1 files changed, 62 insertions, 2 deletions
diff --git a/Timeline/Entities/UserInfo.cs b/Timeline/Entities/UserInfo.cs
index d9c5acad..a1860552 100644
--- a/Timeline/Entities/UserInfo.cs
+++ b/Timeline/Entities/UserInfo.cs
@@ -1,14 +1,20 @@
 using System;
+using System.Collections.Generic;
 using System.Linq;
 using Timeline.Models;
 
 namespace Timeline.Entities
 {
-    public class UserInfo
+    public sealed class UserInfo
     {
         public UserInfo()
         {
+        }
 
+        public UserInfo(string username, params string[] roles)
+        {
+            Username = username;
+            Roles = roles;
         }
 
         public UserInfo(User user)
@@ -17,10 +23,64 @@ namespace Timeline.Entities
                 throw new ArgumentNullException(nameof(user));
 
             Username = user.Name;
-            Roles = user.RoleString.Split(',').Select(s => s.Trim()).ToArray();
+
+            if (user.RoleString == null)
+                Roles = null;
+            else
+                Roles = user.RoleString.Split(',').Select(r => r.Trim()).ToArray();
         }
 
         public string Username { get; set; }
         public string[] Roles { get; set; }
+
+        public static IEqualityComparer<UserInfo> EqualityComparer { get; } = new EqualityComparerImpl();
+        public static IComparer<UserInfo> Comparer { get; } = Comparer<UserInfo>.Create(Compare);
+
+        private class EqualityComparerImpl : IEqualityComparer<UserInfo>
+        {
+            bool IEqualityComparer<UserInfo>.Equals(UserInfo x, UserInfo y)
+            {
+                return Compare(x, y) == 0;
+            }
+
+            int IEqualityComparer<UserInfo>.GetHashCode(UserInfo obj)
+            {
+                return obj.Username.GetHashCode() ^ NormalizeRoles(obj.Roles).GetHashCode();
+            }
+        }
+
+        private static string NormalizeRoles(string[] rawRoles)
+        {
+            var roles = rawRoles.Where(r => !string.IsNullOrWhiteSpace(r)).Select(r => r.Trim()).ToList();
+            roles.Sort();
+            return string.Join(',', roles);
+        }
+
+        public static int Compare(UserInfo left, UserInfo right)
+        {
+            if (left == null)
+            {
+                if (right == null)
+                    return 0;
+                return -1;
+            }
+
+            if (right == null)
+                return 1;
+
+            var uc = string.Compare(left.Username, right.Username);
+            if (uc != 0)
+                return uc;
+
+            var leftRoles = NormalizeRoles(left.Roles);
+            var rightRoles = NormalizeRoles(right.Roles);
+
+            return string.Compare(leftRoles, rightRoles);
+        }
+
+        public override string ToString()
+        {
+            return $"Username: {Username} ; Roles: {Roles}";
+        }
     }
 }