package channel

import "time"

// CloseOnTimeout returns a channel which receives all values from all sources in order of arrival.
// If no source is sending a value in the given timeout duration, the channel will be closed
func CloseOnTimeout[T any](timeout time.Duration, sources ...<-chan T) <-chan T {
	input := Merge(sources...)
	output := make(chan T, cap(input))

	go func() {
		defer close(output)

		for {
			timer := time.NewTimer(timeout)

			select {
			case value, ok := <-input:
				if !ok {
					return
				}
				output <- value
			case <-timer.C:
				return
			}
		}
	}()

	return output
}