUser> userValidator,
            IPasswordValidator<TUser> passwordValidator, IUserNameNormalizer userNameNormalizer,
            IEnumerable<IUserTokenProvider<TUser>> tokenProviders)
        {
            if (store == null)
            {
                throw new ArgumentNullException(nameof(store));
            }
            if (optionsAccessor == null || optionsAccessor.Options == null)
            {
                throw new ArgumentNullException(nameof(optionsAccessor));
            }
            if (passwordHasher == null)
            {
                throw new ArgumentNullException(nameof(passwordHasher));
            }
            Store = store;
            Options = optionsAccessor.Options;
            PasswordHasher = passwordHasher;
            UserValidator = userValidator;
            PasswordValidator = passwordValidator;
            UserNameNormalizer = userNameNormalizer;
            // TODO: Email/Sms/Token services

            if (tokenProviders != null)
            {
                foreach (var tokenProvider in tokenProviders)
                {
                    RegisterTokenProvider(tokenProvider);
                }
            }
        }

        /// <summary>
        ///     Persistence abstraction that the Manager operates against
        /// </summary>
        protected internal IUserStore<TUser> Store { get; set; }

        /// <summary>
        ///     Used to hash/verify passwords
        /// </summary>
        public IPasswordHasher<TUser> PasswordHasher
        {
            get
            {
                ThrowIfDisposed();
                return _passwordHasher;
            }
            set
            {
                ThrowIfDisposed();
                if (value == null)
                {
                    throw new ArgumentNullException("value");
                }
                _passwordHasher = value;
            }
        }

        /// <summary>
        ///     Used to validate users before persisting changes
        /// </summary>
        public IUserValidator<TUser> UserValidator { get; set; }

        /// <summary>
        ///     Used to validate passwords before persisting changes
        /// </summary>
        public IPasswordValidator<TUser> PasswordValidator { get; set; }

        /// <summary>
        ///     Used to normalize user names for uniqueness
        /// </summary>
        public IUserNameNormalizer UserNameNormalizer { get; set; }

        /// <summary>
        ///     Used to send email
        /// </summary>
        public IIdentityMessageService EmailService { get; set; }

        /// <summary>
        ///     Used to send a sms message
        /// </summary>
        public IIdentityMessageService SmsService { get; set; }

        public IdentityOptions Options
        {
            get
            {
                ThrowIfDisposed();
                return _options;
            }
            set
            {
                ThrowIfDisposed();
                if (value == null)
                {
                    throw new ArgumentNullException("value");
                }
                _options = value;
            }
        }

        /// <summary>
        ///     Returns true if the store is an IUserTwoFactorStore
        /// </summary>
        public virtual bool SupportsUserTwoFactor
        {
            get
            {
                ThrowIfDisposed();
                return Store is IUserTwoFactorStore<TUser>;
            }
        }

        /// <summary>
        ///     Returns true if the store is an IUserPasswordStore
        /// </summary>
        public virtual bool SupportsUserPassword
        {
            get
            {
                ThrowIfDisposed();
                return Store is IUserPasswordStore<TUser>;
            }
        }

        /// <summary>
        ///     Returns true if the store is an IUserSecurityStore
        /// </summary>
        public virtual bool SupportsUserSecurityStamp
        {
            get
            {
                ThrowIfDisposed();
                return Store is IUserSecurityStampStore<TUser>;
            }
        }

        /// <summary>
        ///     Returns true if the store is an IUserRoleStore
        /// </summary>
        public virtual bool SupportsUserRole
        {
            get
            {
                ThrowIfDisposed();
                return Store is IUserRoleStore<TUser>;
            }
        }

        /// <summary>
        ///     Returns true if the store is an IUserLoginStore
        /// </summary>
        public virtual bool SupportsUserLogin
        {
            get
            {
                ThrowIfDisposed();
                return Store is IUserLoginStore<TUser>;
            }
        }

        /// <summary>
        ///     Returns true if the store is an IUserEmailStore
        /// </summary>
        public virtual bool SupportsUserEmail
        {
            get
            {
                ThrowIfDisposed();
                return Store is IUserEmailStore<TUser>;
            }
        }

        /// <summary>
        ///     Returns true if the store is an IUserPhoneNumberStore
        /// </summary>
        public virtual bool SupportsUserPhoneNumber
        {
            get
            {
                ThrowIfDisposed();
                return Store is IUserPhoneNumberStore<TUser>;
            }
        }

        /// <summary>
        ///     Returns true if the store is an IUserClaimStore
        /// </summary>
        public virtual bool SupportsUserClaim
        {
            get
            {
                ThrowIfDisposed();
                return Store is IUserClaimStore<TUser>;
            }
        }

        /// <summary>
        ///     Returns true if the store is an IUserLockoutStore
        /// </summary>
        public virtual bool SupportsUserLockout
        {
            get
            {
                ThrowIfDisposed();
                return Store is IUserLockoutStore<TUser>;
            }
        }

        /// <summary>
        ///     Returns true if the store is an IQueryableUserStore
        /// </summary>
        public virtual bool SupportsQueryableUsers
        {
            get
            {
                ThrowIfDisposed();
                return Store is IQueryableUserStore<TUser>;
            }
        }

        /// <summary>
        ///     Returns an IQueryable of users if the store is an IQueryableUserStore
        /// </summary>
        public virtual IQueryable<TUser> Users
        {
            get
            {
                var queryableStore = Store as IQueryableUserStore<TUser>;
                if (queryableStore == null)
                {
                    throw new NotSupportedException(Resources.StoreNotIQueryableUserStore);
                }
                return queryableStore.Users;
            }
        }

        /// <summary>
        ///     Dispose the store context
        /// </summary>
        public void Dispose()
        {
            Dispose(true);
            GC.SuppressFinalize(this);
        }

        private async Task<IdentityResult> ValidateUserInternal(TUser user, CancellationToken cancellationToken)
        {
            return (UserValidator == null)
                ? IdentityResult.Success
                : await UserValidator.ValidateAsync(this, user, cancellationToken);
        }

        /// <summary>
        ///     Create a user with no password
        /// </summary>
        /// <param name="user"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        public virtual async Task<IdentityResult> CreateAsync(TUser user,
            CancellationToken cancellationToken = default(CancellationToken))
        {
            ThrowIfDisposed();
            await UpdateSecurityStampInternal(user, cancellationToken);
            var result = await ValidateUserInternal(user, cancellationToken);
            if (!result.Succeeded)
            {
                return result;
            }
            if (Options.Lockout.EnabledByDefault && SupportsUserLockout)
            {
                await GetUserLockoutStore().SetLockoutEnabledAsync(user, true, cancellationToken);
            }
            await UpdateNormalizedUserNameAsync(user, cancellationToken);
            await Store.CreateAsync(user, cancellationToken);
            return IdentityResult.Success;
        }

