"""Pytest fixtures — gerçek test DB, async client, get_db override.

ARCHITECTURE §13: DB mock yasak. Gerçek MySQL kullanılır.
NullPool: her test kendi loop'unda; cross-loop connection reuse engellenir.
"""
import uuid
from collections.abc import AsyncGenerator

import pytest_asyncio
from httpx import ASGITransport, AsyncClient
from sqlalchemy.ext.asyncio import (
    AsyncSession,
    async_sessionmaker,
    create_async_engine,
)
from sqlalchemy.pool import NullPool

from app.config import settings
from app.database import get_db
from app.main import app

test_engine = create_async_engine(
    settings.database_url, poolclass=NullPool, echo=False
)
TestSessionFactory = async_sessionmaker(
    bind=test_engine, class_=AsyncSession, expire_on_commit=False, autoflush=False
)


async def _override_get_db() -> AsyncGenerator[AsyncSession, None]:
    async with TestSessionFactory() as session:
        try:
            yield session
        except Exception:
            await session.rollback()
            raise


@pytest_asyncio.fixture
async def client() -> AsyncGenerator[AsyncClient, None]:
    app.dependency_overrides[get_db] = _override_get_db
    transport = ASGITransport(app=app)
    async with AsyncClient(transport=transport, base_url="http://test") as c:
        yield c
    app.dependency_overrides.clear()


@pytest_asyncio.fixture
async def db() -> AsyncGenerator[AsyncSession, None]:
    async with TestSessionFactory() as session:
        yield session


def unique_email() -> str:
    return f"t_{uuid.uuid4().hex[:10]}@example.com"