feat: Add 'up X' and 'down X' commands to adjust media player volume

Co-authored-by: aider (gemini/gemini-2.5-pro) <aider@aider.chat>

main.py

@@ -234,6 +234,45 @@ async def send_media_command(command):
     logging.warning("No active media player found to send command to.")
 
 
+async def adjust_volume(direction, amount):
+    """Adjusts the volume of the media player."""
+    logging.info(f"Attempting to adjust volume {direction} by {amount}")
+    introspection = await bus.introspect(BLUEZ_SERVICE, '/')
+    manager_obj = bus.get_proxy_object(BLUEZ_SERVICE, '/', introspection)
+    manager_iface = manager_obj.get_interface('org.freedesktop.DBus.ObjectManager')
+    managed_objects = await manager_iface.call_get_managed_objects()
+
+    for path, ifaces in managed_objects.items():
+        if MEDIA_PLAYER_IFACE in ifaces:
+            logging.info(f"Found media player: {path}. Adjusting volume...")
+            try:
+                player_introspection = await bus.introspect(BLUEZ_SERVICE, path)
+                player_obj = bus.get_proxy_object(BLUEZ_SERVICE, path, player_introspection)
+                player_props = player_obj.get_interface('org.freedesktop.DBus.Properties')
+
+                current_volume_variant = await player_props.call_get(MEDIA_PLAYER_IFACE, 'Volume')
+                current_volume = current_volume_variant.value
+                logging.info(f"Current volume is {current_volume} (0-127)")
+
+                if direction == 'up':
+                    new_volume = current_volume + amount
+                else: # direction == 'down'
+                    new_volume = current_volume - amount
+
+                # Volume is a uint8, but AVRCP standard is 0-127.
+                new_volume = max(0, min(127, new_volume))
+
+                logging.info(f"Setting new volume to {new_volume}")
+                await player_props.call_set(MEDIA_PLAYER_IFACE, 'Volume', Variant('y', new_volume))
+
+                logging.info(f"Successfully adjusted volume on {path}")
+                return
+            except Exception as e:
+                logging.error(f"Failed to adjust volume on {path}: {e}")
+
+    logging.warning("No active media player found to adjust volume.")
+
+
 async def process_bluetooth_command(topic, text):
     global pairing_task
     logging.info('Bluetooth command: %s', text)
@@ -247,6 +286,14 @@ async def process_bluetooth_command(topic, text):
     elif text in ["play", "pause", "next", "prev"]:
         command = "previous" if text == "prev" else text
         await send_media_command(command)
+    elif text.startswith("up ") or text.startswith("down "):
+        parts = text.split()
+        if len(parts) == 2 and parts[1].isdigit():
+            direction = parts[0]
+            amount = int(parts[1])
+            await adjust_volume(direction, amount)
+        else:
+            logging.warning(f"Invalid volume command format: {text}")
 
 async def process_mqtt(message):
     text = message.payload.decode()