"""P3 优化单元测试 — generation.py 三项优化.

覆盖：
  P3-1: _download_library_assets strict 模式
  P3-2: 归属校验合并到同一 DB session
  P3-3: _verify_url_accessible HEAD 重试
"""

from __future__ import annotations

import sys
from pathlib import Path
from types import SimpleNamespace
from unittest.mock import MagicMock, patch

import pytest

sys.path.insert(0, str(Path(__file__).resolve().parents[2] / "apps" / "worker"))


# ── P3-3: _verify_url_accessible 重试 ───────────────────────────────────────


class TestVerifyUrlAccessibleRetry:
    """_verify_url_accessible 重试逻辑."""

    @patch("time.sleep")
    @patch("urllib.request.OpenerDirector.open")
    def test_first_attempt_success(self, mock_open, mock_sleep):
        """首次成功，不重试."""
        from worker_app.tasks.generation import _verify_url_accessible

        mock_resp = MagicMock()
        mock_resp.status = 200
        mock_resp.__enter__ = MagicMock(return_value=mock_resp)
        mock_resp.__exit__ = MagicMock(return_value=False)
        mock_open.return_value = mock_resp

        assert _verify_url_accessible("https://example.com/file.mp4") is True
        assert mock_open.call_count == 1
        mock_sleep.assert_not_called()

    @patch("time.sleep")
    @patch("urllib.request.OpenerDirector.open")
    def test_retry_then_success(self, mock_open, mock_sleep):
        """首次失败，重试后成功."""
        from worker_app.tasks.generation import _verify_url_accessible

        # 第一次失败（网络异常），第二次成功
        mock_resp_ok = MagicMock()
        mock_resp_ok.status = 200
        mock_resp_ok.__enter__ = MagicMock(return_value=mock_resp_ok)
        mock_resp_ok.__exit__ = MagicMock(return_value=False)

        mock_open.side_effect = [
            OSError("connection reset"),
            mock_resp_ok,
        ]

        assert _verify_url_accessible("https://example.com/file.mp4") is True
        assert mock_open.call_count == 2
        mock_sleep.assert_called_once_with(1)

    @patch("time.sleep")
    @patch("urllib.request.OpenerDirector.open")
    def test_all_retries_exhausted(self, mock_open, mock_sleep):
        """全部重试耗尽，返回 False."""
        from worker_app.tasks.generation import _verify_url_accessible

        mock_open.side_effect = OSError("connection refused")

        assert _verify_url_accessible("https://example.com/file.mp4") is False
        # 1 首次 + 2 重试 = 3 次
        assert mock_open.call_count == 3
        assert mock_sleep.call_count == 2

    @patch("time.sleep")
    @patch("urllib.request.OpenerDirector.open")
    def test_http_500_then_success(self, mock_open, mock_sleep):
        """HTTP 500 后重试成功."""
        from worker_app.tasks.generation import _verify_url_accessible

        mock_resp_500 = MagicMock()
        mock_resp_500.status = 500
        mock_resp_500.__enter__ = MagicMock(return_value=mock_resp_500)
        mock_resp_500.__exit__ = MagicMock(return_value=False)

        mock_resp_200 = MagicMock()
        mock_resp_200.status = 200
        mock_resp_200.__enter__ = MagicMock(return_value=mock_resp_200)
        mock_resp_200.__exit__ = MagicMock(return_value=False)

        mock_open.side_effect = [mock_resp_500, mock_resp_200]

        assert _verify_url_accessible("https://example.com/file.mp4") is True
        assert mock_open.call_count == 2

    @patch("time.sleep")
    @patch("urllib.request.OpenerDirector.open")
    def test_custom_retries_zero(self, mock_open, mock_sleep):
        """retries=0 时不重试."""
        from worker_app.tasks.generation import _verify_url_accessible

        mock_open.side_effect = OSError("timeout")

        assert _verify_url_accessible("https://example.com/file.mp4", retries=0) is False
        assert mock_open.call_count == 1
        mock_sleep.assert_not_called()


# ── P3-1: _download_library_assets strict 模式 ──────────────────────────────


def _make_mock_asset(
    asset_id: str,
    name: str,
    file_url: str | None,
    asset_library_id: str = "lib-1",
    project_id: str = "",
):
    """构造 mock AssetModel 实例."""
    return SimpleNamespace(
        id=asset_id,
        name=name,
        file_url=file_url,
        asset_library_id=asset_library_id,
        project_id=project_id,
        status="ready",
        file_type="video",
        created_at="2026-01-01",
    )


def _setup_mock_session(assets):
    """构造 mock session，返回 (mock_session, mock_query_chain)."""
    mock_session = MagicMock()
    mock_query = MagicMock()

    # chain: session.query().filter().filter().order_by().all()
    mock_session.query.return_value = mock_query
    mock_query.filter.return_value = mock_query
    mock_query.order_by.return_value = mock_query
    mock_query.all.return_value = assets

    return mock_session


class TestDownloadLibraryAssetsStrictMode:
    """_download_library_assets strict 模式."""

