import logging

from fastapi import FastAPI

from app.utils.config import settings


def register_metrics(app: FastAPI):
    """
    Register Prometheus metrics endpoint.
    """
    try:
        from prometheus_fastapi_instrumentator import Instrumentator

        instrumentator = (
            Instrumentator().instrument(
                app,
                metric_namespace="freeleaps_{}".format(settings.FREELEAPS_PRODUCT_ID),
                metric_subsystem=settings.ENVIRONMENT
            )
        )
        instrumentator.expose(app, endpoint="/api/_/metrics", should_gzip=True)
        logging.info("Metrics endpoint exposed at /api/_/metrics")

    except ImportError:
        logging.warning("prometheus-fastapi-instrumentator not installed, metrics endpoint will not be available")