"""Diagnostics and predicted temperatures exposed as HA sensors."""
from __future__ import annotations

from homeassistant.components.sensor import SensorDeviceClass, SensorEntity, SensorStateClass
from homeassistant.const import UnitOfTemperature
from homeassistant.helpers.update_coordinator import CoordinatorEntity

from .const import DOMAIN
from .evaluation import HORIZONS, WINDOW_DAYS


async def async_setup_entry(hass, entry, async_add_entities) -> None:
    coordinator = hass.data[DOMAIN][entry.entry_id]
    entities = [MPCStatus(coordinator, entry.entry_id), MPCWeightedTemp(coordinator, entry.entry_id), MPCOutdoorTemperature(coordinator, entry.entry_id)]
    entities += [MPCRoomPrediction(coordinator, entry.entry_id, room) for room in coordinator.rooms]
    entities += [MPCForecastError(coordinator, entry.entry_id, horizon) for horizon in HORIZONS]
    async_add_entities(entities)


class MPCStatus(CoordinatorEntity, SensorEntity):
    _attr_has_entity_name = True
    _attr_name = "Heating MPC Status"
    _attr_icon = "mdi:brain"
    # Per-source report ages change every poll; recording them adds a new
    # attribute row to the database every five minutes. Current values stay visible.
    _unrecorded_attributes = frozenset({"input_quality", "weather_comparison"})

    def __init__(self, coordinator, entry_id):
        super().__init__(coordinator)
        self._attr_unique_id = f"{entry_id}_status"

    @property
    def native_value(self):
        return self.coordinator.data.get("status")

    @property
    def extra_state_attributes(self):
        data = self.coordinator.data
        # Forecast details live on their own entities.
        return {key: value for key, value in data.items() if key not in (
            "status", "prediction_60m", "prediction_end", "prediction_trajectory", "forecast_accuracy")}


class MPCWeightedTemp(CoordinatorEntity, SensorEntity):
    _attr_has_entity_name = True
    _attr_name = "Heating MPC Weighted Temperature"
    _attr_device_class = SensorDeviceClass.TEMPERATURE
    _attr_native_unit_of_measurement = UnitOfTemperature.CELSIUS

    def __init__(self, coordinator, entry_id):
        super().__init__(coordinator)
        self._attr_unique_id = f"{entry_id}_weighted_temp"

    @property
    def native_value(self):
        return self.coordinator.data.get("weighted_temperature")


class MPCRoomPrediction(CoordinatorEntity, SensorEntity):
    _attr_has_entity_name = True
    _attr_device_class = SensorDeviceClass.TEMPERATURE
    _attr_native_unit_of_measurement = UnitOfTemperature.CELSIUS
    _attr_icon = "mdi:chart-line"

    def __init__(self, coordinator, entry_id, room):
        super().__init__(coordinator)
        self.room = room
        self._attr_unique_id = f"{entry_id}_{room}_predicted_60min"
        self._attr_name = f"MPC {room} 60min Prediction"

    # Change every poll; the 60-minute value itself is recorded.
    _unrecorded_attributes = frozenset({"forecast_15min", "plan_15min"})

    @property
    def native_value(self):
        return self.coordinator.data.get("prediction_60m", {}).get(self.room)

    @property
    def extra_state_attributes(self):
        data = self.coordinator.data
        return {
            "forecast_15min": data.get("prediction_trajectory", {}).get(self.room),
            "plan_15min": data.get("plan_15min"),
            "basis": "proposed MPC plan; counterfactual while Generic Thermostat controls the relay",
        }

class MPCOutdoorTemperature(CoordinatorEntity, SensorEntity):
    """Display chosen outdoor temperature and all currently valid alternatives."""
    _attr_has_entity_name = True
    _attr_name = "MPC Outdoor Temperature"
    _attr_device_class = SensorDeviceClass.TEMPERATURE
    _attr_native_unit_of_measurement = UnitOfTemperature.CELSIUS
    _attr_icon = "mdi:thermometer"

    def __init__(self, coordinator, entry_id):
        super().__init__(coordinator)
        self._attr_unique_id = f"{entry_id}_outside_temperature"

    @property
    def native_value(self):
        return self.coordinator.data.get("weather", {}).get("temperature")

    @property
    def extra_state_attributes(self):
        data = self.coordinator.data
        return {
            "active_source": data.get("weather_active_sources", {}).get("temperature"),
            "alternatives": data.get("weather_comparison", {}).get("temperature", {}),
        }


class MPCForecastError(CoordinatorEntity, SensorEntity):
    """Mean absolute error of the thermal model at one horizon, replayed against reality."""
    _attr_has_entity_name = True
    _attr_device_class = SensorDeviceClass.TEMPERATURE_DELTA
    _attr_native_unit_of_measurement = UnitOfTemperature.CELSIUS
    _attr_state_class = SensorStateClass.MEASUREMENT
    _attr_suggested_display_precision = 2
    _attr_icon = "mdi:target"
    _unrecorded_attributes = frozenset({"rooms"})

    def __init__(self, coordinator, entry_id, horizon):
        super().__init__(coordinator)
        self.horizon = horizon
        self._attr_unique_id = f"{entry_id}_forecast_error_{horizon}min"
        self._attr_name = f"Heating MPC Forecast Error {horizon} min"

    @property
    def _accuracy(self):
        return self.coordinator.data.get("forecast_accuracy", {}).get(self.horizon, {})

    @property
    def native_value(self):
        return self._accuracy.get("mae")

    @property
    def extra_state_attributes(self):
        accuracy = self._accuracy
        return {
            "samples": accuracy.get("samples", 0),
            "bias": accuracy.get("bias"),
            "persistence_mae": accuracy.get("persistence_mae"),
            "skill": accuracy.get("skill"),
            "rooms": accuracy.get("rooms", {}),
            "window_days": WINDOW_DAYS,
            "unit_of_attributes": "°C",
            "basis": ("thermal model replayed with the actual relay history; outdoor "
                      "temperature held at the start value"),
        }