"""Tests for _writeback_edit_plan_config in generation_tasks route.

覆盖 CI 增量覆盖率不足的代码：
- generation_tasks.py 行 160-193 (_writeback_edit_plan_config 函数体)
- generation_tasks.py 行 371-372 (路由中调用该函数)
"""

from __future__ import annotations

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

import pytest

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

from app.api.routes.generation_tasks import _writeback_edit_plan_config


@pytest.fixture
def mock_db():
    """Mock SQLAlchemy Session."""
    db = MagicMock()
    db.query.return_value = db
    db.filter.return_value = db
    return db


@pytest.fixture
def mock_plan():
    """Mock EditPlanModel instance."""
    plan = MagicMock()
    plan.config = {"existing_key": "existing_value"}
    return plan


class TestWritebackEditPlanConfig:
    """_writeback_edit_plan_config 全分支覆盖"""

    # ---- 行 160-161: plan_id 为空直接返回 ----
    def test_empty_plan_id_returns_immediately(self, mock_db):
        _writeback_edit_plan_config(plan_id="", task_id="task_1", title_config={"text": "hi"}, db=mock_db)
        mock_db.query.assert_not_called()
        mock_db.commit.assert_not_called()

    def test_none_plan_id_returns_immediately(self, mock_db):
        _writeback_edit_plan_config(plan_id=None, task_id="task_1", title_config=None, db=mock_db)
        mock_db.query.assert_not_called()

    # ---- 行 165-168: plan 不存在 → warning + 不 commit ----
    def test_plan_not_found_no_commit(self, mock_db):
        mock_db.first.return_value = None

        _writeback_edit_plan_config(plan_id="plan_999", task_id="task_1", title_config=None, db=mock_db)

        mock_db.query.assert_called_once()
        mock_db.commit.assert_not_called()

    # ---- 行 170-182: 正常写入 + title_config ----
    def test_success_with_title_config(self, mock_db, mock_plan):
        mock_db.first.return_value = mock_plan

        _writeback_edit_plan_config(
            plan_id="plan_123",
            task_id="task_456",
            title_config={"text": "标题", "font_size": 36},
            db=mock_db,
        )

        assert mock_plan.config["generation_task_id"] == "task_456"
        assert mock_plan.config["title_config"] == {"text": "标题", "font_size": 36}
        assert mock_plan.config["existing_key"] == "existing_value"
        mock_db.commit.assert_called_once()

    # ---- 行 170-175: 正常写入、无 title_config ----
    def test_success_without_title_config(self, mock_db, mock_plan):
        mock_db.first.return_value = mock_plan

        _writeback_edit_plan_config(plan_id="plan_123", task_id="task_789", title_config=None, db=mock_db)

        assert mock_plan.config["generation_task_id"] == "task_789"
        assert "title_config" not in mock_plan.config
        mock_db.commit.assert_called_once()

    # ---- 行 170: config 不是 dict → 兜底空 dict ----
    def test_config_not_dict_uses_empty_dict(self, mock_db):
        bad_plan = MagicMock()
        bad_plan.config = "not_a_dict"
        mock_db.first.return_value = bad_plan

        _writeback_edit_plan_config(plan_id="plan_123", task_id="task_1", title_config=None, db=mock_db)

        assert isinstance(bad_plan.config, dict)
        assert bad_plan.config["generation_task_id"] == "task_1"
        mock_db.commit.assert_called_once()

    # ---- 行 183-189: DB 异常 → warning + rollback ----
    def test_db_exception_triggers_rollback(self, mock_db, mock_plan):
        mock_db.first.return_value = mock_plan
        mock_db.commit.side_effect = RuntimeError("DB connection lost")

        # 不应抛异常
        _writeback_edit_plan_config(plan_id="plan_123", task_id="task_1", title_config=None, db=mock_db)

        mock_db.rollback.assert_called_once()

    # ---- 行 190-193: rollback 也失败 → 静默 ----
    def test_rollback_failure_silent(self, mock_db, mock_plan):
        mock_db.first.return_value = mock_plan
        mock_db.commit.side_effect = RuntimeError("commit failed")
        mock_db.rollback.side_effect = RuntimeError("rollback also failed")

        # 两个异常都不应抛出
        _writeback_edit_plan_config(plan_id="plan_123", task_id="task_1", title_config=None, db=mock_db)
        mock_db.rollback.assert_called_once()

    # ---- 行 173: title_config 为空 dict → 不写入 title_config ----
    def test_empty_title_config_not_written(self, mock_db, mock_plan):
        mock_db.first.return_value = mock_plan

        _writeback_edit_plan_config(plan_id="plan_123", task_id="task_1", title_config={}, db=mock_db)

        # 空 dict 为 falsy，不写入
        assert "title_config" not in mock_plan.config
        assert mock_plan.config["generation_task_id"] == "task_1"