"""Support for KNX/IP datetime."""
from __future__ import annotations

from datetime import datetime

from xknx import XKNX
from xknx.devices import DateTime as XknxDateTime

from homeassistant import config_entries
from homeassistant.components.datetime import DateTimeEntity
from homeassistant.const import (
    CONF_ENTITY_CATEGORY,
    CONF_NAME,
    STATE_UNAVAILABLE,
    STATE_UNKNOWN,
    Platform,
)
from homeassistant.core import HomeAssistant
from homeassistant.helpers.entity_platform import AddEntitiesCallback
from homeassistant.helpers.restore_state import RestoreEntity
from homeassistant.helpers.typing import ConfigType
import homeassistant.util.dt as dt_util

from .const import (
    CONF_RESPOND_TO_READ,
    CONF_STATE_ADDRESS,
    CONF_SYNC_STATE,
    DATA_KNX_CONFIG,
    DOMAIN,
    KNX_ADDRESS,
)
from .knx_entity import KnxEntity


async def async_setup_entry(
    hass: HomeAssistant,
    config_entry: config_entries.ConfigEntry,
    async_add_entities: AddEntitiesCallback,
) -> None:
    """Set up entities for KNX platform."""
    xknx: XKNX = hass.data[DOMAIN].xknx
    config: list[ConfigType] = hass.data[DATA_KNX_CONFIG][Platform.DATETIME]

    async_add_entities(KNXDateTime(xknx, entity_config) for entity_config in config)


def _create_xknx_device(xknx: XKNX, config: ConfigType) -> XknxDateTime:
    """Return a XKNX DateTime object to be used within XKNX."""
    return XknxDateTime(
        xknx,
        name=config[CONF_NAME],
        broadcast_type="DATETIME",
        localtime=False,
        group_address=config[KNX_ADDRESS],
        group_address_state=config.get(CONF_STATE_ADDRESS),
        respond_to_read=config[CONF_RESPOND_TO_READ],
        sync_state=config[CONF_SYNC_STATE],
    )


class KNXDateTime(KnxEntity, DateTimeEntity, RestoreEntity):
    """Representation of a KNX datetime."""

    _device: XknxDateTime

    def __init__(self, xknx: XKNX, config: ConfigType) -> None:
        """Initialize a KNX time."""
        super().__init__(_create_xknx_device(xknx, config))
        self._attr_entity_category = config.get(CONF_ENTITY_CATEGORY)
        self._attr_unique_id = str(self._device.remote_value.group_address)

    async def async_added_to_hass(self) -> None:
        """Restore last state."""
        await super().async_added_to_hass()
        if (
            not self._device.remote_value.readable
            and (last_state := await self.async_get_last_state()) is not None
            and last_state.state not in (STATE_UNKNOWN, STATE_UNAVAILABLE)
        ):
            self._device.remote_value.value = (
                datetime.fromisoformat(last_state.state)
                .astimezone(dt_util.DEFAULT_TIME_ZONE)
                .timetuple()
            )

    @property
    def native_value(self) -> datetime | None:
        """Return the latest value."""
        if (time_struct := self._device.remote_value.value) is None:
            return None
        return datetime(
            year=time_struct.tm_year,
            month=time_struct.tm_mon,
            day=time_struct.tm_mday,
            hour=time_struct.tm_hour,
            minute=time_struct.tm_min,
            second=min(time_struct.tm_sec, 59),  # account for leap seconds
            tzinfo=dt_util.DEFAULT_TIME_ZONE,
        )

    async def async_set_value(self, value: datetime) -> None:
        """Change the value."""
        await self._device.set(value.astimezone(dt_util.DEFAULT_TIME_ZONE).timetuple())