Use m.direct for direct message names.

src/Scylla/Model.elm

@@ -1,6 +1,6 @@
 module Scylla.Model exposing (..)
 import Scylla.Api exposing (..)
-import Scylla.Sync exposing (SyncResponse, HistoryResponse, JoinedRoom, senderName, roomName, roomJoinedUsers)
+import Scylla.Sync exposing (SyncResponse, HistoryResponse, JoinedRoom, senderName, roomName, roomJoinedUsers, findFirst, directMessagesDecoder)
 import Scylla.Login exposing (LoginResponse, Username, Password)
 import Scylla.UserData exposing (UserData)
 import Scylla.Route exposing (Route(..), RoomId)
@@ -13,7 +13,7 @@ import Url.Builder
 import Dict exposing (Dict)
 import Time exposing (Posix)
 import File exposing (File)
-import Json.Decode
+import Json.Decode as Decode
 import Browser
 import Http
 import Url exposing (Url)
@@ -54,7 +54,7 @@ type Msg =
     | ReceiveUserData Username (Result Http.Error UserData) -- HTTP, receive user data
     | ReceiveCompletedReadMarker (Result Http.Error ()) -- HTTP, read marker request completed
     | ReceiveCompletedTypingIndicator (Result Http.Error ()) -- HTTP, typing indicator request completed
-    | ReceiveStoreData Json.Decode.Value -- We are send back a value on request from localStorage.
+    | ReceiveStoreData Decode.Value -- We are send back a value on request from localStorage.
     | TypingTick Posix -- Tick for updating the typing status
     | History RoomId -- Load history for a room
     | ReceiveHistoryResponse RoomId (Result Http.Error HistoryResponse) -- HTTP, receive history
@@ -74,24 +74,21 @@ type Msg =
 displayName : Model -> Username -> String
 displayName m s = Maybe.withDefault (senderName s) <| Maybe.andThen .displayName <| Dict.get s m.userData
 
-roomDisplayName : Model -> JoinedRoom -> String
-roomDisplayName m jr =
+roomDisplayName : Model -> RoomId -> JoinedRoom -> String
+roomDisplayName m rid jr =
     let
         customName = roomName jr
-        roomUsers = List.filter ((/=) m.loginUsername) <| roomJoinedUsers jr
-        singleUserName = if List.length roomUsers == 1 then List.head roomUsers else Nothing
-        singleUserDisplayName = Maybe.andThen
-            (\u -> Maybe.andThen .displayName <| Dict.get u m.userData) singleUserName
-        firstOption d os = case os of
-            [] -> d
-            ((Just v)::_) -> v
-            (Nothing::xs) -> firstOption d xs
+        direct = m.sync.accountData
+            |> Maybe.andThen .events
+            |> Maybe.andThen (findFirst ((==) "m.direct" << .type_))
+            |> Maybe.map (Decode.decodeValue directMessagesDecoder << .content)
+            |> Maybe.andThen Result.toMaybe
+            |> Maybe.andThen (Dict.get rid)
     in
-        firstOption "<No Name>"
-            [ customName
-            , singleUserDisplayName
-            , singleUserName
-            ]
+        case (customName, direct) of
+            (Just s, _) -> s
+            (_, Just u) -> displayName m u
+            _ -> "<No Name>"
 
 roomUrl : String -> String
 roomUrl s = Url.Builder.absolute [ "room", s ] []

src/Scylla/Sync.elm

@@ -258,6 +258,22 @@ historyResponseDecoder =
         |> required "end" string
         |> required "chunk" (list roomEventDecoder)
 
