"""
Pytest configuration and global fixtures.
Initializes a temporary in-memory/file-based SQLite database for unit & integration tests.
"""
from __future__ import annotations

import asyncio
from typing import AsyncGenerator, Generator
import pytest
from httpx import ASGITransport, AsyncClient
from sqlalchemy.ext.asyncio import AsyncSession, create_async_engine, async_sessionmaker

import sys
import os

# Adjust path to import app, agents, and services modules (local dev & container support)
base_dir = os.path.abspath(os.path.join(os.path.dirname(__file__), ".."))
sys.path.insert(0, os.path.join(base_dir, "backend"))
sys.path.insert(0, base_dir)
for extra_path in ["/app", "/agents", "/services"]:
    if os.path.exists(extra_path) and extra_path not in sys.path:
        sys.path.insert(0, extra_path)

from app.core.config import settings
from app.core.database import Base, get_db as db_get_db
from app.core.dependencies import get_db as dep_get_db
from app.main import app

# ── Test Database Configuration ───────────────────────────────
TEST_DB_URL = "sqlite+aiosqlite:///:memory:"

test_engine = create_async_engine(
    TEST_DB_URL,
    connect_args={"check_same_thread": False},
)

TestAsyncSessionLocal = async_sessionmaker(
    bind=test_engine,
    class_=AsyncSession,
    expire_on_commit=False,
    autocommit=False,
    autoflush=False,
)


@pytest.fixture(scope="session", autouse=True)
async def init_test_db():
    """Create all tables in the test database on session startup."""
    async with test_engine.begin() as conn:
        await conn.run_sync(Base.metadata.create_all)
    yield
    async with test_engine.begin() as conn:
        await conn.run_sync(Base.metadata.drop_all)
    await test_engine.dispose()


@pytest.fixture
async def db_session() -> AsyncGenerator[AsyncSession, None]:
    """Provide an isolated database session per test with rollback safety."""
    async with TestAsyncSessionLocal() as session:
        try:
            yield session
        finally:
            await session.rollback()
            await session.close()


@pytest.fixture
async def client(db_session: AsyncSession) -> AsyncGenerator[AsyncClient, None]:
    """Provide an HTTPX AsyncClient with database session overridden."""
    async def override_get_db():
        yield db_session

    app.dependency_overrides[db_get_db] = override_get_db
    app.dependency_overrides[dep_get_db] = override_get_db
    transport = ASGITransport(app=app)
    async with AsyncClient(transport=transport, base_url="http://test") as ac:
        yield ac
    app.dependency_overrides.clear()