package playback

func IsSessionPlaying(
	session SessionSnapshot,
	statuses PlaybackStatusSnapshot,
) bool {
	if statuses.Generation != session.Generation {
		return false
	}

	switch session.Plan.Topology {
	case TopologyIndependent:
		hasActiveFeed := session.Plan.Video.Active || session.Plan.Audio.Active
		if !hasActiveFeed {
			return false
		}
		if session.Plan.Video.Active && !statusIsPlaying(
			statuses.Video,
			statuses.HasVideo,
			session.Generation,
		) {
			return false
		}
		if session.Plan.Audio.Active && !statusIsPlaying(
			statuses.Audio,
			statuses.HasAudio,
			session.Generation,
		) {
			return false
		}
		return true

	case TopologySynchronized:
		return statusIsPlaying(
			statuses.Sync,
			statuses.HasSync,
			session.Generation,
		)

	case TopologyIdle:
		return false

	default:
		return false
	}
}

func statusIsPlaying(status Status, present bool, generation uint64) bool {
	return present &&
		status.Generation == generation &&
		status.State == StatePlaying
}