"""Provide the functionality to group entities."""
import asyncio
import logging
from typing import Any, Iterable, List, Optional, cast

import voluptuous as vol

from homeassistant import core as ha
from homeassistant.const import (
    ATTR_ASSUMED_STATE,
    ATTR_ENTITY_ID,
    ATTR_ICON,
    ATTR_NAME,
    CONF_ICON,
    CONF_NAME,
    ENTITY_MATCH_ALL,
    ENTITY_MATCH_NONE,
    SERVICE_RELOAD,
    STATE_CLOSED,
    STATE_HOME,
    STATE_LOCKED,
    STATE_NOT_HOME,
    STATE_OFF,
    STATE_OK,
    STATE_ON,
    STATE_OPEN,
    STATE_PROBLEM,
    STATE_UNKNOWN,
    STATE_UNLOCKED,
)
from homeassistant.core import callback
import homeassistant.helpers.config_validation as cv
from homeassistant.helpers.entity import Entity, async_generate_entity_id
from homeassistant.helpers.entity_component import EntityComponent
from homeassistant.helpers.event import async_track_state_change
from homeassistant.helpers.typing import HomeAssistantType
from homeassistant.loader import bind_hass

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

DOMAIN = "group"

ENTITY_ID_FORMAT = DOMAIN + ".{}"

CONF_ENTITIES = "entities"
CONF_ALL = "all"

ATTR_ADD_ENTITIES = "add_entities"
ATTR_AUTO = "auto"
ATTR_ENTITIES = "entities"
ATTR_OBJECT_ID = "object_id"
ATTR_ORDER = "order"
ATTR_ALL = "all"

SERVICE_SET = "set"
SERVICE_REMOVE = "remove"

_LOGGER = logging.getLogger(__name__)


def _conf_preprocess(value):
    """Preprocess alternative configuration formats."""
    if not isinstance(value, dict):
        value = {CONF_ENTITIES: value}

    return value


GROUP_SCHEMA = vol.All(
    vol.Schema(
        {
            vol.Optional(CONF_ENTITIES): vol.Any(cv.entity_ids, None),
            CONF_NAME: cv.string,
            CONF_ICON: cv.icon,
            CONF_ALL: cv.boolean,
        }
    )
)

CONFIG_SCHEMA = vol.Schema(
    {DOMAIN: vol.Schema({cv.match_all: vol.All(_conf_preprocess, GROUP_SCHEMA)})},
    extra=vol.ALLOW_EXTRA,
)

# List of ON/OFF state tuples for groupable states
_GROUP_TYPES = [
    (STATE_ON, STATE_OFF),
    (STATE_HOME, STATE_NOT_HOME),
    (STATE_OPEN, STATE_CLOSED),
    (STATE_LOCKED, STATE_UNLOCKED),
    (STATE_PROBLEM, STATE_OK),
]


def _get_group_on_off(state):
    """Determine the group on/off states based on a state."""
    for states in _GROUP_TYPES:
        if state in states:
            return states

    return None, None


@bind_hass
def is_on(hass, entity_id):
    """Test if the group state is in its ON-state."""
    state = hass.states.get(entity_id)

    if state:
        group_on, _ = _get_group_on_off(state.state)

        # If we found a group_type, compare to ON-state
        return group_on is not None and state.state == group_on

    return False


@bind_hass
def expand_entity_ids(hass: HomeAssistantType, entity_ids: Iterable[Any]) -> List[str]:
    """Return entity_ids with group entity ids replaced by their members.

    Async friendly.
    """
    found_ids: List[str] = []
    for entity_id in entity_ids:
        if not isinstance(entity_id, str) or entity_id in (
            ENTITY_MATCH_NONE,
            ENTITY_MATCH_ALL,
        ):
            continue

        entity_id = entity_id.lower()

        try:
            # If entity_id points at a group, expand it
            domain, _ = ha.split_entity_id(entity_id)

            if domain == DOMAIN:
                child_entities = get_entity_ids(hass, entity_id)
                if entity_id in child_entities:
                    child_entities = list(child_entities)
                    child_entities.remove(entity_id)
                found_ids.extend(
                    ent_id
                    for ent_id in expand_entity_ids(hass, child_entities)
                    if ent_id not in found_ids
                )

            else:
                if entity_id not in found_ids:
                    found_ids.append(entity_id)

        except AttributeError:
            # Raised by split_entity_id if entity_id is not a string
            pass

    return found_ids


@bind_hass
def get_entity_ids(
    hass: HomeAssistantType, entity_id: str, domain_filter: Optional[str] = None
) -> List[str]:
    """Get members of this group.

