Use correct fetch for plugs

frontend/lib/devices.dart

@@ -13,22 +13,39 @@ class Category {
   static Future<List<Category>> fetch(String base_url) async {
     final response = await http.get(Uri.parse("$base_url/devices"));
 
-    if (response.statusCode == 200) {
+    if (response.statusCode != 200) {
+      throw Exception("Failed to fetch devices");
+    }
+
     List<Category> categories = [];
 
-      Map<String, List<Map<String, dynamic>>> json = jsonDecode(response.body);
+    Map<String, List<List<dynamic>>> json = jsonDecode(response.body);
 
-      for (MapEntry<String, List<Map<String, dynamic>>> category_entry
-          in json.entries) {
+    for (MapEntry<String, List<List<dynamic>>> category_entry in json.entries) {
       Category category = Category(category_entry.key);
 
-        for (Map<String, dynamic> device_map in category_entry.value) {
+      for (List<dynamic> device_info in category_entry.value) {
+        String device_id = device_info[0];
+        String? device_descriptor = device_info[1];
+        bool power_control = device_info[2];
+
+        final response =
+            await http.get(Uri.parse("$base_url/plug_state/$device_id"));
+
+        if (response.statusCode != 200) {
+          throw Exception("Failed to fetch plug_state for $device_id");
+        }
+
+        Map<String, dynamic> device_state = jsonDecode(response.body);
+
         Device device = Device(
-              device_map["device_id"],
-              device_map["device_descriptor"],
-              device_map["led"],
-              device_map["power"],
-              device_map["power_draw"]);
+          device_id,
+          device_descriptor,
+          device_state["led"],
+          device_state["power"],
+          device_state["power_draw"],
+          power_control && device_state["power_draw"] < 15,
+        );
 
         category.devices.add(device);
       }
@@ -37,9 +54,6 @@ class Category {
     }
 
     return categories;
-    } else {
-      throw Exception("Failed to fetch devices");
-    }
   }
 }
 
@@ -79,7 +93,8 @@ class Device {
   bool led_state;
   bool power_state;
   double power_draw;
+  bool power_control;
 
   Device(this.device_id, this.device_descriptor, this.led_state,
-      this.power_state, this.power_draw);
+      this.power_state, this.power_draw, this.power_control);
 }

frontend/lib/main.dart

@@ -63,7 +63,7 @@ class _MyHomePageState extends State<MyHomePage> {
         future: Category.fetch("smart.gavania.de"),
         builder: (context, AsyncSnapshot<List<Category>> categories) {
           if (!categories.hasData) {
-            return const Scaffold();
+            throw Exception("categories not ready");
           }
 
           return Scaffold(