from __future__ import annotations

from contextlib import AsyncExitStack, asynccontextmanager
from datetime import datetime, timedelta, timezone
from typing import AsyncGenerator

import anyio
import pytest
from anyio import CancelScope
from freezegun.api import FrozenDateTimeFactory

from apscheduler import (
    CoalescePolicy,
    ConflictPolicy,
    Event,
    Job,
    JobOutcome,
    JobResult,
    Schedule,
    ScheduleAdded,
    ScheduleRemoved,
    ScheduleUpdated,
    Task,
    TaskAdded,
    TaskLookupError,
    TaskUpdated,
)
from apscheduler.abc import DataStore, EventBroker
from apscheduler.triggers.date import DateTrigger

pytestmark = pytest.mark.anyio


@pytest.fixture
def schedules() -> list[Schedule]:
    trigger = DateTrigger(datetime(2020, 9, 13, tzinfo=timezone.utc))
    schedule1 = Schedule(id="s1", task_id="task1", trigger=trigger)
    schedule1.next_fire_time = trigger.next()

    trigger = DateTrigger(datetime(2020, 9, 14, tzinfo=timezone.utc))
    schedule2 = Schedule(id="s2", task_id="task2", trigger=trigger)
    schedule2.next_fire_time = trigger.next()

    trigger = DateTrigger(datetime(2020, 9, 15, tzinfo=timezone.utc))
    schedule3 = Schedule(id="s3", task_id="task1", trigger=trigger)
    return [schedule1, schedule2, schedule3]


@asynccontextmanager
async def capture_events(
    datastore: DataStore,
    limit: int,
    event_types: set[type[Event]] | None = None,
) -> AsyncGenerator[list[Event], None]:
    def listener(event: Event) -> None:
        events.append(event)
        if len(events) == limit:
            limit_event.set()
            subscription.unsubscribe()

    events: list[Event] = []
    limit_event = anyio.Event()
    subscription = datastore._event_broker.subscribe(listener, event_types)
    yield events
    if limit:
        with anyio.fail_after(3):
            await limit_event.wait()


async def test_add_replace_task(datastore: DataStore) -> None:
    import math

    event_types = {TaskAdded, TaskUpdated}
    async with capture_events(datastore, 3, event_types) as events:
        await datastore.add_task(Task(id="test_task", func=print, executor="async"))
        await datastore.add_task(
            Task(id="test_task2", func=math.ceil, executor="async")
        )
        await datastore.add_task(Task(id="test_task", func=repr, executor="async"))

        tasks = await datastore.get_tasks()
        assert len(tasks) == 2
        assert tasks[0].id == "test_task"
        assert tasks[0].func is repr
        assert tasks[1].id == "test_task2"
        assert tasks[1].func is math.ceil

    received_event = events.pop(0)
    assert isinstance(received_event, TaskAdded)
    assert received_event.task_id == "test_task"

    received_event = events.pop(0)
    assert isinstance(received_event, TaskAdded)
    assert received_event.task_id == "test_task2"

    received_event = events.pop(0)
    assert isinstance(received_event, TaskUpdated)
    assert received_event.task_id == "test_task"

    assert not events


async def test_add_schedules(datastore: DataStore, schedules: list[Schedule]) -> None:
    async with capture_events(datastore, 3, {ScheduleAdded}) as events:
        for schedule in schedules:
            await datastore.add_schedule(schedule, ConflictPolicy.exception)

        assert await datastore.get_schedules() == schedules
        assert await datastore.get_schedules({"s1", "s2", "s3"}) == schedules
        assert await datastore.get_schedules({"s1"}) == [schedules[0]]
        assert await datastore.get_schedules({"s2"}) == [schedules[1]]
        assert await datastore.get_schedules({"s3"}) == [schedules[2]]

    for event, schedule in zip(events, schedules):
        assert event.schedule_id == schedule.id
        assert event.next_fire_time == schedule.next_fire_time


async def test_replace_schedules(
    datastore: DataStore, schedules: list[Schedule]
) -> None:
    async with capture_events(datastore, 1, {ScheduleUpdated}) as events:
        for schedule in schedules:
            await datastore.add_schedule(schedule, ConflictPolicy.exception)

        next_fire_time = schedules[2].trigger.next()
        schedule = Schedule(
            id="s3",
            task_id="foo",
            trigger=schedules[2].trigger,
            args=(),
            kwargs={},
            coalesce=CoalescePolicy.earliest,
            misfire_grace_time=None,
            tags=frozenset(),
        )
        schedule.next_fire_time = next_fire_time
        await datastore.add_schedule(schedule, ConflictPolicy.replace)