        /// <summary>
        ///     Update a user
        /// </summary>
        /// <param name="user"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        public virtual async Task<IdentityResult> UpdateAsync(TUser user,
            CancellationToken cancellationToken = default(CancellationToken))
        {
            ThrowIfDisposed();
            if (user == null)
            {
                throw new ArgumentNullException("user");
            }
            var result = await ValidateUserInternal(user, cancellationToken);
            if (!result.Succeeded)
            {
                return result;
            }
            await UpdateNormalizedUserNameAsync(user, cancellationToken);
            await Store.UpdateAsync(user, cancellationToken);
            return IdentityResult.Success;
        }

        /// <summary>
        ///     Delete a user
        /// </summary>
        /// <param name="user"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        public virtual async Task<IdentityResult> DeleteAsync(TUser user,
            CancellationToken cancellationToken = default(CancellationToken))
        {
            ThrowIfDisposed();
            if (user == null)
            {
                throw new ArgumentNullException("user");
            }
            await Store.DeleteAsync(user, cancellationToken);
            return IdentityResult.Success;
        }

        /// <summary>
        ///     Find a user by id
        /// </summary>
        /// <param name="userId"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        public virtual Task<TUser> FindByIdAsync(string userId,
            CancellationToken cancellationToken = default(CancellationToken))
        {
            ThrowIfDisposed();
            return Store.FindByIdAsync(userId, cancellationToken);
        }

        /// <summary>
        ///     Find a user by name
        /// </summary>
        /// <param name="userName"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        public virtual Task<TUser> FindByNameAsync(string userName,
            CancellationToken cancellationToken = default(CancellationToken))
        {
            ThrowIfDisposed();
            if (userName == null)
            {
                throw new ArgumentNullException("userName");
            }
            userName = NormalizeUserName(userName);
            return Store.FindByNameAsync(userName, cancellationToken);
        }

        // IUserPasswordStore methods
        private IUserPasswordStore<TUser> GetPasswordStore()
        {
            var cast = Store as IUserPasswordStore<TUser>;
            if (cast == null)
            {
                throw new NotSupportedException(Resources.StoreNotIUserPasswordStore);
            }
            return cast;
        }

        /// <summary>
        ///     Create a user and associates it with the given password
        /// </summary>
        /// <param name="user"></param>
        /// <param name="password"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        public virtual async Task<IdentityResult> CreateAsync(TUser user, string password,
            CancellationToken cancellationToken = default(CancellationToken))
        {
            ThrowIfDisposed();
            var passwordStore = GetPasswordStore();
            if (user == null)
            {
                throw new ArgumentNullException("user");
            }
            if (password == null)
            {
                throw new ArgumentNullException("password");
            }
            var result = await UpdatePasswordInternal(passwordStore, user, password, cancellationToken);
            if (!result.Succeeded)
            {
                return result;
            }
            return await CreateAsync(user, cancellationToken);
        }

        /// <summary>
        /// Normalize a user name for uniqueness comparisons
        /// </summary>
        /// <param name="userName"></param>
        /// <returns></returns>
        public virtual string NormalizeUserName(string userName)
        {
            return (UserNameNormalizer == null) ? userName : UserNameNormalizer.Normalize(userName);
        }

        /// <summary>
        /// Update the user's normalized user name
        /// </summary>
        /// <param name="user"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        public virtual async Task UpdateNormalizedUserNameAsync(TUser user,
            CancellationToken cancellationToken = default(CancellationToken))
        {
            var userName = await GetUserNameAsync(user, cancellationToken);
            await Store.SetNormalizedUserNameAsync(user, NormalizeUserName(userName), cancellationToken);
        }

        /// <summary>
        /// Get the user's name
        /// </summary>
        /// <param name="user"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        public virtual async Task<string> GetUserNameAsync(TUser user,
            CancellationToken cancellationToken = default(CancellationToken))
        {
            ThrowIfDisposed();
            if (user == null)
            {
                throw new ArgumentNullException("user");
            }
            return await Store.GetUserNameAsync(user, cancellationToken);
        }

        /// <summary>
        /// Set the user's name
        /// </summary>
        /// <param name="user"></param>
        /// <param name="userName"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        public virtual async Task<IdentityResult> SetUserNameAsync(TUser user, string userName,
            CancellationToken cancellationToken = default(CancellationToken))
        {
            ThrowIfDisposed();
            if (user == null)
            {
                throw new ArgumentNullException("user");
            }
            await UpdateUserName(user, userName, cancellationToken);
            return await UpdateAsync(user, cancellationToken);
        }

        private async Task UpdateUserName(TUser user, string userName, CancellationToken cancellationToken)
        {
            await Store.SetUserNameAsync(user, userName, cancellationToken);
            await UpdateNormalizedUserNameAsync(user, cancellationToken);
        }

        /// <summary>
        /// Get the user's id
        /// </summary>
        /// <param name="user"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        public virtual async Task<string> GetUserIdAsync(TUser user,
            CancellationToken cancellationToken = default(CancellationToken))
        {
            ThrowIfDisposed();
            return await Store.GetUserIdAsync(user, cancellationToken);
        }

        /// <summary>
        ///     Return a user with the specified username and password or null if there is no match.
        /// </summary>
        /// <param name="userName"></param>
        /// <param name="password"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        public virtual async Task<TUser> FindByUserNamePasswordAsync(string userName, string password,
            CancellationToken cancellationToken = default(CancellationToken))
        {
            ThrowIfDisposed();
            userName = NormalizeUserName(userName);
            var user = await FindByNameAsync(userName, cancellationToken);
            if (user == null)
            {
                return null;
            }
            return await CheckPasswordAsync(user, password, cancellationToken) ? user : null;
        }

        /// <summary>
        ///     Returns true if the password combination is valid for the user
        /// </summary>
        /// <param name="user"></param>
        /// <param name="password"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        public virtual async Task<bool> CheckPasswordAsync(TUser user, string password,
            CancellationToken cancellationToken = default(CancellationToken))
        {
            ThrowIfDisposed();
            var passwordStore = GetPasswordStore();
            if (user == null)
            {
                return false;
            }
            return await VerifyPasswordAsync(passwordStore, user, password, cancellationToken);
        }

        /// <summary>
        ///     Returns true if the user has a password
        /// </summary>
        /// <param name="user"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        public virtual async Task<bool> HasPasswordAsync(TUser user,
            CancellationToken cancellationToken = default(CancellationToken))
        {
            ThrowIfDisposed();
            var passwordStore = GetPasswordStore();
            if (user == null)
            {
                throw new ArgumentNullException("user");
            }
            return await passwordStore.HasPasswordAsync(user, cancellationToken);
        }