    @patch("worker_app.tasks.generation.SessionLocal")
    @patch("worker_app.tasks.generation.download_asset")
    def test_strict_mode_raises_on_download_failure(self, mock_download, mock_session_factory):
        """strict=True 时，单个素材下载失败立即抛 RuntimeError."""
        from worker_app.tasks.generation import _download_library_assets

        assets = [
            _make_mock_asset("a1", "video1.mp4", "uploads/video1.mp4"),
            _make_mock_asset("a2", "video2.mp4", "uploads/video2.mp4"),
        ]
        mock_session = _setup_mock_session(assets)
        mock_session_factory.return_value = mock_session

        # 第一个成功，第二个失败
        mock_download.side_effect = [True, False]

        with pytest.raises(RuntimeError, match="素材下载失败"):
            _download_library_assets(
                Path("/tmp"),
                asset_library_id="lib-1",
                asset_ids=["a1", "a2"],
                strict=True,
            )

    @patch("worker_app.tasks.generation.SessionLocal")
    @patch("worker_app.tasks.generation.download_asset")
    def test_non_strict_mode_returns_partial_results(self, mock_download, mock_session_factory):
        """strict=False 时，跳过失败素材，返回成功列表."""
        from worker_app.tasks.generation import _download_library_assets

        assets = [
            _make_mock_asset("a1", "video1.mp4", "uploads/video1.mp4"),
            _make_mock_asset("a2", "video2.mp4", "uploads/video2.mp4"),
            _make_mock_asset("a3", "video3.mp4", "uploads/video3.mp4"),
        ]
        mock_session = _setup_mock_session(assets)
        mock_session_factory.return_value = mock_session

        # 第一个成功，第二个失败，第三个成功
        mock_download.side_effect = [True, False, True]

        result = _download_library_assets(
            Path("/tmp"),
            asset_library_id="lib-1",
            asset_ids=["a1", "a2", "a3"],
            strict=False,
        )

        assert len(result) == 2

    @patch("worker_app.tasks.generation.SessionLocal")
    @patch("worker_app.tasks.generation.download_asset")
    def test_non_strict_all_fail_raises(self, mock_download, mock_session_factory):
        """strict=False 但全部失败时仍抛 RuntimeError."""
        from worker_app.tasks.generation import _download_library_assets

        assets = [
            _make_mock_asset("a1", "video1.mp4", "uploads/video1.mp4"),
        ]
        mock_session = _setup_mock_session(assets)
        mock_session_factory.return_value = mock_session
        mock_download.return_value = False

        with pytest.raises(RuntimeError, match="全部下载失败"):
            _download_library_assets(
                Path("/tmp"),
                asset_library_id="lib-1",
                asset_ids=["a1"],
                strict=False,
            )

    @patch("worker_app.tasks.generation.SessionLocal")
    @patch("worker_app.tasks.generation.download_asset")
    def test_strict_mode_raises_on_missing_file_url(self, mock_download, mock_session_factory):
        """strict=True 时，素材缺少 file_url 立即抛异常."""
        from worker_app.tasks.generation import _download_library_assets

        assets = [
            _make_mock_asset("a1", "video1.mp4", None),  # file_url 为空
        ]
        mock_session = _setup_mock_session(assets)
        mock_session_factory.return_value = mock_session

        with pytest.raises(RuntimeError, match="素材缺少 file_url"):
            _download_library_assets(
                Path("/tmp"),
                asset_library_id="lib-1",
                strict=True,
            )

        # download_asset 不应被调用
        mock_download.assert_not_called()

    @patch("worker_app.tasks.generation.SessionLocal")
    @patch("worker_app.tasks.generation.download_asset")
    def test_default_is_strict(self, mock_download, mock_session_factory):
        """默认 strict=True."""
        from worker_app.tasks.generation import _download_library_assets

        assets = [
            _make_mock_asset("a1", "video1.mp4", "uploads/video1.mp4"),
        ]
        mock_session = _setup_mock_session(assets)
        mock_session_factory.return_value = mock_session
        mock_download.return_value = False

        # 不传 strict 参数，默认严格模式
        with pytest.raises(RuntimeError, match="素材下载失败"):
            _download_library_assets(
                Path("/tmp"),
                asset_library_id="lib-1",
            )


# ── P3-2: 归属校验合并到同一 session ────────────────────────────────────────


class TestDownloadLibraryAssetsOwnershipValidation:
    """归属校验合并到 _download_library_assets 同一 session."""

