"""Support for recording details."""
from __future__ import annotations

import abc
import asyncio
from collections.abc import Callable, Iterable
from dataclasses import dataclass
from datetime import datetime
import logging
import threading
from typing import TYPE_CHECKING, Any

from homeassistant.core import Event
from homeassistant.helpers.typing import UndefinedType

from . import entity_registry, purge, statistics
from .const import DOMAIN
from .db_schema import Statistics, StatisticsShortTerm
from .models import StatisticData, StatisticMetaData
from .util import periodic_db_cleanups, session_scope

_LOGGER = logging.getLogger(__name__)


if TYPE_CHECKING:
    from .core import Recorder


@dataclass(slots=True)
class RecorderTask:
    """ABC for recorder tasks."""

    commit_before = True

    @abc.abstractmethod
    def run(self, instance: Recorder) -> None:
        """Handle the task."""


@dataclass(slots=True)
class ChangeStatisticsUnitTask(RecorderTask):
    """Object to store statistics_id and unit to convert unit of statistics."""

    statistic_id: str
    new_unit_of_measurement: str
    old_unit_of_measurement: str

    def run(self, instance: Recorder) -> None:
        """Handle the task."""
        statistics.change_statistics_unit(
            instance,
            self.statistic_id,
            self.new_unit_of_measurement,
            self.old_unit_of_measurement,
        )


@dataclass(slots=True)
class ClearStatisticsTask(RecorderTask):
    """Object to store statistics_ids which for which to remove statistics."""

    statistic_ids: list[str]

    def run(self, instance: Recorder) -> None:
        """Handle the task."""
        statistics.clear_statistics(instance, self.statistic_ids)


@dataclass(slots=True)
class UpdateStatisticsMetadataTask(RecorderTask):
    """Object to store statistics_id and unit for update of statistics metadata."""

    statistic_id: str
    new_statistic_id: str | None | UndefinedType
    new_unit_of_measurement: str | None | UndefinedType

    def run(self, instance: Recorder) -> None:
        """Handle the task."""
        statistics.update_statistics_metadata(
            instance,
            self.statistic_id,
            self.new_statistic_id,
            self.new_unit_of_measurement,
        )


@dataclass(slots=True)
class UpdateStatesMetadataTask(RecorderTask):
    """Task to update states metadata."""

    entity_id: str
    new_entity_id: str

    def run(self, instance: Recorder) -> None:
        """Handle the task."""
        entity_registry.update_states_metadata(
            instance,
            self.entity_id,
            self.new_entity_id,
        )


@dataclass(slots=True)
class PurgeTask(RecorderTask):
    """Object to store information about purge task."""

    purge_before: datetime
    repack: bool
    apply_filter: bool

    def run(self, instance: Recorder) -> None:
        """Purge the database."""
        if purge.purge_old_data(
            instance, self.purge_before, self.repack, self.apply_filter
        ):
            with instance.get_session() as session:
                instance.recorder_runs_manager.load_from_db(session)
            # We always need to do the db cleanups after a purge
            # is finished to ensure the WAL checkpoint and other
            # tasks happen after a vacuum.
            periodic_db_cleanups(instance)
            return
        # Schedule a new purge task if this one didn't finish
        instance.queue_task(
            PurgeTask(self.purge_before, self.repack, self.apply_filter)
        )


@dataclass(slots=True)
class PurgeEntitiesTask(RecorderTask):
    """Object to store entity information about purge task."""

    entity_filter: Callable[[str], bool]
    purge_before: datetime

    def run(self, instance: Recorder) -> None:
        """Purge entities from the database."""
        if purge.purge_entity_data(instance, self.entity_filter, self.purge_before):
            return
        # Schedule a new purge task if this one didn't finish
        instance.queue_task(PurgeEntitiesTask(self.entity_filter, self.purge_before))


@dataclass(slots=True)
class PerodicCleanupTask(RecorderTask):
    """An object to insert into the recorder to trigger cleanup tasks.