        schedules = await datastore.get_schedules({schedule.id})
        assert schedules[0].task_id == "foo"
        assert schedules[0].next_fire_time == next_fire_time
        assert schedules[0].args == ()
        assert schedules[0].kwargs == {}
        assert schedules[0].coalesce is CoalescePolicy.earliest
        assert schedules[0].misfire_grace_time is None
        assert schedules[0].tags == frozenset()

    received_event = events.pop(0)
    assert received_event.schedule_id == "s3"
    assert received_event.next_fire_time == datetime(2020, 9, 15, tzinfo=timezone.utc)
    assert not events


async def test_remove_schedules(
    datastore: DataStore, schedules: list[Schedule]
) -> None:
    async with capture_events(datastore, 2, {ScheduleRemoved}) as events:
        for schedule in schedules:
            await datastore.add_schedule(schedule, ConflictPolicy.exception)

        await datastore.remove_schedules(["s1", "s2"])
        assert await datastore.get_schedules() == [schedules[2]]

    received_event = events.pop(0)
    assert received_event.schedule_id == "s1"

    received_event = events.pop(0)
    assert received_event.schedule_id == "s2"

    assert not events


@pytest.mark.freeze_time(datetime(2020, 9, 14, tzinfo=timezone.utc))
async def test_acquire_release_schedules(
    datastore: DataStore, schedules: list[Schedule]
) -> None:
    event_types = {ScheduleRemoved, ScheduleUpdated}
    async with capture_events(datastore, 2, event_types) as events:
        for schedule in schedules:
            await datastore.add_schedule(schedule, ConflictPolicy.exception)

        # The first scheduler gets the first due schedule
        schedules1 = await datastore.acquire_schedules("dummy-id1", 1)
        assert len(schedules1) == 1
        assert schedules1[0].id == "s1"

        # The second scheduler gets the second due schedule
        schedules2 = await datastore.acquire_schedules("dummy-id2", 1)
        assert len(schedules2) == 1
        assert schedules2[0].id == "s2"

        # The third scheduler gets nothing
        schedules3 = await datastore.acquire_schedules("dummy-id3", 1)
        assert not schedules3

        # Update the schedules and check that the job store actually deletes the
        # first one and updates the second one
        schedules1[0].next_fire_time = None
        schedules2[0].next_fire_time = datetime(2020, 9, 15, tzinfo=timezone.utc)

        # Release all the schedules
        await datastore.release_schedules("dummy-id1", schedules1)
        await datastore.release_schedules("dummy-id2", schedules2)

        # Check that the first schedule is gone
        schedules = await datastore.get_schedules()
        assert len(schedules) == 2
        assert schedules[0].id == "s2"
        assert schedules[1].id == "s3"

    # Check for the appropriate update and delete events
    received_event = events.pop(0)
    assert isinstance(received_event, ScheduleRemoved)
    assert received_event.schedule_id == "s1"

    received_event = events.pop(0)
    assert isinstance(received_event, ScheduleUpdated)
    assert received_event.schedule_id == "s2"
    assert received_event.next_fire_time == datetime(2020, 9, 15, tzinfo=timezone.utc)

    assert not events


async def test_release_schedule_two_identical_fire_times(datastore: DataStore) -> None:
    """Regression test for #616."""
    for i in range(1, 3):
        trigger = DateTrigger(datetime(2020, 9, 13, tzinfo=timezone.utc))
        schedule = Schedule(id=f"s{i}", task_id="task1", trigger=trigger)
        schedule.next_fire_time = trigger.next()
        await datastore.add_schedule(schedule, ConflictPolicy.exception)

    schedules = await datastore.acquire_schedules("foo", 3)
    schedules[0].next_fire_time = None
    await datastore.release_schedules("foo", schedules)

    remaining = await datastore.get_schedules({s.id for s in schedules})
    assert len(remaining) == 1
    assert remaining[0].id == schedules[1].id


async def test_release_two_schedules_at_once(datastore: DataStore) -> None:
    """Regression test for #621."""
    for i in range(2):
        trigger = DateTrigger(datetime(2020, 9, 13, tzinfo=timezone.utc))
        schedule = Schedule(id=f"s{i}", task_id="task1", trigger=trigger)
        schedule.next_fire_time = trigger.next()
        await datastore.add_schedule(schedule, ConflictPolicy.exception)

    schedules = await datastore.acquire_schedules("foo", 3)
    await datastore.release_schedules("foo", schedules)

    remaining = await datastore.get_schedules({s.id for s in schedules})
    assert len(remaining) == 2


async def test_acquire_schedules_lock_timeout(
    datastore: DataStore, schedules: list[Schedule], freezer
) -> None:
    """
    Test that a scheduler can acquire schedules that were acquired by another
    scheduler but not released within the lock timeout period.

