"""Shared fixtures for Chrysopedia integration tests.

Provides:
- Async SQLAlchemy engine/session against a real PostgreSQL test database
- httpx.AsyncClient wired to the FastAPI app with dependency overrides
- Sample transcript fixture path and temporary storage directory

Key design choice: function-scoped engine with NullPool avoids asyncpg
"another operation in progress" errors caused by session-scoped connection
reuse between the ASGI test client and verification queries.
"""

import os
import pathlib

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

# Ensure backend/ is on sys.path so "from models import ..." works
import sys
sys.path.insert(0, str(pathlib.Path(__file__).resolve().parent.parent))

from database import Base, get_session  # noqa: E402
from main import app  # noqa: E402

TEST_DATABASE_URL = os.getenv(
    "TEST_DATABASE_URL",
    "postgresql+asyncpg://chrysopedia:changeme@localhost:5433/chrysopedia_test",
)


@pytest_asyncio.fixture()
async def db_engine():
    """Create a per-test async engine (NullPool) and create/drop all tables."""
    engine = create_async_engine(TEST_DATABASE_URL, echo=False, poolclass=NullPool)

    # Create all tables fresh for each test
    async with engine.begin() as conn:
        await conn.run_sync(Base.metadata.drop_all)
        await conn.run_sync(Base.metadata.create_all)

    yield engine

    # Drop all tables after test
    async with engine.begin() as conn:
        await conn.run_sync(Base.metadata.drop_all)

    await engine.dispose()


@pytest_asyncio.fixture()
async def client(db_engine, tmp_path):
    """Async HTTP test client wired to FastAPI with dependency overrides."""
    session_factory = async_sessionmaker(
        db_engine, class_=AsyncSession, expire_on_commit=False
    )

    async def _override_get_session():
        async with session_factory() as session:
            yield session

    # Override DB session dependency
    app.dependency_overrides[get_session] = _override_get_session

    # Override transcript_storage_path via environment variable
    os.environ["TRANSCRIPT_STORAGE_PATH"] = str(tmp_path)
    # Clear the lru_cache so Settings picks up the new env var
    from config import get_settings
    get_settings.cache_clear()

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

    # Teardown: clean overrides and restore settings cache
    app.dependency_overrides.clear()
    os.environ.pop("TRANSCRIPT_STORAGE_PATH", None)
    get_settings.cache_clear()


@pytest.fixture()
def sample_transcript_path() -> pathlib.Path:
    """Path to the sample 5-segment transcript JSON fixture."""
    return pathlib.Path(__file__).parent / "fixtures" / "sample_transcript.json"


@pytest.fixture()
def tmp_transcript_dir(tmp_path) -> pathlib.Path:
    """Temporary directory for transcript storage during tests."""
    return tmp_path