"""This platform allows several switches to be grouped into one switch."""
from __future__ import annotations

import logging
from typing import Any

import voluptuous as vol

from homeassistant.components.switch import DOMAIN, PLATFORM_SCHEMA, SwitchEntity
from homeassistant.config_entries import ConfigEntry
from homeassistant.const import (
    ATTR_ENTITY_ID,
    CONF_ENTITIES,
    CONF_NAME,
    CONF_UNIQUE_ID,
    SERVICE_TURN_OFF,
    SERVICE_TURN_ON,
    STATE_ON,
    STATE_UNAVAILABLE,
    STATE_UNKNOWN,
)
from homeassistant.core import Event, HomeAssistant, callback
from homeassistant.helpers import config_validation as cv, entity_registry as er
from homeassistant.helpers.entity_platform import AddEntitiesCallback
from homeassistant.helpers.event import async_track_state_change_event
from homeassistant.helpers.typing import ConfigType, DiscoveryInfoType

from . import GroupEntity

DEFAULT_NAME = "Switch Group"
CONF_ALL = "all"

# No limit on parallel updates to enable a group calling another group
PARALLEL_UPDATES = 0

PLATFORM_SCHEMA = PLATFORM_SCHEMA.extend(
    {
        vol.Required(CONF_ENTITIES): cv.entities_domain(DOMAIN),
        vol.Optional(CONF_NAME, default=DEFAULT_NAME): cv.string,
        vol.Optional(CONF_UNIQUE_ID): cv.string,
        vol.Optional(CONF_ALL, default=False): cv.boolean,
    }
)

_LOGGER = logging.getLogger(__name__)


async def async_setup_platform(
    hass: HomeAssistant,
    config: ConfigType,
    async_add_entities: AddEntitiesCallback,
    discovery_info: DiscoveryInfoType | None = None,
) -> None:
    """Set up the Switch Group platform."""
    async_add_entities(
        [
            SwitchGroup(
                config.get(CONF_UNIQUE_ID),
                config[CONF_NAME],
                config[CONF_ENTITIES],
                config.get(CONF_ALL, False),
            )
        ]
    )


async def async_setup_entry(
    hass: HomeAssistant,
    config_entry: ConfigEntry,
    async_add_entities: AddEntitiesCallback,
) -> None:
    """Initialize Switch Group config entry."""
    registry = er.async_get(hass)
    entities = er.async_validate_entity_ids(
        registry, config_entry.options[CONF_ENTITIES]
    )
    async_add_entities(
        [
            SwitchGroup(
                config_entry.entry_id,
                config_entry.title,
                entities,
                config_entry.options.get(CONF_ALL),
            )
        ]
    )


class SwitchGroup(GroupEntity, SwitchEntity):
    """Representation of a switch group."""

    _attr_available = False
    _attr_should_poll = False

    def __init__(
        self,
        unique_id: str | None,
        name: str,
        entity_ids: list[str],
        mode: bool | None,
    ) -> None:
        """Initialize a switch group."""
        self._entity_ids = entity_ids

        self._attr_name = name
        self._attr_extra_state_attributes = {ATTR_ENTITY_ID: entity_ids}
        self._attr_unique_id = unique_id
        self.mode = any
        if mode:
            self.mode = all

    async def async_added_to_hass(self) -> None:
        """Register callbacks."""

        @callback
        def async_state_changed_listener(event: Event) -> None:
            """Handle child updates."""
            self.async_set_context(event.context)
            self.async_defer_or_update_ha_state()

        self.async_on_remove(
            async_track_state_change_event(
                self.hass, self._entity_ids, async_state_changed_listener
            )
        )

        await super().async_added_to_hass()

    async def async_turn_on(self, **kwargs: Any) -> None:
        """Forward the turn_on command to all switches in the group."""
        data = {ATTR_ENTITY_ID: self._entity_ids}
        _LOGGER.debug("Forwarded turn_on command: %s", data)

        await self.hass.services.async_call(
            DOMAIN,
            SERVICE_TURN_ON,
            data,
            blocking=True,
            context=self._context,
        )

    async def async_turn_off(self, **kwargs: Any) -> None:
        """Forward the turn_off command to all switches in the group."""
        data = {ATTR_ENTITY_ID: self._entity_ids}
        await self.hass.services.async_call(
            DOMAIN,
            SERVICE_TURN_OFF,
            data,
            blocking=True,
            context=self._context,
        )

    @callback
    def async_update_group_state(self) -> None:
        """Query all members and determine the switch group state."""
        states = [
            state.state
            for entity_id in self._entity_ids
            if (state := self.hass.states.get(entity_id)) is not None
        ]

        valid_state = self.mode(
            state not in (STATE_UNKNOWN, STATE_UNAVAILABLE) for state in states
        )

        if not valid_state:
            # Set as unknown if any / all member is unknown or unavailable
            self._attr_is_on = None
        else:
            # Set as ON if any / all member is ON
            self._attr_is_on = self.mode(state == STATE_ON for state in states)

        # Set group as unavailable if all members are unavailable or missing
        self._attr_available = any(state != STATE_UNAVAILABLE for state in states)