        /// <summary>
        ///     Add a user password only if one does not already exist
        /// </summary>
        /// <param name="user"></param>
        /// <param name="password"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        public virtual async Task<IdentityResult> AddPasswordAsync(TUser user, string password,
            CancellationToken cancellationToken = default(CancellationToken))
        {
            ThrowIfDisposed();
            var passwordStore = GetPasswordStore();
            if (user == null)
            {
                throw new ArgumentNullException("user");
            }
            var hash = await passwordStore.GetPasswordHashAsync(user, cancellationToken);
            if (hash != null)
            {
                return new IdentityResult(Resources.UserAlreadyHasPassword);
            }
            var result = await UpdatePasswordInternal(passwordStore, user, password, cancellationToken);
            if (!result.Succeeded)
            {
                return result;
            }
            return await UpdateAsync(user, cancellationToken);
        }

        /// <summary>
        ///     Change a user password
        /// </summary>
        /// <param name="user"></param>
        /// <param name="currentPassword"></param>
        /// <param name="newPassword"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        public virtual async Task<IdentityResult> ChangePasswordAsync(TUser user, string currentPassword,
            string newPassword, CancellationToken cancellationToken = default(CancellationToken))
        {
            ThrowIfDisposed();
            var passwordStore = GetPasswordStore();
            if (user == null)
            {
                throw new ArgumentNullException("user");
            }
            if (await VerifyPasswordAsync(passwordStore, user, currentPassword, cancellationToken))
            {
                var result = await UpdatePasswordInternal(passwordStore, user, newPassword, cancellationToken);
                if (!result.Succeeded)
                {
                    return result;
                }
                return await UpdateAsync(user, cancellationToken);
            }
            return IdentityResult.Failed(Resources.PasswordMismatch);
        }

        /// <summary>
        ///     Remove a user's password
        /// </summary>
        /// <param name="user"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        public virtual async Task<IdentityResult> RemovePasswordAsync(TUser user,
            CancellationToken cancellationToken = default(CancellationToken))
        {
            ThrowIfDisposed();
            var passwordStore = GetPasswordStore();
            if (user == null)
            {
                throw new ArgumentNullException("user");
            }
            await passwordStore.SetPasswordHashAsync(user, null, cancellationToken);
            await UpdateSecurityStampInternal(user, cancellationToken);
            return await UpdateAsync(user, cancellationToken);
        }

        internal async Task<IdentityResult> UpdatePasswordInternal(IUserPasswordStore<TUser> passwordStore,
            TUser user, string newPassword, CancellationToken cancellationToken)
        {
            if (PasswordValidator != null)
            {
                var result = await PasswordValidator.ValidateAsync(user, newPassword, this, cancellationToken);
                if (!result.Succeeded)
                {
                    return result;
                }
            }
            await
                passwordStore.SetPasswordHashAsync(user, PasswordHasher.HashPassword(user, newPassword), cancellationToken);
            await UpdateSecurityStampInternal(user, cancellationToken);
            return IdentityResult.Success;
        }

        /// <summary>
        /// By default, retrieves the hashed password from the user store and calls PasswordHasher.VerifyHashPassword
        /// </summary>
        /// <param name="store"></param>
        /// <param name="user"></param>
        /// <param name="password"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        protected virtual async Task<bool> VerifyPasswordAsync(IUserPasswordStore<TUser> store, TUser user,
            string password, CancellationToken cancellationToken = default(CancellationToken))
        {
            var hash = await store.GetPasswordHashAsync(user, cancellationToken);
            return PasswordHasher.VerifyHashedPassword(user, hash, password) != PasswordVerificationResult.Failed;
        }

        // IUserSecurityStampStore methods
        private IUserSecurityStampStore<TUser> GetSecurityStore()
        {
            var cast = Store as IUserSecurityStampStore<TUser>;
            if (cast == null)
            {
                throw new NotSupportedException(Resources.StoreNotIUserSecurityStampStore);
            }
            return cast;
        }

        /// <summary>
        ///     Returns the current security stamp for a user
        /// </summary>
        /// <param name="user"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        public virtual async Task<string> GetSecurityStampAsync(TUser user,
            CancellationToken cancellationToken = default(CancellationToken))
        {
            ThrowIfDisposed();
            var securityStore = GetSecurityStore();
            if (user == null)
            {
                throw new ArgumentNullException("user");
            }
            return await securityStore.GetSecurityStampAsync(user, cancellationToken);
        }

        /// <summary>
        ///     GenerateAsync a new security stamp for a user, used for SignOutEverywhere functionality
        /// </summary>
        /// <param name="user"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        public virtual async Task<IdentityResult> UpdateSecurityStampAsync(TUser user,
            CancellationToken cancellationToken = default(CancellationToken))
        {
            ThrowIfDisposed();
            GetSecurityStore();
            if (user == null)
            {
                throw new ArgumentNullException("user");
            }
            await UpdateSecurityStampInternal(user, cancellationToken);
            return await UpdateAsync(user, cancellationToken);
        }

        /// <summary>
        ///     GenerateAsync a password reset token for the user using the UserTokenProvider
        /// </summary>
        /// <param name="user"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        public virtual async Task<string> GeneratePasswordResetTokenAsync(TUser user,
            CancellationToken cancellationToken = default(CancellationToken))
        {
            ThrowIfDisposed();
            return await GenerateUserTokenAsync(user, Options.PasswordResetTokenProvider, "ResetPassword", cancellationToken);
        }

        /// <summary>
        ///     Reset a user's password using a reset password token
        /// </summary>
        /// <param name="user"></param>
        /// <param name="token"></param>
        /// <param name="newPassword"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        public virtual async Task<IdentityResult> ResetPasswordAsync(TUser user, string token, string newPassword,
            CancellationToken cancellationToken = default(CancellationToken))
        {
            ThrowIfDisposed();
            if (user == null)
            {
                throw new ArgumentNullException("user");
            }
            // Make sure the token is valid and the stamp matches
            if (!await VerifyUserTokenAsync(user, Options.PasswordResetTokenProvider, "ResetPassword", token, cancellationToken))
            {
                return IdentityResult.Failed(Resources.InvalidToken);
            }
            var passwordStore = GetPasswordStore();
            var result = await UpdatePasswordInternal(passwordStore, user, newPassword, cancellationToken);
            if (!result.Succeeded)
            {
                return result;
            }
            return await UpdateAsync(user, cancellationToken);
        }

        // Update the security stamp if the store supports it
        internal async Task UpdateSecurityStampInternal(TUser user, CancellationToken cancellationToken)
        {
            if (SupportsUserSecurityStamp)
            {
                await GetSecurityStore().SetSecurityStampAsync(user, NewSecurityStamp(), cancellationToken);
            }
        }

        private static string NewSecurityStamp()
        {
            return Guid.NewGuid().ToString();
        }

        // IUserLoginStore methods
        private IUserLoginStore<TUser> GetLoginStore()
        {
            var cast = Store as IUserLoginStore<TUser>;
            if (cast == null)
            {
                throw new NotSupportedException(Resources.StoreNotIUserLoginStore);
            }
            return cast;
        }

