import { PromiseLikeTask } from './task.ts';
import { AsyncIterableTask } from './stream-task.ts';
import type { Task, WorkerHandle } from './runner.ts';

/**
 * Returns a copy of the task pinned to a specific worker.
 * The original task is unchanged.
 * @param worker - The worker handle to pin the task to.
 * @param task - The task to assign.
 * @returns A new task with the same id and args, pinned to the given worker.
 */
export function assign<T>(worker: WorkerHandle, task: Task<T>): Task<T> {
  if (task instanceof AsyncIterableTask) {
    const copy = new AsyncIterableTask(task.id, task.args);
    copy.worker = worker;
    return copy as unknown as Task<T>;
  }
  const copy = new PromiseLikeTask(task.id, task.args);
  copy.worker = worker;
  return copy as unknown as Task<T>;
}