// Copyright (c) .NET Foundation. 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.Linq;
using System.Security.Claims;
using System.Threading;
using System.Threading.Tasks;
using MongoDbGenericRepository;
using MongoDB.Driver;
using AspNetCore.Identity.MongoDbCore.Extensions;
using AspNetCore.Identity.MongoDbCore.Models;
using AspNetCore.Identity.MongoDbCore.Infrastructure;
using Microsoft.AspNetCore.Identity;

namespace AspNetCore.Identity.MongoDbCore
{
    /// <summary>
    /// Creates a new instance of a persistence store for the specified user type.
    /// </summary>
    /// <typeparam name="TUser">The type representing a user.</typeparam>
    public class MongoUserOnlyStore<TUser> : MongoUserOnlyStore<TUser, IMongoDbContext, string> 
        where TUser : MongoIdentityUser<string>, new()
    {
        /// <summary>
        /// Constructs a new instance of <see cref="MongoUserOnlyStore{TUser}"/>.
        /// </summary>
        /// <param name="context">The <see cref="IMongoDbContext"/>.</param>
        /// <param name="describer">The <see cref="IdentityErrorDescriber"/>.</param>
        public MongoUserOnlyStore(IMongoDbContext context, IdentityErrorDescriber describer = null) : base(context, describer) { }
    }

    /// <summary>
    /// Represents a new instance of a persistence store for the specified user and role types.
    /// </summary>
    /// <typeparam name="TUser">The type representing a user.</typeparam>
    /// <typeparam name="TContext">The type of the data context class used to access the store.</typeparam>
    public class MongoUserOnlyStore<TUser, TContext> : MongoUserOnlyStore<TUser, TContext, string>
        where TUser : MongoIdentityUser<string>
        where TContext : IMongoDbContext
    {
        /// <summary>
        /// Constructs a new instance of <see cref="MongoUserOnlyStore{TUser, TContext}"/>.
        /// </summary>
        /// <param name="context">The <see cref="IMongoDbContext"/>.</param>
        /// <param name="describer">The <see cref="IdentityErrorDescriber"/>.</param>
        public MongoUserOnlyStore(TContext context, IdentityErrorDescriber describer = null) : base(context, describer) { }
    }

    /// <summary>
    /// Represents a new instance of a persistence store for the specified user and role types.
    /// </summary>
    /// <typeparam name="TUser">The type representing a user.</typeparam>
    /// <typeparam name="TContext">The type of the data context class used to access the store.</typeparam>
    /// <typeparam name="TKey">The type of the primary key for a role.</typeparam>
    public class MongoUserOnlyStore<TUser, TContext, TKey> : MongoUserOnlyStore<TUser, TContext, TKey, IdentityUserClaim<TKey>, IdentityUserLogin<TKey>, IdentityUserToken<TKey>>
        where TUser : MongoIdentityUser<TKey>
        where TContext : IMongoDbContext
        where TKey : IEquatable<TKey>
    {
        /// <summary>
        /// Constructs a new instance of <see cref="MongoUserOnlyStore{TUser, TContext, TKey}"/>.
        /// </summary>
        /// <param name="context">The <see cref="IMongoDbContext"/>.</param>
        /// <param name="describer">The <see cref="IdentityErrorDescriber"/>.</param>
        public MongoUserOnlyStore(TContext context, IdentityErrorDescriber describer = null) : base(context, describer) { }
    }

    /// <summary>
    /// Represents a new instance of a persistence store for the specified user and role types.
    /// </summary>
    /// <typeparam name="TUser">The type representing a user.</typeparam>
    /// <typeparam name="TContext">The type of the data context class used to access the store.</typeparam>
    /// <typeparam name="TKey">The type of the primary key for a role.</typeparam>
    /// <typeparam name="TUserClaim">The type representing a claim.</typeparam>
    /// <typeparam name="TUserLogin">The type representing a user external login.</typeparam>
    /// <typeparam name="TUserToken">The type representing a user token.</typeparam>
    public class MongoUserOnlyStore<TUser, TContext, TKey, TUserClaim, TUserLogin, TUserToken> :
        UserStoreBase<TUser, TKey, TUserClaim, TUserLogin, TUserToken>,
        IUserAuthenticationTokenStore<TUser>
        where TUser : MongoIdentityUser<TKey>
        where TContext : IMongoDbContext
        where TKey : IEquatable<TKey>
        where TUserClaim : IdentityUserClaim<TKey>, new()
        where TUserLogin : IdentityUserLogin<TKey>, new()
        where TUserToken : IdentityUserToken<TKey>, new()
    {
        /// <summary>
        /// Creates a new instance of the store.
        /// </summary>
        /// <param name="context">The context used to access the store.</param>
        /// <param name="describer">The <see cref="IdentityErrorDescriber"/> used to describe store errors.</param>
        public MongoUserOnlyStore(TContext context, IdentityErrorDescriber describer = null) : base(describer ?? new IdentityErrorDescriber())
        {
            if (context == null)
            {
                throw new ArgumentNullException(nameof(context));
            }
            Context = context;
        }

        /// <summary>
        /// Gets the database context for this store.
        /// </summary>
        private static TContext Context { get; set; }

        private static IMongoRepository _mongoRepository;
        private static IMongoRepository MongoRepository
        {
            get
            {
                if (_mongoRepository == null)
                {
                    _mongoRepository = new MongoRepository(Context);
                }
                return _mongoRepository;
            }
        }

        private IMongoCollection<TUser> UsersCollection { get { return Context.GetCollection<TUser>(); } }

        /// <summary>
        /// Gets or sets a flag indicating if changes should be persisted after CreateAsync, UpdateAsync and DeleteAsync are called.
        /// </summary>
        /// <value>
        /// True if changes should be automatically persisted, otherwise false.
        /// </value>
        public bool AutoSaveChanges { get; set; } = true;

        /// <summary>Saves the current store.</summary>
        /// <param name="cancellationToken">The <see cref="CancellationToken"/> used to propagate notifications that the operation should be canceled.</param>
        /// <returns>The <see cref="Task"/> that represents the asynchronous operation.</returns>
        protected Task SaveChanges(CancellationToken cancellationToken)
        {
            return Task.CompletedTask;
        }

