"""Provides functionality to interact with lights."""
import csv
import dataclasses
from datetime import timedelta
import logging
import os
from typing import Dict, List, Optional, Tuple, cast

import voluptuous as vol

from homeassistant.const import (
    SERVICE_TOGGLE,
    SERVICE_TURN_OFF,
    SERVICE_TURN_ON,
    STATE_ON,
)
from homeassistant.core import callback
import homeassistant.helpers.config_validation as cv
from homeassistant.helpers.config_validation import (  # noqa: F401
    PLATFORM_SCHEMA,
    PLATFORM_SCHEMA_BASE,
    make_entity_service_schema,
)
from homeassistant.helpers.entity import ToggleEntity
from homeassistant.helpers.entity_component import EntityComponent
from homeassistant.helpers.typing import HomeAssistantType
from homeassistant.loader import bind_hass
import homeassistant.util.color as color_util

# mypy: allow-untyped-defs, no-check-untyped-defs

DOMAIN = "light"
SCAN_INTERVAL = timedelta(seconds=30)
DATA_PROFILES = "light_profiles"

ENTITY_ID_FORMAT = DOMAIN + ".{}"

# Bitfield of features supported by the light entity
SUPPORT_BRIGHTNESS = 1
SUPPORT_COLOR_TEMP = 2
SUPPORT_EFFECT = 4
SUPPORT_FLASH = 8
SUPPORT_COLOR = 16
SUPPORT_TRANSITION = 32
SUPPORT_WHITE_VALUE = 128

# Float that represents transition time in seconds to make change.
ATTR_TRANSITION = "transition"

# Lists holding color values
ATTR_RGB_COLOR = "rgb_color"
ATTR_XY_COLOR = "xy_color"
ATTR_HS_COLOR = "hs_color"
ATTR_COLOR_TEMP = "color_temp"
ATTR_KELVIN = "kelvin"
ATTR_MIN_MIREDS = "min_mireds"
ATTR_MAX_MIREDS = "max_mireds"
ATTR_COLOR_NAME = "color_name"
ATTR_WHITE_VALUE = "white_value"

# Brightness of the light, 0..255 or percentage
ATTR_BRIGHTNESS = "brightness"
ATTR_BRIGHTNESS_PCT = "brightness_pct"
ATTR_BRIGHTNESS_STEP = "brightness_step"
ATTR_BRIGHTNESS_STEP_PCT = "brightness_step_pct"

# String representing a profile (built-in ones or external defined).
ATTR_PROFILE = "profile"

# If the light should flash, can be FLASH_SHORT or FLASH_LONG.
ATTR_FLASH = "flash"
FLASH_SHORT = "short"
FLASH_LONG = "long"

# List of possible effects
ATTR_EFFECT_LIST = "effect_list"

# Apply an effect to the light, can be EFFECT_COLORLOOP.
ATTR_EFFECT = "effect"
EFFECT_COLORLOOP = "colorloop"
EFFECT_RANDOM = "random"
EFFECT_WHITE = "white"

COLOR_GROUP = "Color descriptors"

LIGHT_PROFILES_FILE = "light_profiles.csv"

# Service call validation schemas
VALID_TRANSITION = vol.All(vol.Coerce(float), vol.Clamp(min=0, max=6553))
VALID_BRIGHTNESS = vol.All(vol.Coerce(int), vol.Clamp(min=0, max=255))
VALID_BRIGHTNESS_PCT = vol.All(vol.Coerce(float), vol.Range(min=0, max=100))
VALID_BRIGHTNESS_STEP = vol.All(vol.Coerce(int), vol.Clamp(min=-255, max=255))
VALID_BRIGHTNESS_STEP_PCT = vol.All(vol.Coerce(float), vol.Clamp(min=-100, max=100))
VALID_FLASH = vol.In([FLASH_SHORT, FLASH_LONG])

