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# or more contributor license agreements.  See the NOTICE file
# distributed with this work for additional information
# regarding copyright ownership.  The ASF licenses this file
# to you under the Apache License, Version 2.0 (the
# "License"); you may not use this file except in compliance
# with the License.  You may obtain a copy of the License at
#
#   http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing,
# software distributed under the License is distributed on an
# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
# KIND, either express or implied.  See the License for the
# specific language governing permissions and limitations
# under the License.
from __future__ import annotations

import logging
from datetime import datetime, timezone
from typing import Any
from uuid import UUID

from celery import Task
from celery.exceptions import SoftTimeLimitExceeded
from celery.signals import task_failure
from flask import current_app
from superset_core.api.tasks import TaskStatus

from superset import is_feature_enabled
from superset.commands.exceptions import CommandException
from superset.commands.logs.prune import LogPruneCommand
from superset.commands.report.exceptions import ReportScheduleUnexpectedError
from superset.commands.report.execute import AsyncExecuteReportScheduleCommand
from superset.commands.report.log_prune import AsyncPruneReportScheduleLogCommand
from superset.commands.sql_lab.query import QueryPruneCommand
from superset.commands.tasks.prune import TaskPruneCommand
from superset.daos.report import ReportScheduleDAO
from superset.daos.tasks import TaskDAO
from superset.extensions import celery_app
from superset.stats_logger import BaseStatsLogger
from superset.tasks.ambient_context import use_context
from superset.tasks.constants import ABORT_STATES, TERMINAL_STATES
from superset.tasks.context import TaskContext
from superset.tasks.cron_util import cron_schedule_window
from superset.tasks.manager import TaskManager
from superset.tasks.registry import TaskRegistry
from superset.utils.core import LoggerLevel
from superset.utils.log import get_logger_from_status

logger = logging.getLogger(__name__)


@task_failure.connect
def log_task_failure(  # pylint: disable=unused-argument
    sender: Task | None = None,
    task_id: str | None = None,
    exception: Exception | None = None,
    args: tuple[Any, ...] | None = None,
    kwargs: dict[str, Any] | None = None,
    traceback: Any = None,
    einfo: Any = None,
    **kw: Any,
) -> None:
    task_name = sender.name if sender else "Unknown"
    logger.exception("Celery task %s failed: %s", task_name, exception, exc_info=einfo)


@celery_app.task(
    name="reports.scheduler",
    bind=True,
    autoretry_for=(Exception,),
    retry_kwargs={
        "max_retries": 3,
        "countdown": 60,
    },  # Retry up to 3 times, wait 60s between
    retry_backoff=True,  # exponential backoff
)
def scheduler(self: Task) -> None:  # pylint: disable=unused-argument
    """
    Celery beat main scheduler for reports
    """
    stats_logger: BaseStatsLogger = current_app.config["STATS_LOGGER"]
    stats_logger.incr("reports.scheduler")

    if not is_feature_enabled("ALERT_REPORTS"):
        return
    active_schedules = ReportScheduleDAO.find_active()
    triggered_at = (
        datetime.fromisoformat(scheduler.request.expires)
        - current_app.config["CELERY_BEAT_SCHEDULER_EXPIRES"]
        if scheduler.request.expires
        else datetime.now(tz=timezone.utc)
    )
    for active_schedule in active_schedules:
        for schedule in cron_schedule_window(
            triggered_at, active_schedule.crontab, active_schedule.timezone
        ):
            logger.info("Scheduling alert %s eta: %s", active_schedule.name, schedule)
            async_options = {"eta": schedule}
            if (
                active_schedule.working_timeout is not None
                and current_app.config["ALERT_REPORTS_WORKING_TIME_OUT_KILL"]
            ):
                async_options["time_limit"] = (
                    active_schedule.working_timeout
                    + current_app.config["ALERT_REPORTS_WORKING_TIME_OUT_LAG"]
                )
                async_options["soft_time_limit"] = (
                    active_schedule.working_timeout
                    + current_app.config["ALERT_REPORTS_WORKING_SOFT_TIME_OUT_LAG"]
                )
            execute.apply_async((active_schedule.id,), **async_options)


