"use client";

import { useEffect, useState } from "react";
import { collection, onSnapshot, query, where, FirestoreError } from "firebase/firestore";
import { onAuthStateChanged } from "firebase/auth";
import { db, auth } from "@/lib/firebase";
import { useAuth } from "@/components/AuthProvider";
import type { VesselTrack } from "@/lib/types";

// Same shape as useAircraft — `vessels` is a live snapshot (one per mmsi,
// overwritten on every sighting, node-26#9), nothing prunes a doc when a
// vessel goes out of range, so staleness is filtered client-side. AIS
// position reports are much less frequent than ADS-B (minutes, not
// seconds), so this window is longer than useAircraft's.
const STALE_AFTER_MS = 10 * 60 * 1000;

export function useVessels() {
  const [vessels, setVessels] = useState<VesselTrack[]>([]);
  const [loading, setLoading] = useState(true);
  const [error, setError] = useState<string | null>(null);
  const { orgId } = useAuth();

  useEffect(() => {
    let unsubFirestore: (() => void) | undefined;

    const unsubAuth = onAuthStateChanged(auth, (user) => {
      if (unsubFirestore) { unsubFirestore(); unsubFirestore = undefined; }

      if (!user || !orgId) {
        setVessels([]);
        setLoading(false);
        return;
      }

      const q = query(collection(db, "vessels"), where("org_id", "==", orgId));
      unsubFirestore = onSnapshot(q, (snap) => {
        const now = Date.now();
        const fresh = snap.docs
          .map((d) => d.data() as VesselTrack)
          .filter((v) => now - new Date(v.last_seen).getTime() < STALE_AFTER_MS);
        setVessels(fresh);
        setLoading(false);
      }, (err: FirestoreError) => { console.error("useVessels:", err); setError(err.message); setLoading(false); });
    });

    return () => {
      unsubAuth();
      if (unsubFirestore) unsubFirestore();
    };
  }, [orgId]);

  return { vessels, loading, error };
}