3 things.

1. Exchange Models and Entities namespace.
2. Fix the bug that input with missing field leads to 500.
3. Write unit tests.

7 files changed, 209 insertions, 42 deletions

diff --git a/Timeline/Models/DatabaseContext.cs b/Timeline/Models/DatabaseContext.cs
deleted file mode 100644
index afd5a333..00000000
--- a/Timeline/Models/DatabaseContext.cs
+++ /dev/null
@@ -1,42 +0,0 @@
-using Microsoft.EntityFrameworkCore;
-using System.ComponentModel.DataAnnotations;
-using System.ComponentModel.DataAnnotations.Schema;
-
-namespace Timeline.Models
-{
-    public static class UserRoles
-    {
-        public const string Admin = "admin";
-        public const string User = "user";
-    }
-
-    [Table("user")]
-    public class User
-    {
-        [Column("id"), Key, DatabaseGenerated(DatabaseGeneratedOption.Identity)]
-        public long Id { get; set; }
-
-        [Column("name"), Required]
-        public string Name { get; set; }
-
-        [Column("password"), Required]
-        public string EncryptedPassword { get; set; }
-
-        [Column("roles"), Required]
-        public string RoleString { get; set; }
-
-        [Column("version"), Required]
-        public long Version { get; set; }
-    }
-
-    public class DatabaseContext : DbContext
-    {
-        public DatabaseContext(DbContextOptions<DatabaseContext> options)
-            : base(options)
-        {
-
-        }
-
-        public DbSet<User> Users { get; set; }
-    }
-}
diff --git a/Timeline/Models/Http/Common.cs b/Timeline/Models/Http/Common.cs
new file mode 100644
index 00000000..74959088
--- /dev/null
+++ b/Timeline/Models/Http/Common.cs
@@ -0,0 +1,51 @@
+namespace Timeline.Models.Http
+{
+    public class CommonResponse
+    {

+        public static class ErrorCodes

+        {

+            /// <summary>

+            /// Used when the model is invaid.

+            /// For example a required field is null.

+            /// </summary>

+            public const int InvalidModel = -100;

+        }
+

+        public static CommonResponse InvalidModel(string message)

+        {

+            return new CommonResponse(ErrorCodes.InvalidModel, message);

+        }
+
+        public CommonResponse()
+        {
+
+        }
+
+        public CommonResponse(int code, string message)
+        {
+            Code = code;
+            Message = message;
+        }
+
+        public int Code { get; set; }
+        public string Message { get; set; }
+    }
+
+    public static class CommonPutResponse
+    {
+        public const int CreatedCode = 0;
+        public const int ModifiedCode = 1;
+
+        public static CommonResponse Created { get; } = new CommonResponse(CreatedCode, "A new item is created.");
+        public static CommonResponse Modified { get; } = new CommonResponse(ModifiedCode, "An existent item is modified.");
+    }
+
+    public static class CommonDeleteResponse
+    {
+        public const int DeletedCode = 0;
+        public const int NotExistsCode = 1;
+
+        public static CommonResponse Deleted { get; } = new CommonResponse(DeletedCode, "An existent item is deleted.");
+        public static CommonResponse NotExists { get; } = new CommonResponse(NotExistsCode, "The item does not exist.");
+    }
+}
diff --git a/Timeline/Models/Http/Token.cs b/Timeline/Models/Http/Token.cs
new file mode 100644
index 00000000..cef679ef
--- /dev/null
+++ b/Timeline/Models/Http/Token.cs
@@ -0,0 +1,32 @@
+using System.ComponentModel.DataAnnotations;

+

+namespace Timeline.Models.Http
+{
+    public class CreateTokenRequest
+    {
+        [Required]
+        public string Username { get; set; }
+        [Required]
+        public string Password { get; set; }
+        // in days, optional
+        [Range(1, 365)]
+        public int? ExpireOffset { get; set; }
+    }
+
+    public class CreateTokenResponse
+    {
+        public string Token { get; set; }
+        public UserInfo User { get; set; }
+    }
+
+    public class VerifyTokenRequest
+    {
+        [Required]
+        public string Token { get; set; }
+    }
+
+    public class VerifyTokenResponse
+    {
+        public UserInfo User { get; set; }
+    }
+}
diff --git a/Timeline/Models/Http/User.cs b/Timeline/Models/Http/User.cs
new file mode 100644
index 00000000..1de7fae2
--- /dev/null
+++ b/Timeline/Models/Http/User.cs
@@ -0,0 +1,26 @@
+using System.ComponentModel.DataAnnotations;