        /// <summary>
        /// Returns the user associated with this login
        /// </summary>
        /// <param name="loginProvider"></param>
        /// <param name="providerKey"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        public virtual Task<TUser> FindByLoginAsync(string loginProvider, string providerKey,
            CancellationToken cancellationToken = default(CancellationToken))
        {
            ThrowIfDisposed();
            var loginStore = GetLoginStore();
            if (loginProvider == null)
            {
                throw new ArgumentNullException("loginProvider");
            }
            if (providerKey == null)
            {
                throw new ArgumentNullException("providerKey");
            }
            return loginStore.FindByLoginAsync(loginProvider, providerKey, cancellationToken);
        }

        /// <summary>
        ///     Remove a user login
        /// </summary>
        /// <param name="user"></param>
        /// <param name="login"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        public virtual async Task<IdentityResult> RemoveLoginAsync(TUser user, string loginProvider, string providerKey,
            CancellationToken cancellationToken = default(CancellationToken))
        {
            ThrowIfDisposed();
            var loginStore = GetLoginStore();
            if (loginProvider == null)
            {
                throw new ArgumentNullException("loginProvider");
            }
            if (providerKey == null)
            {
                throw new ArgumentNullException("providerKey");
            }
            if (user == null)
            {
                throw new ArgumentNullException("user");
            }
            await loginStore.RemoveLoginAsync(user, loginProvider, providerKey, cancellationToken);
            await UpdateSecurityStampInternal(user, cancellationToken);
            return await UpdateAsync(user, cancellationToken);
        }

        /// <summary>
        ///     Associate a login with a user
        /// </summary>
        /// <param name="user"></param>
        /// <param name="login"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        public virtual async Task<IdentityResult> AddLoginAsync(TUser user, UserLoginInfo login,
            CancellationToken cancellationToken = default(CancellationToken))
        {
            ThrowIfDisposed();
            var loginStore = GetLoginStore();
            if (login == null)
            {
                throw new ArgumentNullException("login");
            }
            if (user == null)
            {
                throw new ArgumentNullException("user");
            }
            var existingUser = await FindByLoginAsync(login.LoginProvider, login.ProviderKey, cancellationToken);
            if (existingUser != null)
            {
                return IdentityResult.Failed(Resources.ExternalLoginExists);
            }
            await loginStore.AddLoginAsync(user, login, cancellationToken);
            return await UpdateAsync(user, cancellationToken);
        }

        /// <summary>
        ///     Gets the logins for a user.
        /// </summary>
        /// <param name="user"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        public virtual async Task<IList<UserLoginInfo>> GetLoginsAsync(TUser user,
            CancellationToken cancellationToken = default(CancellationToken))
        {
            ThrowIfDisposed();
            var loginStore = GetLoginStore();
            if (user == null)
            {
                throw new ArgumentNullException("user");
            }
            return await loginStore.GetLoginsAsync(user, cancellationToken);
        }

        // IUserClaimStore methods
        private IUserClaimStore<TUser> GetClaimStore()
        {
            var cast = Store as IUserClaimStore<TUser>;
            if (cast == null)
            {
                throw new NotSupportedException(Resources.StoreNotIUserClaimStore);
            }
            return cast;
        }

        /// <summary>
        ///     Add a user claim
        /// </summary>
        /// <param name="user"></param>
        /// <param name="claim"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        public virtual Task<IdentityResult> AddClaimAsync(TUser user, Claim claim,
            CancellationToken cancellationToken = default(CancellationToken))
        {
            ThrowIfDisposed();
            var claimStore = GetClaimStore();
            if (claim == null)
            {
                throw new ArgumentNullException("claim");
            }
            if (user == null)
            {
                throw new ArgumentNullException("user");
            }
            return AddClaimsAsync(user, new Claim[] { claim }, cancellationToken);
        }

        /// <summary>
        ///     Add a user claim
        /// </summary>
        /// <param name="user"></param>
        /// <param name="claim"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        public virtual async Task<IdentityResult> AddClaimsAsync(TUser user, IEnumerable<Claim> claims,
            CancellationToken cancellationToken = default(CancellationToken))
        {
            ThrowIfDisposed();
            var claimStore = GetClaimStore();
            if (claims == null)
            {
                throw new ArgumentNullException("claims");
            }
            if (user == null)
            {
                throw new ArgumentNullException("user");
            }
            await claimStore.AddClaimsAsync(user, claims, cancellationToken);
            return await UpdateAsync(user, cancellationToken);
        }

        /// <summary>
        ///     Updates the give claim information with the given new claim information
        /// </summary>
        /// <param name="user"></param>
        /// <param name="claim"></param>
        /// <param name="newClaim"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        public virtual async Task<IdentityResult> ReplaceClaimAsync(TUser user, Claim claim, Claim newClaim,
             CancellationToken cancellationToken = default(CancellationToken))
        {
            ThrowIfDisposed();
            var claimStore = GetClaimStore();
            if (claim == null)
            {
                throw new ArgumentNullException("claim");
            }
            if (newClaim == null)
            {
                throw new ArgumentNullException("newClaim");
            }
            if (user == null)
            {
                throw new ArgumentNullException("user");
            }
            await claimStore.ReplaceClaimAsync(user, claim, newClaim, cancellationToken);
            return await UpdateAsync(user, cancellationToken);
        }

        /// <summary>
        ///     Remove a user claim
        /// </summary>
        /// <param name="user"></param>
        /// <param name="claim"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        public virtual Task<IdentityResult> RemoveClaimAsync(TUser user, Claim claim,
            CancellationToken cancellationToken = default(CancellationToken))
        {
            ThrowIfDisposed();
            var claimStore = GetClaimStore();
            if (user == null)
            {
                throw new ArgumentNullException("user");
            }
            if (claim == null)
            {
                throw new ArgumentNullException("claim");
            }
            return RemoveClaimsAsync(user, new Claim[] { claim }, cancellationToken);
        }

        /// <summary>
        ///     Remove a user claim
        /// </summary>
        /// <param name="user"></param>
        /// <param name="claims"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        public virtual async Task<IdentityResult> RemoveClaimsAsync(TUser user, IEnumerable<Claim> claims,
            CancellationToken cancellationToken = default(CancellationToken))
        {
            ThrowIfDisposed();
            var claimStore = GetClaimStore();
            if (user == null)
            {
                throw new ArgumentNullException("user");
            }
            if (claims == null)
            {
                throw new ArgumentNullException("claims");
            }
            await claimStore.RemoveClaimsAsync(user, claims, cancellationToken);
            return await UpdateAsync(user, cancellationToken);
        }