    """
    await datastore.add_schedule(schedules[0], ConflictPolicy.exception)

    # First, one scheduler acquires the first available schedule
    acquired1 = await datastore.acquire_schedules("dummy-id1", 1)
    assert len(acquired1) == 1
    assert acquired1[0].id == "s1"

    # Try to acquire the schedule just at the threshold (now == acquired_until).
    # This should not yield any schedules.
    freezer.tick(30)
    acquired2 = await datastore.acquire_schedules("dummy-id2", 1)
    assert not acquired2

    # Right after that, the schedule should be available
    freezer.tick(1)
    acquired3 = await datastore.acquire_schedules("dummy-id2", 1)
    assert len(acquired3) == 1
    assert acquired3[0].id == "s1"


async def test_acquire_multiple_workers(datastore: DataStore) -> None:
    await datastore.add_task(
        Task(id="task1", func=asynccontextmanager, executor="async")
    )
    jobs = [Job(task_id="task1") for _ in range(2)]
    for job in jobs:
        await datastore.add_job(job)

    # The first worker gets the first job in the queue
    jobs1 = await datastore.acquire_jobs("worker1", 1)
    assert len(jobs1) == 1
    assert jobs1[0].id == jobs[0].id

    # The second worker gets the second job
    jobs2 = await datastore.acquire_jobs("worker2", 1)
    assert len(jobs2) == 1
    assert jobs2[0].id == jobs[1].id

    # The third worker gets nothing
    jobs3 = await datastore.acquire_jobs("worker3", 1)
    assert not jobs3


async def test_job_release_success(datastore: DataStore) -> None:
    await datastore.add_task(
        Task(id="task1", func=asynccontextmanager, executor="async")
    )
    job = Job(task_id="task1", result_expiration_time=timedelta(minutes=1))
    await datastore.add_job(job)

    acquired = await datastore.acquire_jobs("worker_id", 2)
    assert len(acquired) == 1
    assert acquired[0].id == job.id

    await datastore.release_job(
        "worker_id",
        acquired[0].task_id,
        JobResult.from_job(
            acquired[0],
            JobOutcome.success,
            return_value="foo",
        ),
    )
    result = await datastore.get_job_result(acquired[0].id)
    assert result.outcome is JobOutcome.success
    assert result.exception is None
    assert result.return_value == "foo"

    # Check that the job and its result are gone
    assert not await datastore.get_jobs({acquired[0].id})
    assert not await datastore.get_job_result(acquired[0].id)


async def test_job_release_failure(datastore: DataStore) -> None:
    await datastore.add_task(
        Task(id="task1", executor="async", func=asynccontextmanager)
    )
    job = Job(task_id="task1", result_expiration_time=timedelta(minutes=1))
    await datastore.add_job(job)

    acquired = await datastore.acquire_jobs("worker_id", 2)
    assert len(acquired) == 1
    assert acquired[0].id == job.id

    await datastore.release_job(
        "worker_id",
        acquired[0].task_id,
        JobResult.from_job(
            acquired[0],
            JobOutcome.error,
            exception=ValueError("foo"),
        ),
    )
    result = await datastore.get_job_result(acquired[0].id)
    assert result.outcome is JobOutcome.error
    assert isinstance(result.exception, ValueError)
    assert result.exception.args == ("foo",)
    assert result.return_value is None

    # Check that the job and its result are gone
    assert not await datastore.get_jobs({acquired[0].id})
    assert not await datastore.get_job_result(acquired[0].id)


async def test_job_release_missed_deadline(datastore: DataStore):
    await datastore.add_task(
        Task(id="task1", func=asynccontextmanager, executor="async")
    )
    job = Job(task_id="task1", result_expiration_time=timedelta(minutes=1))
    await datastore.add_job(job)

    acquired = await datastore.acquire_jobs("worker_id", 2)
    assert len(acquired) == 1
    assert acquired[0].id == job.id

    await datastore.release_job(
        "worker_id",
        acquired[0].task_id,
        JobResult.from_job(
            acquired[0],
            JobOutcome.missed_start_deadline,
        ),
    )
    result = await datastore.get_job_result(acquired[0].id)
    assert result.outcome is JobOutcome.missed_start_deadline
    assert result.exception is None
    assert result.return_value is None

