"""
Outlet/Relay Accessory Implementation for HomeKit

Implements simple relay/outlet (on/off switch):
- On (read/write)
- OutletInUse (always true)
"""

from pyhap.accessory import Accessory
from pyhap.const import CATEGORY_OUTLET


class OutletAccessory(Accessory):
    """Relay/Outlet for simple on/off control."""
    
    category = CATEGORY_OUTLET
    
    def __init__(self, driver, device, api_client, display_name=None, *args, **kwargs):
        """
        Initialize the outlet accessory.
        
        Args:
            driver: HAP driver instance
            device: Device object from DeviceRegistry
            api_client: ApiClient for sending commands
            display_name: Optional display name (defaults to device.friendly_name)
        """
        name = display_name or device.friendly_name or device.name
        super().__init__(driver, name, *args, **kwargs)
        self.device = device
        self.api_client = api_client
        
        # Add Outlet service
        self.outlet_service = self.add_preload_service('Outlet')
        
        # Get On characteristic and set callback
        self.on_char = self.outlet_service.get_characteristic('On')
        self.on_char.setter_callback = self.set_on
        
        # OutletInUse is always true (relay is always functional)
        self.in_use_char = self.outlet_service.get_characteristic('OutletInUse')
        self.in_use_char.set_value(True)
    
    def set_on(self, value):
        """Called when HomeKit wants to turn outlet on/off."""
        power_state = "on" if value else "off"
        payload = {
            "type": "relay",
            "payload": {"power": power_state}
        }
        self.api_client.post_device_set(self.device.device_id, payload["type"], payload["payload"])
    
    def update_state(self, state_payload):
        """Update state from API event."""
        if "power" in state_payload:
            is_on = state_payload["power"] == "on"
            self.on_char.set_value(is_on)