Observable Repo pattern using BroadcastChannel

MentionsRepository.kt

@ExperimentalCoroutinesApi
@FlowPreview
class MentionsRepository(
    private val middleEnd: MiddleEnd,
    private val mentionsDao: MentionDao,
    private val mapper: MentionsMapper
) {

    private val mentionsBroadcastChannel = BroadcastChannel<DataState<List<MentionDisplayModel>>>(Channel.BUFFERED)

    fun observeMentions() = mentionsBroadcastChannel.asFlow()

    suspend fun loadMentions() {
        try {
            emitCachedMentions()
            mentionsBroadcastChannel.send(DataState.Loading)

            val request = GqlRequest(GET_MENTIONS, MentionsRequest(Slice(10)))
            val response = middleEnd.getMentions(request)
            val mentions = response.data.mentions.edges?.mapNotNull { it.node }

            mentions?.let { mentionsDao.insertMentions(mentions) }
            emitCachedMentions()
        } catch (ex: Exception) {
            mentionsBroadcastChannel.send(DataState.Error(ex))
        }
    }

    suspend fun markMentionAsRead(mentionId: String) {
        val recordsUpdated = mentionsDao.markMentionAsRead(mentionId)
        instalog("Updated $recordsUpdated records")
        emitCachedMentions()
    }

    private suspend fun emitCachedMentions() {
        val mentions = mentionsDao.getMentions()
        if (mentions.isNotEmpty()) {
            mentionsBroadcastChannel.send(DataState.Success(mapper.mapToDisplayModelList(mentions)))
        }
    }
}