    Trigger cleanup tasks when auto purge is disabled.
    """

    def run(self, instance: Recorder) -> None:
        """Handle the task."""
        periodic_db_cleanups(instance)


@dataclass(slots=True)
class StatisticsTask(RecorderTask):
    """An object to insert into the recorder queue to run a statistics task."""

    start: datetime
    fire_events: bool

    def run(self, instance: Recorder) -> None:
        """Run statistics task."""
        if statistics.compile_statistics(instance, self.start, self.fire_events):
            return
        # Schedule a new statistics task if this one didn't finish
        instance.queue_task(StatisticsTask(self.start, self.fire_events))


@dataclass(slots=True)
class CompileMissingStatisticsTask(RecorderTask):
    """An object to insert into the recorder queue to run a compile missing statistics."""

    def run(self, instance: Recorder) -> None:
        """Run statistics task to compile missing statistics."""
        if statistics.compile_missing_statistics(instance):
            return
        # Schedule a new statistics task if this one didn't finish
        instance.queue_task(CompileMissingStatisticsTask())


@dataclass(slots=True)
class ImportStatisticsTask(RecorderTask):
    """An object to insert into the recorder queue to run an import statistics task."""

    metadata: StatisticMetaData
    statistics: Iterable[StatisticData]
    table: type[Statistics | StatisticsShortTerm]

    def run(self, instance: Recorder) -> None:
        """Run statistics task."""
        if statistics.import_statistics(
            instance, self.metadata, self.statistics, self.table
        ):
            return
        # Schedule a new statistics task if this one didn't finish
        instance.queue_task(
            ImportStatisticsTask(self.metadata, self.statistics, self.table)
        )


@dataclass(slots=True)
class AdjustStatisticsTask(RecorderTask):
    """An object to insert into the recorder queue to run an adjust statistics task."""

    statistic_id: str
    start_time: datetime
    sum_adjustment: float
    adjustment_unit: str

    def run(self, instance: Recorder) -> None:
        """Run statistics task."""
        if statistics.adjust_statistics(
            instance,
            self.statistic_id,
            self.start_time,
            self.sum_adjustment,
            self.adjustment_unit,
        ):
            return
        # Schedule a new adjust statistics task if this one didn't finish
        instance.queue_task(
            AdjustStatisticsTask(
                self.statistic_id,
                self.start_time,
                self.sum_adjustment,
                self.adjustment_unit,
            )
        )


@dataclass(slots=True)
class WaitTask(RecorderTask):
    """An object to insert into the recorder queue.

    Tell it set the _queue_watch event.
    """

    commit_before = False

    def run(self, instance: Recorder) -> None:
        """Handle the task."""
        instance._queue_watch.set()  # pylint: disable=[protected-access]


@dataclass(slots=True)
class DatabaseLockTask(RecorderTask):
    """An object to insert into the recorder queue to prevent writes to the database."""

    database_locked: asyncio.Event
    database_unlock: threading.Event
    queue_overflow: bool

    def run(self, instance: Recorder) -> None:
        """Handle the task."""
        instance._lock_database(self)  # pylint: disable=[protected-access]


@dataclass(slots=True)
class StopTask(RecorderTask):
    """An object to insert into the recorder queue to stop the event handler."""

    commit_before = False

    def run(self, instance: Recorder) -> None:
        """Handle the task."""
        instance.stop_requested = True


@dataclass(slots=True)
class EventTask(RecorderTask):
    """An event to be processed."""

    event: Event
    commit_before = False

    def run(self, instance: Recorder) -> None:
        """Handle the task."""
        # pylint: disable-next=[protected-access]
        instance._process_one_event(self.event)


@dataclass(slots=True)
class KeepAliveTask(RecorderTask):
    """A keep alive to be sent."""

    commit_before = False

    def run(self, instance: Recorder) -> None:
        """Handle the task."""
        # pylint: disable-next=[protected-access]
        instance._send_keep_alive()


@dataclass(slots=True)
class CommitTask(RecorderTask):
    """Commit the event session."""

    commit_before = False

    def run(self, instance: Recorder) -> None:
        """Handle the task."""
        # pylint: disable-next=[protected-access]
        instance._commit_event_session_or_retry()


@dataclass(slots=True)
class AddRecorderPlatformTask(RecorderTask):
    """Add a recorder platform."""

    domain: str
    platform: Any
    commit_before = False

    def run(self, instance: Recorder) -> None:
        """Handle the task."""
        hass = instance.hass
        domain = self.domain
        platform = self.platform
        platforms: dict[str, Any] = hass.data[DOMAIN].recorder_platforms
        platforms[domain] = platform


@dataclass(slots=True)
class SynchronizeTask(RecorderTask):
    """Ensure all pending data has been committed."""

