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,
			session.Plan.Video,
		) {
			return false
		}
		if session.Plan.Audio.Active && !statusIsPlaying(
			statuses.Audio,
			statuses.HasAudio,
			session.Generation,
			session.Plan.Audio,
		) {
			return false
		}
		return true

	case TopologySynchronized:
		return statuses.HasSync &&
			statuses.Sync.Generation == session.Generation &&
			statuses.Sync.State == StatePlaying &&
			sameSyncSource(statuses.Sync.Pair, session.Plan.Sync)

	case TopologyIdle:
		return false

	default:
		return false
	}
}

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

func sameFeedSource(a, b FeedConfig) bool {
	return a.Domain == b.Domain && a.UUID == b.UUID
}

func sameSyncSource(a, b SyncPairConfig) bool {
	return sameFeedSource(a.Video, b.Video) &&
		sameFeedSource(a.Audio, b.Audio)
}