        /// <summary>
        /// Creates the specified <paramref name="user"/> in the user store.
        /// </summary>
        /// <param name="user">The user to create.</param>
        /// <param name="cancellationToken">The <see cref="CancellationToken"/> used to propagate notifications that the operation should be canceled.</param>
        /// <returns>The <see cref="Task"/> that represents the asynchronous operation, containing the <see cref="IdentityResult"/> of the creation operation.</returns>
        public async override Task<IdentityResult> CreateAsync(TUser user, CancellationToken cancellationToken = default(CancellationToken))
        {
            cancellationToken.ThrowIfCancellationRequested();
            ThrowIfDisposed();
            if (user == null)
            {
                throw new ArgumentNullException(nameof(user));
            }
            await UsersCollection.InsertOneAsync(user);
            await SaveChanges(cancellationToken);
            return IdentityResult.Success;
        }

        /// <summary>
        /// Updates the specified <paramref name="user"/> in the user store.
        /// </summary>
        /// <param name="user">The user to update.</param>
        /// <param name="cancellationToken">The <see cref="CancellationToken"/> used to propagate notifications that the operation should be canceled.</param>
        /// <returns>The <see cref="Task"/> that represents the asynchronous operation, containing the <see cref="IdentityResult"/> of the update operation.</returns>
        public async override Task<IdentityResult> UpdateAsync(TUser user, CancellationToken cancellationToken = default(CancellationToken))
        {
            cancellationToken.ThrowIfCancellationRequested();
            ThrowIfDisposed();
            if (user == null)
            {
                throw new ArgumentNullException(nameof(user));
            }
            var oldStamp = user.ConcurrencyStamp;
            user.ConcurrencyStamp = Guid.NewGuid().ToString();
            var updateRes = await UsersCollection.ReplaceOneAsync(x => x.Id.Equals(user.Id) 
                                                               && x.ConcurrencyStamp.Equals(oldStamp), 
                                                             user);
            if(updateRes.ModifiedCount == 0)
            {
                return IdentityResult.Failed(ErrorDescriber.ConcurrencyFailure());
            }
            return IdentityResult.Success;
        }

        /// <summary>
        /// Deletes the specified <paramref name="user"/> from the user store.
        /// </summary>
        /// <param name="user">The user to delete.</param>
        /// <param name="cancellationToken">The <see cref="CancellationToken"/> used to propagate notifications that the operation should be canceled.</param>
        /// <returns>The <see cref="Task"/> that represents the asynchronous operation, containing the <see cref="IdentityResult"/> of the update operation.</returns>
        public async override Task<IdentityResult> DeleteAsync(TUser user, CancellationToken cancellationToken = default(CancellationToken))
        {
            cancellationToken.ThrowIfCancellationRequested();
            ThrowIfDisposed();
            if (user == null)
            {
                throw new ArgumentNullException(nameof(user));
            }
            user.Claims.Clear();
            user.Roles.Clear();
            user.Logins.Clear();
            user.Tokens.Clear();
            var oldStamp = user.ConcurrencyStamp;
            user.ConcurrencyStamp = Guid.NewGuid().ToString();
            var deleteRes = await UsersCollection.DeleteOneAsync(x => x.Id.Equals(user.Id)
                                                              && x.ConcurrencyStamp.Equals(oldStamp));
            if (deleteRes.DeletedCount == 0)
            {
                return IdentityResult.Failed(ErrorDescriber.ConcurrencyFailure());
            }
            return IdentityResult.Success;
        }

        /// <summary>
        /// Finds and returns a user, if any, who has the specified <paramref name="userId"/>.
        /// </summary>
        /// <param name="userId">The user ID to search for.</param>
        /// <param name="cancellationToken">The <see cref="CancellationToken"/> used to propagate notifications that the operation should be canceled.</param>
        /// <returns>
        /// The <see cref="Task"/> that represents the asynchronous operation, containing the user matching the specified <paramref name="userId"/> if it exists.
        /// </returns>
        public override Task<TUser> FindByIdAsync(string userId, CancellationToken cancellationToken = default(CancellationToken))
        {
            cancellationToken.ThrowIfCancellationRequested();
            ThrowIfDisposed();
            var id = ConvertIdFromString(userId);
            return MongoRepository.GetByIdAsync<TUser, TKey>(id);
        }

        /// <summary>
        /// Finds and returns a user, if any, who has the specified normalized user name.
        /// </summary>
        /// <param name="normalizedUserName">The normalized user name to search for.</param>
        /// <param name="cancellationToken">The <see cref="CancellationToken"/> used to propagate notifications that the operation should be canceled.</param>
        /// <returns>
        /// The <see cref="Task"/> that represents the asynchronous operation, containing the user matching the specified <paramref name="normalizedUserName"/> if it exists.
        /// </returns>
        public override Task<TUser> FindByNameAsync(string normalizedUserName, CancellationToken cancellationToken = default(CancellationToken))
        {
            cancellationToken.ThrowIfCancellationRequested();
            ThrowIfDisposed();
            return MongoRepository.GetOneAsync<TUser, TKey>(u => u.NormalizedUserName == normalizedUserName);
        }

        /// <summary>
        /// A navigation property for the users the store contains.
        /// </summary>
        public override IQueryable<TUser> Users
        {
            get { return UsersCollection.AsQueryable(); }
        }

        /// <summary>
        /// Return a user with the matching userId if it exists.
        /// </summary>
        /// <param name="userId">The user's id.</param>
        /// <param name="cancellationToken">The <see cref="CancellationToken"/> used to propagate notifications that the operation should be canceled.</param>
        /// <returns>The user if it exists.</returns>
        protected override Task<TUser> FindUserAsync(TKey userId, CancellationToken cancellationToken)
        {
            return MongoRepository.GetOneAsync<TUser, TKey>(u => u.Id.Equals(userId));
        }

