"""Support for Lutron lights."""

from __future__ import annotations

from collections.abc import Mapping
from typing import Any

from pylutron import Lutron, LutronEntity, Output

from homeassistant.components.light import (
    ATTR_BRIGHTNESS,
    ATTR_FLASH,
    ATTR_TRANSITION,
    ColorMode,
    LightEntity,
    LightEntityFeature,
)
from homeassistant.config_entries import ConfigEntry
from homeassistant.core import HomeAssistant
from homeassistant.helpers.entity_platform import AddConfigEntryEntitiesCallback

from . import LutronConfigEntry
from .const import CONF_DEFAULT_DIMMER_LEVEL, DEFAULT_DIMMER_LEVEL
from .entity import LutronDevice


async def async_setup_entry(
    hass: HomeAssistant,
    config_entry: LutronConfigEntry,
    async_add_entities: AddConfigEntryEntitiesCallback,
) -> None:
    """Set up the Lutron light platform.

    Adds dimmers from the Main Repeater associated with the config_entry as
    light entities.
    """
    entry_data = config_entry.runtime_data

    async_add_entities(
        (
            LutronLight(area_name, device, entry_data.client, config_entry)
            for area_name, device in entry_data.lights
        ),
        True,
    )


def to_lutron_level(level):
    """Convert the given Home Assistant light level (0-255) to Lutron (0.0-100.0)."""
    return float((level * 100) / 255)


def to_hass_level(level):
    """Convert the given Lutron (0.0-100.0) light level to Home Assistant (0-255)."""
    return int((level * 255) / 100)


class LutronLight(LutronDevice, LightEntity):
    """Representation of a Lutron Light, including dimmable."""

    _attr_color_mode = ColorMode.BRIGHTNESS
    _attr_supported_color_modes = {ColorMode.BRIGHTNESS}
    _attr_supported_features = LightEntityFeature.TRANSITION | LightEntityFeature.FLASH
    _lutron_device: Output
    _prev_brightness: int | None = None
    _attr_name = None

    def __init__(
        self,
        area_name: str,
        lutron_device: LutronEntity,
        controller: Lutron,
        config_entry: ConfigEntry,
    ) -> None:
        """Initialize the device."""
        super().__init__(area_name, lutron_device, controller)
        self._config_entry = config_entry

    def turn_on(self, **kwargs: Any) -> None:
        """Turn the light on."""
        if flash := kwargs.get(ATTR_FLASH):
            self._lutron_device.flash(0.5 if flash == "short" else 1.5)
        else:
            if ATTR_BRIGHTNESS in kwargs and self._lutron_device.is_dimmable:
                brightness = kwargs[ATTR_BRIGHTNESS]
            elif self._prev_brightness == 0:
                brightness = self._config_entry.options.get(
                    CONF_DEFAULT_DIMMER_LEVEL, DEFAULT_DIMMER_LEVEL
                )
            else:
                brightness = self._prev_brightness
            self._prev_brightness = brightness
            args = {"new_level": to_lutron_level(brightness)}
            if ATTR_TRANSITION in kwargs:
                args["fade_time_seconds"] = kwargs[ATTR_TRANSITION]
            self._lutron_device.set_level(**args)

    def turn_off(self, **kwargs: Any) -> None:
        """Turn the light off."""
        args = {"new_level": 0}
        if ATTR_TRANSITION in kwargs:
            args["fade_time_seconds"] = kwargs[ATTR_TRANSITION]
        self._lutron_device.set_level(**args)

    @property
    def extra_state_attributes(self) -> Mapping[str, Any] | None:
        """Return the state attributes."""
        return {"lutron_integration_id": self._lutron_device.id}

    def _request_state(self) -> None:
        """Request the state from the device."""
        _ = self._lutron_device.level

    def _update_attrs(self) -> None:
        """Update the state attributes."""
        level = self._lutron_device.last_level()
        self._attr_is_on = level > 0
        hass_level = to_hass_level(level)
        self._attr_brightness = hass_level
        if self._prev_brightness is None or hass_level != 0:
            self._prev_brightness = hass_level
