group chat handler 1.kt

fun initListener(){
  val db = FirebaseFirestore.getInstance()
  val groupMsgCollection= db.collectionGroup("group_messages")
  groupMsgCollection.whereArrayContains("to", userId!!)
      .addSnapshotListener { snapshots, error ->
        if (error != null || snapshots == null || snapshots.metadata.isFromCache) {
            LogMessage.v("Error ${error?.localizedMessage}")
            return@addSnapshotListener
        }
        onSnapShotChanged(snapshots)
    }
}

fun onSnapShotChanged(snapshots: QuerySnapshot){
  val messageList= mutableListOf<GroupMessage>()
   for(snapShot in snapshots){
       val message = snapShot.document.data.toDataClass<GroupMessage>()
       messagesList.add(message)
}
  groupMessageDao.insertMessages(messageList)
}