"""FastAPI dependency injection providers."""

from typing import AsyncGenerator

from fastapi import Request
from sqlalchemy.ext.asyncio import AsyncSession

from src.infrastructure.db import AsyncSessionLocal
from src.infrastructure.redis import RedisCache, get_redis


async def get_db_session() -> AsyncGenerator[AsyncSession, None]:
    """Yield a database session for FastAPI dependency injection."""
    session = AsyncSessionLocal()
    try:
        yield session
        await session.commit()
    except Exception:
        await session.rollback()
        raise
    finally:
        await session.close()


async def get_cache() -> AsyncGenerator[RedisCache, None]:
    """Yield a Redis cache instance."""
    redis = await get_redis()
    yield RedisCache(redis)


def get_client_ip(request: Request) -> str:
    """Extract client IP from request, handling proxies."""
    forwarded = request.headers.get("x-forwarded-for")
    if forwarded:
        return forwarded.split(",")[0].strip()
    return request.client.host if request.client else "unknown"