frontend/src/hooks/useActiveSessions.ts

import { useEffect, useState } from "react";
import { API_BASE } from "../api/client";

interface ActiveSession {
  client_id: string;
  last_seen: string;
}

interface ActiveSessionsResult {
  count: number;
  sessions: ActiveSession[];
  loading: boolean;
}

export function useActiveSessions(intervalMs = 30_000): ActiveSessionsResult {
  const [count, setCount] = useState(0);
  const [sessions, setSessions] = useState<ActiveSession[]>([]);
  const [loading, setLoading] = useState(true);

  useEffect(() => {
    let cancelled = false;

    async function fetch_() {
      try {
        const res = await fetch(`${API_BASE}/api/active-sessions`);
        if (!res.ok || cancelled) return;
        const data = await res.json();
        setCount(data.count ?? 0);
        setSessions(data.active_sessions ?? []);
      } catch {
        // silencioso — no interrumpir el flujo principal
      } finally {
        if (!cancelled) setLoading(false);
      }
    }

    fetch_();
    const id = window.setInterval(fetch_, intervalMs);
    return () => {
      cancelled = true;
      clearInterval(id);
    };
  }, [intervalMs]);

  return { count, sessions, loading };
}