Commit from last night

dashboard/lib/dashboard/mqtt_subscriber.ex

@@ -1,13 +1,12 @@
 defmodule Dashboard.MqttSubscriber do
   @moduledoc """
-  MQTT subscriber that listens to systant host messages and broadcasts updates via Phoenix PubSub.
+  Simple MQTT subscriber for development dashboard.
   """
   use GenServer
   require Logger
 
   alias Phoenix.PubSub
 
-  @mqtt_topic "systant/+/stats"
   @pubsub_topic "systant:hosts"
 
   def start_link(opts) do
@@ -20,28 +19,17 @@ defmodule Dashboard.MqttSubscriber do
 
   @impl true
   def init(_opts) do
-    # Start MQTT connection
-    client_id = "systant_dashboard_#{System.unique_integer([:positive])}"
-    
-    connection_opts = [
-      client_id: client_id,
+    # Start MQTT connection in a supervised way
+    {:ok, _pid} = Tortoise.Supervisor.start_child(
+      :dashboard_mqtt,
+      client_id: :dashboard_mqtt,
       server: {Tortoise.Transport.Tcp, host: "mqtt.home", port: 1883},
-      handler: {__MODULE__, []}
-    ]
-
-    case Tortoise.Supervisor.start_child(client_id, connection_opts) do
-      {:ok, _pid} ->
-        Logger.info("MQTT subscriber connected as #{client_id}")
-        
-        # Subscribe to systant stats topic
-        Tortoise.Connection.subscribe(client_id, @mqtt_topic, qos: 0)
-        
-        {:ok, %{client_id: client_id, hosts: %{}}}
-      
-      {:error, reason} ->
-        Logger.error("Failed to start MQTT connection: #{inspect(reason)}")
-        {:stop, reason}
-    end
+      handler: {__MODULE__, []},
+      subscriptions: [{"systant/+/stats", 0}]
+    )
+    
+    Logger.info("Dashboard MQTT subscriber started")
+    {:ok, %{hosts: %{}}}
   end
 
   @impl true
@@ -50,73 +38,41 @@ defmodule Dashboard.MqttSubscriber do
   end
 
   @impl true
-  def handle_info({:tortoise, {:publish, @mqtt_topic, payload, _opts}}, state) do
-    case Jason.decode(payload) do
-      {:ok, data} ->
-        # Extract hostname from topic
-        hostname = extract_hostname_from_topic(@mqtt_topic)
-        
-        # Update host data with timestamp
-        host_data = Map.put(data, "last_seen", DateTime.utc_now())
-        updated_hosts = Map.put(state.hosts, hostname, host_data)
-        
-        # Broadcast update via PubSub
-        PubSub.broadcast(Dashboard.PubSub, @pubsub_topic, {:host_update, hostname, host_data})
-        
-        Logger.debug("Received update from #{hostname}: #{inspect(data)}")
-        
-        {:noreply, %{state | hosts: updated_hosts}}
-      
-      {:error, reason} ->
-        Logger.warning("Failed to decode JSON payload: #{inspect(reason)}")
-        {:noreply, state}
-    end
+  def handle_info(_msg, state) do
+    {:noreply, state}
   end
 
-  def handle_info({:tortoise, {:publish, topic, payload, _opts}}, state) do
-    # Extract hostname from the actual topic
+  # Tortoise handler callbacks
+  def connection(_status, _state), do: []
+  def subscription(_status, _topic, _state), do: []
+  
+  def handle_message(topic, payload, _state) do
     case String.split(topic, "/") do
       ["systant", hostname, "stats"] ->
         case Jason.decode(payload) do
           {:ok, data} ->
-            # Update host data with timestamp
             host_data = Map.put(data, "last_seen", DateTime.utc_now())
-            updated_hosts = Map.put(state.hosts, hostname, host_data)
             
-            # Broadcast update via PubSub
+            # Broadcast to LiveView
             PubSub.broadcast(Dashboard.PubSub, @pubsub_topic, {:host_update, hostname, host_data})
             
-            Logger.debug("Received update from #{hostname}: #{inspect(data)}")
+            # Update our state
+            GenServer.cast(__MODULE__, {:update_host, hostname, host_data})
             
-            {:noreply, %{state | hosts: updated_hosts}}
-          
-          {:error, reason} ->
-            Logger.warning("Failed to decode JSON payload: #{inspect(reason)}")
-            {:noreply, state}
+          {:error, _reason} ->
+            :ok
         end
-      
       _ ->
-        Logger.debug("Received message on unexpected topic: #{topic}")
-        {:noreply, state}
+        :ok
     end
+    []
   end
 
-  def handle_info({:tortoise, _msg}, state) do
-    # Handle other tortoise messages (connection status, etc.)
-    {:noreply, state}
+  @impl true
+  def handle_cast({:update_host, hostname, host_data}, state) do
+    updated_hosts = Map.put(state.hosts, hostname, host_data)
+    {:noreply, %{state | hosts: updated_hosts}}
   end
 
-  # Private functions
-
-  defp extract_hostname_from_topic(topic) do
-    case String.split(topic, "/") do
-      ["systant", hostname, "stats"] -> hostname
-      _ -> "unknown"
-    end
-  end
-
-  # Tortoise handler callbacks (required when using handler: {module, args})
-  def connection(_status, _state), do: []
-  def subscription(_status, _topic_filter, _state), do: []
   def terminate(_reason, _state), do: []
 end