# utils/metrics.py
from prometheus_client import Counter, CollectorRegistry
from typing import Optional
import streamlit as st

# Single global registry
_registry: Optional[CollectorRegistry] = None
_login_counter: Optional[Counter] = None

def get_metrics_registry() -> CollectorRegistry:
    """Get or create the metrics registry."""
    global _registry
    if _registry is None:
        _registry = CollectorRegistry()
    return _registry

def get_login_attempts_counter() -> Counter:
    """Get or create the login attempts counter."""
    global _login_counter
    if _login_counter is None:
        _login_counter = Counter(
            'login_attempts_total',
            'Total login attempts',
            registry=get_metrics_registry()
        )
    return _login_counter

def clear_metrics():
    """Clear all metrics and registry."""
    global _registry, _login_counter
    if _registry is not None:
        _registry = None
    if _login_counter is not None:
        _login_counter = None