    Async friendly.
    """
    group = hass.states.get(entity_id)

    if not group or ATTR_ENTITY_ID not in group.attributes:
        return []

    entity_ids = group.attributes[ATTR_ENTITY_ID]
    if not domain_filter:
        return cast(List[str], entity_ids)

    domain_filter = f"{domain_filter.lower()}."

    return [ent_id for ent_id in entity_ids if ent_id.startswith(domain_filter)]


@bind_hass
def groups_with_entity(hass: HomeAssistantType, entity_id: str) -> List[str]:
    """Get all groups that contain this entity.

    Async friendly.
    """
    if DOMAIN not in hass.data:
        return []

    groups = []

    for group in hass.data[DOMAIN].entities:
        if entity_id in group.tracking:
            groups.append(group.entity_id)

    return groups


async def async_setup(hass, config):
    """Set up all groups found defined in the configuration."""
    component = hass.data.get(DOMAIN)

    if component is None:
        component = hass.data[DOMAIN] = EntityComponent(_LOGGER, DOMAIN, hass)

    await _async_process_config(hass, config, component)

    async def reload_service_handler(service):
        """Remove all user-defined groups and load new ones from config."""
        auto = list(filter(lambda e: not e.user_defined, component.entities))

        conf = await component.async_prepare_reload()
        if conf is None:
            return
        await _async_process_config(hass, conf, component)

        await component.async_add_entities(auto)

    hass.services.async_register(
        DOMAIN, SERVICE_RELOAD, reload_service_handler, schema=vol.Schema({})
    )

    service_lock = asyncio.Lock()

    async def locked_service_handler(service):
        """Handle a service with an async lock."""
        async with service_lock:
            await groups_service_handler(service)

    async def groups_service_handler(service):
        """Handle dynamic group service functions."""
        object_id = service.data[ATTR_OBJECT_ID]
        entity_id = f"{DOMAIN}.{object_id}"
        group = component.get_entity(entity_id)

        # new group
        if service.service == SERVICE_SET and group is None:
            entity_ids = (
                service.data.get(ATTR_ENTITIES)
                or service.data.get(ATTR_ADD_ENTITIES)
                or None
            )

            extra_arg = {
                attr: service.data[attr]
                for attr in (ATTR_ICON,)
                if service.data.get(attr) is not None
            }

            await Group.async_create_group(
                hass,
                service.data.get(ATTR_NAME, object_id),
                object_id=object_id,
                entity_ids=entity_ids,
                user_defined=False,
                mode=service.data.get(ATTR_ALL),
                **extra_arg,
            )
            return

        if group is None:
            _LOGGER.warning("%s:Group '%s' doesn't exist!", service.service, object_id)
            return

        # update group
        if service.service == SERVICE_SET:
            need_update = False

            if ATTR_ADD_ENTITIES in service.data:
                delta = service.data[ATTR_ADD_ENTITIES]
                entity_ids = set(group.tracking) | set(delta)
                await group.async_update_tracked_entity_ids(entity_ids)

            if ATTR_ENTITIES in service.data:
                entity_ids = service.data[ATTR_ENTITIES]
                await group.async_update_tracked_entity_ids(entity_ids)

            if ATTR_NAME in service.data:
                group.name = service.data[ATTR_NAME]
                need_update = True

            if ATTR_ICON in service.data:
                group.icon = service.data[ATTR_ICON]
                need_update = True

            if ATTR_ALL in service.data:
                group.mode = all if service.data[ATTR_ALL] else any
                need_update = True

            if need_update:
                group.async_write_ha_state()

