import httpx
from fastapi import FastAPI, Request, Response

app = FastAPI()

SERVICES = {
    "users":         "http://user-service:8000",
    "products":      "http://catalog-service:8000",
    "orders":        "http://order-service:8000",
    "notifications": "http://notif-service:8000",
}

TIMEOUT = 5.0

@app.get("/health")
def health():
    return {"status": "ok", "service": "api-gateway"}

@app.api_route("/{full_path:path}", methods=["GET", "POST", "PUT", "DELETE", "PATCH"])
async def gateway(full_path: str, request: Request):
    # Extraire le nom du service depuis le début du chemin
    # ex: "users/1" → service="users", "orders" → service="orders"
    parts = full_path.split("/", 1)
    service_key = parts[0]

    base_url = SERVICES.get(service_key)
    if not base_url:
        return Response(
            content=f'{{"detail": "Service \'{service_key}\' inconnu"}}',
            status_code=404,
            media_type="application/json",
        )

    target_url = f"{base_url}/{full_path}"
    if request.url.query:
        target_url += f"?{request.url.query}"

    body = await request.body()

    async with httpx.AsyncClient() as client:
        try:
            response = await client.request(
                method=request.method,
                url=target_url,
                content=body,
                headers={"Content-Type": request.headers.get("Content-Type", "application/json")},
                timeout=TIMEOUT,
            )
        except httpx.TimeoutException:
            return Response(
                content='{"detail": "Service timeout"}',
                status_code=504,
                media_type="application/json",
            )
        except Exception as e:
            return Response(
                content=f'{{"detail": "Gateway error: {str(e)}"}}',
                status_code=502,
                media_type="application/json",
            )

    return Response(
        content=response.content,
        status_code=response.status_code,
        media_type=response.headers.get("content-type"),
    )