"""Representation of Z-Wave updates."""

import asyncio
from collections import Counter
from collections.abc import Awaitable, Callable
from dataclasses import dataclass
from datetime import datetime, timedelta
from typing import Any, Final, cast, override

from awesomeversion import AwesomeVersion
from zwave_js_server.exceptions import BaseZwaveJSServerError, FailedZWaveCommand
from zwave_js_server.model.driver import Driver
from zwave_js_server.model.firmware import (
    FirmwareUpdateInfo,
    FirmwareUpdateProgress,
    FirmwareUpdateResult,
)
from zwave_js_server.model.node import Node as ZwaveNode
from zwave_js_server.model.node.firmware import NodeFirmwareUpdateInfo

from homeassistant.components.update import (
    UpdateDeviceClass,
    UpdateEntity,
    UpdateEntityDescription,
    UpdateEntityFeature,
    UpdateEntityStateAttribute,
)
from homeassistant.const import EntityCategory
from homeassistant.core import CoreState, HomeAssistant, callback
from homeassistant.exceptions import HomeAssistantError
from homeassistant.helpers.dispatcher import async_dispatcher_connect
from homeassistant.helpers.entity_platform import AddConfigEntryEntitiesCallback
from homeassistant.helpers.event import async_call_later
from homeassistant.helpers.restore_state import ExtraStoredData

from .const import API_KEY_FIRMWARE_UPDATE_SERVICE, DOMAIN, LOGGER
from .entity import ZWaveNodeBaseEntity
from .models import ZwaveJSConfigEntry

PARALLEL_UPDATES = 1

UPDATE_DELAY_STRING = "delay"
UPDATE_DELAY_INTERVAL = 15  # In seconds
ATTR_LATEST_VERSION_FIRMWARE = "latest_version_firmware"


@dataclass(frozen=True, kw_only=True)
class ZWaveUpdateEntityDescription(UpdateEntityDescription):
    """Class describing Z-Wave update entity."""

    install_method: Callable[
        [ZWaveFirmwareUpdateEntity, FirmwareUpdateInfo],
        Awaitable[FirmwareUpdateResult],
    ]
    progress_method: Callable[[ZWaveFirmwareUpdateEntity], Callable[[], None]]
    finished_method: Callable[[ZWaveFirmwareUpdateEntity], Callable[[], None]]


CONTROLLER_UPDATE_ENTITY_DESCRIPTION = ZWaveUpdateEntityDescription(
    key="controller_firmware_update",
    install_method=(
        lambda entity, firmware_update_info: entity.driver.async_firmware_update_otw(
            update_info=firmware_update_info
        )
    ),
    progress_method=lambda entity: entity.driver.on(
        "firmware update progress", entity.update_progress
    ),
    finished_method=lambda entity: entity.driver.on(
        "firmware update finished", entity.update_finished
    ),
)
NODE_UPDATE_ENTITY_DESCRIPTION = ZWaveUpdateEntityDescription(
    key="node_firmware_update",
    install_method=(
        lambda entity, firmware_update_info: (
            entity.driver.controller.async_firmware_update_ota(
                entity.node, cast(NodeFirmwareUpdateInfo, firmware_update_info)
            )
        )
    ),
    progress_method=lambda entity: entity.node.on(
        "firmware update progress", entity.update_progress
    ),
    finished_method=lambda entity: entity.node.on(
        "firmware update finished", entity.update_finished
    ),
)


@dataclass
class ZWaveFirmwareUpdateExtraStoredData(ExtraStoredData):
    """Extra stored data for Z-Wave node firmware update entity."""

    latest_version_firmware: FirmwareUpdateInfo | None

    @override
    def as_dict(self) -> dict[str, Any]:
        """Return a dict representation of the extra data."""
        return {
            ATTR_LATEST_VERSION_FIRMWARE: self.latest_version_firmware.to_dict()
            if self.latest_version_firmware
            else None
        }

    @classmethod
    def from_dict(cls, data: dict[str, Any]) -> ZWaveFirmwareUpdateExtraStoredData:
        """Initialize the extra data from a dict."""
        # If there was no firmware info stored, or if it's stale info, we don't restore
        # anything.
        if (
            not (firmware_dict := data[ATTR_LATEST_VERSION_FIRMWARE])
            or "normalizedVersion" not in firmware_dict
        ):
            return cls(None)

        return cls(FirmwareUpdateInfo.from_dict(firmware_dict))


async def async_setup_entry(
    hass: HomeAssistant,
    config_entry: ZwaveJSConfigEntry,
    async_add_entities: AddConfigEntryEntitiesCallback,
) -> None:
    """Set up Z-Wave update entity from config entry."""
    client = config_entry.runtime_data.client
    cnt: Counter = Counter()

