"""
基础单元测试 —— 测试 TodoService 的核心功能。

运行方式：
    cd codegen-runs/codegen_a2cef5070965479b93c5b3c07d4c8216
    pytest tests/ -v
"""

import pytest
from app.services import TodoService, TodoCreate, TodoUpdate


@pytest.fixture
def service() -> TodoService:
    """每个测试用例使用独立的 TodoService 实例。"""
    return TodoService()


class TestTodoService:
    """TodoService 核心功能测试。"""

    def test_list_todos_should_return_mock_data(self, service: TodoService):
        """测试初始化时自动生成假数据。"""
        todos = service.list_todos()
        assert len(todos) == 5  # 初始化了 5 条假数据

    def test_create_todo_should_return_created_todo(self, service: TodoService):
        """测试创建待办事项。"""
        todo_in = TodoCreate(title="新任务", completed=True)
        todo = service.create_todo(todo_in)
        assert todo.title == "新任务"
        assert todo.completed is True
        assert todo.id > 0

    def test_get_todo_should_return_correct_todo(self, service: TodoService):
        """测试根据 ID 获取待办事项。"""
        # 先创建
        created = service.create_todo(TodoCreate(title="测试任务"))
        # 再获取
        fetched = service.get_todo(created.id)
        assert fetched is not None
        assert fetched.id == created.id
        assert fetched.title == "测试任务"

    def test_get_todo_should_return_none_when_not_found(self, service: TodoService):
        """测试获取不存在的待办事项返回 None。"""
        todo = service.get_todo(99999)
        assert todo is None

    def test_update_todo_should_update_title(self, service: TodoService):
        """测试部分更新待办事项的标题。"""
        created = service.create_todo(TodoCreate(title="旧标题"))
        updated = service.update_todo(created.id, TodoUpdate(title="新标题"))
        assert updated is not None
        assert updated.title == "新标题"
        assert updated.completed is False  # 未更新的字段保持不变

    def test_update_todo_should_update_completed(self, service: TodoService):
        """测试部分更新待办事项的完成状态。"""
        created = service.create_todo(TodoCreate(title="任务", completed=False))
        updated = service.update_todo(created.id, TodoUpdate(completed=True))
        assert updated is not None
        assert updated.completed is True
        assert updated.title == "任务"  # 未更新的字段保持不变

    def test_update_todo_should_return_none_when_not_found(self, service: TodoService):
        """测试更新不存在的待办事项返回 None。"""
        result = service.update_todo(99999, TodoUpdate(title="无"))
        assert result is None

    def test_delete_todo_should_return_true(self, service: TodoService):
        """测试删除存在的待办事项返回 True。"""
        created = service.create_todo(TodoCreate(title="待删除"))
        result = service.delete_todo(created.id)
        assert result is True
        # 确认已删除
        assert service.get_todo(created.id) is None

    def test_delete_todo_should_return_false_when_not_found(self, service: TodoService):
        """测试删除不存在的待办事项返回 False。"""
        result = service.delete_todo(99999)
        assert result is False

    def test_list_todos_after_create_and_delete(self, service: TodoService):
        """测试增删操作后列表长度的变化。"""
        initial_count = len(service.list_todos())
        # 创建 2 个
        t1 = service.create_todo(TodoCreate(title="A"))
        t2 = service.create_todo(TodoCreate(title="B"))
        assert len(service.list_todos()) == initial_count + 2
        # 删除 1 个
        service.delete_todo(t1.id)
        assert len(service.list_todos()) == initial_count + 1
        # 删除另一个
        service.delete_todo(t2.id)
        assert len(service.list_todos()) == initial_count


@pytest.mark.asyncio
async def test_fastapi_health_check():
    """简单的 FastAPI 健康检查测试（使用 TestClient）。"""
    from httpx import AsyncClient, ASGITransport
    from app.main import app

    transport = ASGITransport(app=app)
    async with AsyncClient(transport=transport, base_url="http://test") as client:
        response = await client.get("/")
        assert response.status_code == 200
        data = response.json()
        assert "service" in data
        assert data["service"] == "Todo 管理服务"