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# 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
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# KIND, either express or implied.  See the License for the
# specific language governing permissions and limitations
# under the License.
# pylint: disable=import-outside-toplevel, unused-argument
from __future__ import annotations

from collections.abc import Generator
from datetime import datetime, timedelta
from typing import TYPE_CHECKING
from unittest.mock import patch

import pytest
from flask.ctx import AppContext

from superset.extensions import db
from superset.key_value.types import JsonKeyValueCodec, KeyValueResource

if TYPE_CHECKING:
    from superset.key_value.models import KeyValueEntry

RESOURCE = KeyValueResource.METASTORE_CACHE
CODEC = JsonKeyValueCodec()
VALUE = {"foo": "bar"}


@pytest.fixture
def clean_key_value_store(app_context: AppContext) -> Generator[None, None, None]:
    # The prune command commits, so a plain session rollback cannot undo its
    # effects. Explicitly empty the table around each test for isolation.
    from superset.key_value.models import KeyValueEntry

    db.session.query(KeyValueEntry).delete()
    db.session.commit()  # pylint: disable=consider-using-transaction
    yield
    db.session.query(KeyValueEntry).delete()
    db.session.commit()  # pylint: disable=consider-using-transaction


def _add_entry(expires_on: datetime | None) -> KeyValueEntry:
    from superset.key_value.models import KeyValueEntry

    entry = KeyValueEntry(
        resource=RESOURCE,
        value=CODEC.encode(VALUE),
        expires_on=expires_on,
    )
    db.session.add(entry)
    db.session.flush()
    return entry


def test_prune_deletes_expired_entries(
    clean_key_value_store: None,
) -> None:
    from superset.key_value.commands.prune import KeyValuePruneCommand
    from superset.key_value.models import KeyValueEntry

    expired_a = _add_entry(datetime.now() - timedelta(days=1))
    expired_b = _add_entry(datetime.now() - timedelta(seconds=5))
    expired_ids = {expired_a.id, expired_b.id}

    KeyValuePruneCommand().run()

    remaining_ids = {row.id for row in db.session.query(KeyValueEntry.id).all()}
    assert expired_ids.isdisjoint(remaining_ids)
    assert db.session.query(KeyValueEntry).count() == 0


def test_prune_retains_non_expired_and_no_expiry_entries(
    clean_key_value_store: None,
) -> None:
    from superset.key_value.commands.prune import KeyValuePruneCommand
    from superset.key_value.models import KeyValueEntry

    future = _add_entry(datetime.now() + timedelta(days=1))
    no_expiry = _add_entry(None)
    expired = _add_entry(datetime.now() - timedelta(days=1))

    KeyValuePruneCommand().run()

    remaining_ids = {row.id for row in db.session.query(KeyValueEntry.id).all()}
    assert future.id in remaining_ids
    assert no_expiry.id in remaining_ids
    assert expired.id not in remaining_ids
    assert db.session.query(KeyValueEntry).count() == 2


def test_prune_empty_store_is_noop(
    clean_key_value_store: None,
) -> None:
    from superset.key_value.commands.prune import KeyValuePruneCommand
    from superset.key_value.models import KeyValueEntry

    assert db.session.query(KeyValueEntry).count() == 0

    # Should not raise and should leave the store empty
    KeyValuePruneCommand().run()

    assert db.session.query(KeyValueEntry).count() == 0


def test_prune_skips_entry_refreshed_after_selection(
    clean_key_value_store: None,
) -> None:
    from superset.key_value.commands.prune import KeyValuePruneCommand
    from superset.key_value.models import KeyValueEntry

    # Simulate the TOCTOU window: an entry is expired when prune selects it but
    # is refreshed (expires_on moved into the future) before the delete runs.
    # The delete re-checks expiry against the cutoff captured at selection time,
    # so the refreshed entry must survive. We inject the refresh right after the
    # command captures its cutoff by patching datetime.now used in the command.
    expired = _add_entry(datetime.now() - timedelta(days=1))
    db.session.commit()  # pylint: disable=consider-using-transaction

    import superset.key_value.commands.prune as prune_module

    real_now = datetime.now
    state = {"refreshed": False}

    class _PatchedDatetime:
        @staticmethod
        def now() -> datetime:
            # The command calls now() once to capture the cutoff. After that
            # call, refresh the entry so the subsequent delete sees a future
            # expires_on but still deletes against the original cutoff.
            current = real_now()
            if not state["refreshed"]:
                state["refreshed"] = True
                db.session.query(KeyValueEntry).filter(
                    KeyValueEntry.id == expired.id
                ).update({KeyValueEntry.expires_on: real_now() + timedelta(days=1)})
                db.session.commit()  # pylint: disable=consider-using-transaction
            return current

    with patch.object(prune_module, "datetime", _PatchedDatetime):
        KeyValuePruneCommand().run()

    remaining_ids = {row.id for row in db.session.query(KeyValueEntry.id).all()}
    assert expired.id in remaining_ids


def test_prune_respects_max_rows_per_run(
    clean_key_value_store: None,
) -> None:
    from superset.key_value.commands.prune import KeyValuePruneCommand
    from superset.key_value.models import KeyValueEntry

    for _ in range(3):
        _add_entry(datetime.now() - timedelta(days=1))

    KeyValuePruneCommand(max_rows_per_run=2).run()

    # Only the two oldest expired rows are removed in a single capped run
    assert db.session.query(KeyValueEntry).count() == 1