    @callback
    def async_add_firmware_update_entity(node: ZwaveNode) -> None:
        """Add firmware update entity."""
        # Delay the first update of each entity to avoid spamming the firmware server.
        # Maintain a counter to schedule first update in UPDATE_DELAY_INTERVAL
        # second increments.
        cnt[UPDATE_DELAY_STRING] += 1
        delay = timedelta(seconds=(cnt[UPDATE_DELAY_STRING] * UPDATE_DELAY_INTERVAL))
        driver = client.driver
        assert driver is not None  # Driver is ready before platforms are loaded.
        if node.is_controller_node:
            # If the node is a controller, we create a controller firmware update entity
            entity = ZWaveFirmwareUpdateEntity(
                driver,
                node,
                delay=delay,
                entity_description=CONTROLLER_UPDATE_ENTITY_DESCRIPTION,
            )
        else:
            # If the node is not a controller, we create a node firmware update entity
            entity = ZWaveFirmwareUpdateEntity(
                driver,
                node,
                delay=delay,
                entity_description=NODE_UPDATE_ENTITY_DESCRIPTION,
            )
        async_add_entities([entity])

    config_entry.async_on_unload(
        async_dispatcher_connect(
            hass,
            f"{DOMAIN}_{config_entry.entry_id}_add_firmware_update_entity",
            async_add_firmware_update_entity,
        )
    )


class ZWaveFirmwareUpdateEntity(ZWaveNodeBaseEntity, UpdateEntity):
    """Representation of a firmware update entity."""

    entity_description: ZWaveUpdateEntityDescription
    _attr_entity_category = EntityCategory.CONFIG
    _attr_device_class = UpdateDeviceClass.FIRMWARE
    _attr_supported_features = (
        UpdateEntityFeature.INSTALL
        | UpdateEntityFeature.RELEASE_NOTES
        | UpdateEntityFeature.PROGRESS
    )
    _remove_on_reinterview = True

    def __init__(
        self,
        driver: Driver,
        node: ZwaveNode,
        delay: timedelta,
        entity_description: ZWaveUpdateEntityDescription,
    ) -> None:
        """Initialize a Z-Wave device firmware update entity."""
        super().__init__(driver, node)
        self.entity_description = entity_description
        self._latest_version_firmware: FirmwareUpdateInfo | None = None
        self._poll_unsub: Callable[[], None] | None = None
        self._progress_unsub: Callable[[], None] | None = None
        self._finished_unsub: Callable[[], None] | None = None
        self._finished_event = asyncio.Event()
        self._result: FirmwareUpdateResult | None = None
        self._delay: Final[timedelta] = delay

        # Entity class attributes
        self._attr_name = "Firmware"
        self._attr_unique_id = f"{self._base_unique_id}.firmware_update"  # pylint: disable=home-assistant-entity-unique-id-redundant-platform
        self._attr_installed_version = node.firmware_version

    @property
    @override
    def extra_restore_state_data(self) -> ZWaveFirmwareUpdateExtraStoredData:
        """Return ZWave Node Firmware Update specific state data to be restored."""
        return ZWaveFirmwareUpdateExtraStoredData(self._latest_version_firmware)

    @callback
    def update_progress(self, event: dict[str, Any]) -> None:
        """Update install progress on event."""
        progress: FirmwareUpdateProgress = event["firmware_update_progress"]
        if not self._latest_version_firmware:
            return
        self._attr_in_progress = True
        self._attr_update_percentage = int(progress.progress)
        self.async_write_ha_state()

    @callback
    def update_finished(self, event: dict[str, Any]) -> None:
        """Update install progress on event."""
        result: FirmwareUpdateResult = event["firmware_update_finished"]
        self._result = result
        self._finished_event.set()

    @callback
    def _unsub_firmware_events_and_reset_progress(
        self, write_state: bool = True
    ) -> None:
        """Unsubscribe from firmware events and reset update install progress."""
        if self._progress_unsub:
            self._progress_unsub()
            self._progress_unsub = None

        if self._finished_unsub:
            self._finished_unsub()
            self._finished_unsub = None

        self._result = None
        self._finished_event.clear()
        self._attr_in_progress = False
        self._attr_update_percentage = None
        if write_state:
            self.async_write_ha_state()

    async def _async_update(self, _: HomeAssistant | datetime | None = None) -> None:
        """Update the entity."""
        if self._poll_unsub:
            self._poll_unsub()
            self._poll_unsub = None

