import {
  BOOKING_WINDOW_WS_EVENTS,
  BOOKING_WINDOW_WS_NAMESPACE,
  type BookingWindowPhaseEvent,
} from "@edr/types";
import { useQueryClient } from "@tanstack/react-query";
import { useEffect } from "react";
import { io } from "socket.io-client";

import { API_BASE_URL } from "@/constants/apiConfig";
import { AUTH_TOKEN_COOKIE, getCookie } from "@/auth/cookies";
import { QUERY_KEYS } from "@/constants/QUERY_KEYS";

// The socket namespace lives at the server root, not under the `/api` REST
// prefix — strip a trailing `/api` if the base URL carries one.
const SOCKET_ORIGIN = String(API_BASE_URL ?? "").replace(/\/api\/?$/, "");

/**
 * Subscribes to live booking-window pushes for staff. Every phase transition
 * the window engine applies invalidates the GL windows carousel and the batch
 * board, so both flip the moment the backend does — polling stays only as a
 * fallback.
 */
export function useBookingWindowSocket(enabled: boolean = true) {
  const qc = useQueryClient();

  useEffect(() => {
    if (!enabled) return;
    const token = getCookie(AUTH_TOKEN_COOKIE);
    if (!token) return;

    const socket = io(`${SOCKET_ORIGIN}/${BOOKING_WINDOW_WS_NAMESPACE}`, {
      auth: { token },
      transports: ["websocket"],
      withCredentials: true,
    });

    socket.on(
      BOOKING_WINDOW_WS_EVENTS.PHASE,
      (_event: BookingWindowPhaseEvent) => {
        qc.invalidateQueries({
          queryKey: ["train-scheduling", "all-booking-windows"],
        });
        qc.invalidateQueries({
          queryKey: QUERY_KEYS.TRAIN_SCHEDULING.batchBoard(),
        });
      },
    );

    return () => {
      socket.off();
      socket.disconnect();
    };
  }, [enabled, qc]);
}