fix: clean up SSE warnings

lib/wanderer_app_web/controllers/api/events_controller.ex

@@ -9,7 +9,6 @@ defmodule WandererAppWeb.Api.EventsController do
   
   alias WandererApp.ExternalEvents.{SseStreamManager, EventFilter, MapEventRelay}
   alias WandererApp.Api.Map, as: ApiMap
-  alias WandererAppWeb.SSE
   alias Plug.Crypto
   
   require Logger
@@ -54,13 +53,13 @@ defmodule WandererAppWeb.Api.EventsController do
       end
     
     # Send SSE headers
-    conn = SSE.send_headers(conn)
+    conn = send_headers(conn)
     
     # Track the connection
     case SseStreamManager.add_client(map_id, api_key, self(), event_filter) do
       {:ok, _} ->
         # Send initial connection event
-        conn = SSE.send_event(conn, %{
+        conn = send_event(conn, %{
           id: Ulid.generate(),
           event: "connected",
           data: %{
@@ -117,7 +116,7 @@ defmodule WandererAppWeb.Api.EventsController do
           case Jason.decode(event_json) do
             {:ok, event} ->
               if EventFilter.matches?(event["type"], event_filter) do
-                SSE.send_event(acc_conn, event)
+                send_event(acc_conn, event)
               else
                 acc_conn
               end
@@ -142,7 +141,7 @@ defmodule WandererAppWeb.Api.EventsController do
           case Jason.decode(event_json) do
             {:ok, event} ->
               if EventFilter.matches?(event["type"], event_filter) do
-                SSE.send_event(conn, event)
+                send_event(conn, event)
               else
                 conn
               end
@@ -157,7 +156,7 @@ defmodule WandererAppWeb.Api.EventsController do
         
       :keepalive ->
         # Send keepalive
-        conn = SSE.send_keepalive(conn)
+        conn = send_keepalive(conn)
         
         # Continue streaming
         stream_events(conn, map_id, api_key, event_filter)
@@ -169,7 +168,7 @@ defmodule WandererAppWeb.Api.EventsController do
     after
       30_000 ->
         # Send keepalive every 30 seconds
-        conn = SSE.send_keepalive(conn)
+        conn = send_keepalive(conn)
         stream_events(conn, map_id, api_key, event_filter)
     end
   rescue
@@ -227,4 +226,80 @@ defmodule WandererAppWeb.Api.EventsController do
         end
     end
   end
+  
+  # SSE helper functions
+  
+  defp send_headers(conn) do
+    conn
+    |> put_resp_content_type("text/event-stream")
+    |> put_resp_header("cache-control", "no-cache")
+    |> put_resp_header("connection", "keep-alive")
+    |> put_resp_header("access-control-allow-origin", "*")
+    |> put_resp_header("access-control-allow-headers", "Cache-Control")
+    |> send_chunked(200)
+  end
+  
+  defp send_event(conn, event) when is_map(event) do
+    sse_data = format_sse_event(event)
+    
+    case chunk(conn, sse_data) do
+      {:ok, conn} ->
+        conn
+        
+      {:error, reason} ->
+        Logger.error("Failed to send SSE event: #{inspect(reason)}")
+        # Return the connection as-is since we can't recover from chunk errors
+        # The error will be caught by the stream_events rescue clause
+        conn
+    end
+  end
+  
+  defp send_keepalive(conn) do
+    case chunk(conn, ": keepalive\n\n") do
+      {:ok, conn} ->
+        conn
+        
+      {:error, reason} ->
+        Logger.error("Failed to send SSE keepalive: #{inspect(reason)}")
+        # Return the connection as-is since we can't recover from chunk errors
+        # The error will be caught by the stream_events rescue clause
+        conn
+    end
+  end
+  
+  defp format_sse_event(event) do
+    data = []
+    
+    # Add event type if present
+    data = 
+      case Map.get(event, :event) do
+        nil -> data
+        event_type -> ["event: #{event_type}\n" | data]
+      end
+    
+    # Add ID if present
+    data = 
+      case Map.get(event, :id) do
+        nil -> data
+        id -> ["id: #{id}\n" | data]
+      end
+    
+    # Add data (required)
+    data = 
+      case Map.get(event, :data) do
+        nil -> 
+          ["data: \n" | data]
+        event_data when is_binary(event_data) -> 
+          ["data: #{event_data}\n" | data]
+        event_data -> 
+          json_data = Jason.encode!(event_data)
+          ["data: #{json_data}\n" | data]
+      end
+    
+    # Reverse to get correct order and add final newline
+    data
+    |> Enum.reverse()
+    |> Enum.join("")
+    |> Kernel.<>("\n")
+  end
 end