+

+namespace Timeline.Models.Http
+{
+    public class UserPutRequest
+    {
+        [Required]
+        public string Password { get; set; }
+        [Required]
+        public bool Administrator { get; set; }
+    }
+
+    public class UserPatchRequest
+    {
+        public string Password { get; set; }
+        public bool? Administrator { get; set; }
+    }
+
+    public class ChangePasswordRequest
+    {
+        [Required]
+        public string OldPassword { get; set; }
+        [Required]
+        public string NewPassword { get; set; }
+    }
+}
diff --git a/Timeline/Models/PutResult.cs b/Timeline/Models/PutResult.cs
new file mode 100644
index 00000000..f11ac138
--- /dev/null
+++ b/Timeline/Models/PutResult.cs
@@ -0,0 +1,17 @@
+namespace Timeline.Models
+{
+    /// <summary>
+    /// Represents the result of a "put" operation.
+    /// </summary>
+    public enum PutResult
+    {
+        /// <summary>
+        /// Indicates the item did not exist and now is created.
+        /// </summary>
+        Created,
+        /// <summary>
+        /// Indicates the item exists already and is modified.
+        /// </summary>
+        Modified
+    }
+}
diff --git a/Timeline/Models/UserInfo.cs b/Timeline/Models/UserInfo.cs
new file mode 100644
index 00000000..b5cb1e7f
--- /dev/null
+++ b/Timeline/Models/UserInfo.cs
@@ -0,0 +1,23 @@
+namespace Timeline.Models
+{
+    public sealed class UserInfo
+    {
+        public UserInfo()
+        {
+        }
+
+        public UserInfo(string username, bool administrator)
+        {
+            Username = username;
+            Administrator = administrator;
+        }
+
+        public string Username { get; set; }
+        public bool Administrator { get; set; }
+
+        public override string ToString()
+        {
+            return $"Username: {Username} ; Administrator: {Administrator}";
+        }
+    }
+}
diff --git a/Timeline/Models/UserUtility.cs b/Timeline/Models/UserUtility.cs
new file mode 100644
index 00000000..711e321a
--- /dev/null
+++ b/Timeline/Models/UserUtility.cs
@@ -0,0 +1,60 @@
+using System;
+using System.Linq;
+using Timeline.Entities;
+using Timeline.Services;
+
+namespace Timeline.Models
+{
+    public static class UserUtility
+    {
+        public const string UserRole = UserRoles.User;
+        public const string AdminRole = UserRoles.Admin;
+
+        public static string[] UserRoleArray { get; } = new string[] { UserRole };
+        public static string[] AdminRoleArray { get; } = new string[] { UserRole, AdminRole };
+
+        public static string[] IsAdminToRoleArray(bool isAdmin)
+        {
+            return isAdmin ? AdminRoleArray : UserRoleArray;
+        }
+
+        public static bool RoleArrayToIsAdmin(string[] roles)
+        {
+            return roles.Contains(AdminRole);
+        }
+
+        public static string[] RoleStringToRoleArray(string roleString)
+        {
+            return roleString.Split(',').ToArray();
+        }
+
+        public static string RoleArrayToRoleString(string[] roles)
+        {
+            return string.Join(',', roles);
+        }
+
+        public static string IsAdminToRoleString(bool isAdmin)
+        {
+            return RoleArrayToRoleString(IsAdminToRoleArray(isAdmin));
+        }
+
+        public static bool RoleStringToIsAdmin(string roleString)
+        {
+            return RoleArrayToIsAdmin(RoleStringToRoleArray(roleString));
+        }
+
+        public static UserInfo CreateUserInfo(User user)
+        {
+            if (user == null)
+                throw new ArgumentNullException(nameof(user));
+            return new UserInfo(user.Name, RoleStringToIsAdmin(user.RoleString));
+        }
+
+        internal static UserCache CreateUserCache(User user)
+        {
+            if (user == null)
+                throw new ArgumentNullException(nameof(user));
+            return new UserCache { Username = user.Name, Administrator = RoleStringToIsAdmin(user.RoleString), Version = user.Version };
+        }
+    }
+}