@celery_app.task(name="reports.execute", bind=True)
def execute(self: Task, report_schedule_id: int) -> None:
    stats_logger: BaseStatsLogger = current_app.config["STATS_LOGGER"]
    stats_logger.incr("reports.execute")

    task_id = None
    try:
        task_id = execute.request.id
        scheduled_dttm = execute.request.eta
        logger.info(
            "Executing alert/report, task id: %s, scheduled_dttm: %s",
            task_id,
            scheduled_dttm,
        )
        AsyncExecuteReportScheduleCommand(
            task_id,
            report_schedule_id,
            scheduled_dttm,
        ).run()
    except ReportScheduleUnexpectedError:
        logger.exception(
            "An unexpected error occurred while executing the report: %s", task_id
        )
        self.update_state(state="FAILURE")
    except CommandException as ex:
        logger_func, level = get_logger_from_status(ex.status)
        logger_func(
            f"A downstream {level} occurred "
            f"while generating a report: {task_id}. {ex.message}",
            exc_info=True,
        )
        if level == LoggerLevel.EXCEPTION:
            self.update_state(state="FAILURE")


@celery_app.task(name="reports.prune_log")
def prune_log() -> None:
    stats_logger: BaseStatsLogger = current_app.config["STATS_LOGGER"]
    stats_logger.incr("reports.prune_log")

    try:
        AsyncPruneReportScheduleLogCommand().run()
    except SoftTimeLimitExceeded as ex:
        logger.warning("A timeout occurred while pruning report schedule logs: %s", ex)
    except CommandException:
        logger.exception("An exception occurred while pruning report schedule logs")


@celery_app.task(name="prune_query", bind=True)
def prune_query(
    self: Task, retention_period_days: int | None = None, **kwargs: Any
) -> None:
    stats_logger: BaseStatsLogger = current_app.config["STATS_LOGGER"]
    stats_logger.incr("prune_query")

    # TODO: Deprecated: Remove support for passing retention period via options in 6.0
    if retention_period_days is None:
        retention_period_days = prune_query.request.properties.get(
            "retention_period_days"
        )
        logger.warning(
            "Your `prune_query` beat schedule uses `options` to pass the retention "
            "period, please use `kwargs` instead."
        )

    try:
        QueryPruneCommand(retention_period_days).run()
    except CommandException as ex:
        logger.exception("An error occurred while pruning queries: %s", ex)


@celery_app.task(name="prune_logs", bind=True)
def prune_logs(
    self: Task,
    retention_period_days: int | None = None,
    max_rows_per_run: int | None = None,
    **kwargs: Any,
) -> None:
    stats_logger: BaseStatsLogger = current_app.config["STATS_LOGGER"]
    stats_logger.incr("prune_logs")

    # TODO: Deprecated: Remove support for passing retention period via options in 6.0
    if retention_period_days is None:
        retention_period_days = prune_logs.request.properties.get(
            "retention_period_days"
        )
        logger.warning(
            "Your `prune_logs` beat schedule uses `options` to pass the retention "
            "period, please use `kwargs` instead."
        )

    try:
        LogPruneCommand(retention_period_days, max_rows_per_run).run()
    except CommandException as ex:
        logger.exception("An error occurred while pruning logs: %s", ex)


@celery_app.task(name="prune_tasks", bind=True)
def prune_tasks(
    self: Task,
    retention_period_days: int | None = None,
    max_rows_per_run: int | None = None,
    **kwargs: Any,
) -> None:
    stats_logger: BaseStatsLogger = current_app.config["STATS_LOGGER"]
    stats_logger.incr("prune_tasks")

    # TODO: Deprecated: Remove support for passing retention period via options in 6.0
    if retention_period_days is None:
        retention_period_days = prune_tasks.request.properties.get(
            "retention_period_days"
        )
        logger.warning(
            "Your `prune_tasks` beat schedule uses `options` to pass the "
            "retention period, please use `kwargs` instead."
        )

    try:
        TaskPruneCommand(retention_period_days, max_rows_per_run).run()
    except CommandException as ex:
        logger.exception("An error occurred while pruning async tasks: %s", ex)


@celery_app.task(name="tasks.execute", bind=True)
def execute_task(  # noqa: C901
    self: Any,  # Celery task instance
    task_uuid: str,
    task_type: str,
    args: tuple[Any, ...],
    kwargs: dict[str, Any],
) -> dict[str, Any]:
    """
    Generic task executor for GTF tasks.

