import asyncio
import os

# Override DATABASE_URL before any app code is imported so the lazy engine
# initialises with SQLite (no asyncpg required in the test environment).
os.environ["DATABASE_URL"] = "sqlite+aiosqlite:///:memory:"

import pytest
import pytest_asyncio
from httpx import AsyncClient, ASGITransport
from sqlalchemy.ext.asyncio import create_async_engine, async_sessionmaker

from app.database import Base, get_db
from app.main import app

TEST_DATABASE_URL = "sqlite+aiosqlite:///:memory:"


@pytest.fixture(scope="session")
def event_loop():
    loop = asyncio.new_event_loop()
    yield loop
    loop.close()


@pytest_asyncio.fixture(scope="session")
async def db_engine():
    engine = create_async_engine(TEST_DATABASE_URL, echo=False)
    async with engine.begin() as conn:
        await conn.run_sync(Base.metadata.create_all)
    yield engine
    await engine.dispose()


@pytest_asyncio.fixture
async def db_session(db_engine):
    factory = async_sessionmaker(db_engine, expire_on_commit=False)
    async with factory() as session:
        yield session
        await session.rollback()


@pytest_asyncio.fixture
async def client(db_session):
    async def override_get_db():
        yield db_session

    app.dependency_overrides[get_db] = override_get_db

    async with AsyncClient(
        transport=ASGITransport(app=app), base_url="http://test"
    ) as ac:
        yield ac

    app.dependency_overrides.clear()