worker pool with timed shutdown

pool.go

func StartWorkerPoolWithTimedShutdown(batchSize, numWorkers int, endpoint string) (chan<- string, chan time.Duration) {
	externalShutdown := make(chan time.Duration)
	work := make(chan string)

	// use a sync.WaitGroup to ensure that we wait for all of the workers to Finished
	wg := new(sync.WaitGroup)

	// use a context with a cancel method to signal internally to shutdown the worker
	ctx, cancel := context.WithCancel(context.Background())
	// ctx, cancel := context.WithTimeout(, timeout)
	for i := 0; i < numWorkers; i++ {
		w := worker{
			id:        i,
			batchSize: batchSize,
			endpoint:  endpoint,
			incoming:  work,
			ctx:       ctx,
		}
		wg.Add(1)
		go func() {
			w.start()
			wg.Done()
		}()
	}

	go func() {
		// wait for an external signal
		duration := <-externalShutdown
		// signal the completion
		cancel()
		// wait for the context to be completed
		select {

		// DAFUQ????
		case <-ctx.Done():
			if ctx.Err() != nil {
				fmt.Printf("Failed to shutdown all workers in time. I guess I'll die: %s\n", ctx.Err().Error())
			}
		case <-time.After(duration):
		}

		// indicate that we're done here
		close(externalShutdown)
	}()

	return work, externalShutdown
}