"""Allow to set up simple automation rules via the config file."""
import asyncio
from functools import partial
import importlib
import logging
from typing import Any, Awaitable, Callable

import voluptuous as vol

from homeassistant.const import (
    ATTR_ENTITY_ID,
    ATTR_NAME,
    CONF_ID,
    CONF_PLATFORM,
    EVENT_AUTOMATION_TRIGGERED,
    EVENT_HOMEASSISTANT_START,
    SERVICE_RELOAD,
    SERVICE_TOGGLE,
    SERVICE_TURN_OFF,
    SERVICE_TURN_ON,
    STATE_ON,
)
from homeassistant.core import Context, CoreState, HomeAssistant
from homeassistant.exceptions import HomeAssistantError
from homeassistant.helpers import condition, extract_domain_configs, script
import homeassistant.helpers.config_validation as cv
from homeassistant.helpers.config_validation import ENTITY_SERVICE_SCHEMA
from homeassistant.helpers.entity import ToggleEntity
from homeassistant.helpers.entity_component import EntityComponent
from homeassistant.helpers.restore_state import RestoreEntity
from homeassistant.helpers.typing import TemplateVarsType
from homeassistant.loader import bind_hass
from homeassistant.util.dt import parse_datetime, utcnow


# mypy: allow-untyped-calls, allow-untyped-defs
# mypy: no-check-untyped-defs, no-warn-return-any

DOMAIN = "automation"
ENTITY_ID_FORMAT = DOMAIN + ".{}"

GROUP_NAME_ALL_AUTOMATIONS = "all automations"

CONF_ALIAS = "alias"
CONF_DESCRIPTION = "description"
CONF_HIDE_ENTITY = "hide_entity"

CONF_CONDITION = "condition"
CONF_ACTION = "action"
CONF_TRIGGER = "trigger"
CONF_CONDITION_TYPE = "condition_type"
CONF_INITIAL_STATE = "initial_state"

CONDITION_USE_TRIGGER_VALUES = "use_trigger_values"
CONDITION_TYPE_AND = "and"
CONDITION_TYPE_OR = "or"

DEFAULT_CONDITION_TYPE = CONDITION_TYPE_AND
DEFAULT_HIDE_ENTITY = False
DEFAULT_INITIAL_STATE = True

ATTR_LAST_TRIGGERED = "last_triggered"
ATTR_VARIABLES = "variables"
SERVICE_TRIGGER = "trigger"

_LOGGER = logging.getLogger(__name__)

AutomationActionType = Callable[[HomeAssistant, TemplateVarsType], Awaitable[None]]


def _platform_validator(config):
    """Validate it is a valid platform."""
    try:
        platform = importlib.import_module(
            ".{}".format(config[CONF_PLATFORM]), __name__
        )
    except ImportError:
        raise vol.Invalid("Invalid platform specified") from None

    return platform.TRIGGER_SCHEMA(config)


_TRIGGER_SCHEMA = vol.All(
    cv.ensure_list,
    [
        vol.All(
            vol.Schema({vol.Required(CONF_PLATFORM): str}, extra=vol.ALLOW_EXTRA),
            _platform_validator,
        )
    ],
)

_CONDITION_SCHEMA = vol.All(cv.ensure_list, [cv.CONDITION_SCHEMA])

PLATFORM_SCHEMA = vol.Schema(
    {
        # str on purpose
        CONF_ID: str,
        CONF_ALIAS: cv.string,
        vol.Optional(CONF_DESCRIPTION): cv.string,
        vol.Optional(CONF_INITIAL_STATE): cv.boolean,
        vol.Optional(CONF_HIDE_ENTITY, default=DEFAULT_HIDE_ENTITY): cv.boolean,
        vol.Required(CONF_TRIGGER): _TRIGGER_SCHEMA,
        vol.Optional(CONF_CONDITION): _CONDITION_SCHEMA,
        vol.Required(CONF_ACTION): cv.SCRIPT_SCHEMA,
    }
)

TRIGGER_SERVICE_SCHEMA = ENTITY_SERVICE_SCHEMA.extend(
    {vol.Optional(ATTR_VARIABLES, default={}): dict}
)

RELOAD_SERVICE_SCHEMA = vol.Schema({})


@bind_hass
def is_on(hass, entity_id):
    """
    Return true if specified automation entity_id is on.