+-- Direct Messages
+type alias DirectMessages = Dict String String
+type alias DirectMessagesRaw = Dict String (List String)
+
+directMessagesDecoder : Decoder DirectMessages
+directMessagesDecoder =
+    Decode.dict (Decode.list Decode.string)
+        |> Decode.map (invertDirectMessages)
+
+invertDirectMessages : DirectMessagesRaw -> DirectMessages
+invertDirectMessages dmr =
+    Dict.foldl
+        (\k lv acc -> List.foldl (\v -> Dict.insert v k) acc lv)
+        Dict.empty
+        dmr
+
 -- Business Logic: Helper Functions
 groupBy : (a -> comparable) -> List a -> Dict comparable (List a)
 groupBy f xs =
@@ -275,7 +291,7 @@ uniqueByTailRecursive f l s acc =
             if Set.member (f x) s
             then uniqueByTailRecursive f tail s acc
             else uniqueByTailRecursive f tail s (x::acc)
-        [] -> acc
+        [] -> List.reverse acc
 
 uniqueBy : (a -> comparable) -> List a -> List a
 uniqueBy f l = uniqueByTailRecursive f l Set.empty []
@@ -304,18 +320,18 @@ findLastEvent = findLastBy .originServerTs
 mergeMaybe : (a -> a -> a) -> Maybe a -> Maybe a -> Maybe a
 mergeMaybe f l r = case (l, r) of
     (Just v1, Just v2) -> Just <| f v1 v2
-    (Just v, Nothing) -> Just v
-    (Nothing, Just v) -> Just v
+    (Just v, Nothing) -> l
+    (Nothing, Just v) -> r
     _ -> Nothing
 
 mergeEvents : List Event -> List Event -> List Event
 mergeEvents l1 l2 = l1 ++ l2
 
 mergeStateEvents : List StateEvent -> List StateEvent -> List StateEvent
-mergeStateEvents l1 l2 = uniqueBy .eventId <| l1 ++ l2
+mergeStateEvents l1 l2 = l1 ++ l2
 
 mergeRoomEvents : List RoomEvent -> List RoomEvent -> List RoomEvent
-mergeRoomEvents l1 l2 = uniqueBy .eventId <| l1 ++ l2
+mergeRoomEvents l1 l2 = l1 ++ l2
 
 mergeStrippedStates : List StrippedState -> List StrippedState -> List StrippedState
 mergeStrippedStates l1 l2 = l1 ++ l2

src/Scylla/Views.elm

@@ -109,18 +109,18 @@ homeserverView m hs rs =
     let
         roomList = div [ class "rooms-list" ]
             <| List.map (\(rid, r) -> roomListElementView m rid r)
-            <| List.sortBy (\(rid, r) -> roomDisplayName m r) rs
+            <| List.sortBy (\(rid, r) -> roomDisplayName m rid r) rs
     in
         div [ class "homeserver-wrapper" ] [ h3 [] [ text hs ], roomList ]
 
-roomListElementView : Model -> String -> JoinedRoom -> Html Msg
-roomListElementView m s jr =
+roomListElementView : Model -> RoomId -> JoinedRoom -> Html Msg
+roomListElementView m rid jr =
     let
-        name = roomDisplayName m jr
+        name = roomDisplayName m rid jr
         isVisible = m.searchText == "" || (String.contains (String.toLower m.searchText) <| String.toLower name)
         isCurrentRoom = case currentRoomId m of
             Nothing -> False
-            Just cr -> cr == s
+            Just cr -> cr == rid
     in
         div [ classList
                 [ ("room-link-wrapper", True)
@@ -129,7 +129,7 @@ roomListElementView m s jr =
                 ]
             ]
             <| roomNotificationCountView jr.unreadNotifications ++
-                [ a [ href <| roomUrl s ] [ text name ] ]
+                [ a [ href <| roomUrl rid ] [ text name ] ]
 
 roomNotificationCountView : Maybe UnreadNotificationCounts -> List (Html Msg)
 roomNotificationCountView ns =
@@ -182,7 +182,7 @@ joinedRoomView m roomId rd =
             ]
     in
         div [ class "room-wrapper" ]
-            [ h2 [] [ text <| roomDisplayName m rd.joinedRoom ]
+            [ h2 [] [ text <| roomDisplayName m roomId rd.joinedRoom ]
             , messagesWrapper
             , messageInput
             , typingWrapper