    @patch("worker_app.tasks.generation.SessionLocal")
    @patch("worker_app.tasks.generation.download_asset")
    def test_ownership_mismatch_raises_value_error(self, mock_download, mock_session_factory):
        """asset_ids 不属于指定素材库时抛 ValueError."""
        from worker_app.tasks.generation import _download_library_assets

        # asset 属于 lib-2，但请求的是 lib-1
        assets = [
            _make_mock_asset("a1", "video1.mp4", "uploads/video1.mp4", asset_library_id="lib-2"),
        ]
        mock_session = _setup_mock_session(assets)
        mock_session_factory.return_value = mock_session

        with pytest.raises(ValueError, match="素材不属于指定素材库"):
            _download_library_assets(
                Path("/tmp"),
                asset_library_id="lib-1",
                asset_ids=["a1"],
            )

        # 不应调用 download_asset（校验在下载前）
        mock_download.assert_not_called()

    @patch("worker_app.tasks.generation.SessionLocal")
    @patch("worker_app.tasks.generation.download_asset")
    def test_missing_asset_ids_raises_value_error(self, mock_download, mock_session_factory):
        """指定的 asset_ids 不存在时抛 ValueError."""
        from worker_app.tasks.generation import _download_library_assets

        # DB 返回空（asset_ids 不存在，query 过滤后无结果）
        mock_session = _setup_mock_session([])
        mock_session_factory.return_value = mock_session

        with pytest.raises(RuntimeError, match="未找到视频素材"):
            _download_library_assets(
                Path("/tmp"),
                asset_library_id="lib-1",
                asset_ids=["nonexistent-id"],
            )

    @patch("worker_app.tasks.generation.SessionLocal")
    @patch("worker_app.tasks.generation.download_asset")
    def test_project_ownership_mismatch_raises(self, mock_download, mock_session_factory):
        """项目级模式下归属不匹配抛 ValueError."""
        from worker_app.tasks.generation import _download_library_assets

        assets = [
            _make_mock_asset(
                "a1",
                "video1.mp4",
                "uploads/video1.mp4",
                asset_library_id="",
                project_id="proj-2",
            ),
        ]
        mock_session = _setup_mock_session(assets)
        mock_session_factory.return_value = mock_session

        with pytest.raises(ValueError, match="素材不属于指定项目"):
            _download_library_assets(
                Path("/tmp"),
                project_id="proj-1",
                asset_ids=["a1"],
            )

        mock_download.assert_not_called()

    @patch("worker_app.tasks.generation.SessionLocal")
    @patch("worker_app.tasks.generation.download_asset")
    def test_ownership_pass_then_download(self, mock_download, mock_session_factory):
        """归属校验通过后正常下载."""
        from worker_app.tasks.generation import _download_library_assets

        assets = [
            _make_mock_asset("a1", "video1.mp4", "uploads/video1.mp4", asset_library_id="lib-1"),
        ]
        mock_session = _setup_mock_session(assets)
        mock_session_factory.return_value = mock_session
        mock_download.return_value = True

        result = _download_library_assets(
            Path("/tmp"),
            asset_library_id="lib-1",
            asset_ids=["a1"],
        )

        assert len(result) == 1
        mock_download.assert_called_once()

    @patch("worker_app.tasks.generation.SessionLocal")
    @patch("worker_app.tasks.generation.download_asset")
    def test_single_session_used(self, mock_download, mock_session_factory):
        """验证只创建了一个 DB session（P3-2 核心）."""
        from worker_app.tasks.generation import _download_library_assets

        assets = [
            _make_mock_asset("a1", "video1.mp4", "uploads/video1.mp4", asset_library_id="lib-1"),
        ]
        mock_session = _setup_mock_session(assets)
        mock_session_factory.return_value = mock_session
        mock_download.return_value = True

        _download_library_assets(
            Path("/tmp"),
            asset_library_id="lib-1",
            asset_ids=["a1"],
        )

        # SessionLocal 只调用一次（合并前会调用两次：校验 + 下载）
        assert mock_session_factory.call_count == 1