    # Check that the job and its result are gone
    assert not await datastore.get_jobs({acquired[0].id})
    assert not await datastore.get_job_result(acquired[0].id)


async def test_job_release_cancelled(datastore: DataStore) -> None:
    await datastore.add_task(
        Task(id="task1", func=asynccontextmanager, executor="async")
    )
    job = Job(task_id="task1", result_expiration_time=timedelta(minutes=1))
    await datastore.add_job(job)

    acquired = await datastore.acquire_jobs("worker1", 2)
    assert len(acquired) == 1
    assert acquired[0].id == job.id

    await datastore.release_job(
        "worker1",
        acquired[0].task_id,
        JobResult.from_job(acquired[0], JobOutcome.cancelled),
    )
    result = await datastore.get_job_result(acquired[0].id)
    assert result.outcome is JobOutcome.cancelled
    assert result.exception is None
    assert result.return_value is None

    # Check that the job and its result are gone
    assert not await datastore.get_jobs({acquired[0].id})
    assert not await datastore.get_job_result(acquired[0].id)


async def test_acquire_jobs_lock_timeout(
    datastore: DataStore, freezer: FrozenDateTimeFactory
) -> None:
    """
    Test that a worker can acquire jobs that were acquired by another scheduler but
    not released within the lock timeout period.

    """
    await datastore.add_task(
        Task(id="task1", func=asynccontextmanager, executor="async")
    )
    job = Job(task_id="task1", result_expiration_time=timedelta(minutes=1))
    await datastore.add_job(job)

    # First, one worker acquires the first available job
    acquired = await datastore.acquire_jobs("worker1", 1)
    assert len(acquired) == 1
    assert acquired[0].id == job.id

    # Try to acquire the job just at the threshold (now == acquired_until).
    # This should not yield any jobs.
    freezer.tick(30)
    assert not await datastore.acquire_jobs("worker2", 1)

    # Right after that, the job should be available
    freezer.tick(1)
    acquired = await datastore.acquire_jobs("worker2", 1)
    assert len(acquired) == 1
    assert acquired[0].id == job.id


async def test_acquire_jobs_max_number_exceeded(datastore: DataStore) -> None:
    await datastore.add_task(
        Task(id="task1", func=asynccontextmanager, executor="async", max_running_jobs=2)
    )
    jobs = [Job(task_id="task1"), Job(task_id="task1"), Job(task_id="task1")]
    for job in jobs:
        await datastore.add_job(job)

    # Check that only 2 jobs are returned from acquire_jobs() even though the limit
    # wqas 3
    acquired_jobs = await datastore.acquire_jobs("worker1", 3)
    assert [job.id for job in acquired_jobs] == [job.id for job in jobs[:2]]

    # Release one job, and the worker should be able to acquire the third job
    await datastore.release_job(
        "worker1",
        acquired_jobs[0].task_id,
        JobResult.from_job(
            acquired_jobs[0],
            JobOutcome.success,
            return_value=None,
        ),
    )
    acquired_jobs = await datastore.acquire_jobs("worker1", 3)
    assert [job.id for job in acquired_jobs] == [jobs[2].id]


async def test_add_get_task(datastore: DataStore) -> None:
    with pytest.raises(TaskLookupError):
        await datastore.get_task("dummyid")

    await datastore.add_task(
        Task(id="dummyid", func=asynccontextmanager, executor="async")
    )
    task = await datastore.get_task("dummyid")
    assert task.id == "dummyid"
    assert task.func is asynccontextmanager


async def test_cancel_start(
    raw_datastore: DataStore, local_broker: EventBroker
) -> None:
    with CancelScope() as scope:
        scope.cancel()
        async with AsyncExitStack() as exit_stack:
            await raw_datastore.start(exit_stack, local_broker)


async def test_cancel_stop(raw_datastore: DataStore, local_broker: EventBroker) -> None:
    with CancelScope() as scope:
        async with AsyncExitStack() as exit_stack:
            await raw_datastore.start(exit_stack, local_broker)
            scope.cancel()