    # commit_before is the default
    event: asyncio.Event

    def run(self, instance: Recorder) -> None:
        """Handle the task."""
        # Does not use a tracked task to avoid
        # blocking shutdown if the recorder is broken
        instance.hass.loop.call_soon_threadsafe(self.event.set)


@dataclass(slots=True)
class PostSchemaMigrationTask(RecorderTask):
    """Post migration task to update schema."""

    old_version: int
    new_version: int

    def run(self, instance: Recorder) -> None:
        """Handle the task."""
        instance._post_schema_migration(  # pylint: disable=[protected-access]
            self.old_version, self.new_version
        )


@dataclass(slots=True)
class StatisticsTimestampMigrationCleanupTask(RecorderTask):
    """An object to insert into the recorder queue to run a statistics migration cleanup task."""

    def run(self, instance: Recorder) -> None:
        """Run statistics timestamp cleanup task."""
        if not statistics.cleanup_statistics_timestamp_migration(instance):
            # Schedule a new statistics migration task if this one didn't finish
            instance.queue_task(StatisticsTimestampMigrationCleanupTask())


@dataclass(slots=True)
class AdjustLRUSizeTask(RecorderTask):
    """An object to insert into the recorder queue to adjust the LRU size."""

    commit_before = False

    def run(self, instance: Recorder) -> None:
        """Handle the task to adjust the size."""
        instance._adjust_lru_size()  # pylint: disable=[protected-access]


@dataclass(slots=True)
class StatesContextIDMigrationTask(RecorderTask):
    """An object to insert into the recorder queue to migrate states context ids."""

    commit_before = False

    def run(self, instance: Recorder) -> None:
        """Run context id migration task."""
        if (
            not instance._migrate_states_context_ids()  # pylint: disable=[protected-access]
        ):
            # Schedule a new migration task if this one didn't finish
            instance.queue_task(StatesContextIDMigrationTask())


@dataclass(slots=True)
class EventsContextIDMigrationTask(RecorderTask):
    """An object to insert into the recorder queue to migrate events context ids."""

    commit_before = False

    def run(self, instance: Recorder) -> None:
        """Run context id migration task."""
        if (
            not instance._migrate_events_context_ids()  # pylint: disable=[protected-access]
        ):
            # Schedule a new migration task if this one didn't finish
            instance.queue_task(EventsContextIDMigrationTask())


@dataclass(slots=True)
class EventTypeIDMigrationTask(RecorderTask):
    """An object to insert into the recorder queue to migrate event type ids."""

    commit_before = True
    # We have to commit before to make sure there are
    # no new pending event_types about to be added to
    # the db since this happens live

    def run(self, instance: Recorder) -> None:
        """Run event type id migration task."""
        if not instance._migrate_event_type_ids():  # pylint: disable=[protected-access]
            # Schedule a new migration task if this one didn't finish
            instance.queue_task(EventTypeIDMigrationTask())


@dataclass(slots=True)
class EntityIDMigrationTask(RecorderTask):
    """An object to insert into the recorder queue to migrate entity_ids to StatesMeta."""

    commit_before = True
    # We have to commit before to make sure there are
    # no new pending states_meta about to be added to
    # the db since this happens live

    def run(self, instance: Recorder) -> None:
        """Run entity_id migration task."""
        if not instance._migrate_entity_ids():  # pylint: disable=[protected-access]
            # Schedule a new migration task if this one didn't finish
            instance.queue_task(EntityIDMigrationTask())
        else:
            # The migration has finished, now we start the post migration
            # to remove the old entity_id data from the states table
            # at this point we can also start using the StatesMeta table
            # so we set active to True
            instance.states_meta_manager.active = True
            instance.queue_task(EntityIDPostMigrationTask())


@dataclass(slots=True)
class EntityIDPostMigrationTask(RecorderTask):
    """An object to insert into the recorder queue to cleanup after entity_ids migration."""

    def run(self, instance: Recorder) -> None:
        """Run entity_id post migration task."""
        if (
            not instance._post_migrate_entity_ids()  # pylint: disable=[protected-access]
        ):
            # Schedule a new migration task if this one didn't finish
            instance.queue_task(EntityIDPostMigrationTask())


@dataclass(slots=True)
class EventIdMigrationTask(RecorderTask):
    """An object to insert into the recorder queue to cleanup legacy event_ids in the states table.

    This task should only be queued if the ix_states_event_id index exists
    since it is used to scan the states table and it will be removed after this
    task is run if its no longer needed.
    """

    def run(self, instance: Recorder) -> None:
        """Clean up the legacy event_id index on states."""
        instance._cleanup_legacy_states_event_ids()  # pylint: disable=[protected-access]


@dataclass(slots=True)
class RefreshEventTypesTask(RecorderTask):
    """An object to insert into the recorder queue to refresh event types."""

    event_types: list[str]

    def run(self, instance: Recorder) -> None:
        """Refresh event types."""
        with session_scope(session=instance.get_session(), read_only=True) as session:
            instance.event_type_manager.get_many(
                self.event_types, session, from_recorder=True
            )