import * as Piecemeal from 'piecemeal/worker';

// Some sort of data access
// ~> here we read from KV, but can be anything
async function* get_data(binding: KV.Namespace) {
  const list = await DATA.list();

  for await (let item of list.keys) {
    yield await DATA.get(item);
  }
}

// A handler you'd typically give a Module or Service Worker
const handler = (request, env, context) => {
  // Notice we're not awaiting or spreading this iterable
  const data = get_data(context.bindings.DATA);

  // Sets up our stream and constructs the Response
  const { pipe, response } = Piecemeal.stream(data);

  // Defers the execution of the iterable, so we respond super quick
  context.waitUntil(pipe());

  return response;
};

import { createServer } from 'node:http';

import * as Piecemeal from 'piecemeal/node';

// An example of some method to retreive some database data
async function* get_data() {
  const keys = await db.fetchAllKeys();

  for await (let key of keys) {
    yield await db.read(key);
  }
}

createServer((req, res) => {
  // Notice we're not awaiting or spreading this iterable
  const data = get_data();

  // Creates a streams — and kicks off the iterable.
  // assumes JSON (can override)
  const stream = Piecemeal.stream(data);

  // Pipes the stream directly to a ServerResponse
  stream.pipe(res);
}).listen(8080);