            return

        # remove group
        if service.service == SERVICE_REMOVE:
            await component.async_remove_entity(entity_id)

    hass.services.async_register(
        DOMAIN,
        SERVICE_SET,
        locked_service_handler,
        schema=vol.All(
            vol.Schema(
                {
                    vol.Required(ATTR_OBJECT_ID): cv.slug,
                    vol.Optional(ATTR_NAME): cv.string,
                    vol.Optional(ATTR_ICON): cv.string,
                    vol.Optional(ATTR_ALL): cv.boolean,
                    vol.Exclusive(ATTR_ENTITIES, "entities"): cv.entity_ids,
                    vol.Exclusive(ATTR_ADD_ENTITIES, "entities"): cv.entity_ids,
                }
            )
        ),
    )

    hass.services.async_register(
        DOMAIN,
        SERVICE_REMOVE,
        groups_service_handler,
        schema=vol.Schema({vol.Required(ATTR_OBJECT_ID): cv.slug}),
    )

    return True


async def _async_process_config(hass, config, component):
    """Process group configuration."""
    for object_id, conf in config.get(DOMAIN, {}).items():
        name = conf.get(CONF_NAME, object_id)
        entity_ids = conf.get(CONF_ENTITIES) or []
        icon = conf.get(CONF_ICON)
        mode = conf.get(CONF_ALL)

        # Don't create tasks and await them all. The order is important as
        # groups get a number based on creation order.
        await Group.async_create_group(
            hass, name, entity_ids, icon=icon, object_id=object_id, mode=mode
        )


class Group(Entity):
    """Track a group of entity ids."""

    def __init__(
        self,
        hass,
        name,
        order=None,
        icon=None,
        user_defined=True,
        entity_ids=None,
        mode=None,
    ):
        """Initialize a group.

        This Object has factory function for creation.
        """
        self.hass = hass
        self._name = name
        self._state = STATE_UNKNOWN
        self._icon = icon
        if entity_ids:
            self.tracking = tuple(ent_id.lower() for ent_id in entity_ids)
        else:
            self.tracking = ()
        self.group_on = None
        self.group_off = None
        self.user_defined = user_defined
        self.mode = any
        if mode:
            self.mode = all
        self._order = order
        self._assumed_state = False
        self._async_unsub_state_changed = None

    @staticmethod
    def create_group(
        hass,
        name,
        entity_ids=None,
        user_defined=True,
        icon=None,
        object_id=None,
        mode=None,
    ):
        """Initialize a group."""
        return asyncio.run_coroutine_threadsafe(
            Group.async_create_group(
                hass, name, entity_ids, user_defined, icon, object_id, mode
            ),
            hass.loop,
        ).result()

    @staticmethod
    async def async_create_group(
        hass,
        name,
        entity_ids=None,
        user_defined=True,
        icon=None,
        object_id=None,
        mode=None,
    ):
        """Initialize a group.

        This method must be run in the event loop.
        """
        group = Group(
            hass,
            name,
            order=len(hass.states.async_entity_ids(DOMAIN)),
            icon=icon,
            user_defined=user_defined,
            entity_ids=entity_ids,
            mode=mode,
        )

        group.entity_id = async_generate_entity_id(
            ENTITY_ID_FORMAT, object_id or name, hass=hass
        )

        # If called before the platform async_setup is called (test cases)
        component = hass.data.get(DOMAIN)

        if component is None:
            component = hass.data[DOMAIN] = EntityComponent(_LOGGER, DOMAIN, hass)

        await component.async_add_entities([group], True)

        return group

    @property
    def should_poll(self):
        """No need to poll because groups will update themselves."""
        return False

    @property
    def name(self):
        """Return the name of the group."""
        return self._name

    @name.setter
    def name(self, value):
        """Set Group name."""
        self._name = value

    @property
    def state(self):
        """Return the state of the group."""
        return self._state

    @property
    def icon(self):
        """Return the icon of the group."""
        return self._icon

    @icon.setter
    def icon(self, value):
        """Set Icon for group."""
        self._icon = value

