4 files changed, 38 insertions, 6 deletions
diff --git a/src/Erebos/Chatroom.hs b/src/Erebos/Chatroom.hs
index f9bf545..bdb101f 100644
--- a/src/Erebos/Chatroom.hs
+++ b/src/Erebos/Chatroom.hs
@@ -50,6 +50,7 @@ import Data.Set qualified as S
 import Data.Text (Text)
 import Data.Time
 
+import Erebos.Conversation.Class
 import Erebos.Identity
 import Erebos.PubKey
 import Erebos.Service
@@ -61,6 +62,12 @@ import Erebos.Storage.Merge
 import Erebos.Util
 
 
+instance ConversationType ChatroomState ChatMessage where
+    convMessageFrom = cmsgFrom
+    convMessageTime = cmsgTime
+    convMessageText = cmsgText
+
+
 data ChatroomData = ChatroomData
     { rdPrev :: [Stored (Signed ChatroomData)]
     , rdName :: Maybe Text
diff --git a/src/Erebos/Conversation.hs b/src/Erebos/Conversation.hs
index 2d007c9..ff8396c 100644
--- a/src/Erebos/Conversation.hs
+++ b/src/Erebos/Conversation.hs
@@ -33,6 +33,7 @@ import Data.Time.Format
 import Data.Time.LocalTime
 
 import Erebos.Chatroom
+import Erebos.Conversation.Class
 import Erebos.DirectMessage
 import Erebos.Identity
 import Erebos.State
@@ -42,17 +43,18 @@ import Erebos.Storable
 data Message = DirectMessageMessage DirectMessage Bool
              | ChatroomMessage ChatMessage Bool
 
+withMessage :: (forall conv msg. ConversationType conv msg => msg -> a) -> Message -> a
+withMessage f (DirectMessageMessage msg _) = f msg
+withMessage f (ChatroomMessage msg _) = f msg
+
 messageFrom :: Message -> ComposedIdentity
-messageFrom (DirectMessageMessage msg _) = msgFrom msg
-messageFrom (ChatroomMessage msg _) = cmsgFrom msg
+messageFrom = withMessage convMessageFrom
 
 messageTime :: Message -> ZonedTime
-messageTime (DirectMessageMessage msg _) = msgTime msg
-messageTime (ChatroomMessage msg _) = cmsgTime msg
+messageTime = withMessage convMessageTime
 
 messageText :: Message -> Maybe Text
-messageText (DirectMessageMessage msg _) = Just $ msgText msg
-messageText (ChatroomMessage msg _) = cmsgText msg
+messageText = withMessage convMessageText
 
 messageUnread :: Message -> Bool
 messageUnread (DirectMessageMessage _ unread) = unread
diff --git a/src/Erebos/Conversation/Class.hs b/src/Erebos/Conversation/Class.hs
new file mode 100644
index 0000000..909dac6
--- /dev/null
+++ b/src/Erebos/Conversation/Class.hs
@@ -0,0 +1,15 @@
+module Erebos.Conversation.Class (
+    ConversationType(..),
+) where
+
+import Data.Text (Text)
+import Data.Time.LocalTime
+import Data.Typeable
+
+import Erebos.Identity
+
+
+class (Typeable conv, Typeable msg) => ConversationType conv msg | conv -> msg, msg -> conv where
+    convMessageFrom :: msg -> ComposedIdentity
+    convMessageTime :: msg -> ZonedTime
+    convMessageText :: msg -> Maybe Text
diff --git a/src/Erebos/DirectMessage.hs b/src/Erebos/DirectMessage.hs
index f518b57..2558abb 100644
--- a/src/Erebos/DirectMessage.hs
+++ b/src/Erebos/DirectMessage.hs
@@ -32,6 +32,7 @@ import Data.Text qualified as T
 import Data.Time.Format
 import Data.Time.LocalTime
 
+import Erebos.Conversation.Class
 import Erebos.Discovery
 import Erebos.Identity
 import Erebos.Network
@@ -42,6 +43,13 @@ import Erebos.Storable
 import Erebos.Storage.Head
 import Erebos.Storage.Merge
 
+
+instance ConversationType DirectMessageThread DirectMessage where
+    convMessageFrom = msgFrom
+    convMessageTime = msgTime
+    convMessageText = Just . msgText
+
+
 data DirectMessage = DirectMessage
     { msgFrom :: ComposedIdentity
     , msgPrev :: [ Stored DirectMessage ]