        /// <summary>
        /// Return a user login with the matching userId, provider, providerKey if it exists.
        /// </summary>
        /// <param name="userId">The user's id.</param>
        /// <param name="loginProvider">The login provider name.</param>
        /// <param name="providerKey">The key provided by the <paramref name="loginProvider"/> to identify a user.</param>
        /// <param name="cancellationToken">The <see cref="CancellationToken"/> used to propagate notifications that the operation should be canceled.</param>
        /// <returns>The user login if it exists.</returns>
        protected override Task<TUserLogin> FindUserLoginAsync(TKey userId, string loginProvider, string providerKey, CancellationToken cancellationToken)
        {
            var user = MongoRepository.GetOne<TUser, TKey>(x => x.Id.Equals(userId) && x.Logins.Any(e => e.LoginProvider == loginProvider && e.ProviderKey == providerKey));
            if (user != null)
            {
                return Task.FromResult((TUserLogin)user.GetUserLogin(loginProvider, providerKey));
            }
            return Task.FromResult(default(TUserLogin));
        }

        /// <summary>
        /// Return a user login with  provider, providerKey if it exists.
        /// </summary>
        /// <param name="loginProvider">The login provider name.</param>
        /// <param name="providerKey">The key provided by the <paramref name="loginProvider"/> to identify a user.</param>
        /// <param name="cancellationToken">The <see cref="CancellationToken"/> used to propagate notifications that the operation should be canceled.</param>
        /// <returns>The user login if it exists.</returns>
        protected override Task<TUserLogin> FindUserLoginAsync(string loginProvider, string providerKey, CancellationToken cancellationToken)
        {
            var user = MongoRepository.GetOne<TUser, TKey>(x => x.Logins.Any(e => e.LoginProvider == loginProvider && e.ProviderKey == providerKey));
            if (user != null)
            {
                return Task.FromResult((TUserLogin)user.GetUserLogin(loginProvider, providerKey));
            }
            return Task.FromResult(default(TUserLogin));
        }

#pragma warning disable CS1998 // Cette méthode async n'a pas d'opérateur 'await' et elle s'exécutera de façon synchrone
                              /// <summary>
                              /// Get the claims associated with the specified <paramref name="user"/> as an asynchronous operation.
                              /// </summary>
                              /// <param name="user">The user whose claims should be retrieved.</param>
                              /// <param name="cancellationToken">The <see cref="CancellationToken"/> used to propagate notifications that the operation should be canceled.</param>
                              /// <returns>A <see cref="Task{TResult}"/> that contains the claims granted to a user.</returns>
        public async override Task<IList<Claim>> GetClaimsAsync(TUser user, CancellationToken cancellationToken = default(CancellationToken))
#pragma warning restore CS1998 // Cette méthode async n'a pas d'opérateur 'await' et elle s'exécutera de façon synchrone
        {
            ThrowIfDisposed();
            if (user == null)
            {
                throw new ArgumentNullException(nameof(user));
            }
            return user.Claims.Select(e => e.ToClaim()).ToList();
        }

        /// <summary>
        /// Adds the <paramref name="claims"/> given to the specified <paramref name="user"/>.
        /// </summary>
        /// <param name="user">The user to add the claim to.</param>
        /// <param name="claims">The claim to add to the user.</param>
        /// <param name="cancellationToken">The <see cref="CancellationToken"/> used to propagate notifications that the operation should be canceled.</param>
        /// <returns>The <see cref="Task"/> that represents the asynchronous operation.</returns>
        public override Task AddClaimsAsync(TUser user, IEnumerable<Claim> claims, CancellationToken cancellationToken = default(CancellationToken))
        {
            ThrowIfDisposed();
            if (user == null)
            {
                throw new ArgumentNullException(nameof(user));
            }
            if (claims == null)
            {
                throw new ArgumentNullException(nameof(claims));
            }
            var addedSome = false;
            foreach (var claim in claims)
            {
                if (user.AddClaim(claim))
                {
                    addedSome |= true;
                }
            }
            if (addedSome)
            {
                var success = MongoRepository.UpdateOne<TUser, TKey, List<MongoClaim>>(user, p => p.Claims, user.Claims);
                if (!success)
                {
                    throw new Exception($"Failed to add claims to user {user.Id.ToString()}");
                }
            }
            return Task.FromResult(false);
        }

        /// <summary>
        /// Replaces the <paramref name="claim"/> on the specified <paramref name="user"/>, with the <paramref name="newClaim"/>.
        /// </summary>
        /// <param name="user">The user to replace the claim on.</param>
        /// <param name="claim">The claim replace.</param>
        /// <param name="newClaim">The new claim replacing the <paramref name="claim"/>.</param>
        /// <param name="cancellationToken">The <see cref="CancellationToken"/> used to propagate notifications that the operation should be canceled.</param>
        /// <returns>The <see cref="Task"/> that represents the asynchronous operation.</returns>
        public async override Task ReplaceClaimAsync(TUser user, Claim claim, Claim newClaim, CancellationToken cancellationToken = default(CancellationToken))
        {
            ThrowIfDisposed();
            if (user == null)
            {
                throw new ArgumentNullException(nameof(user));
            }
            if (claim == null)
            {
                throw new ArgumentNullException(nameof(claim));
            }
            if (newClaim == null)
            {
                throw new ArgumentNullException(nameof(newClaim));
            }

            if (user.ReplaceClaim(claim, newClaim))
            {
                await MongoRepository.UpdateOneAsync<TUser, TKey, List<MongoClaim>>(user, e => e.Claims, user.Claims);
            }
        }

        /// <summary>
        /// Removes the <paramref name="claims"/> given from the specified <paramref name="user"/>.
        /// </summary>
        /// <param name="user">The user to remove the claims from.</param>
        /// <param name="claims">The claim to remove.</param>
        /// <param name="cancellationToken">The <see cref="CancellationToken"/> used to propagate notifications that the operation should be canceled.</param>
        /// <returns>The <see cref="Task"/> that represents the asynchronous operation.</returns>
        public async override Task RemoveClaimsAsync(TUser user, IEnumerable<Claim> claims, CancellationToken cancellationToken = default(CancellationToken))
        {
            ThrowIfDisposed();
            if (user == null)
            {
                throw new ArgumentNullException(nameof(user));
            }
            if (claims == null)
            {
                throw new ArgumentNullException(nameof(claims));
            }
            if (user.RemoveClaims(claims))
            {
                await MongoRepository.UpdateOneAsync<TUser, TKey, List<MongoClaim>>(user, e => e.Claims, user.Claims);
            }
        }