LIGHT_TURN_ON_SCHEMA = {
    vol.Exclusive(ATTR_PROFILE, COLOR_GROUP): cv.string,
    ATTR_TRANSITION: VALID_TRANSITION,
    vol.Exclusive(ATTR_BRIGHTNESS, ATTR_BRIGHTNESS): VALID_BRIGHTNESS,
    vol.Exclusive(ATTR_BRIGHTNESS_PCT, ATTR_BRIGHTNESS): VALID_BRIGHTNESS_PCT,
    vol.Exclusive(ATTR_BRIGHTNESS_STEP, ATTR_BRIGHTNESS): VALID_BRIGHTNESS_STEP,
    vol.Exclusive(ATTR_BRIGHTNESS_STEP_PCT, ATTR_BRIGHTNESS): VALID_BRIGHTNESS_STEP_PCT,
    vol.Exclusive(ATTR_COLOR_NAME, COLOR_GROUP): cv.string,
    vol.Exclusive(ATTR_RGB_COLOR, COLOR_GROUP): vol.All(
        vol.ExactSequence((cv.byte, cv.byte, cv.byte)), vol.Coerce(tuple)
    ),
    vol.Exclusive(ATTR_XY_COLOR, COLOR_GROUP): vol.All(
        vol.ExactSequence((cv.small_float, cv.small_float)), vol.Coerce(tuple)
    ),
    vol.Exclusive(ATTR_HS_COLOR, COLOR_GROUP): vol.All(
        vol.ExactSequence(
            (
                vol.All(vol.Coerce(float), vol.Range(min=0, max=360)),
                vol.All(vol.Coerce(float), vol.Range(min=0, max=100)),
            )
        ),
        vol.Coerce(tuple),
    ),
    vol.Exclusive(ATTR_COLOR_TEMP, COLOR_GROUP): vol.All(
        vol.Coerce(int), vol.Range(min=1)
    ),
    vol.Exclusive(ATTR_KELVIN, COLOR_GROUP): cv.positive_int,
    ATTR_WHITE_VALUE: vol.All(vol.Coerce(int), vol.Range(min=0, max=255)),
    ATTR_FLASH: VALID_FLASH,
    ATTR_EFFECT: cv.string,
}


_LOGGER = logging.getLogger(__name__)


@bind_hass
def is_on(hass, entity_id):
    """Return if the lights are on based on the statemachine."""
    return hass.states.is_state(entity_id, STATE_ON)


def preprocess_turn_on_alternatives(hass, params):
    """Process extra data for turn light on request.

    Async friendly.
    """
    # Bail out, we process this later.
    if ATTR_BRIGHTNESS_STEP in params or ATTR_BRIGHTNESS_STEP_PCT in params:
        return

    if ATTR_PROFILE in params:
        hass.data[DATA_PROFILES].apply_profile(params.pop(ATTR_PROFILE), params)

    color_name = params.pop(ATTR_COLOR_NAME, None)
    if color_name is not None:
        try:
            params[ATTR_RGB_COLOR] = color_util.color_name_to_rgb(color_name)
        except ValueError:
            _LOGGER.warning("Got unknown color %s, falling back to white", color_name)
            params[ATTR_RGB_COLOR] = (255, 255, 255)

    kelvin = params.pop(ATTR_KELVIN, None)
    if kelvin is not None:
        mired = color_util.color_temperature_kelvin_to_mired(kelvin)
        params[ATTR_COLOR_TEMP] = int(mired)

    brightness_pct = params.pop(ATTR_BRIGHTNESS_PCT, None)
    if brightness_pct is not None:
        params[ATTR_BRIGHTNESS] = round(255 * brightness_pct / 100)

    xy_color = params.pop(ATTR_XY_COLOR, None)
    if xy_color is not None:
        params[ATTR_HS_COLOR] = color_util.color_xy_to_hs(*xy_color)

    rgb_color = params.pop(ATTR_RGB_COLOR, None)
    if rgb_color is not None:
        params[ATTR_HS_COLOR] = color_util.color_RGB_to_hs(*rgb_color)


def filter_turn_off_params(params):
    """Filter out params not used in turn off."""
    return {k: v for k, v in params.items() if k in (ATTR_TRANSITION, ATTR_FLASH)}


async def async_setup(hass, config):
    """Expose light control via state machine and services."""
    component = hass.data[DOMAIN] = EntityComponent(
        _LOGGER, DOMAIN, hass, SCAN_INTERVAL
    )
    await component.async_setup(config)

    profiles = hass.data[DATA_PROFILES] = Profiles(hass)
    await profiles.async_initialize()

    def preprocess_data(data):
        """Preprocess the service data."""
        base = {
            entity_field: data.pop(entity_field)
            for entity_field in cv.ENTITY_SERVICE_FIELDS
            if entity_field in data
        }

        preprocess_turn_on_alternatives(hass, data)
        base["params"] = data
        return base

    async def async_handle_light_on_service(light, call):
        """Handle turning a light on.

