"""Support for deCONZ sensors."""
from pydeconz.sensor import (
    AirQuality,
    Battery,
    Consumption,
    Daylight,
    GenericStatus,
    Humidity,
    LightLevel,
    Power,
    Pressure,
    Switch,
    Temperature,
    Thermostat,
    Time,
)

from homeassistant.components.sensor import (
    DOMAIN,
    STATE_CLASS_MEASUREMENT,
    STATE_CLASS_TOTAL_INCREASING,
    SensorEntity,
    SensorEntityDescription,
)
from homeassistant.const import (
    ATTR_TEMPERATURE,
    ATTR_VOLTAGE,
    DEVICE_CLASS_BATTERY,
    DEVICE_CLASS_ENERGY,
    DEVICE_CLASS_HUMIDITY,
    DEVICE_CLASS_ILLUMINANCE,
    DEVICE_CLASS_POWER,
    DEVICE_CLASS_PRESSURE,
    DEVICE_CLASS_TEMPERATURE,
    ENERGY_KILO_WATT_HOUR,
    ENTITY_CATEGORY_DIAGNOSTIC,
    LIGHT_LUX,
    PERCENTAGE,
    POWER_WATT,
    PRESSURE_HPA,
    TEMP_CELSIUS,
)
from homeassistant.core import callback
from homeassistant.helpers.dispatcher import (
    async_dispatcher_connect,
    async_dispatcher_send,
)

from .const import ATTR_DARK, ATTR_ON
from .deconz_device import DeconzDevice
from .gateway import get_gateway_from_config_entry

DECONZ_SENSORS = (
    AirQuality,
    Consumption,
    Daylight,
    GenericStatus,
    Humidity,
    LightLevel,
    Power,
    Pressure,
    Temperature,
    Time,
)

ATTR_CURRENT = "current"
ATTR_POWER = "power"
ATTR_DAYLIGHT = "daylight"
ATTR_EVENT_ID = "event_id"

ENTITY_DESCRIPTIONS = {
    Battery: SensorEntityDescription(
        key="battery",
        device_class=DEVICE_CLASS_BATTERY,
        state_class=STATE_CLASS_MEASUREMENT,
        native_unit_of_measurement=PERCENTAGE,
        entity_category=ENTITY_CATEGORY_DIAGNOSTIC,
    ),
    Consumption: SensorEntityDescription(
        key="consumption",
        device_class=DEVICE_CLASS_ENERGY,
        state_class=STATE_CLASS_TOTAL_INCREASING,
        native_unit_of_measurement=ENERGY_KILO_WATT_HOUR,
    ),
    Daylight: SensorEntityDescription(
        key="daylight",
        icon="mdi:white-balance-sunny",
        entity_registry_enabled_default=False,
    ),
    Humidity: SensorEntityDescription(
        key="humidity",
        device_class=DEVICE_CLASS_HUMIDITY,
        state_class=STATE_CLASS_MEASUREMENT,
        native_unit_of_measurement=PERCENTAGE,
    ),
    LightLevel: SensorEntityDescription(
        key="lightlevel",
        device_class=DEVICE_CLASS_ILLUMINANCE,
        native_unit_of_measurement=LIGHT_LUX,
    ),
    Power: SensorEntityDescription(
        key="power",
        device_class=DEVICE_CLASS_POWER,
        state_class=STATE_CLASS_MEASUREMENT,
        native_unit_of_measurement=POWER_WATT,
    ),
    Pressure: SensorEntityDescription(
        key="pressure",
        device_class=DEVICE_CLASS_PRESSURE,
        state_class=STATE_CLASS_MEASUREMENT,
        native_unit_of_measurement=PRESSURE_HPA,
    ),
    Temperature: SensorEntityDescription(
        key="temperature",
        device_class=DEVICE_CLASS_TEMPERATURE,
        state_class=STATE_CLASS_MEASUREMENT,
        native_unit_of_measurement=TEMP_CELSIUS,
    ),
}


async def async_setup_entry(hass, config_entry, async_add_entities):
    """Set up the deCONZ sensors."""
    gateway = get_gateway_from_config_entry(hass, config_entry)
    gateway.entities[DOMAIN] = set()

    battery_handler = DeconzBatteryHandler(gateway)

    @callback
    def async_add_sensor(sensors=gateway.api.sensors.values()):
        """Add sensors from deCONZ.

        Create DeconzBattery if sensor has a battery attribute.
        Create DeconzSensor if not a battery, switch or thermostat and not a binary sensor.
        """
        entities = []

        for sensor in sensors:

            if not gateway.option_allow_clip_sensor and sensor.type.startswith("CLIP"):
                continue

            if sensor.battery is not None:
                battery_handler.remove_tracker(sensor)

                known_batteries = set(gateway.entities[DOMAIN])
                new_battery = DeconzBattery(sensor, gateway)
                if new_battery.unique_id not in known_batteries:
                    entities.append(new_battery)

            else:
                battery_handler.create_tracker(sensor)

            if (
                isinstance(sensor, DECONZ_SENSORS)
                and not isinstance(sensor, Thermostat)
                and sensor.unique_id not in gateway.entities[DOMAIN]
            ):
                entities.append(DeconzSensor(sensor, gateway))

            if sensor.secondary_temperature:
                known_temperature_sensors = set(gateway.entities[DOMAIN])
                new_temperature_sensor = DeconzTemperature(sensor, gateway)
                if new_temperature_sensor.unique_id not in known_temperature_sensors:
                    entities.append(new_temperature_sensor)

        if entities:
            async_add_entities(entities)

    config_entry.async_on_unload(
        async_dispatcher_connect(
            hass,
            gateway.signal_new_sensor,
            async_add_sensor,
        )
    )

    async_add_sensor(
        [gateway.api.sensors[key] for key in sorted(gateway.api.sensors, key=int)]
    )


class DeconzSensor(DeconzDevice, SensorEntity):
    """Representation of a deCONZ sensor."""

