package sdl

import "errors"

// setPlaying associates a channel no. to the Track playing.
func (e *Engine) setPlaying(channel int, t *Track) {
	e.channelMu.Lock()
	defer e.channelMu.Unlock()
	e.channelsPlaying[channel] = t
}

// unsetPlaying associates a channel no. to the Track playing.
func (e *Engine) unsetPlaying(channel int) error {
	e.channelMu.Lock()
	defer e.channelMu.Unlock()
	if track, ok := e.channelsPlaying[channel]; ok {
		track.channel = -1
		delete(e.channelsPlaying, channel)
		return nil
	}
	return errors.New("didn't even know channel %d was playing a sound")
}

// isPlaying checks if a sound effect is playing on a channel.
func (e *Engine) isPlaying(channel int) bool {
	e.channelMu.RLock()
	defer e.channelMu.RUnlock()
	_, ok := e.channelsPlaying[channel]
	return ok
}