        # If hass hasn't started yet, push the next update to the next day so that we
        # can preserve the offsets we've created between each node
        if self.hass.state is not CoreState.running:
            self._poll_unsub = async_call_later(
                self.hass, timedelta(days=1), self._async_update
            )
            return

        try:
            # Retrieve all firmware updates including non-stable ones but filter
            # non-stable channels out
            all_updates = (
                await self.driver.controller.async_get_available_firmware_updates(
                    self.node, API_KEY_FIRMWARE_UPDATE_SERVICE, True
                )
            )
            available_firmware_updates = [
                update for update in all_updates if update.channel == "stable"
            ]
        except FailedZWaveCommand as err:
            LOGGER.debug(
                "Failed to get firmware updates for node %s: %s",
                self.node.node_id,
                err,
            )
        else:
            # If we have an available firmware update that is a higher version than
            # what's on the node, we should advertise it, otherwise the installed
            # version is the latest.
            if (
                available_firmware_updates
                and (
                    latest_firmware := max(
                        available_firmware_updates,
                        key=lambda x: AwesomeVersion(x.version),
                    )
                )
                and AwesomeVersion(latest_firmware.version)
                > AwesomeVersion(self.node.firmware_version)
            ):
                self._latest_version_firmware = latest_firmware
                self._attr_latest_version = latest_firmware.version
                self.async_write_ha_state()
            elif self._attr_latest_version != self._attr_installed_version:
                self._attr_latest_version = self._attr_installed_version
                self.async_write_ha_state()
        finally:
            self._poll_unsub = async_call_later(
                self.hass, timedelta(days=1), self._async_update
            )

    @override
    async def async_release_notes(self) -> str | None:
        """Get release notes."""
        if self._latest_version_firmware is None:
            return None
        return self._latest_version_firmware.changelog

    @override
    async def async_install(
        self, version: str | None, backup: bool, **kwargs: Any
    ) -> None:
        """Install an update."""
        firmware = self._latest_version_firmware
        assert firmware
        self._unsub_firmware_events_and_reset_progress(False)
        self._attr_in_progress = True
        self._attr_update_percentage = None
        self.async_write_ha_state()

        self._progress_unsub = self.entity_description.progress_method(self)
        self._finished_unsub = self.entity_description.finished_method(self)

        try:
            await self.entity_description.install_method(self, firmware)
        except BaseZwaveJSServerError as err:
            self._unsub_firmware_events_and_reset_progress()
            raise HomeAssistantError(err) from err

        # We need to block until we receive the `firmware update finished` event
        await self._finished_event.wait()
        assert self._result is not None

        # If the update was not successful, we should throw an error
        # to let the user know
        if not self._result.success:
            error_msg = self._result.status.name.replace("_", " ").title()
            self._unsub_firmware_events_and_reset_progress()
            raise HomeAssistantError(error_msg)

        # If we get here, all files were installed successfully
        self._attr_installed_version = self._attr_latest_version = firmware.version
        self._latest_version_firmware = None
        self._unsub_firmware_events_and_reset_progress()

    @override
    async def async_added_to_hass(self) -> None:
        """Call when entity is added."""
        await super().async_added_to_hass()

        # Make sure these variables are set for the elif evaluation
        state = None
        latest_version = None

        # If we have a complete previous state, use that to set the latest version
        if (
            (state := await self.async_get_last_state())
            and (
                latest_version := state.attributes.get(
                    UpdateEntityStateAttribute.LATEST_VERSION
                )
            )
            is not None
            and (extra_data := await self.async_get_last_extra_data())
            and (
                latest_version_firmware := ZWaveFirmwareUpdateExtraStoredData.from_dict(
                    extra_data.as_dict()
                ).latest_version_firmware
            )
        ):
            self._attr_latest_version = latest_version
            self._latest_version_firmware = latest_version_firmware
        # If we have no state or latest version to restore, or the latest version is
        # the same as the installed version, we can set the latest
        # version to installed so that the entity starts as off. If we have partial
        # restore data due to an upgrade to an HA version where this feature is released
        # from one that is not the entity will start in an unknown state until we can
        # correct on next update
        elif (
            not state
            or not latest_version
            or latest_version == self._attr_installed_version
        ):
            self._attr_latest_version = self._attr_installed_version

        # Spread updates out in 15 second increments
        # to avoid spamming the firmware server
        self.async_on_remove(
            async_call_later(self.hass, self._delay, self._async_update)
        )

    @override
    async def async_will_remove_from_hass(self) -> None:
        """Call when entity will be removed."""
        if self._poll_unsub:
            self._poll_unsub()
            self._poll_unsub = None

        self._unsub_firmware_events_and_reset_progress(False)
