Split front and back end.

1 files changed, 97 insertions, 0 deletions

diff --git a/BackEnd/Timeline/Services/UserTokenManager.cs b/BackEnd/Timeline/Services/UserTokenManager.cs
new file mode 100644
index 00000000..813dae67
--- /dev/null
+++ b/BackEnd/Timeline/Services/UserTokenManager.cs
@@ -0,0 +1,97 @@
+using Microsoft.Extensions.Logging;

+using System;

+using System.Threading.Tasks;

+using Timeline.Helpers;

+using Timeline.Models;

+using Timeline.Services.Exceptions;

+

+namespace Timeline.Services

+{

+    public class UserTokenCreateResult

+    {

+        public string Token { get; set; } = default!;

+        public User User { get; set; } = default!;

+    }

+

+    public interface IUserTokenManager

+    {

+        /// <summary>

+        /// Try to create a token for given username and password.

+        /// </summary>

+        /// <param name="username">The username.</param>

+        /// <param name="password">The password.</param>

+        /// <param name="expireAt">The expire time of the token.</param>

+        /// <returns>The created token and the user info.</returns>

+        /// <exception cref="ArgumentNullException">Thrown when <paramref name="username"/> or <paramref name="password"/> is null.</exception>

+        /// <exception cref="ArgumentException">Thrown when <paramref name="username"/> is of bad format.</exception>

+        /// <exception cref="UserNotExistException">Thrown when the user with <paramref name="username"/> does not exist.</exception>

+        /// <exception cref="BadPasswordException">Thrown when <paramref name="password"/> is wrong.</exception>

+        public Task<UserTokenCreateResult> CreateToken(string username, string password, DateTime? expireAt = null);

+

+        /// <summary>

+        /// Verify a token and get the saved user info. This also check the database for existence of the user.

+        /// </summary>

+        /// <param name="token">The token.</param>

+        /// <returns>The user stored in token.</returns>

+        /// <exception cref="ArgumentNullException">Thrown when <paramref name="token"/> is null.</exception>

+        /// <exception cref="UserTokenTimeExpireException">Thrown when the token is expired.</exception>

+        /// <exception cref="UserTokenBadVersionException">Thrown when the token is of bad version.</exception>

+        /// <exception cref="UserTokenBadFormatException">Thrown when the token is of bad format.</exception>

+        /// <exception cref="UserNotExistException">Thrown when the user specified by the token does not exist. Usually the user had been deleted after the token was issued.</exception>

+        public Task<User> VerifyToken(string token);

+    }

+

+    public class UserTokenManager : IUserTokenManager

+    {

+        private readonly ILogger<UserTokenManager> _logger;

+        private readonly IUserService _userService;

+        private readonly IUserTokenService _userTokenService;

+        private readonly IClock _clock;

+

+        public UserTokenManager(ILogger<UserTokenManager> logger, IUserService userService, IUserTokenService userTokenService, IClock clock)

+        {

+            _logger = logger;

+            _userService = userService;

+            _userTokenService = userTokenService;

+            _clock = clock;

+        }

+

+        public async Task<UserTokenCreateResult> CreateToken(string username, string password, DateTime? expireAt = null)

+        {

+            expireAt = expireAt?.MyToUtc();

+

+            if (username == null)

+                throw new ArgumentNullException(nameof(username));

+            if (password == null)

+                throw new ArgumentNullException(nameof(password));

+

+            var user = await _userService.VerifyCredential(username, password);

+            var token = _userTokenService.GenerateToken(new UserTokenInfo { Id = user.Id!.Value, Version = user.Version!.Value, ExpireAt = expireAt });

+

+            return new UserTokenCreateResult { Token = token, User = user };

+        }

+

+

+        public async Task<User> VerifyToken(string token)

+        {

+            if (token == null)

+                throw new ArgumentNullException(nameof(token));

+

+            var tokenInfo = _userTokenService.VerifyToken(token);

+

+            if (tokenInfo.ExpireAt.HasValue)

+            {

+                var currentTime = _clock.GetCurrentTime();

+                if (tokenInfo.ExpireAt < currentTime)

+                    throw new UserTokenTimeExpireException(token, tokenInfo.ExpireAt.Value, currentTime);

+            }

+

+            var user = await _userService.GetUserById(tokenInfo.Id);

+

+            if (tokenInfo.Version < user.Version)

+                throw new UserTokenBadVersionException(token, tokenInfo.Version, user.Version.Value);

+

+            return user;

+        }

+    }

+}