        If brightness is set to 0, this service will turn the light off.
        """
        params = call.data["params"]

        if not params:
            profiles.apply_default(light.entity_id, params)

        # Only process params once we processed brightness step
        if params and (
            ATTR_BRIGHTNESS_STEP in params or ATTR_BRIGHTNESS_STEP_PCT in params
        ):
            brightness = light.brightness if light.is_on else 0

            if ATTR_BRIGHTNESS_STEP in params:
                brightness += params.pop(ATTR_BRIGHTNESS_STEP)

            else:
                brightness += round(params.pop(ATTR_BRIGHTNESS_STEP_PCT) / 100 * 255)

            params[ATTR_BRIGHTNESS] = max(0, min(255, brightness))

            preprocess_turn_on_alternatives(hass, params)

        # Zero brightness: Light will be turned off
        if params.get(ATTR_BRIGHTNESS) == 0:
            await light.async_turn_off(**filter_turn_off_params(params))
        else:
            await light.async_turn_on(**params)

    async def async_handle_toggle_service(light, call):
        """Handle toggling a light."""
        if light.is_on:
            off_params = filter_turn_off_params(call.data["params"])
            await light.async_turn_off(**off_params)
        else:
            await async_handle_light_on_service(light, call)

    # Listen for light on and light off service calls.

    component.async_register_entity_service(
        SERVICE_TURN_ON,
        vol.All(cv.make_entity_service_schema(LIGHT_TURN_ON_SCHEMA), preprocess_data),
        async_handle_light_on_service,
    )

    component.async_register_entity_service(
        SERVICE_TURN_OFF,
        {ATTR_TRANSITION: VALID_TRANSITION, ATTR_FLASH: VALID_FLASH},
        "async_turn_off",
    )

    component.async_register_entity_service(
        SERVICE_TOGGLE,
        vol.All(cv.make_entity_service_schema(LIGHT_TURN_ON_SCHEMA), preprocess_data),
        async_handle_toggle_service,
    )

    return True


async def async_setup_entry(hass, entry):
    """Set up a config entry."""
    return await hass.data[DOMAIN].async_setup_entry(entry)


async def async_unload_entry(hass, entry):
    """Unload a config entry."""
    return await hass.data[DOMAIN].async_unload_entry(entry)


def _coerce_none(value: str) -> None:
    """Coerce an empty string as None."""

    if not isinstance(value, str):
        raise vol.Invalid("Expected a string")

    if value:
        raise vol.Invalid("Not an empty string")


@dataclasses.dataclass
class Profile:
    """Representation of a profile."""

    name: str
    color_x: Optional[float] = dataclasses.field(repr=False)
    color_y: Optional[float] = dataclasses.field(repr=False)
    brightness: Optional[int]
    transition: Optional[int] = None
    hs_color: Optional[Tuple[float, float]] = dataclasses.field(init=False)

    SCHEMA = vol.Schema(  # pylint: disable=invalid-name
        vol.Any(
            vol.ExactSequence(
                (
                    str,
                    vol.Any(cv.small_float, _coerce_none),
                    vol.Any(cv.small_float, _coerce_none),
                    vol.Any(cv.byte, _coerce_none),
                )
            ),
            vol.ExactSequence(
                (
                    str,
                    vol.Any(cv.small_float, _coerce_none),
                    vol.Any(cv.small_float, _coerce_none),
                    vol.Any(cv.byte, _coerce_none),
                    vol.Any(VALID_TRANSITION, _coerce_none),
                )
            ),
        )
    )

    def __post_init__(self) -> None:
        """Convert xy to hs color."""
        if None in (self.color_x, self.color_y):
            self.hs_color = None
            return

        self.hs_color = color_util.color_xy_to_hs(
            cast(float, self.color_x), cast(float, self.color_y)
        )

    @classmethod
    def from_csv_row(cls, csv_row: List[str]) -> "Profile":
        """Create profile from a CSV row tuple."""
        return cls(*cls.SCHEMA(csv_row))


class Profiles:
    """Representation of available color profiles."""

    def __init__(self, hass: HomeAssistantType):
        """Initialize profiles."""
        self.hass = hass
        self.data: Dict[str, Profile] = {}

    def _load_profile_data(self) -> Dict[str, Profile]:
        """Load built-in profiles and custom profiles."""
        profile_paths = [
            os.path.join(os.path.dirname(__file__), LIGHT_PROFILES_FILE),
            self.hass.config.path(LIGHT_PROFILES_FILE),
        ]
        profiles = {}

        for profile_path in profile_paths:
            if not os.path.isfile(profile_path):
                continue
            with open(profile_path) as inp:
                reader = csv.reader(inp)

