// Process a batch of work items in parallel using a worker pool.
// Compares sequential (dedicated worker) vs parallel (pool) execution.
// Requires Node v24+.
//
// Run: node examples/parallel-batch/main.ts

import { workers } from '../../src/index.ts';
import { heavyWork } from './heavy-work.ts';

const items = Array.from({ length: 20 }, (_, i) => i + 1);

// Sequential: each call awaits on the dedicated worker
console.log('Sequential (dedicated worker)...');
const seqStart = performance.now();
const seqResults = [];
for (const item of items) {
  seqResults.push(await heavyWork(item));
}
const seqTime = (performance.now() - seqStart).toFixed(0);
console.log(`  ${items.length} items in ${seqTime}ms\n`);

// Parallel: distribute across a pool of 4 workers
let parTime: string;
console.log('Parallel (worker pool, 4 workers)...');
{
  using run = workers(4);
  const parStart = performance.now();
  const parResults = await Promise.all(items.map((item) => run(heavyWork(item))));
  parTime = (performance.now() - parStart).toFixed(0);
  console.log(`  ${items.length} items in ${parTime}ms\n`);
}

console.log(`Speedup: ~${(Number(seqTime) / Number(parTime)).toFixed(1)}x`);