        /// <summary>
        /// Adds the <paramref name="login"/> given to the specified <paramref name="user"/>.
        /// </summary>
        /// <param name="user">The user to add the login to.</param>
        /// <param name="login">The login to add to the user.</param>
        /// <param name="cancellationToken">The <see cref="CancellationToken"/> used to propagate notifications that the operation should be canceled.</param>
        /// <returns>The <see cref="Task"/> that represents the asynchronous operation.</returns>
        public override Task AddLoginAsync(TUser user, UserLoginInfo login,
            CancellationToken cancellationToken = default(CancellationToken))
        {
            cancellationToken.ThrowIfCancellationRequested();
            ThrowIfDisposed();

            if (user == null)
            {
                throw new ArgumentNullException(nameof(user));
            }

            if (login == null)
            {
                throw new ArgumentNullException(nameof(login));
            }

            if (user.AddLogin(login))
            {
                MongoRepository.UpdateOne<TUser, TKey, List<UserLoginInfo>>(user, e => e.Logins, user.Logins);
            }

            return Task.FromResult(false);
        }

#pragma warning disable CS1998 // Cette méthode async n'a pas d'opérateur 'await' et elle s'exécutera de façon synchrone
                              /// <summary>
                              /// Removes the <paramref name="loginProvider"/> given from the specified <paramref name="user"/>.
                              /// </summary>
                              /// <param name="user">The user to remove the login from.</param>
                              /// <param name="loginProvider">The login to remove from the user.</param>
                              /// <param name="providerKey">The key provided by the <paramref name="loginProvider"/> to identify a user.</param>
                              /// <param name="cancellationToken">The <see cref="CancellationToken"/> used to propagate notifications that the operation should be canceled.</param>
                              /// <returns>The <see cref="Task"/> that represents the asynchronous operation.</returns>
        public override async Task RemoveLoginAsync(TUser user, string loginProvider, string providerKey,
#pragma warning restore CS1998 // Cette méthode async n'a pas d'opérateur 'await' et elle s'exécutera de façon synchrone
            CancellationToken cancellationToken = default(CancellationToken))
        {
            cancellationToken.ThrowIfCancellationRequested();
            ThrowIfDisposed();
            if (user == null)
            {
                throw new ArgumentNullException(nameof(user));
            }
            var entry = user.Logins.FirstOrDefault(e => e.LoginProvider == loginProvider && e.ProviderKey == providerKey);
            if (entry != null)
            {
                user.RemoveLogin(entry);
            }
        }

#pragma warning disable CS1998 // Cette méthode async n'a pas d'opérateur 'await' et elle s'exécutera de façon synchrone
                              /// <summary>
                              /// Retrieves the associated logins for the specified <param ref="user"/>.
                              /// </summary>
                              /// <param name="user">The user whose associated logins to retrieve.</param>
                              /// <param name="cancellationToken">The <see cref="CancellationToken"/> used to propagate notifications that the operation should be canceled.</param>
                              /// <returns>
                              /// The <see cref="Task"/> for the asynchronous operation, containing a list of <see cref="UserLoginInfo"/> for the specified <paramref name="user"/>, if any.
                              /// </returns>
        public async override Task<IList<UserLoginInfo>> GetLoginsAsync(TUser user, CancellationToken cancellationToken = default(CancellationToken))
#pragma warning restore CS1998 // Cette méthode async n'a pas d'opérateur 'await' et elle s'exécutera de façon synchrone
        {
            cancellationToken.ThrowIfCancellationRequested();
            ThrowIfDisposed();
            if (user == null)
            {
                throw new ArgumentNullException(nameof(user));
            }
            return user.Logins.ToList();
        }

        /// <summary>
        /// Retrieves the user associated with the specified login provider and login provider key.
        /// </summary>
        /// <param name="loginProvider">The login provider who provided the <paramref name="providerKey"/>.</param>
        /// <param name="providerKey">The key provided by the <paramref name="loginProvider"/> to identify a user.</param>
        /// <param name="cancellationToken">The <see cref="CancellationToken"/> used to propagate notifications that the operation should be canceled.</param>
        /// <returns>
        /// The <see cref="Task"/> for the asynchronous operation, containing the user, if any which matched the specified login provider and key.
        /// </returns>
        public async override Task<TUser> FindByLoginAsync(string loginProvider, string providerKey,
            CancellationToken cancellationToken = default(CancellationToken))
        {
            cancellationToken.ThrowIfCancellationRequested();
            ThrowIfDisposed();
            var userLogin = await FindUserLoginAsync(loginProvider, providerKey, cancellationToken);
            if (userLogin != null)
            {
                return await FindUserAsync(userLogin.UserId, cancellationToken);
            }
            return null;
        }

        /// <summary>
        /// Gets the user, if any, associated with the specified, normalized email address.
        /// </summary>
        /// <param name="normalizedEmail">The normalized email address to return the user for.</param>
        /// <param name="cancellationToken">The <see cref="CancellationToken"/> used to propagate notifications that the operation should be canceled.</param>
        /// <returns>
        /// The task object containing the results of the asynchronous lookup operation, the user if any associated with the specified normalized email address.
        /// </returns>
        public override Task<TUser> FindByEmailAsync(string normalizedEmail, CancellationToken cancellationToken = default(CancellationToken))
        {
            cancellationToken.ThrowIfCancellationRequested();
            ThrowIfDisposed();
            return MongoRepository.GetOneAsync<TUser, TKey>(u => u.NormalizedEmail == normalizedEmail);
        }

        /// <summary>
        /// Retrieves all users with the specified claim.
        /// </summary>
        /// <param name="claim">The claim whose users should be retrieved.</param>
        /// <param name="cancellationToken">The <see cref="CancellationToken"/> used to propagate notifications that the operation should be canceled.</param>
        /// <returns>
        /// The <see cref="Task"/> contains a list of users, if any, that contain the specified claim. 
        /// </returns>
        public async override Task<IList<TUser>> GetUsersForClaimAsync(Claim claim, CancellationToken cancellationToken = default(CancellationToken))
        {
            cancellationToken.ThrowIfCancellationRequested();
            ThrowIfDisposed();
            if (claim == null)
            {
                throw new ArgumentNullException(nameof(claim));
            }
            var filter = Builders<TUser>.Filter.ElemMatch(x => x.Claims, userClaims => userClaims.Value.Equals(claim.Value)
                                                                                    && userClaims.Type.Equals(claim.Type));
            var cursor = UsersCollection.Find(filter);
            var res = await cursor.ToListAsync();
            return res;
        }

