Prepare to join servers

lib/birdy_chat_web/api/messages/controller.ex

@@ -4,11 +4,30 @@ defmodule BirdyChatWeb.Api.Messages.Controller do
   def create(conn, params) do
     case BirdyChat.Message.validate(params) do
       {:ok, changeset} ->
-        case BirdyChat.MessageWriter.write(changeset.changes) do
-          :ok ->
+        case BirdyChat.Message.find_peer(changeset.changes) do
+          {:ok, :local} ->
+            case BirdyChat.MessageWriter.write(changeset.changes) do
+              :ok ->
+                conn
+                |> put_status(:created)
+                |> render(:create, message: changeset.changes)
+            end
+
+          {:ok, peer_name} ->
+            BirdyChatWeb.ServerChannel.broadcast!(peer_name, changeset.changes)
+
             conn
             |> put_status(:created)
             |> render(:create, message: changeset.changes)
+
+          {:error, :not_found} ->
+            changeset =
+              changeset
+              |> Ecto.Changeset.add_error(:to, "Unknown 'to' server")
+
+            conn
+            |> put_status(:unprocessable_entity)
+            |> render(:error, changeset: changeset)
         end
 
       {:error, changeset} ->

lib/birdy_chat_web/channels/server_channel.ex

@@ -24,6 +24,13 @@ defmodule BirdyChatWeb.ServerChannel do
     end
   end
 
+  # This is how we send messages
+  def broadcast!(peer, message) do
+    channel = "server:#{peer}"
+    encoded_message = :erlang.term_to_binary(message)
+    BirdyChatWeb.Endpoint.broadcast!(channel, "new_message", {:binary, encoded_message})
+  end
+
   # Simple token-based authentication. Servers should use the same Phoenix secret key so they will
   # have the basis for generating tokens.
   defp authorised?(%{"token" => token}, server_id) do