import Piscina from 'piscina';
import path from 'node:path';
import { availableParallelism } from 'node:os';

const configuredThreads = Number(
  process.env.DOCX_WORKERS || 4
);

const maxThreads = Math.max(
  1,
  Math.min(
    Number.isFinite(configuredThreads) && configuredThreads > 0
      ? Math.floor(configuredThreads)
      : 4,
    Math.max(1, availableParallelism() - 1)
  )
);

const globalForDocx = globalThis as typeof globalThis & {
  docxPool?: Piscina;
};

export const docxPool =
  globalForDocx.docxPool ??=
    new Piscina({
      filename: path.resolve(
        process.cwd(),
        'workers/dist/docx.worker.mjs'
      ),
      minThreads: 1,
      maxThreads,
      idleTimeout: 30000,
      maxQueue: 'auto',
      concurrentTasksPerWorker: 1
    });