1 files changed, 58 insertions, 8 deletions
diff --git a/Software/Visual_Studio/Tango.Web/Authentication/TokensManager.cs b/Software/Visual_Studio/Tango.Web/Authentication/TokensManager.cs
index 701a87a3c..8e0eb4288 100644
--- a/Software/Visual_Studio/Tango.Web/Authentication/TokensManager.cs
+++ b/Software/Visual_Studio/Tango.Web/Authentication/TokensManager.cs
@@ -7,35 +7,85 @@ using System.Threading.Tasks;
 
 namespace Tango.Web.Authentication
 {
-    public class TokensManager<T>
+    public class TokensManager<T> where T : IEquatable<T>
     {
-        private Dictionary<String, T> _tokens;
+        private Dictionary<String, TokenWrapper> _tokens;
+
+        private class TokenWrapper : IEquatable<TokenWrapper>
+        {
+            public DateTime Date { get; set; }
+
+            public T Value { get; set; }
+
+            public bool Equals(TokenWrapper other)
+            {
+                return Value.Equals(other.Value);
+            }
+        }
 
         public TokensManager()
         {
-            _tokens = new Dictionary<String, T>();
+            _tokens = new Dictionary<string, TokenWrapper>();
+            ExpirationTime = TimeSpan.FromHours(1);
         }
 
-        public String CreateNew(T userID)
+        public TimeSpan ExpirationTime { get; set; }
+
+        public String GetOrCreate(T tokenObject)
         {
-            String token = Guid.NewGuid().ToString();
-            _tokens.Add(token, userID);
-            return token;
+            var existing_token = _tokens.FirstOrDefault(x => x.Value.Value.Equals(tokenObject));
+
+            if (existing_token.Key != null)
+            {
+                return existing_token.Key;
+            }
+            else
+            {
+                String token = Guid.NewGuid().ToString();
+                _tokens.Add(token, new TokenWrapper()
+                {
+                    Value = tokenObject,
+                    Date = DateTime.Now,
+                });
+                return token;
+            }
         }
 
         public bool Exists(String token)
         {
+            RemoveOrRenewExpired(token);
+
             return _tokens.ContainsKey(token);
         }
 
         public T GetTokenObject(String token)
         {
+            RemoveOrRenewExpired(token);
+
             if (!_tokens.ContainsKey(token))
             {
                 throw new AuthenticationException("Invalid token.");
             }
 
-            return _tokens[token];
+            return _tokens[token].Value;
+        }
+
+        private void RemoveOrRenewExpired(String token)
+        {
+            DateTime now = DateTime.Now;
+
+            if (_tokens.ContainsKey(token))
+            {
+                _tokens[token].Date = now;
+            }
+
+            foreach (var t in _tokens.ToList())
+            {
+                if (now > t.Value.Date.Add(ExpirationTime))
+                {
+                    _tokens.Remove(t.Key);
+                }
+            }
         }
     }
 }