delivery-tracker/frontend/src/hooks/useWebSocket.ts

import { useEffect, useCallback } from 'react';
import { useDeliveryStore } from '../stores/deliveryStore';
import type { Delivery } from '../types';

type WebSocketEvent = 
  | { type: 'delivery.created'; payload: Delivery }
  | { type: 'delivery.updated'; payload: Delivery }
  | { type: 'delivery.deleted'; payload: { id: string } };

type EventHandler = (event: WebSocketEvent) => void;

class MockWebSocket {
  private handlers: EventHandler[] = [];
  private isConnected = false;

  connect() {
    this.isConnected = true;
    console.log('WebSocket connected (mock)');
  }

  disconnect() {
    this.isConnected = false;
    console.log('WebSocket disconnected (mock)');
  }

  subscribe(handler: EventHandler) {
    this.handlers.push(handler);
    return () => {
      this.handlers = this.handlers.filter((h) => h !== handler);
    };
  }

  emit(event: WebSocketEvent) {
    if (!this.isConnected) return;
    this.handlers.forEach((handler) => handler(event));
  }

  simulateIncomingEvent(event: WebSocketEvent) {
    this.emit(event);
  }
}

const mockWebSocket = new MockWebSocket();

export const useWebSocket = () => {
  const { addDelivery, updateDelivery, deleteDelivery } = useDeliveryStore();

  useEffect(() => {
    mockWebSocket.connect();

    const unsubscribe = mockWebSocket.subscribe((event) => {
      switch (event.type) {
        case 'delivery.created':
          addDelivery(event.payload);
          break;
        case 'delivery.updated':
          updateDelivery(event.payload.id, event.payload);
          break;
        case 'delivery.deleted':
          deleteDelivery(event.payload.id);
          break;
      }
    });

    return () => {
      unsubscribe();
      mockWebSocket.disconnect();
    };
  }, [addDelivery, updateDelivery, deleteDelivery]);

  const sendEvent = useCallback((event: WebSocketEvent) => {
    mockWebSocket.emit(event);
  }, []);

  return { sendEvent, isConnected: true };
};

export const simulateIncomingDelivery = (delivery: Delivery) => {
  mockWebSocket.simulateIncomingEvent({
    type: 'delivery.created',
    payload: delivery,
  });
};