        /// <summary>
        ///     Get a users's claims
        /// </summary>
        /// <param name="user"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        public virtual async Task<IList<Claim>> GetClaimsAsync(TUser user,
            CancellationToken cancellationToken = default(CancellationToken))
        {
            ThrowIfDisposed();
            var claimStore = GetClaimStore();
            if (user == null)
            {
                throw new ArgumentNullException("user");
            }
            return await claimStore.GetClaimsAsync(user, cancellationToken);
        }

        private IUserRoleStore<TUser> GetUserRoleStore()
        {
            var cast = Store as IUserRoleStore<TUser>;
            if (cast == null)
            {
                throw new NotSupportedException(Resources.StoreNotIUserRoleStore);
            }
            return cast;
        }

        /// <summary>
        ///     Add a user to a role
        /// </summary>
        /// <param name="user"></param>
        /// <param name="role"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        public virtual async Task<IdentityResult> AddToRoleAsync(TUser user, string role,
            CancellationToken cancellationToken = default(CancellationToken))
        {
            ThrowIfDisposed();
            var userRoleStore = GetUserRoleStore();
            if (user == null)
            {
                throw new ArgumentNullException("user");
            }
            var userRoles = await userRoleStore.GetRolesAsync(user, cancellationToken);
            if (userRoles.Contains(role))
            {
                return new IdentityResult(Resources.UserAlreadyInRole);
            }
            await userRoleStore.AddToRoleAsync(user, role, cancellationToken);
            return await UpdateAsync(user, cancellationToken);
        }

        /// <summary>
        ///     Add a user to roles
        /// </summary>
        /// <param name="user"></param>
        /// <param name="roles"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        public virtual async Task<IdentityResult> AddToRolesAsync(TUser user, IEnumerable<string> roles,
            CancellationToken cancellationToken = default(CancellationToken))
        {
            ThrowIfDisposed();
            var userRoleStore = GetUserRoleStore();
            if (user == null)
            {
                throw new ArgumentNullException("user");
            }
            if (roles == null)
            {
                throw new ArgumentNullException("roles");
            }
            var userRoles = await userRoleStore.GetRolesAsync(user, cancellationToken);
            foreach (var role in roles)
            {
                if (userRoles.Contains(role))
                {
                    return new IdentityResult(Resources.UserAlreadyInRole);
                }
                await userRoleStore.AddToRoleAsync(user, role, cancellationToken);
            }
            return await UpdateAsync(user, cancellationToken);
        }

        /// <summary>
        ///     Remove a user from a role.
        /// </summary>
        /// <param name="user"></param>
        /// <param name="role"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        public virtual async Task<IdentityResult> RemoveFromRoleAsync(TUser user, string role,
            CancellationToken cancellationToken = default(CancellationToken))
        {
            ThrowIfDisposed();
            var userRoleStore = GetUserRoleStore();
            if (user == null)
            {
                throw new ArgumentNullException("user");
            }
            if (!await userRoleStore.IsInRoleAsync(user, role, cancellationToken))
            {
                return new IdentityResult(Resources.UserNotInRole);
            }
            await userRoleStore.RemoveFromRoleAsync(user, role, cancellationToken);
            return await UpdateAsync(user, cancellationToken);
        }

        /// <summary>
        ///     Remove a user from a specified roles.
        /// </summary>
        /// <param name="user"></param>
        /// <param name="roles"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        public virtual async Task<IdentityResult> RemoveFromRolesAsync(TUser user, IEnumerable<string> roles,
            CancellationToken cancellationToken = default(CancellationToken))
        {
            ThrowIfDisposed();
            var userRoleStore = GetUserRoleStore();
            if (user == null)
            {
                throw new ArgumentNullException("user");
            }
            if (roles == null)
            {
                throw new ArgumentNullException("roles");
            }
            foreach (var role in roles)
            {
                if (!await userRoleStore.IsInRoleAsync(user, role, cancellationToken))
                {
                    return new IdentityResult(Resources.UserNotInRole);
                }
                await userRoleStore.RemoveFromRoleAsync(user, role, cancellationToken);
            }
            return await UpdateAsync(user, cancellationToken);
        }

        /// <summary>
        ///     Returns the roles for the user
        /// </summary>
        /// <param name="user"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        public virtual async Task<IList<string>> GetRolesAsync(TUser user,
            CancellationToken cancellationToken = default(CancellationToken))
        {
            ThrowIfDisposed();
            var userRoleStore = GetUserRoleStore();
            if (user == null)
            {
                throw new ArgumentNullException("user");
            }
            return await userRoleStore.GetRolesAsync(user, cancellationToken);
        }

        /// <summary>
        ///     Returns true if the user is in the specified role
        /// </summary>
        /// <param name="user"></param>
        /// <param name="role"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        public virtual async Task<bool> IsInRoleAsync(TUser user, string role,
            CancellationToken cancellationToken = default(CancellationToken))
        {
            ThrowIfDisposed();
            var userRoleStore = GetUserRoleStore();
            if (user == null)
            {
                throw new ArgumentNullException("user");
            }
            return await userRoleStore.IsInRoleAsync(user, role, cancellationToken);
        }

        // IUserEmailStore methods
        internal IUserEmailStore<TUser> GetEmailStore()
        {
            var cast = Store as IUserEmailStore<TUser>;
            if (cast == null)
            {
                throw new NotSupportedException(Resources.StoreNotIUserEmailStore);
            }
            return cast;
        }

        /// <summary>
        ///     Get a user's email
        /// </summary>
        /// <param name="user"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        public virtual async Task<string> GetEmailAsync(TUser user,
            CancellationToken cancellationToken = default(CancellationToken))
        {
            ThrowIfDisposed();
            var store = GetEmailStore();
            if (user == null)
            {
                throw new ArgumentNullException("user");
            }
            return await store.GetEmailAsync(user, cancellationToken);
        }

        /// <summary>
        ///     Set a user's email
        /// </summary>
        /// <param name="user"></param>
        /// <param name="email"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        public virtual async Task<IdentityResult> SetEmailAsync(TUser user, string email,
            CancellationToken cancellationToken = default(CancellationToken))
        {
            ThrowIfDisposed();

            var store = GetEmailStore();
            if (user == null)
            {
                throw new ArgumentNullException("user");
            }
            await store.SetEmailAsync(user, email, cancellationToken);
            await store.SetEmailConfirmedAsync(user, false, cancellationToken);
            await UpdateSecurityStampInternal(user, cancellationToken);
            return await UpdateAsync(user, cancellationToken);
        }

        /// <summary>
        ///     FindByLoginAsync a user by his email
        /// </summary>
        /// <param name="email"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        public virtual Task<TUser> FindByEmailAsync(string email,
            CancellationToken cancellationToken = default(CancellationToken))
        {
            ThrowIfDisposed();
            var store = GetEmailStore();
            if (email == null)
            {
                throw new ArgumentNullException("email");
            }
            return store.FindByEmailAsync(email, cancellationToken);
        }

        /// <summary>
        ///     Get the confirmation token for the user
        /// </summary>
        /// <param name="user"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        public virtual Task<string> GenerateEmailConfirmationTokenAsync(TUser user,
            CancellationToken cancellationToken = default(CancellationToken))
        {
            ThrowIfDisposed();
            return GenerateUserTokenAsync(user, Options.EmailConfirmationTokenProvider, "Confirmation", cancellationToken);
        }