        #region Token Management

        /// <summary>
        /// Find a user token if it exists.
        /// </summary>
        /// <param name="user">The token owner.</param>
        /// <param name="loginProvider">The login provider for the token.</param>
        /// <param name="name">The name of the token.</param>
        /// <param name="cancellationToken">The <see cref="CancellationToken"/> used to propagate notifications that the operation should be canceled.</param>
        /// <returns>The user token if it exists.</returns>
        protected override Task<TUserToken> FindTokenAsync(TUser user, string loginProvider, string name, CancellationToken cancellationToken)
        {
            return Task.FromResult((TUserToken)user.GetToken(loginProvider, name));
        }

        /// <summary>
        /// Add a new user token.
        /// </summary>
        /// <param name="token">The token to be added.</param>
        /// <returns></returns>
        protected override Task AddUserTokenAsync(TUserToken token)
        {
            var user = MongoRepository.GetById<TUser, TKey>(token.UserId);
            if (user != null)
            {
                if (user.AddUserToken(token))
                {
                    MongoRepository.UpdateOne<TUser, TKey, List<Token>>(user, e => e.Tokens, user.Tokens);
                }
            }
            return Task.CompletedTask;
        }

        /// <summary>
        /// Remove a new user token.
        /// </summary>
        /// <param name="token">The token to be removed.</param>
        /// <returns></returns>
        protected override Task RemoveUserTokenAsync(TUserToken token)
        {
            var user = MongoRepository.GetById<TUser, TKey>(token.UserId);
            if (user != null)
            {
                if (user.RemoveUserToken(token))
                {
                    MongoRepository.UpdateOne<TUser, TKey, List<Token>>(user, e => e.Tokens, user.Tokens);
                }
            }
            return Task.CompletedTask;
        }

        #endregion Token Management

        #region UserStoreBase overrides

        /// <summary>
        /// Sets the given <paramref name="userName" /> for the specified <paramref name="user"/>.
        /// </summary>
        /// <param name="user">The user whose name should be set.</param>
        /// <param name="userName">The user name to set.</param>
        /// <param name="cancellationToken">The <see cref="CancellationToken"/> used to propagate notifications that the operation should be canceled.</param>
        /// <returns>The <see cref="Task"/> that represents the asynchronous operation.</returns>
        public override Task SetUserNameAsync(TUser user, string userName, CancellationToken cancellationToken = default(CancellationToken))
        {
            cancellationToken.ThrowIfCancellationRequested();
            ThrowIfDisposed();
            if (user == null)
            {
                throw new ArgumentNullException(nameof(user));
            }

            if (user.UserName != userName)
            {
                user.UserName = userName;
                MongoRepository.UpdateOne<TUser, TKey, string>(user, e => e.UserName, user.UserName);
            }
            return Task.CompletedTask;
        }

        /// <summary>
        /// Sets the given normalized name for the specified <paramref name="user"/>.
        /// </summary>
        /// <param name="user">The user whose name should be set.</param>
        /// <param name="normalizedName">The normalized name to set.</param>
        /// <param name="cancellationToken">The <see cref="CancellationToken"/> used to propagate notifications that the operation should be canceled.</param>
        /// <returns>The <see cref="Task"/> that represents the asynchronous operation.</returns>
        public override Task SetNormalizedUserNameAsync(TUser user, string normalizedName, CancellationToken cancellationToken = default(CancellationToken))
        {
            cancellationToken.ThrowIfCancellationRequested();
            ThrowIfDisposed();
            if (user == null)
            {
                throw new ArgumentNullException(nameof(user));
            }

            if (user.NormalizedUserName != normalizedName)
            {
                user.NormalizedUserName = normalizedName;
                MongoRepository.UpdateOne<TUser, TKey, string>(user, e => e.NormalizedUserName, user.NormalizedUserName);
            }
            return Task.CompletedTask;
        }

        /// <summary>
        /// Sets the password hash for a user.
        /// </summary>
        /// <param name="user">The user to set the password hash for.</param>
        /// <param name="passwordHash">The password hash to set.</param>
        /// <param name="cancellationToken">The <see cref="CancellationToken"/> used to propagate notifications that the operation should be canceled.</param>
        /// <returns>The <see cref="Task"/> that represents the asynchronous operation.</returns>
        public override Task SetPasswordHashAsync(TUser user, string passwordHash, CancellationToken cancellationToken = default(CancellationToken))
        {
            cancellationToken.ThrowIfCancellationRequested();
            ThrowIfDisposed();
            if (user == null)
            {
                throw new ArgumentNullException(nameof(user));
            }

            if (user.PasswordHash != passwordHash)
            {
                user.PasswordHash = passwordHash;
                MongoRepository.UpdateOne<TUser, TKey, string>(user, e => e.PasswordHash, user.PasswordHash);
            }
            return Task.CompletedTask;
        }

        /// <summary>
        /// Sets the flag indicating whether the specified <paramref name="user"/>'s email address has been confirmed or not.
        /// </summary>
        /// <param name="user">The user whose email confirmation status should be set.</param>
        /// <param name="confirmed">A flag indicating if the email address has been confirmed, true if the address is confirmed otherwise false.</param>
        /// <param name="cancellationToken">The <see cref="CancellationToken"/> used to propagate notifications that the operation should be canceled.</param>
        /// <returns>The task object representing the asynchronous operation.</returns>
        public override Task SetEmailConfirmedAsync(TUser user, bool confirmed, CancellationToken cancellationToken = default(CancellationToken))
        {
            cancellationToken.ThrowIfCancellationRequested();
            ThrowIfDisposed();
            if (user == null)
            {
                throw new ArgumentNullException(nameof(user));
            }
            if (user.EmailConfirmed != confirmed)
            {
                user.EmailConfirmed = confirmed;
                MongoRepository.UpdateOne<TUser, TKey, bool>(user, e => e.EmailConfirmed, user.EmailConfirmed);
            }
            return Task.CompletedTask;
        }