    Async friendly.
    """
    return hass.states.is_state(entity_id, STATE_ON)


async def async_setup(hass, config):
    """Set up the automation."""
    component = EntityComponent(
        _LOGGER, DOMAIN, hass, group_name=GROUP_NAME_ALL_AUTOMATIONS
    )

    await _async_process_config(hass, config, component)

    async def trigger_service_handler(service_call):
        """Handle automation triggers."""
        tasks = []
        for entity in await component.async_extract_from_service(service_call):
            tasks.append(
                entity.async_trigger(
                    service_call.data.get(ATTR_VARIABLES),
                    skip_condition=True,
                    context=service_call.context,
                )
            )

        if tasks:
            await asyncio.wait(tasks)

    async def turn_onoff_service_handler(service_call):
        """Handle automation turn on/off service calls."""
        tasks = []
        method = f"async_{service_call.service}"
        for entity in await component.async_extract_from_service(service_call):
            tasks.append(getattr(entity, method)())

        if tasks:
            await asyncio.wait(tasks)

    async def toggle_service_handler(service_call):
        """Handle automation toggle service calls."""
        tasks = []
        for entity in await component.async_extract_from_service(service_call):
            if entity.is_on:
                tasks.append(entity.async_turn_off())
            else:
                tasks.append(entity.async_turn_on())

        if tasks:
            await asyncio.wait(tasks)

    async def reload_service_handler(service_call):
        """Remove all automations and load new ones from config."""
        conf = await component.async_prepare_reload()
        if conf is None:
            return
        await _async_process_config(hass, conf, component)

    hass.services.async_register(
        DOMAIN, SERVICE_TRIGGER, trigger_service_handler, schema=TRIGGER_SERVICE_SCHEMA
    )

    hass.services.async_register(
        DOMAIN, SERVICE_RELOAD, reload_service_handler, schema=RELOAD_SERVICE_SCHEMA
    )

    hass.services.async_register(
        DOMAIN, SERVICE_TOGGLE, toggle_service_handler, schema=ENTITY_SERVICE_SCHEMA
    )

    for service in (SERVICE_TURN_ON, SERVICE_TURN_OFF):
        hass.services.async_register(
            DOMAIN, service, turn_onoff_service_handler, schema=ENTITY_SERVICE_SCHEMA
        )

    return True


class AutomationEntity(ToggleEntity, RestoreEntity):
    """Entity to show status of entity."""

    def __init__(
        self,
        automation_id,
        name,
        async_attach_triggers,
        cond_func,
        async_action,
        hidden,
        initial_state,
    ):
        """Initialize an automation entity."""
        self._id = automation_id
        self._name = name
        self._async_attach_triggers = async_attach_triggers
        self._async_detach_triggers = None
        self._cond_func = cond_func
        self._async_action = async_action
        self._last_triggered = None
        self._hidden = hidden
        self._initial_state = initial_state
        self._is_enabled = False

    @property
    def name(self):
        """Name of the automation."""
        return self._name

    @property
    def should_poll(self):
        """No polling needed for automation entities."""
        return False

    @property
    def state_attributes(self):
        """Return the entity state attributes."""
        return {ATTR_LAST_TRIGGERED: self._last_triggered}

    @property
    def hidden(self) -> bool:
        """Return True if the automation entity should be hidden from UIs."""
        return self._hidden

    @property
    def is_on(self) -> bool:
        """Return True if entity is on."""
        return self._async_detach_triggers is not None or self._is_enabled

    async def async_added_to_hass(self) -> None:
        """Startup with initial state or previous state."""
        await super().async_added_to_hass()

        state = await self.async_get_last_state()
        if state:
            enable_automation = state.state == STATE_ON
            last_triggered = state.attributes.get("last_triggered")
            if last_triggered is not None:
                self._last_triggered = parse_datetime(last_triggered)
            _LOGGER.debug(
                "Loaded automation %s with state %s from state "
                " storage last state %s",
                self.entity_id,
                enable_automation,
                state,
            )
        else:
            enable_automation = DEFAULT_INITIAL_STATE
            _LOGGER.debug(
                "Automation %s not in state storage, state %s from " "default is used.",
                self.entity_id,
                enable_automation,
            )

        if self._initial_state is not None:
            enable_automation = self._initial_state
            _LOGGER.debug(
                "Automation %s initial state %s overridden from "
                "config initial_state",
                self.entity_id,
                enable_automation,
            )

        if enable_automation:
            await self.async_enable()

    async def async_turn_on(self, **kwargs: Any) -> None:
        """Turn the entity on and update the state."""
        await self.async_enable()

    async def async_turn_off(self, **kwargs: Any) -> None:
        """Turn the entity off."""
        await self.async_disable()

    async def async_trigger(self, variables, skip_condition=False, context=None):
        """Trigger automation.