        /// <summary>
        ///     Confirm the user with confirmation token
        /// </summary>
        /// <param name="user"></param>
        /// <param name="token"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        public virtual async Task<IdentityResult> ConfirmEmailAsync(TUser user, string token,
            CancellationToken cancellationToken = default(CancellationToken))
        {
            ThrowIfDisposed();
            var store = GetEmailStore();
            if (user == null)
            {
                throw new ArgumentNullException("user");
            }
            if (!await VerifyUserTokenAsync(user, Options.EmailConfirmationTokenProvider, "Confirmation", token, cancellationToken))
            {
                return IdentityResult.Failed(Resources.InvalidToken);
            }
            await store.SetEmailConfirmedAsync(user, true, cancellationToken);
            return await UpdateAsync(user, cancellationToken);
        }

        /// <summary>
        ///     Returns true if the user's email has been confirmed
        /// </summary>
        /// <param name="user"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        public virtual async Task<bool> IsEmailConfirmedAsync(TUser user,
            CancellationToken cancellationToken = default(CancellationToken))
        {
            ThrowIfDisposed();
            var store = GetEmailStore();
            if (user == null)
            {
                throw new ArgumentNullException("user");
            }
            return await store.GetEmailConfirmedAsync(user, cancellationToken);
        }

        // IUserPhoneNumberStore methods
        internal IUserPhoneNumberStore<TUser> GetPhoneNumberStore()
        {
            var cast = Store as IUserPhoneNumberStore<TUser>;
            if (cast == null)
            {
                throw new NotSupportedException(Resources.StoreNotIUserPhoneNumberStore);
            }
            return cast;
        }

        /// <summary>
        ///     Get a user's phoneNumber
        /// </summary>
        /// <param name="user"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        public virtual async Task<string> GetPhoneNumberAsync(TUser user,
            CancellationToken cancellationToken = default(CancellationToken))
        {
            ThrowIfDisposed();
            var store = GetPhoneNumberStore();
            if (user == null)
            {
                throw new ArgumentNullException("user");
            }
            return await store.GetPhoneNumberAsync(user, cancellationToken);
        }

        /// <summary>
        ///     Set a user's phoneNumber
        /// </summary>
        /// <param name="user"></param>
        /// <param name="phoneNumber"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        public virtual async Task<IdentityResult> SetPhoneNumberAsync(TUser user, string phoneNumber,
            CancellationToken cancellationToken = default(CancellationToken))
        {
            ThrowIfDisposed();
            var store = GetPhoneNumberStore();
            if (user == null)
            {
                throw new ArgumentNullException("user");
            }
            await store.SetPhoneNumberAsync(user, phoneNumber, cancellationToken);
            await store.SetPhoneNumberConfirmedAsync(user, false, cancellationToken);
            await UpdateSecurityStampInternal(user, cancellationToken);
            return await UpdateAsync(user, cancellationToken);
        }

        /// <summary>
        ///     Set a user's phoneNumber with the verification token
        /// </summary>
        /// <param name="user"></param>
        /// <param name="phoneNumber"></param>
        /// <param name="token"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        public virtual async Task<IdentityResult> ChangePhoneNumberAsync(TUser user, string phoneNumber, string token,
            CancellationToken cancellationToken = default(CancellationToken))
        {
            ThrowIfDisposed();
            var store = GetPhoneNumberStore();
            if (user == null)
            {
                throw new ArgumentNullException("user");
            }
            if (!await VerifyChangePhoneNumberTokenAsync(user, token, phoneNumber, cancellationToken))
            {
                return IdentityResult.Failed(Resources.InvalidToken);
            }
            await store.SetPhoneNumberAsync(user, phoneNumber, cancellationToken);
            await store.SetPhoneNumberConfirmedAsync(user, true, cancellationToken);
            await UpdateSecurityStampInternal(user, cancellationToken);
            return await UpdateAsync(user, cancellationToken);
        }

        /// <summary>
        ///     Returns true if the user's phone number has been confirmed
        /// </summary>
        /// <param name="user"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        public virtual async Task<bool> IsPhoneNumberConfirmedAsync(TUser user,
            CancellationToken cancellationToken = default(CancellationToken))
        {
            ThrowIfDisposed();
            var store = GetPhoneNumberStore();
            if (user == null)
            {
                throw new ArgumentNullException("user");
            }
            return await store.GetPhoneNumberConfirmedAsync(user, cancellationToken);
        }

        // Two factor APIS

        internal async Task<SecurityToken> CreateSecurityTokenAsync(TUser user, CancellationToken cancellationToken)
        {
            return
                new SecurityToken(Encoding.Unicode.GetBytes(await GetSecurityStampAsync(user, cancellationToken)));
        }

        /// <summary>
        ///     Get a phone number code for a user and phone number
        /// </summary>
        /// <param name="user"></param>
        /// <param name="phoneNumber"></param>
        /// <returns></returns>
        public virtual async Task<string> GenerateChangePhoneNumberTokenAsync(TUser user, string phoneNumber,
            CancellationToken cancellationToken = default(CancellationToken))
        {
            ThrowIfDisposed();
            return Rfc6238AuthenticationService.GenerateCode(
                await CreateSecurityTokenAsync(user, cancellationToken), phoneNumber)
                   .ToString(CultureInfo.InvariantCulture);
        }

        /// <summary>
        ///     Verify a phone number code for a specific user and phone number
        /// </summary>
        /// <param name="user"></param>
        /// <param name="token"></param>
        /// <param name="phoneNumber"></param>
        /// <returns></returns>
        public virtual async Task<bool> VerifyChangePhoneNumberTokenAsync(TUser user, string token, string phoneNumber,
            CancellationToken cancellationToken = default(CancellationToken))
        {
            ThrowIfDisposed();
            var securityToken = await CreateSecurityTokenAsync(user, cancellationToken);
            int code;
            if (securityToken != null && Int32.TryParse(token, out code))
            {
                return Rfc6238AuthenticationService.ValidateCode(securityToken, code, phoneNumber);
            }
            return false;
        }

        /// <summary>
        ///     Verify a user token with the specified purpose
        /// </summary>
        /// <param name="user"></param>
        /// <param name="purpose"></param>
        /// <param name="token"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        public virtual async Task<bool> VerifyUserTokenAsync(TUser user, string tokenProvider, string purpose, string token,
            CancellationToken cancellationToken = default(CancellationToken))
        {
            ThrowIfDisposed();
            if (user == null)
            {
                throw new ArgumentNullException("user");
            }
            if (tokenProvider == null)
            {
                throw new ArgumentNullException(nameof(tokenProvider));
            }
            if (!_tokenProviders.ContainsKey(tokenProvider))
            {
                throw new NotSupportedException(string.Format(CultureInfo.CurrentCulture, Resources.NoTokenProvider, tokenProvider));
            }
            // Make sure the token is valid
            return await _tokenProviders[tokenProvider].ValidateAsync(purpose, token, this, user, cancellationToken);
        }

