Send read receipts for messages received after opening room.

src/Main.elm

@@ -72,6 +72,7 @@ update msg model = case msg of
     ChangeRoomText r t -> ({ model | roomText = Dict.insert r t model.roomText}, Cmd.none)
     SendRoomText r -> updateSendRoomText model r
     SendRoomTextResponse r -> (model, Cmd.none)
+    ReceiveCompletedReadMarker r -> (model, Cmd.none)
 
 updateViewportAfterMessage : Model -> Result Browser.Dom.Error Viewport -> (Model, Cmd Msg)
 updateViewportAfterMessage m vr = 
@@ -135,7 +136,8 @@ updateSyncResponse model r notify =
                     , room = s
                     }) <| notification sr
             else Cmd.none
-        roomMessages sr = case currentRoomId model of
+        room = currentRoomId model
+        roomMessages sr = case room of
             Just rid -> List.filter (((==) "m.room.message") << .type_)
                 <| Maybe.withDefault []
                 <| Maybe.andThen .events
@@ -148,6 +150,9 @@ updateSyncResponse model r notify =
             <| roomMessages sr
                 then Cmd.none
                 else Task.attempt ViewportAfterMessage (Browser.Dom.getViewportOf "events-wrapper")
+        setReadReceiptCmd sr = case (room, List.head <| List.reverse <| roomMessages sr) of
+            (Just rid, Just re) -> setReadMarkers model.apiUrl token rid re.eventId <| Just re.eventId
+            _ -> Cmd.none
     in
         case r of
             Ok sr -> ({ model | sync = mergeSyncResponse model.sync sr }, Cmd.batch
@@ -155,6 +160,7 @@ updateSyncResponse model r notify =
                 , newUserCmd sr
                 , notificationCmd sr
                 , setScrollCmd sr
+                , setReadReceiptCmd sr
                 ])
             _ -> (model, syncCmd)
 

src/Scylla/Http.elm

@@ -1,6 +1,7 @@
 module Scylla.Http exposing (..)
 import Scylla.Model exposing (..)
 import Scylla.Api exposing (..)
+import Scylla.Route exposing (RoomId)
 import Scylla.Sync exposing (syncResponseDecoder)
 import Scylla.Login exposing (loginResponseDecoder, Username, Password)
 import Scylla.UserData exposing (userDataDecoder, UserData)
@@ -81,3 +82,20 @@ userData apiUrl token username = request
     , timeout = Nothing
     , tracker = Nothing
     }
+
+setReadMarkers : ApiUrl -> ApiToken -> String -> RoomId -> Maybe String -> Cmd Msg
+setReadMarkers apiUrl token roomId fullyRead readReceipt =
+    let
+        readReciptFields = case readReceipt of
+            Just s -> [ ("m.read", string s) ]
+            _ -> []
+    in
+        request
+            { method = "POST"
+            , headers = authenticatedHeaders token
+            , url = (fullClientUrl apiUrl) ++ "/rooms/" ++ roomId ++ "/read_markers"
+            , body = jsonBody <| object <| [ ("m.fully_read", string fullyRead) ] ++ readReciptFields
+            , expect = expectWhatever ReceiveCompletedReadMarker
+            , timeout = Nothing
+            , tracker = Nothing
+            }

src/Scylla/Model.elm

@@ -43,6 +43,7 @@ type Msg =
     | ReceiveSyncResponse (Result Http.Error SyncResponse) -- HTTP, Sync has finished
     | ReceiveLoginResponse (Result Http.Error LoginResponse) -- HTTP, Login has finished
     | ReceiveUserData Username (Result Http.Error UserData)
+    | ReceiveCompletedReadMarker (Result Http.Error ())
 
 displayName : Model -> Username -> String
 displayName m s = Maybe.withDefault (senderName s) <| Maybe.andThen .displayName <| Dict.get s m.userData