    TYPE = DOMAIN

    def __init__(self, device, gateway):
        """Initialize deCONZ binary sensor."""
        super().__init__(device, gateway)

        if entity_description := ENTITY_DESCRIPTIONS.get(type(device)):
            self.entity_description = entity_description

    @callback
    def async_update_callback(self):
        """Update the sensor's state."""
        keys = {"on", "reachable", "state"}
        if self._device.changed_keys.intersection(keys):
            super().async_update_callback()

    @property
    def native_value(self):
        """Return the state of the sensor."""
        return self._device.state

    @property
    def extra_state_attributes(self):
        """Return the state attributes of the sensor."""
        attr = {}

        if self._device.on is not None:
            attr[ATTR_ON] = self._device.on

        if self._device.secondary_temperature is not None:
            attr[ATTR_TEMPERATURE] = self._device.secondary_temperature

        if isinstance(self._device, Consumption):
            attr[ATTR_POWER] = self._device.power

        elif isinstance(self._device, Daylight):
            attr[ATTR_DAYLIGHT] = self._device.daylight

        elif isinstance(self._device, LightLevel):

            if self._device.dark is not None:
                attr[ATTR_DARK] = self._device.dark

            if self._device.daylight is not None:
                attr[ATTR_DAYLIGHT] = self._device.daylight

        elif isinstance(self._device, Power):
            attr[ATTR_CURRENT] = self._device.current
            attr[ATTR_VOLTAGE] = self._device.voltage

        return attr


class DeconzTemperature(DeconzDevice, SensorEntity):
    """Representation of a deCONZ temperature sensor.

    Extra temperature sensor on certain Xiaomi devices.
    """

    TYPE = DOMAIN

    def __init__(self, device, gateway):
        """Initialize deCONZ temperature sensor."""
        super().__init__(device, gateway)

        self.entity_description = ENTITY_DESCRIPTIONS[Temperature]
        self._attr_name = f"{self._device.name} Temperature"

    @property
    def unique_id(self):
        """Return a unique identifier for this device."""
        return f"{self.serial}-temperature"

    @callback
    def async_update_callback(self):
        """Update the sensor's state."""
        keys = {"temperature", "reachable"}
        if self._device.changed_keys.intersection(keys):
            super().async_update_callback()

    @property
    def native_value(self):
        """Return the state of the sensor."""
        return self._device.secondary_temperature


class DeconzBattery(DeconzDevice, SensorEntity):
    """Battery class for when a device is only represented as an event."""

    TYPE = DOMAIN

    def __init__(self, device, gateway):
        """Initialize deCONZ battery level sensor."""
        super().__init__(device, gateway)

        self.entity_description = ENTITY_DESCRIPTIONS[Battery]
        self._attr_name = f"{self._device.name} Battery Level"

    @callback
    def async_update_callback(self):
        """Update the battery's state, if needed."""
        keys = {"battery", "reachable"}
        if self._device.changed_keys.intersection(keys):
            super().async_update_callback()

    @property
    def unique_id(self):
        """Return a unique identifier for this device.

        Normally there should only be one battery sensor per device from deCONZ.
        With specific Danfoss devices each endpoint can report its own battery state.
        """
        if self._device.manufacturer == "Danfoss" and self._device.model_id in [
            "0x8030",
            "0x8031",
            "0x8034",
            "0x8035",
        ]:
            return f"{super().unique_id}-battery"
        return f"{self.serial}-battery"

    @property
    def native_value(self):
        """Return the state of the battery."""
        return self._device.battery

    @property
    def extra_state_attributes(self):
        """Return the state attributes of the battery."""
        attr = {}

        if isinstance(self._device, Switch):
            for event in self.gateway.events:
                if self._device == event.device:
                    attr[ATTR_EVENT_ID] = event.event_id

        return attr


class DeconzSensorStateTracker:
    """Track sensors without a battery state and signal when battery state exist."""

    def __init__(self, sensor, gateway):
        """Set up tracker."""
        self.sensor = sensor
        self.gateway = gateway
        sensor.register_callback(self.async_update_callback)

    @callback
    def close(self):
        """Clean up tracker."""
        self.sensor.remove_callback(self.async_update_callback)
        self.gateway = None
        self.sensor = None

    @callback
    def async_update_callback(self):
        """Sensor state updated."""
        if "battery" in self.sensor.changed_keys:
            async_dispatcher_send(
                self.gateway.hass,
                self.gateway.signal_new_sensor,
                [self.sensor],
            )


class DeconzBatteryHandler:
    """Creates and stores trackers for sensors without a battery state."""

    def __init__(self, gateway):
        """Set up battery handler."""
        self.gateway = gateway
        self._trackers = set()

    @callback
    def create_tracker(self, sensor):
        """Create new tracker for battery state."""
        for tracker in self._trackers:
            if sensor == tracker.sensor:
                return
        self._trackers.add(DeconzSensorStateTracker(sensor, self.gateway))

    @callback
    def remove_tracker(self, sensor):
        """Remove tracker of battery state."""
        for tracker in self._trackers:
            if sensor == tracker.sensor:
                tracker.close()
                self._trackers.remove(tracker)
                break