        This method is a coroutine.
        """
        if not skip_condition and not self._cond_func(variables):
            return

        # Create a new context referring to the old context.
        parent_id = None if context is None else context.id
        trigger_context = Context(parent_id=parent_id)

        self.async_set_context(trigger_context)
        self.hass.bus.async_fire(
            EVENT_AUTOMATION_TRIGGERED,
            {ATTR_NAME: self._name, ATTR_ENTITY_ID: self.entity_id},
            context=trigger_context,
        )
        await self._async_action(self.entity_id, variables, trigger_context)
        self._last_triggered = utcnow()
        await self.async_update_ha_state()

    async def async_will_remove_from_hass(self):
        """Remove listeners when removing automation from HASS."""
        await super().async_will_remove_from_hass()
        await self.async_disable()

    async def async_enable(self):
        """Enable this automation entity.

        This method is a coroutine.
        """
        if self._is_enabled:
            return

        self._is_enabled = True

        # HomeAssistant is starting up
        if self.hass.state != CoreState.not_running:
            self._async_detach_triggers = await self._async_attach_triggers(
                self.async_trigger
            )
            self.async_write_ha_state()
            return

        async def async_enable_automation(event):
            """Start automation on startup."""
            # Don't do anything if no longer enabled or already attached
            if not self._is_enabled or self._async_detach_triggers is not None:
                return

            self._async_detach_triggers = await self._async_attach_triggers(
                self.async_trigger
            )

        self.hass.bus.async_listen_once(
            EVENT_HOMEASSISTANT_START, async_enable_automation
        )
        self.async_write_ha_state()

    async def async_disable(self):
        """Disable the automation entity."""
        if not self._is_enabled:
            return

        self._is_enabled = False

        if self._async_detach_triggers is not None:
            self._async_detach_triggers()
            self._async_detach_triggers = None

        self.async_write_ha_state()

    @property
    def device_state_attributes(self):
        """Return automation attributes."""
        if self._id is None:
            return None

        return {CONF_ID: self._id}


async def _async_process_config(hass, config, component):
    """Process config and add automations.

    This method is a coroutine.
    """
    entities = []

    for config_key in extract_domain_configs(config, DOMAIN):
        conf = config[config_key]

        for list_no, config_block in enumerate(conf):
            automation_id = config_block.get(CONF_ID)
            name = config_block.get(CONF_ALIAS) or f"{config_key} {list_no}"

            hidden = config_block[CONF_HIDE_ENTITY]
            initial_state = config_block.get(CONF_INITIAL_STATE)

            action = _async_get_action(hass, config_block.get(CONF_ACTION, {}), name)

            if CONF_CONDITION in config_block:
                cond_func = await _async_process_if(hass, config, config_block)

                if cond_func is None:
                    continue
            else:

                def cond_func(variables):
                    """Condition will always pass."""
                    return True

            async_attach_triggers = partial(
                _async_process_trigger,
                hass,
                config,
                config_block.get(CONF_TRIGGER, []),
                name,
            )
            entity = AutomationEntity(
                automation_id,
                name,
                async_attach_triggers,
                cond_func,
                action,
                hidden,
                initial_state,
            )

            entities.append(entity)

    if entities:
        await component.async_add_entities(entities)


def _async_get_action(hass, config, name):
    """Return an action based on a configuration."""
    script_obj = script.Script(hass, config, name)

    async def action(entity_id, variables, context):
        """Execute an action."""
        _LOGGER.info("Executing %s", name)

        try:
            await script_obj.async_run(variables, context)
        except Exception as err:  # pylint: disable=broad-except
            script_obj.async_log_exception(
                _LOGGER, f"Error while executing automation {entity_id}", err
            )

    return action


async def _async_process_if(hass, config, p_config):
    """Process if checks."""
    if_configs = p_config.get(CONF_CONDITION)

    checks = []
    for if_config in if_configs:
        try:
            checks.append(await condition.async_from_config(hass, if_config, False))
        except HomeAssistantError as ex:
            _LOGGER.warning("Invalid condition: %s", ex)
            return None

    def if_action(variables=None):
        """AND all conditions."""
        return all(check(hass, variables) for check in checks)

    return if_action


async def _async_process_trigger(hass, config, trigger_configs, name, action):
    """Set up the triggers.

    This method is a coroutine.
    """
    removes = []
    info = {"name": name}

    for conf in trigger_configs:
        platform = importlib.import_module(".{}".format(conf[CONF_PLATFORM]), __name__)

        remove = await platform.async_attach_trigger(hass, conf, action, info)

        if not remove:
            _LOGGER.error("Error setting up trigger %s", name)
            continue

        _LOGGER.info("Initialized trigger %s", name)
        removes.append(remove)

    if not removes:
        return None

    def remove_triggers():
        """Remove attached triggers."""
        for remove in removes:
            remove()

    return remove_triggers
