from slowapi import Limiter
from slowapi.util import get_remote_address
from fastapi import Request
from app.config import settings

def get_real_client_ip(request: Request) -> str:
    """Extract real client IP address behind reverse proxies (Cloudflare, Railway, Vercel, ALB)."""
    cf_ip = request.headers.get("CF-Connecting-IP")
    if cf_ip:
        return cf_ip.strip()
    
    forwarded = request.headers.get("X-Forwarded-For")
    if forwarded:
        return forwarded.split(",")[0].strip()
    
    real_ip = request.headers.get("X-Real-IP")
    if real_ip:
        return real_ip.strip()
        
    return get_remote_address(request)

limiter = Limiter(key_func=get_real_client_ip, default_limits=[settings.RATE_LIMIT])