        /// <summary>
        /// Sets the <paramref name="email"/> address for a <paramref name="user"/>.
        /// </summary>
        /// <param name="user">The user whose email should be set.</param>
        /// <param name="email">The email to set.</param>
        /// <param name="cancellationToken">The <see cref="CancellationToken"/> used to propagate notifications that the operation should be canceled.</param>
        /// <returns>The task object representing the asynchronous operation.</returns>
        public override Task SetEmailAsync(TUser user, string email, CancellationToken cancellationToken = default(CancellationToken))
        {
            cancellationToken.ThrowIfCancellationRequested();
            ThrowIfDisposed();
            if (user == null)
            {
                throw new ArgumentNullException(nameof(user));
            }

            if (user.Email != email)
            {
                user.Email = email;
                MongoRepository.UpdateOne<TUser, TKey, string>(user, e => e.Email, user.Email);
            }
            return Task.CompletedTask;
        }

        /// <summary>
        /// Sets the normalized email for the specified <paramref name="user"/>.
        /// </summary>
        /// <param name="user">The user whose email address to set.</param>
        /// <param name="normalizedEmail">The normalized email to set for the specified <paramref name="user"/>.</param>
        /// <param name="cancellationToken">The <see cref="CancellationToken"/> used to propagate notifications that the operation should be canceled.</param>
        /// <returns>The task object representing the asynchronous operation.</returns>
        public override Task SetNormalizedEmailAsync(TUser user, string normalizedEmail, CancellationToken cancellationToken = default(CancellationToken))
        {
            cancellationToken.ThrowIfCancellationRequested();
            ThrowIfDisposed();
            if (user == null)
            {
                throw new ArgumentNullException(nameof(user));
            }

            if (user.NormalizedEmail != normalizedEmail)
            {
                user.NormalizedEmail = normalizedEmail;
                MongoRepository.UpdateOne<TUser, TKey, string>(user, e => e.NormalizedEmail, user.NormalizedEmail);
            }
            user.NormalizedEmail = normalizedEmail;
            return Task.CompletedTask;
        }

        /// <summary>
        /// Locks out a user until the specified end date has passed. Setting a end date in the past immediately unlocks a user.
        /// </summary>
        /// <param name="user">The user whose lockout date should be set.</param>
        /// <param name="lockoutEnd">The <see cref="DateTimeOffset"/> after which the <paramref name="user"/>'s lockout should end.</param>
        /// <param name="cancellationToken">The <see cref="CancellationToken"/> used to propagate notifications that the operation should be canceled.</param>
        /// <returns>The <see cref="Task"/> that represents the asynchronous operation.</returns>
        public override Task SetLockoutEndDateAsync(TUser user, DateTimeOffset? lockoutEnd, CancellationToken cancellationToken = default(CancellationToken))
        {
            cancellationToken.ThrowIfCancellationRequested();
            ThrowIfDisposed();
            if (user == null)
            {
                throw new ArgumentNullException(nameof(user));
            }

            if (user.LockoutEnd != lockoutEnd)
            {
                user.LockoutEnd = lockoutEnd;
                MongoRepository.UpdateOne<TUser, TKey, DateTimeOffset?>(user, e => e.LockoutEnd, user.LockoutEnd);
            }
            return Task.CompletedTask;
        }

        /// <summary>
        /// Records that a failed access has occurred, incrementing the failed access count.
        /// </summary>
        /// <param name="user">The user whose cancellation count should be incremented.</param>
        /// <param name="cancellationToken">The <see cref="CancellationToken"/> used to propagate notifications that the operation should be canceled.</param>
        /// <returns>The <see cref="Task"/> that represents the asynchronous operation, containing the incremented failed access count.</returns>
        public override Task<int> IncrementAccessFailedCountAsync(TUser user, CancellationToken cancellationToken = default(CancellationToken))
        {
            cancellationToken.ThrowIfCancellationRequested();
            ThrowIfDisposed();
            if (user == null)
            {
                throw new ArgumentNullException(nameof(user));
            }
            user.AccessFailedCount++;
            MongoRepository.UpdateOne<TUser, TKey, int>(user, e => e.AccessFailedCount, user.AccessFailedCount);
            return Task.FromResult(user.AccessFailedCount);
        }

        /// <summary>
        /// Resets a user's failed access count.
        /// </summary>
        /// <param name="user">The user whose failed access count should be reset.</param>
        /// <param name="cancellationToken">The <see cref="CancellationToken"/> used to propagate notifications that the operation should be canceled.</param>
        /// <returns>The <see cref="Task"/> that represents the asynchronous operation.</returns>
        /// <remarks>This is typically called after the account is successfully accessed.</remarks>
        public override Task ResetAccessFailedCountAsync(TUser user, CancellationToken cancellationToken = default(CancellationToken))
        {
            cancellationToken.ThrowIfCancellationRequested();
            ThrowIfDisposed();
            if (user == null)
            {
                throw new ArgumentNullException(nameof(user));
            }

            if (user.AccessFailedCount != 0)
            {
                user.AccessFailedCount = 0;
                MongoRepository.UpdateOne<TUser, TKey, int>(user, e => e.AccessFailedCount, user.AccessFailedCount);
            }
            return Task.CompletedTask;
        }

        /// <summary>
        /// Set the flag indicating if the specified <paramref name="user"/> can be locked out..
        /// </summary>
        /// <param name="user">The user whose ability to be locked out should be set.</param>
        /// <param name="enabled">A flag indicating if lock out can be enabled for the specified <paramref name="user"/>.</param>
        /// <param name="cancellationToken">The <see cref="CancellationToken"/> used to propagate notifications that the operation should be canceled.</param>
        /// <returns>The <see cref="Task"/> that represents the asynchronous operation.</returns>
        public override Task SetLockoutEnabledAsync(TUser user, bool enabled, CancellationToken cancellationToken = default(CancellationToken))
        {
            cancellationToken.ThrowIfCancellationRequested();
            ThrowIfDisposed();
            if (user == null)
            {
                throw new ArgumentNullException(nameof(user));
            }

            if (user.LockoutEnabled != enabled)
            {
                user.LockoutEnabled = enabled;
                MongoRepository.UpdateOne<TUser, TKey, bool>(user, e => e.LockoutEnabled, user.LockoutEnabled);
            }
            return Task.CompletedTask;
        }

