import { io, Socket } from 'socket.io-client';
import { Store } from '@reduxjs/toolkit';
import { SocketEvents } from '@utils/constants';
import { DeliveryOffer } from '@interfaces';
import { setDeliveryOffer } from '@store/commonReducers/delivery';
import { RouteNames } from '@utils/constants';

// Must match the REST API base URL (without trailing slash)
const BASE_URL = 'https://8415-202-8-116-13.ngrok-free.app';

type Callback = (data: any) => void;

/**
 * Global singleton socket service powered by socket.io-client.
 *
 * Usage:
 *   bootstrapSocketService(store, navRef)   // call once in App.tsx
 *   socketService.connect(token)            // when user authenticates
 *   socketService.disconnect()              // on logout
 */
class SocketService {
  private socket: Socket | null = null;
  private store: Store | null = null;
  private navigationRef: any = null;

  /**
   * Must be called once at app startup so the service can dispatch actions
   * and navigate globally when a `delivery_offer` event arrives.
   * Each parameter is only updated if a non-null value is provided, allowing
   * the store and navigationRef to be injected independently.
   */
  bootstrap(store: Store | null, navigationRef: any) {
    if (store) { this.store = store; }
    if (navigationRef) { this.navigationRef = navigationRef; }
  }

  /**
   * Open the socket connection with JWT auth.
   */
  connect(token: string) {
    if (this.socket?.connected) {
      console.log('[Socket] Already connected');
      return;
    }

    this.socket = io(BASE_URL, {
      auth: { token },
      transports: ['websocket'],
      reconnection: true,
      reconnectionAttempts: Infinity,
      reconnectionDelay: 2000,
    });

    this.socket.on('connect', () => {
      console.log('[Socket] Connected — id:', this.socket?.id);
    });

    this.socket.on('connect_error', (err: Error) => {
      console.error('[Socket] Connection error:', err.message);
    });

    this.socket.on('disconnect', (reason: string) => {
      console.log('[Socket] Disconnected:', reason);
    });

    // ── Listen for delivery offers ─────────────────────────────────────
    this.socket.on(
      SocketEvents.DeliveryOffer,
      (data: DeliveryOffer) => {
        console.log('[Socket] delivery_offer received:', data);

        if (this.store) {
          this.store.dispatch(setDeliveryOffer(data));
        }

        // Navigate to NewJobRequest screen regardless of current screen
        if (this.navigationRef?.isReady()) {
          this.navigationRef.navigate(RouteNames.NewJobRequest);
        }
      },
    );
  }

  /**
   * Gracefully close the socket connection.
   */
  disconnect() {
    if (this.socket) {
      this.socket.removeAllListeners();
      this.socket.disconnect();
      this.socket = null;
      console.log('[Socket] Disconnected (manual)');
    }
  }

  /**
   * Notify the server that the partner is available for deliveries.
   */
  goOnline() {
    this.socket?.emit(SocketEvents.GoOnline);
    console.log('[Socket] Emitted go_online');
  }

  /**
   * Notify the server that the partner is no longer available.
   */
  goOffline() {
    this.socket?.emit(SocketEvents.GoOffline);
    console.log('[Socket] Emitted go_offline');
  }

  /**
   * Send a location update to the server.
   */
  updateLocation(coords: { latitude: number; longitude: number }) {
    this.socket?.emit(SocketEvents.LocationUpdate, coords);
  }

  /**
   * Register a custom listener on the underlying socket.
   */
  on(event: string, callback: Callback) {
    this.socket?.on(event, callback);
  }

  /**
   * Remove a custom listener from the underlying socket.
   */
  off(event: string, callback?: Callback) {
    if (callback) {
      this.socket?.off(event, callback);
    } else {
      this.socket?.removeAllListeners(event);
    }
  }

  /**
   * Whether the socket is currently connected.
   */
  get connected(): boolean {
    return this.socket?.connected ?? false;
  }
}

export const socketService = new SocketService();