import asyncio
import uuid
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.database import Base, get_db
from app.main import create_app

# Use a unique in-memory-like approach: create a separate test DB schema
TEST_DATABASE_URL = "postgresql+asyncpg://ai_assistant:changeme@localhost:5432/ai_assistant_test"


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


@pytest.fixture(scope="session")
async def test_engine():
    engine = create_async_engine(TEST_DATABASE_URL)
    async with engine.begin() as conn:
        await conn.run_sync(Base.metadata.drop_all)
        await conn.run_sync(Base.metadata.create_all)
    yield engine
    async with engine.begin() as conn:
        await conn.run_sync(Base.metadata.drop_all)
    await engine.dispose()


@pytest.fixture
async def db_session(test_engine) -> AsyncGenerator[AsyncSession, None]:
    session_factory = async_sessionmaker(test_engine, class_=AsyncSession, expire_on_commit=False)
    async with session_factory() as session:
        yield session
        await session.rollback()


@pytest.fixture
async def client(test_engine) -> AsyncGenerator[AsyncClient, None]:
    session_factory = async_sessionmaker(test_engine, class_=AsyncSession, expire_on_commit=False)

    async def override_get_db():
        async with session_factory() as session:
            try:
                yield session
                await session.commit()
            except Exception:
                await session.rollback()
                raise

    app = create_app()
    app.dependency_overrides[get_db] = override_get_db

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