        /// <summary>
        /// Sets the telephone number for the specified <paramref name="user"/>.
        /// </summary>
        /// <param name="user">The user whose telephone number should be set.</param>
        /// <param name="phoneNumber">The telephone number to set.</param>
        /// <param name="cancellationToken">The <see cref="CancellationToken"/> used to propagate notifications that the operation should be canceled.</param>
        /// <returns>The <see cref="Task"/> that represents the asynchronous operation.</returns>
        public override Task SetPhoneNumberAsync(TUser user, string phoneNumber, CancellationToken cancellationToken = default(CancellationToken))
        {
            cancellationToken.ThrowIfCancellationRequested();
            ThrowIfDisposed();
            if (user == null)
            {
                throw new ArgumentNullException(nameof(user));
            }
            if (user.PhoneNumber != phoneNumber)
            {
                user.PhoneNumber = phoneNumber;
                MongoRepository.UpdateOne<TUser, TKey, string>(user, e => e.PhoneNumber, user.PhoneNumber);
            }
            return Task.CompletedTask;
        }

        /// <summary>
        /// Sets a flag indicating if the specified <paramref name="user"/>'s phone number has been confirmed..
        /// </summary>
        /// <param name="user">The user whose telephone number confirmation status should be set.</param>
        /// <param name="confirmed">A flag indicating whether the user's telephone number has been confirmed.</param>
        /// <param name="cancellationToken">The <see cref="CancellationToken"/> used to propagate notifications that the operation should be canceled.</param>
        /// <returns>The <see cref="Task"/> that represents the asynchronous operation.</returns>
        public override Task SetPhoneNumberConfirmedAsync(TUser user, bool confirmed, CancellationToken cancellationToken = default(CancellationToken))
        {
            cancellationToken.ThrowIfCancellationRequested();
            ThrowIfDisposed();
            if (user == null)
            {
                throw new ArgumentNullException(nameof(user));
            }

            if (user.PhoneNumberConfirmed != confirmed)
            {
                user.PhoneNumberConfirmed = confirmed;
                MongoRepository.UpdateOne<TUser, TKey, bool>(user, e => e.PhoneNumberConfirmed, user.PhoneNumberConfirmed);
            }
            return Task.CompletedTask;
        }


        /// <summary>
        /// Sets the provided security <paramref name="stamp"/> for the specified <paramref name="user"/>.
        /// </summary>
        /// <param name="user">The user whose security stamp should be set.</param>
        /// <param name="stamp">The security stamp to set.</param>
        /// <param name="cancellationToken">The <see cref="CancellationToken"/> used to propagate notifications that the operation should be canceled.</param>
        /// <returns>The <see cref="Task"/> that represents the asynchronous operation.</returns>
        public override Task SetSecurityStampAsync(TUser user, string stamp, CancellationToken cancellationToken = default(CancellationToken))
        {
            cancellationToken.ThrowIfCancellationRequested();
            ThrowIfDisposed();
            if (user == null)
            {
                throw new ArgumentNullException(nameof(user));
            }
            if (stamp == null)
            {
                throw new ArgumentNullException(nameof(stamp));
            }

            if (user.SecurityStamp != stamp)
            {
                user.SecurityStamp = stamp;
                MongoRepository.UpdateOne<TUser, TKey, string>(user, e => e.SecurityStamp, user.SecurityStamp);
            }
            return Task.CompletedTask;
        }

        /// <summary>
        /// Sets a flag indicating whether the specified <paramref name="user"/> has two factor authentication enabled or not,
        /// as an asynchronous operation.
        /// </summary>
        /// <param name="user">The user whose two factor authentication enabled status should be set.</param>
        /// <param name="enabled">A flag indicating whether the specified <paramref name="user"/> has two factor authentication enabled.</param>
        /// <param name="cancellationToken">The <see cref="CancellationToken"/> used to propagate notifications that the operation should be canceled.</param>
        /// <returns>The <see cref="Task"/> that represents the asynchronous operation.</returns>
        public override Task SetTwoFactorEnabledAsync(TUser user, bool enabled, CancellationToken cancellationToken = default(CancellationToken))
        {
            cancellationToken.ThrowIfCancellationRequested();
            ThrowIfDisposed();
            if (user == null)
            {
                throw new ArgumentNullException(nameof(user));
            }
            if (user.TwoFactorEnabled != enabled)
            {
                user.TwoFactorEnabled = enabled;
                MongoRepository.UpdateOne<TUser, TKey, bool>(user, e => e.TwoFactorEnabled, user.TwoFactorEnabled);
            }
            return Task.CompletedTask;
        }

        /// <summary>
        /// Sets the token value for a particular user.
        /// </summary>
        /// <param name="user">The user.</param>
        /// <param name="loginProvider">The authentication provider for the token.</param>
        /// <param name="name">The name of the token.</param>
        /// <param name="value">The value of the token.</param>
        /// <param name="cancellationToken">The <see cref="CancellationToken"/> used to propagate notifications that the operation should be canceled.</param>
        /// <returns>The <see cref="Task"/> that represents the asynchronous operation.</returns>
        public override async Task SetTokenAsync(TUser user, string loginProvider, string name, string value, CancellationToken cancellationToken)
        {
            cancellationToken.ThrowIfCancellationRequested();
            ThrowIfDisposed();

            if (user == null)
            {
                throw new ArgumentNullException(nameof(user));
            }

            var token = await FindTokenAsync(user, loginProvider, name, cancellationToken);
            if (token == null)
            {
                if (user.AddUserToken(CreateUserToken(user, loginProvider, name, value)))
                {
                    MongoRepository.UpdateOne<TUser, TKey, List<Token>>(user, e => e.Tokens, user.Tokens);
                }
                //await AddUserTokenAsync(CreateUserToken(user, loginProvider, name, value));
            }
            else
            {
                if (user.SetToken(token, value))
                {
                    MongoRepository.UpdateOne<TUser, TKey, List<Token>>(user, e => e.Tokens, user.Tokens);
                }
            }
        }

