import pytest
import pytest_asyncio
from sqlalchemy.ext.asyncio import create_async_engine, AsyncSession
from sqlmodel import SQLModel
from sqlalchemy.orm import sessionmaker
from httpx import AsyncClient, ASGITransport
from app.main import app
from app.database import get_session

@pytest_asyncio.fixture(scope="function")
async def engine():
    """Create a fresh in-memory SQLite engine for each test."""
    engine = create_async_engine(
        "sqlite+aiosqlite:///:memory:",
        echo=False,
    )
    # Create tables for each test to ensure a clean state
    async with engine.begin() as conn:
        await conn.run_sync(SQLModel.metadata.create_all)
    yield engine
    await engine.dispose()

@pytest_asyncio.fixture
async def session_factory(engine):
    """Create async session factory."""
    return sessionmaker(engine, class_=AsyncSession, expire_on_commit=False)

@pytest_asyncio.fixture
async def db_session(session_factory):
    """Create a database session for a test."""
    async with session_factory() as session:
        yield session
        # Rollback is still good practice, though engine is fresh each time

@pytest.fixture
def sample_session_data():
    """Sample sleep session data for testing."""
    return {
        "start_time": "2024-01-15T21:30:00Z",
    }

@pytest_asyncio.fixture
async def api_client(db_session):
    """Provides an AsyncClient for testing API endpoints with the test database session."""
    async def override():
        yield db_session
    app.dependency_overrides[get_session] = override
    async with AsyncClient(
        transport=ASGITransport(app=app), base_url="http://test"
    ) as client:
        yield client
    app.dependency_overrides.clear()