"""Support for showing the date and the time."""

from collections.abc import Callable, Mapping
from datetime import datetime, timedelta
import logging
from typing import Any

import voluptuous as vol

from homeassistant.components.sensor import (
    ENTITY_ID_FORMAT,
    PLATFORM_SCHEMA as SENSOR_PLATFORM_SCHEMA,
    SensorEntity,
)
from homeassistant.config_entries import ConfigEntry
from homeassistant.const import CONF_DISPLAY_OPTIONS, EVENT_CORE_CONFIG_UPDATE
from homeassistant.core import CALLBACK_TYPE, Event, HomeAssistant, callback
from homeassistant.helpers import config_validation as cv
from homeassistant.helpers.entity_platform import (
    AddConfigEntryEntitiesCallback,
    AddEntitiesCallback,
)
from homeassistant.helpers.event import async_track_point_in_utc_time
from homeassistant.helpers.typing import ConfigType, DiscoveryInfoType
from homeassistant.util import dt as dt_util

from .const import OPTION_TYPES

_LOGGER = logging.getLogger(__name__)

TIME_STR_FORMAT = "%H:%M"


PLATFORM_SCHEMA = SENSOR_PLATFORM_SCHEMA.extend(
    {
        vol.Optional(CONF_DISPLAY_OPTIONS, default=["time"]): vol.All(
            cv.ensure_list, [vol.In(OPTION_TYPES)]
        )
    }
)


async def async_setup_platform(
    hass: HomeAssistant,
    config: ConfigType,
    async_add_entities: AddEntitiesCallback,
    discovery_info: DiscoveryInfoType | None = None,
) -> None:
    """Set up the Time and Date sensor."""
    if hass.config.time_zone is None:
        _LOGGER.error("Timezone is not set in Home Assistant configuration")  # type: ignore[unreachable]
        return

    async_add_entities(
        [TimeDateSensor(variable) for variable in config[CONF_DISPLAY_OPTIONS]]
    )


async def async_setup_entry(
    hass: HomeAssistant,
    entry: ConfigEntry,
    async_add_entities: AddConfigEntryEntitiesCallback,
) -> None:
    """Set up the Time & Date sensor."""

    async_add_entities(
        [TimeDateSensor(entry.options[CONF_DISPLAY_OPTIONS], entry.entry_id)]
    )


class TimeDateSensor(SensorEntity):
    """Implementation of a Time and Date sensor."""

    _attr_should_poll = False
    _attr_has_entity_name = True
    _state: str | None = None
    unsub: CALLBACK_TYPE | None = None

    def __init__(self, option_type: str, entry_id: str | None = None) -> None:
        """Initialize the sensor."""
        self._attr_translation_key = option_type
        self.type = option_type
        self.entity_id = ENTITY_ID_FORMAT.format(option_type)
        self._attr_unique_id = option_type if entry_id else None

        self._update_internal_state(dt_util.utcnow())

    @property
    def native_value(self) -> str | None:
        """Return the state of the sensor."""
        return self._state

    @property
    def icon(self) -> str:
        """Icon to use in the frontend, if any."""
        if "date" in self.type and "time" in self.type:
            return "mdi:calendar-clock"
        if "date" in self.type:
            return "mdi:calendar"
        return "mdi:clock"

    @callback
    def async_start_preview(
        self,
        preview_callback: Callable[[str, Mapping[str, Any]], None],
    ) -> CALLBACK_TYPE:
        """Render a preview."""

        @callback
        def point_in_time_listener(time_date: datetime | None) -> None:
            """Update preview."""

            now = dt_util.utcnow()
            self._update_internal_state(now)
            self.unsub = async_track_point_in_utc_time(
                self.hass, point_in_time_listener, self.get_next_interval(now)
            )
            calculated_state = self._async_calculate_state()
            preview_callback(calculated_state.state, calculated_state.attributes)

        @callback
        def async_stop_preview() -> None:
            """Stop preview."""
            if self.unsub:
                self.unsub()
                self.unsub = None

        point_in_time_listener(None)
        return async_stop_preview

    async def async_added_to_hass(self) -> None:
        """Set up first update."""

        async def async_update_config(event: Event) -> None:
            """Handle core config update."""
            self._update_state_and_setup_listener()
            self.async_write_ha_state()

        self.async_on_remove(
            self.hass.bus.async_listen(EVENT_CORE_CONFIG_UPDATE, async_update_config)
        )
        self._update_state_and_setup_listener()

    async def async_will_remove_from_hass(self) -> None:
        """Cancel next update."""
        if self.unsub:
            self.unsub()
            self.unsub = None

    def get_next_interval(self, time_date: datetime) -> datetime:
        """Compute next time an update should occur."""
        if self.type == "date":
            tomorrow = dt_util.as_local(time_date) + timedelta(days=1)
            return dt_util.start_of_local_day(tomorrow)

        timestamp = dt_util.as_timestamp(time_date)
        interval = 60

        delta = interval - (timestamp % interval)
        next_interval = time_date + timedelta(seconds=delta)
        _LOGGER.debug("%s + %s -> %s (%s)", time_date, delta, next_interval, self.type)

        return next_interval

    def _update_internal_state(self, time_date: datetime) -> None:
        time = dt_util.as_local(time_date).strftime(TIME_STR_FORMAT)
        time_utc = time_date.strftime(TIME_STR_FORMAT)
        date = dt_util.as_local(time_date).date().isoformat()
        date_utc = time_date.date().isoformat()

        if self.type == "time":
            self._state = time
        elif self.type == "date":
            self._state = date
        elif self.type == "date_time":
            self._state = f"{date}, {time}"
        elif self.type == "date_time_utc":
            self._state = f"{date_utc}, {time_utc}"
        elif self.type == "time_date":
            self._state = f"{time}, {date}"
        elif self.type == "time_utc":
            self._state = time_utc
        elif self.type == "date_time_iso":
            self._state = dt_util.parse_datetime(
                f"{date} {time}", raise_on_error=True
            ).isoformat()

    def _update_state_and_setup_listener(self) -> None:
        """Update state and setup listener for next interval."""
        now = dt_util.utcnow()
        self._update_internal_state(now)
        self.unsub = async_track_point_in_utc_time(
            self.hass, self.point_in_time_listener, self.get_next_interval(now)
        )

    @callback
    def point_in_time_listener(self, time_date: datetime) -> None:
        """Get the latest data and update state."""
        self._update_state_and_setup_listener()
        self.async_write_ha_state()