        /// <summary>
        /// Deletes a token for a user.
        /// </summary>
        /// <param name="user">The user.</param>
        /// <param name="loginProvider">The authentication provider for the token.</param>
        /// <param name="name">The name of the token.</param>
        /// <param name="cancellationToken">The <see cref="CancellationToken"/> used to propagate notifications that the operation should be canceled.</param>
        /// <returns>The <see cref="Task"/> that represents the asynchronous operation.</returns>
        public override async Task RemoveTokenAsync(TUser user, string loginProvider, string name, CancellationToken cancellationToken)
        {
            cancellationToken.ThrowIfCancellationRequested();
            ThrowIfDisposed();

            if (user == null)
            {
                throw new ArgumentNullException(nameof(user));
            }
            var entry = await FindTokenAsync(user, loginProvider, name, cancellationToken);
            if (entry != null)
            {
                if (user.RemoveUserToken(entry))
                {
                    MongoRepository.UpdateOne<TUser, TKey, List<Token>>(user, e => e.Tokens, user.Tokens);
                }
            }
        }

        /// <summary>
        /// Returns the token value.
        /// </summary>
        /// <param name="user">The user.</param>
        /// <param name="loginProvider">The authentication provider for the token.</param>
        /// <param name="name">The name of the token.</param>
        /// <param name="cancellationToken">The <see cref="CancellationToken"/> used to propagate notifications that the operation should be canceled.</param>
        /// <returns>The <see cref="Task"/> that represents the asynchronous operation.</returns>
        public override async Task<string> GetTokenAsync(TUser user, string loginProvider, string name, CancellationToken cancellationToken)
        {
            cancellationToken.ThrowIfCancellationRequested();
            ThrowIfDisposed();

            if (user == null)
            {
                throw new ArgumentNullException(nameof(user));
            }
            var entry = await FindTokenAsync(user, loginProvider, name, cancellationToken);
            return entry?.Value;
        }

        private const string InternalLoginProvider = "[AspNetUserStore]";
        private const string AuthenticatorKeyTokenName = "AuthenticatorKey";
        private const string RecoveryCodeTokenName = "RecoveryCodes";

        /// <summary>
        /// Sets the authenticator key for the specified <paramref name="user"/>.
        /// </summary>
        /// <param name="user">The user whose authenticator key should be set.</param>
        /// <param name="key">The authenticator key to set.</param>
        /// <param name="cancellationToken">The <see cref="CancellationToken"/> used to propagate notifications that the operation should be canceled.</param>
        /// <returns>The <see cref="Task"/> that represents the asynchronous operation.</returns>
        public override Task SetAuthenticatorKeyAsync(TUser user, string key, CancellationToken cancellationToken)
            => SetTokenAsync(user, InternalLoginProvider, AuthenticatorKeyTokenName, key, cancellationToken);

        /// <summary>
        /// Get the authenticator key for the specified <paramref name="user" />.
        /// </summary>
        /// <param name="user">The user whose security stamp should be set.</param>
        /// <param name="cancellationToken">The <see cref="CancellationToken"/> used to propagate notifications that the operation should be canceled.</param>
        /// <returns>The <see cref="Task"/> that represents the asynchronous operation, containing the security stamp for the specified <paramref name="user"/>.</returns>
        public override Task<string> GetAuthenticatorKeyAsync(TUser user, CancellationToken cancellationToken)
            => GetTokenAsync(user, InternalLoginProvider, AuthenticatorKeyTokenName, cancellationToken);

        /// <summary>
        /// Returns how many recovery code are still valid for a user.
        /// </summary>
        /// <param name="user">The user who owns the recovery code.</param>
        /// <param name="cancellationToken">The <see cref="CancellationToken"/> used to propagate notifications that the operation should be canceled.</param>
        /// <returns>The number of valid recovery codes for the user..</returns>
        public override async Task<int> CountCodesAsync(TUser user, CancellationToken cancellationToken)
        {
            cancellationToken.ThrowIfCancellationRequested();
            ThrowIfDisposed();

            if (user == null)
            {
                throw new ArgumentNullException(nameof(user));
            }
            var mergedCodes = await GetTokenAsync(user, InternalLoginProvider, RecoveryCodeTokenName, cancellationToken) ?? "";
            if (mergedCodes.Length > 0)
            {
                return mergedCodes.Split(';').Length;
            }
            return 0;
        }

        /// <summary>
        /// Updates the recovery codes for the user while invalidating any previous recovery codes.
        /// </summary>
        /// <param name="user">The user to store new recovery codes for.</param>
        /// <param name="recoveryCodes">The new recovery codes for the user.</param>
        /// <param name="cancellationToken">The <see cref="CancellationToken"/> used to propagate notifications that the operation should be canceled.</param>
        /// <returns>The new recovery codes for the user.</returns>
        public override Task ReplaceCodesAsync(TUser user, IEnumerable<string> recoveryCodes, CancellationToken cancellationToken)
        {
            var mergedCodes = string.Join(";", recoveryCodes);
            return SetTokenAsync(user, InternalLoginProvider, RecoveryCodeTokenName, mergedCodes, cancellationToken);
        }

        /// <summary>
        /// Returns whether a recovery code is valid for a user. Note: recovery codes are only valid
        /// once, and will be invalid after use.
        /// </summary>
        /// <param name="user">The user who owns the recovery code.</param>
        /// <param name="code">The recovery code to use.</param>
        /// <param name="cancellationToken">The <see cref="CancellationToken"/> used to propagate notifications that the operation should be canceled.</param>
        /// <returns>True if the recovery code was found for the user.</returns>
        public override async Task<bool> RedeemCodeAsync(TUser user, string code, CancellationToken cancellationToken)
        {
            cancellationToken.ThrowIfCancellationRequested();
            ThrowIfDisposed();

            if (user == null)
            {
                throw new ArgumentNullException(nameof(user));
            }
            if (code == null)
            {
                throw new ArgumentNullException(nameof(code));
            }

            var mergedCodes = await GetTokenAsync(user, InternalLoginProvider, RecoveryCodeTokenName, cancellationToken) ?? "";
            var splitCodes = mergedCodes.Split(';');
            if (splitCodes.Contains(code))
            {
                var updatedCodes = new List<string>(splitCodes.Where(s => s != code));
                await ReplaceCodesAsync(user, updatedCodes, cancellationToken);
                return true;
            }
            return false;
        }

        #endregion
    }
}