    This executor:
    1. Checks if task was aborted before execution starts
    2. Fetches task from metastore
    3. Builds context (task + user) and sets ambient context via contextvars
    4. Executes the task function (which accesses context via get_context())
    5. Updates task status throughout lifecycle using atomic conditional updates
    6. Runs cleanup handlers on task end (success/failure/abortion)
    7. Resets context after execution

    Uses atomic conditional status updates to prevent race conditions with
    concurrent abort operations.

    :param task_uuid: UUID of the task to execute
    :param task_type: Type of the task (for registry lookup)
    :param args: Positional arguments for the task function
    :param kwargs: Keyword arguments for the task function
    :returns: Dict with status and task_uuid
    """
    from superset.commands.tasks.internal_update import InternalStatusTransitionCommand

    # Convert string UUID to native UUID (Celery deserializes as string)
    native_uuid = UUID(task_uuid)

    task = TaskDAO.find_one_or_none(uuid=native_uuid)
    if not task:
        logger.error("Task %s not found in metastore", task_uuid)
        return {"status": "error", "message": "Task not found"}

    # AUTOMATIC PRE-EXECUTION CHECK: Don't execute if already aborted/aborting
    if task.status in ABORT_STATES:
        logger.info(
            "Task %s (uuid=%s) was aborted before execution started",
            task_type,
            task_uuid,
        )
        # Atomic transition to ABORTED (if not already)
        InternalStatusTransitionCommand(
            task_uuid=native_uuid,
            new_status=TaskStatus.ABORTED,
            expected_status=[TaskStatus.PENDING, TaskStatus.ABORTING],
            set_ended_at=True,
        ).run()
        return {"status": TaskStatus.ABORTED.value, "task_uuid": task_uuid}

    # Atomic transition: PENDING → IN_PROGRESS (set started_at for duration tracking)
    if not InternalStatusTransitionCommand(
        task_uuid=native_uuid,
        new_status=TaskStatus.IN_PROGRESS,
        expected_status=TaskStatus.PENDING,
        set_started_at=True,
    ).run():
        # Status wasn't PENDING - task may have been aborted concurrently
        logger.warning(
            "Task %s (uuid=%s) failed PENDING → IN_PROGRESS transition "
            "(may have been aborted concurrently)",
            task_type,
            task_uuid,
        )
        refreshed = TaskDAO.find_one_or_none(uuid=native_uuid)
        return {
            "status": refreshed.status if refreshed else "unknown",
            "task_uuid": task_uuid,
        }

    # Update cached status (no DB read needed - we just wrote IN_PROGRESS)
    task.status = TaskStatus.IN_PROGRESS.value

    # Build context from task (includes user who created the task)
    ctx = TaskContext(task)

    # Start timeout timer if configured (timer starts from execution time)
    if timeout := task.properties_dict.get("timeout"):
        ctx.start_timeout_timer(timeout)
        logger.debug(
            "Started timeout timer for task %s: %d seconds",
            task_uuid,
            timeout,
        )

    try:
        # Get registered executor function
        executor_fn = TaskRegistry.get_executor(task_type)

        logger.info(
            "Executing task %s (uuid=%s) with function %s.%s",
            task_type,
            task_uuid,
            executor_fn.__module__,
            executor_fn.__name__,
        )

        # Execute with ambient context (no ctx parameter!)
        with use_context(ctx):
            executor_fn(*args, **kwargs)