    @property
    def state_attributes(self):
        """Return the state attributes for the group."""
        data = {ATTR_ENTITY_ID: self.tracking, ATTR_ORDER: self._order}
        if not self.user_defined:
            data[ATTR_AUTO] = True
        return data

    @property
    def assumed_state(self):
        """Test if any member has an assumed state."""
        return self._assumed_state

    def update_tracked_entity_ids(self, entity_ids):
        """Update the member entity IDs."""
        asyncio.run_coroutine_threadsafe(
            self.async_update_tracked_entity_ids(entity_ids), self.hass.loop
        ).result()

    async def async_update_tracked_entity_ids(self, entity_ids):
        """Update the member entity IDs.

        This method must be run in the event loop.
        """
        await self.async_stop()
        self.tracking = tuple(ent_id.lower() for ent_id in entity_ids)
        self.group_on, self.group_off = None, None

        await self.async_update_ha_state(True)
        self.async_start()

    @callback
    def async_start(self):
        """Start tracking members.

        This method must be run in the event loop.
        """
        if self._async_unsub_state_changed is None:
            self._async_unsub_state_changed = async_track_state_change(
                self.hass, self.tracking, self._async_state_changed_listener
            )

    async def async_stop(self):
        """Unregister the group from Home Assistant.

        This method must be run in the event loop.
        """
        if self._async_unsub_state_changed:
            self._async_unsub_state_changed()
            self._async_unsub_state_changed = None

    async def async_update(self):
        """Query all members and determine current group state."""
        self._state = STATE_UNKNOWN
        self._async_update_group_state()

    async def async_added_to_hass(self):
        """Handle addition to Home Assistant."""
        if self.tracking:
            self.async_start()

    async def async_will_remove_from_hass(self):
        """Handle removal from Home Assistant."""
        if self._async_unsub_state_changed:
            self._async_unsub_state_changed()
            self._async_unsub_state_changed = None

    async def _async_state_changed_listener(self, entity_id, old_state, new_state):
        """Respond to a member state changing.

        This method must be run in the event loop.
        """
        # removed
        if self._async_unsub_state_changed is None:
            return

        self._async_update_group_state(new_state)
        self.async_write_ha_state()

    @property
    def _tracking_states(self):
        """Return the states that the group is tracking."""
        states = []

        for entity_id in self.tracking:
            state = self.hass.states.get(entity_id)

            if state is not None:
                states.append(state)

        return states

    @callback
    def _async_update_group_state(self, tr_state=None):
        """Update group state.

        Optionally you can provide the only state changed since last update
        allowing this method to take shortcuts.

        This method must be run in the event loop.
        """
        # To store current states of group entities. Might not be needed.
        states = None
        gr_state = self._state
        gr_on = self.group_on
        gr_off = self.group_off

        # We have not determined type of group yet
        if gr_on is None:
            if tr_state is None:
                states = self._tracking_states

                for state in states:
                    gr_on, gr_off = _get_group_on_off(state.state)
                    if gr_on is not None:
                        break
            else:
                gr_on, gr_off = _get_group_on_off(tr_state.state)

            if gr_on is not None:
                self.group_on, self.group_off = gr_on, gr_off

        # We cannot determine state of the group
        if gr_on is None:
            return

        if tr_state is None or (
            (gr_state == gr_on and tr_state.state == gr_off)
            or (gr_state == gr_off and tr_state.state == gr_on)
            or tr_state.state not in (gr_on, gr_off)
        ):
            if states is None:
                states = self._tracking_states

            if self.mode(state.state == gr_on for state in states):
                self._state = gr_on
            else:
                self._state = gr_off

        elif tr_state.state in (gr_on, gr_off):
            self._state = tr_state.state

        if (
            tr_state is None
            or self._assumed_state
            and not tr_state.attributes.get(ATTR_ASSUMED_STATE)
        ):
            if states is None:
                states = self._tracking_states

            self._assumed_state = self.mode(
                state.attributes.get(ATTR_ASSUMED_STATE) for state in states
            )

        elif tr_state.attributes.get(ATTR_ASSUMED_STATE):
            self._assumed_state = True