                # Skip the header
                next(reader, None)

                try:
                    for rec in reader:
                        profile = Profile.from_csv_row(rec)
                        profiles[profile.name] = profile

                except vol.MultipleInvalid as ex:
                    _LOGGER.error(
                        "Error parsing light profile row '%s' from %s: %s",
                        rec,
                        profile_path,
                        ex,
                    )
                    continue
        return profiles

    async def async_initialize(self) -> None:
        """Load and cache profiles."""
        self.data = await self.hass.async_add_executor_job(self._load_profile_data)

    @callback
    def apply_default(self, entity_id: str, params: Dict) -> None:
        """Return the default turn-on profile for the given light."""
        for _entity_id in (entity_id, "group.all_lights"):
            name = f"{_entity_id}.default"
            if name in self.data:
                self.apply_profile(name, params)
                return

    @callback
    def apply_profile(self, name: str, params: Dict) -> None:
        """Apply a profile."""
        profile = self.data.get(name)

        if profile is None:
            return

        if profile.hs_color is not None:
            params.setdefault(ATTR_HS_COLOR, profile.hs_color)
        if profile.brightness is not None:
            params.setdefault(ATTR_BRIGHTNESS, profile.brightness)
        if profile.transition is not None:
            params.setdefault(ATTR_TRANSITION, profile.transition)


class LightEntity(ToggleEntity):
    """Representation of a light."""

    @property
    def brightness(self):
        """Return the brightness of this light between 0..255."""
        return None

    @property
    def hs_color(self):
        """Return the hue and saturation color value [float, float]."""
        return None

    @property
    def color_temp(self):
        """Return the CT color value in mireds."""
        return None

    @property
    def min_mireds(self):
        """Return the coldest color_temp that this light supports."""
        # Default to the Philips Hue value that HA has always assumed
        # https://developers.meethue.com/documentation/core-concepts
        return 153

    @property
    def max_mireds(self):
        """Return the warmest color_temp that this light supports."""
        # Default to the Philips Hue value that HA has always assumed
        # https://developers.meethue.com/documentation/core-concepts
        return 500

    @property
    def white_value(self):
        """Return the white value of this light between 0..255."""
        return None

    @property
    def effect_list(self):
        """Return the list of supported effects."""
        return None

    @property
    def effect(self):
        """Return the current effect."""
        return None

    @property
    def capability_attributes(self):
        """Return capability attributes."""
        data = {}
        supported_features = self.supported_features

        if supported_features & SUPPORT_COLOR_TEMP:
            data[ATTR_MIN_MIREDS] = self.min_mireds
            data[ATTR_MAX_MIREDS] = self.max_mireds

        if supported_features & SUPPORT_EFFECT:
            data[ATTR_EFFECT_LIST] = self.effect_list

        return data

    @property
    def state_attributes(self):
        """Return state attributes."""
        if not self.is_on:
            return None

        data = {}
        supported_features = self.supported_features

        if supported_features & SUPPORT_BRIGHTNESS:
            data[ATTR_BRIGHTNESS] = self.brightness

        if supported_features & SUPPORT_COLOR_TEMP:
            data[ATTR_COLOR_TEMP] = self.color_temp

        if supported_features & SUPPORT_COLOR and self.hs_color:
            hs_color = self.hs_color
            data[ATTR_HS_COLOR] = (round(hs_color[0], 3), round(hs_color[1], 3))
            data[ATTR_RGB_COLOR] = color_util.color_hs_to_RGB(*hs_color)
            data[ATTR_XY_COLOR] = color_util.color_hs_to_xy(*hs_color)

        if supported_features & SUPPORT_WHITE_VALUE:
            data[ATTR_WHITE_VALUE] = self.white_value

        if supported_features & SUPPORT_EFFECT:
            data[ATTR_EFFECT] = self.effect

        return {key: val for key, val in data.items() if val is not None}

    @property
    def supported_features(self):
        """Flag supported features."""
        return 0


class Light(LightEntity):
    """Representation of a light (for backwards compatibility)."""

    def __init_subclass__(cls, **kwargs):
        """Print deprecation warning."""
        super().__init_subclass__(**kwargs)
        _LOGGER.warning(
            "Light is deprecated, modify %s to extend LightEntity",
            cls.__name__,
        )