import { Topic } from "encore.dev/pubsub";

interface OrderCreatedEvent {
  orderId: string;
  userId: string;
  total: number;
}

// Package level declaration
export const orderCreated = new Topic<OrderCreatedEvent>("order-created", {
  deliveryGuarantee: "at-least-once",
});

await orderCreated.publish({
  orderId: "123",
  userId: "user-456",
  total: 99.99,
});

import { Subscription } from "encore.dev/pubsub";

const _ = new Subscription(orderCreated, "send-confirmation-email", {
  handler: async (event) => {
    await sendEmail(event.userId, event.orderId);
  },
});

import { Topic, Attribute } from "encore.dev/pubsub";

interface CartEvent {
  cartId: Attribute<string>;  // Used for ordering
  userId: string;
  action: "add" | "remove";
  productId: string;
}

// Ordered topic: events with same cartId delivered in order
export const cartEvents = new Topic<CartEvent>("cart-events", {
  deliveryGuarantee: "at-least-once",
  orderingAttribute: "cartId",
});

import { Publisher } from "encore.dev/pubsub";

const publisherRef = orderCreated.ref<Publisher>();

async function notifyOrder(ref: typeof publisherRef, orderId: string) {
  await ref.publish({ orderId, userId: "123", total: 99.99 });
}