"""recompose_chapter：锁竞争时 retry（可配置）。"""

from __future__ import annotations

from contextlib import contextmanager
from unittest.mock import MagicMock, patch

import pytest
from celery.exceptions import Retry

from app.core.config import settings
from app.tasks.chapter_compose_tasks import recompose_chapter


class _FakeSyncDb:
    """模拟 `with get_sync_db() as session`。"""

    def __init__(self, session: MagicMock) -> None:
        self._session = session

    def __enter__(self) -> MagicMock:
        return self._session

    def __exit__(self, *exc: object) -> bool:
        return False


def test_recompose_retries_when_lock_busy_and_flag_on(
    monkeypatch: pytest.MonkeyPatch,
) -> None:
    monkeypatch.setattr(
        settings, "memoir_recompose_retry_on_lock_contention", True, raising=False
    )
    session = MagicMock()
    ch = MagicMock()
    ch.markdown_compose_dirty = True
    ch.user_id = "user-1"
    ch.category = "childhood"
    session.get.return_value = ch

    with (
        patch(
            "app.tasks.chapter_compose_tasks.get_sync_db",
            return_value=_FakeSyncDb(session),
        ),
        patch(
            "app.tasks.chapter_compose_tasks.acquire_chapter_pipeline_lock",
            return_value=None,
        ),
    ):
        with patch.object(
            recompose_chapter, "retry", side_effect=Retry("lock_busy")
        ) as mock_retry:
            with pytest.raises(Retry):
                recompose_chapter.run("chapter-1")
        mock_retry.assert_called_once()
        _, kwargs = mock_retry.call_args
        assert "countdown" in kwargs


def test_recompose_skips_when_lock_busy_and_flag_off(
    monkeypatch: pytest.MonkeyPatch,
) -> None:
    monkeypatch.setattr(
        settings, "memoir_recompose_retry_on_lock_contention", False, raising=False
    )
    session = MagicMock()
    ch = MagicMock()
    ch.markdown_compose_dirty = True
    ch.user_id = "user-1"
    ch.category = "childhood"
    session.get.return_value = ch

    with (
        patch(
            "app.tasks.chapter_compose_tasks.get_sync_db",
            return_value=_FakeSyncDb(session),
        ),
        patch(
            "app.tasks.chapter_compose_tasks.acquire_chapter_pipeline_lock",
            return_value=None,
        ),
    ):
        with patch.object(recompose_chapter, "retry") as mock_retry:
            out = recompose_chapter.run("chapter-1")
        assert out == {"status": "skip_lock_contention"}
        mock_retry.assert_not_called()