        # Mark execution as completed to prevent late abort handlers
        ctx.mark_execution_completed()

        # Determine terminal status based on abort detection
        # Use atomic conditional updates to prevent overwriting concurrent abort
        if ctx._abort_detected or ctx.timeout_triggered:
            # Abort was detected - will be handled in finally block
            pass
        else:
            # Normal completion - also allow ABORTING → SUCCESS for late abort
            # (task finished before abort was detected)
            if InternalStatusTransitionCommand(
                task_uuid=native_uuid,
                new_status=TaskStatus.SUCCESS,
                expected_status=[TaskStatus.IN_PROGRESS, TaskStatus.ABORTING],
                set_ended_at=True,
            ).run():
                # Emit stats metric for success
                stats_logger: BaseStatsLogger = current_app.config["STATS_LOGGER"]
                stats_logger.incr("gtf.task.success")
                logger.info(
                    "Task %s (uuid=%s) completed successfully", task_type, task_uuid
                )
            else:
                # Transition failed - task was likely already in a terminal state
                logger.info(
                    "Task %s (uuid=%s) completion transition failed "
                    "(task may already be in terminal state)",
                    task_type,
                    task_uuid,
                )

    except Exception as ex:
        # Mark execution as completed to prevent late abort handlers
        ctx.mark_execution_completed()

        # Atomic transition to FAILURE (only if still IN_PROGRESS or ABORTING)
        InternalStatusTransitionCommand(
            task_uuid=native_uuid,
            new_status=TaskStatus.FAILURE,
            expected_status=[TaskStatus.IN_PROGRESS, TaskStatus.ABORTING],
            properties={"error_message": str(ex)},
            set_ended_at=True,
        ).run()

        logger.error(
            "Task %s (uuid=%s) failed with error: %s",
            task_type,
            task_uuid,
            str(ex),
            exc_info=True,
        )

        # Emit stats metric for failure
        stats_logger = current_app.config["STATS_LOGGER"]
        stats_logger.incr("gtf.task.failure")

    finally:
        # ALWAYS run cleanup handlers (also stops timeout timer)
        ctx._run_cleanup()

        # Handle abort/timeout terminal transitions
        # Use atomic updates to safely transition ABORTING → terminal state
        if ctx._abort_detected or ctx.timeout_triggered:
            if ctx.abort_handlers_completed:
                # All handlers succeeded - determine terminal state based on cause
                if ctx.timeout_triggered:
                    InternalStatusTransitionCommand(
                        task_uuid=native_uuid,
                        new_status=TaskStatus.TIMED_OUT,
                        expected_status=TaskStatus.ABORTING,
                        set_ended_at=True,
                    ).run()
                    logger.info(
                        "Task %s (uuid=%s) timed out and completed cleanup",
                        task_type,
                        task_uuid,
                    )
                else:
                    InternalStatusTransitionCommand(
                        task_uuid=native_uuid,
                        new_status=TaskStatus.ABORTED,
                        expected_status=TaskStatus.ABORTING,
                        set_ended_at=True,
                    ).run()
                    logger.info(
                        "Task %s (uuid=%s) was aborted by user",
                        task_type,
                        task_uuid,
                    )
            else:
                # Handlers didn't complete successfully - mark as FAILURE
                InternalStatusTransitionCommand(
                    task_uuid=native_uuid,
                    new_status=TaskStatus.FAILURE,
                    expected_status=TaskStatus.ABORTING,
                    properties={"error_message": "Abort handlers did not complete"},
                    set_ended_at=True,
                ).run()
                logger.warning(
                    "Task %s (uuid=%s) stuck in ABORTING - marking as FAILURE",
                    task_type,
                    task_uuid,
                )

        # Refresh to get final status for return value and completion notification
        refreshed = TaskDAO.find_one_or_none(uuid=native_uuid)
        final_status = refreshed.status if refreshed else "unknown"

        # Publish completion notification for any waiters (e.g., sync callers)
        if final_status in TERMINAL_STATES:
            TaskManager.publish_completion(native_uuid, final_status)

    return {"status": final_status, "task_uuid": task_uuid}