import { describe, it } from 'node:test';
import assert from 'node:assert/strict';
import { inert, isTask, workers } from 'moroutine';
import type { Task } from 'moroutine';
import { checkPrime, upper, countUp } from './fixtures/is-task.ts';

describe('isTask', () => {
  it('exposes a stable id on the moroutine', () => {
    assert.equal(typeof checkPrime.id, 'string');
    assert.ok(checkPrime.id.length > 0);
    assert.notEqual(checkPrime.id, upper.id);
  });

  it('identifies tasks produced by a moroutine', () => {
    const t = inert(checkPrime(7));
    assert.ok(isTask(checkPrime, t));
    assert.ok(!isTask(upper, t));
  });

  it('works across value and streaming moroutines', () => {
    const v = inert(checkPrime(7));
    const s = inert(countUp(3));
    assert.ok(isTask(checkPrime, v));
    assert.ok(!isTask(countUp, v));
    assert.ok(isTask(countUp, s));
    assert.ok(!isTask(checkPrime, s));
  });

  it('narrows task args for downstream dispatch', async () => {
    using run = workers(1);
    const tasks: Array<Task<boolean, [n: number]> | Task<string, [s: string]>> = [
      inert(checkPrime(5)),
      inert(upper('hi')),
    ];
    const results: Array<boolean | string> = [];
    for (const t of tasks) {
      if (isTask(checkPrime, t)) {
        // t is Task<boolean, [n: number]> — args typed as [n: number]
        const [n] = t.args;
        assert.equal(typeof n, 'number');
        results.push(await run(t));
      } else {
        const [s] = t.args;
        assert.equal(typeof s, 'string');
        results.push(await run(t));
      }
    }
    assert.deepEqual(results, [true, 'HI']);
  });
});