        /// <summary>
        ///     Get a user token for a specific purpose
        /// </summary>
        /// <param name="purpose"></param>
        /// <param name="user"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        public virtual async Task<string> GenerateUserTokenAsync(TUser user, string tokenProvider, string purpose,
            CancellationToken cancellationToken = default(CancellationToken))
        {
            ThrowIfDisposed();
            if (user == null)
            {
                throw new ArgumentNullException("user");
            }
            if (tokenProvider == null)
            {
                throw new ArgumentNullException(nameof(tokenProvider));
            }
            if (!_tokenProviders.ContainsKey(tokenProvider))
            {
                throw new NotSupportedException(string.Format(CultureInfo.CurrentCulture, Resources.NoTokenProvider, tokenProvider));
            }
            return await _tokenProviders[tokenProvider].GenerateAsync(purpose, this, user, cancellationToken);
        }

        /// <summary>
        ///     Register a user token provider
        /// </summary>
        /// <param name="twoFactorProvider"></param>
        /// <param name="provider"></param>
        public virtual void RegisterTokenProvider(IUserTokenProvider<TUser> provider)
        {
            ThrowIfDisposed();
            if (provider == null)
            {
                throw new ArgumentNullException("provider");
            }
            _tokenProviders[provider.Name] = provider;
        }

        /// <summary>
        ///     Returns a list of valid two factor providers for a user
        /// </summary>
        /// <param name="user"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        public virtual async Task<IList<string>> GetValidTwoFactorProvidersAsync(TUser user,
            CancellationToken cancellationToken = default(CancellationToken))
        {
            ThrowIfDisposed();
            if (user == null)
            {
                throw new ArgumentNullException("user");
            }
            var results = new List<string>();
            foreach (var f in _tokenProviders)
            {
                if (await f.Value.CanGenerateTwoFactorTokenAsync(this, user, cancellationToken))
                {
                    results.Add(f.Key);
                }
            }
            return results;
        }

        /// <summary>
        ///     Verify a user token with the specified provider
        /// </summary>
        /// <param name="user"></param>
        /// <param name="twoFactorProvider"></param>
        /// <param name="token"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        public virtual async Task<bool> VerifyTwoFactorTokenAsync(TUser user, string tokenProvider, string token,
            CancellationToken cancellationToken = default(CancellationToken))
        {
            ThrowIfDisposed();
            if (user == null)
            {
                throw new ArgumentNullException("user");
            }
            if (!_tokenProviders.ContainsKey(tokenProvider))
            {
                throw new NotSupportedException(String.Format(CultureInfo.CurrentCulture,
                    Resources.NoTokenProvider, tokenProvider));
            }
            // Make sure the token is valid
            return await _tokenProviders[tokenProvider].ValidateAsync("TwoFactor", token, this, user, cancellationToken);
        }

        /// <summary>
        ///     Get a user token for a specific user factor provider
        /// </summary>
        /// <param name="user"></param>
        /// <param name="twoFactorProvider"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        public virtual async Task<string> GenerateTwoFactorTokenAsync(TUser user, string tokenProvider,
            CancellationToken cancellationToken = default(CancellationToken))
        {
            ThrowIfDisposed();
            if (user == null)
            {
                throw new ArgumentNullException("user");
            }
            if (!_tokenProviders.ContainsKey(tokenProvider))
            {
                throw new NotSupportedException(String.Format(CultureInfo.CurrentCulture,
                    Resources.NoTokenProvider, tokenProvider));
            }
            return await _tokenProviders[tokenProvider].GenerateAsync("TwoFactor", this, user, cancellationToken);
        }

        /// <summary>
        ///     Notify a user with a token from a specific user factor provider
        /// </summary>
        /// <param name="user"></param>
        /// <param name="tokenProvider"></param>
        /// <param name="token"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        public virtual async Task<IdentityResult> NotifyTwoFactorTokenAsync(TUser user, string tokenProvider,
            string token, CancellationToken cancellationToken = default(CancellationToken))
        {
            ThrowIfDisposed();
            if (user == null)
            {
                throw new ArgumentNullException("user");
            }
            if (tokenProvider == null)
            {
                throw new ArgumentNullException(nameof(tokenProvider));
            }
            if (!_tokenProviders.ContainsKey(tokenProvider))
            {
                throw new NotSupportedException(String.Format(CultureInfo.CurrentCulture,
                    Resources.NoTokenProvider, tokenProvider));
            }
            await _tokenProviders[tokenProvider].NotifyAsync(token, this, user, cancellationToken);
            return IdentityResult.Success;
        }

        // IUserFactorStore methods
        internal IUserTwoFactorStore<TUser> GetUserTwoFactorStore()
        {
            var cast = Store as IUserTwoFactorStore<TUser>;
            if (cast == null)
            {
                throw new NotSupportedException(Resources.StoreNotIUserTwoFactorStore);
            }
            return cast;
        }

        /// <summary>
        ///     Get a user's two factor provider
        /// </summary>
        /// <param name="user"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        public virtual async Task<bool> GetTwoFactorEnabledAsync(TUser user,
            CancellationToken cancellationToken = default(CancellationToken))
        {
            ThrowIfDisposed();
            var store = GetUserTwoFactorStore();
            if (user == null)
            {
                throw new ArgumentNullException("user");
            }
            return await store.GetTwoFactorEnabledAsync(user, cancellationToken);
        }

        /// <summary>
        ///     Set whether a user has two factor enabled or not
        /// </summary>
        /// <param name="user"></param>
        /// <param name="enabled"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        public virtual async Task<IdentityResult> SetTwoFactorEnabledAsync(TUser user, bool enabled,
            CancellationToken cancellationToken = default(CancellationToken))
        {
            ThrowIfDisposed();
            var store = GetUserTwoFactorStore();
            if (user == null)
            {
                throw new ArgumentNullException("user");
            }
            await store.SetTwoFactorEnabledAsync(user, enabled, cancellationToken);
            await UpdateSecurityStampInternal(user, cancellationToken);
            return await UpdateAsync(user, cancellationToken);
        }

        // SMS/Email methods

        /// <summary>
        ///     Send an email to the user
        /// </summary>
        /// <param name="user"></param>
        /// <param name="subject"></param>
        /// <param name="body"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        public virtual async Task SendEmailAsync(TUser user, string subject, string body,
            CancellationToken cancellationToken = default(CancellationToken))
        {
            ThrowIfDisposed();
            if (user == null)
            {
                throw new ArgumentNullException("user");
            }
            if (EmailService != null)
            {
                var msg = new IdentityMessage
                {
                    Destination = await GetEmailAsync(user, cancellationToken),
                    Subject = subject,
                    Body = body,
                };
                await EmailService.SendAsync(msg, cancellationToken);
            }
        }

