"""Gemeinsame Test-Fixtures. Nutzt eine separate Testdatenbank."""

import os

# Muss vor dem ersten Import der Anwendung gesetzt sein, da die Settings gecacht werden.
os.environ.setdefault(
    "DATABASE_URL",
    os.environ.get(
        "TEST_DATABASE_URL",
        "postgresql+asyncpg://moneyfy:moneyfy@127.0.0.1:5432/moneyfy_test",
    ),
)
os.environ.setdefault("SECRET_KEY", "test-secret-key")
os.environ.setdefault("ENVIRONMENT", "test")

from collections.abc import AsyncGenerator

import pytest
from httpx import ASGITransport, AsyncClient
from sqlalchemy.ext.asyncio import (
    AsyncSession,
    async_sessionmaker,
    create_async_engine,
)

from app.core.config import settings
from app.db.session import get_session
from app.main import app as fastapi_app
from app.models import Base


@pytest.fixture(scope="session")
def anyio_backend() -> str:
    return "asyncio"


@pytest.fixture(scope="session")
async def engine():
    """Legt das Schema einmal pro Testlauf frisch an."""
    test_engine = create_async_engine(str(settings.database_url), poolclass=None)
    async with test_engine.begin() as conn:
        await conn.run_sync(Base.metadata.drop_all)
        await conn.run_sync(Base.metadata.create_all)
    yield test_engine
    await test_engine.dispose()


@pytest.fixture
async def session(engine) -> AsyncGenerator[AsyncSession, None]:
    """Eine Session je Test, am Ende wird zurückgerollt."""
    connection = await engine.connect()
    transaction = await connection.begin()
    # `create_savepoint` sorgt dafür, dass session.commit() nur den Savepoint freigibt
    # und der abschließende Rollback wirklich alle Testdaten entfernt.
    maker = async_sessionmaker(
        bind=connection,
        expire_on_commit=False,
        autoflush=False,
        join_transaction_mode="create_savepoint",
    )
    async with maker() as db_session:
        yield db_session
    await transaction.rollback()
    await connection.close()


@pytest.fixture
async def client(session: AsyncSession) -> AsyncGenerator[AsyncClient, None]:
    """HTTP-Client gegen die App, alle Requests laufen in der Test-Transaktion."""

    async def _override() -> AsyncGenerator[AsyncSession, None]:
        yield session

    fastapi_app.dependency_overrides[get_session] = _override
    transport = ASGITransport(app=fastapi_app)
    async with AsyncClient(transport=transport, base_url="http://test") as http_client:
        yield http_client
    fastapi_app.dependency_overrides.clear()