        /// <summary>
        ///     Send a user a sms message
        /// </summary>
        /// <param name="user"></param>
        /// <param name="message"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        public virtual async Task SendSmsAsync(TUser user, string message,
            CancellationToken cancellationToken = default(CancellationToken))
        {
            ThrowIfDisposed();
            if (user == null)
            {
                throw new ArgumentNullException("user");
            }
            if (SmsService != null)
            {
                var msg = new IdentityMessage
                {
                    Destination = await GetPhoneNumberAsync(user, cancellationToken),
                    Body = message
                };
                await SmsService.SendAsync(msg, cancellationToken);
            }
        }

        // IUserLockoutStore methods
        internal IUserLockoutStore<TUser> GetUserLockoutStore()
        {
            var cast = Store as IUserLockoutStore<TUser>;
            if (cast == null)
            {
                throw new NotSupportedException(Resources.StoreNotIUserLockoutStore);
            }
            return cast;
        }

        /// <summary>
        ///     Returns true if the user is locked out
        /// </summary>
        /// <param name="user"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        public virtual async Task<bool> IsLockedOutAsync(TUser user,
            CancellationToken cancellationToken = default(CancellationToken))
        {
            ThrowIfDisposed();
            var store = GetUserLockoutStore();
            if (user == null)
            {
                throw new ArgumentNullException("user");
            }
            if (!await store.GetLockoutEnabledAsync(user, cancellationToken))
            {
                return false;
            }
            var lockoutTime = await store.GetLockoutEndDateAsync(user, cancellationToken).ConfigureAwait((false));
            return lockoutTime >= DateTimeOffset.UtcNow;
        }

        /// <summary>
        ///     Sets whether the user allows lockout
        /// </summary>
        /// <param name="user"></param>
        /// <param name="enabled"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        public virtual async Task<IdentityResult> SetLockoutEnabledAsync(TUser user, bool enabled,
            CancellationToken cancellationToken = default(CancellationToken))
        {
            ThrowIfDisposed();
            var store = GetUserLockoutStore();
            if (user == null)
            {
                throw new ArgumentNullException("user");
            }
            await store.SetLockoutEnabledAsync(user, enabled, cancellationToken);
            return await UpdateAsync(user, cancellationToken);
        }

        /// <summary>
        ///     Returns whether the user allows lockout
        /// </summary>
        /// <param name="user"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        public virtual async Task<bool> GetLockoutEnabledAsync(TUser user,
            CancellationToken cancellationToken = default(CancellationToken))
        {
            ThrowIfDisposed();
            var store = GetUserLockoutStore();
            if (user == null)
            {
                throw new ArgumentNullException("user");
            }
            return await store.GetLockoutEnabledAsync(user, cancellationToken);
        }

        /// <summary>
        ///     Returns the user lockout end date
        /// </summary>
        /// <param name="user"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        public virtual async Task<DateTimeOffset> GetLockoutEndDateAsync(TUser user,
            CancellationToken cancellationToken = default(CancellationToken))
        {
            ThrowIfDisposed();
            var store = GetUserLockoutStore();
            if (user == null)
            {
                throw new ArgumentNullException("user");
            }
            return await store.GetLockoutEndDateAsync(user, cancellationToken);
        }

        /// <summary>
        ///     Sets the user lockout end date
        /// </summary>
        /// <param name="user"></param>
        /// <param name="lockoutEnd"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        public virtual async Task<IdentityResult> SetLockoutEndDateAsync(TUser user, DateTimeOffset lockoutEnd,
            CancellationToken cancellationToken = default(CancellationToken))
        {
            ThrowIfDisposed();
            var store = GetUserLockoutStore();
            if (user == null)
            {
                throw new ArgumentNullException("user");
            }
            if (!await store.GetLockoutEnabledAsync(user, cancellationToken).ConfigureAwait((false)))
            {
                return IdentityResult.Failed(Resources.LockoutNotEnabled);
            }
            await store.SetLockoutEndDateAsync(user, lockoutEnd, cancellationToken);
            return await UpdateAsync(user, cancellationToken);
        }

        /// <summary>
        /// Increments the access failed count for the user and if the failed access account is greater than or equal
        /// to the MaxFailedAccessAttempsBeforeLockout, the user will be locked out for the next
        /// DefaultAccountLockoutTimeSpan and the AccessFailedCount will be reset to 0.
        /// </summary>
        /// <param name="user"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        public virtual async Task<IdentityResult> AccessFailedAsync(TUser user,
            CancellationToken cancellationToken = default(CancellationToken))
        {
            ThrowIfDisposed();
            var store = GetUserLockoutStore();
            if (user == null)
            {
                throw new ArgumentNullException("user");
            }
            // If this puts the user over the threshold for lockout, lock them out and reset the access failed count
            var count = await store.IncrementAccessFailedCountAsync(user, cancellationToken);
            if (count < Options.Lockout.MaxFailedAccessAttempts)
            {
                return await UpdateAsync(user, cancellationToken);
            }
            await store.SetLockoutEndDateAsync(user, DateTimeOffset.UtcNow.Add(Options.Lockout.DefaultLockoutTimeSpan),
                cancellationToken);
            await store.ResetAccessFailedCountAsync(user, cancellationToken);
            return await UpdateAsync(user, cancellationToken);
        }

        /// <summary>
        ///     Resets the access failed count for the user to 0
        /// </summary>
        /// <param name="user"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        public virtual async Task<IdentityResult> ResetAccessFailedCountAsync(TUser user,
            CancellationToken cancellationToken = default(CancellationToken))
        {
            ThrowIfDisposed();
            var store = GetUserLockoutStore();
            if (user == null)
            {
                throw new ArgumentNullException("user");
            }
            await store.ResetAccessFailedCountAsync(user, cancellationToken);
            return await UpdateAsync(user, cancellationToken);
        }

        /// <summary>
        ///     Returns the number of failed access attempts for the user
        /// </summary>
        /// <param name="user"></param>
        /// <param name="cancellationToken"></param>
        /// <returns></returns>
        public virtual async Task<int> GetAccessFailedCountAsync(TUser user,
            CancellationToken cancellationToken = default(CancellationToken))
        {
            ThrowIfDisposed();
            var store = GetUserLockoutStore();
            if (user == null)
            {
                throw new ArgumentNullException("user");
            }
            return await store.GetAccessFailedCountAsync(user, cancellationToken);
        }

        private void ThrowIfDisposed()
        {
            if (_disposed)
            {
                throw new ObjectDisposedException(GetType().Name);
            }
        }

        /// <summary>
        ///     When disposing, actually dipose the store context
        /// </summary>
        /// <param name="disposing"></param>
        protected virtual void Dispose(bool disposing)
        {
            if (disposing && !_disposed)
            {
                Store.Dispose();
                _disposed = true;
            }
        }
    }
}