SUPERCILEX

val teamsQuery get() = "owners.${uid!!}".let {
    FirebaseFirestore.getInstance().collection("teams").whereGreaterThanOrEqualTo(it, 0).orderBy(it)
}

object TeamsLiveData : LiveData<ObservableSnapshotArray<T>>(), FirebaseAuth.AuthStateListener {
    init {
        FirebaseAuth.getInstance().addAuthStateListener(this)
    }

    override fun onAuthStateChanged(auth: FirebaseAuth) {

SUPERCILEX

"owners.$uid".let {
    FirebaseFirestore.getInstance().collection("teams").whereGreaterThanOrEqualTo(it, 0).orderBy(it)
}

SUPERCILEX

FirebaseFirestore.getInstance().collection("teams").whereEqualTo("owners.$uid", true)

SUPERCILEX

// Please don't actually use this method, it's just a nice example of how painful the listener registration API is.
// I wrote it with a case of YAGNI before I really understood the Firestore APIs—you should
// be using `Query#get()` if you need the most up-to-date copy of your documents.
fun Query.getFromServer(): Task<QuerySnapshot> = TaskCompletionSource<QuerySnapshot>().apply {
    val listener = object : EventListener<QuerySnapshot> {
        lateinit var registration: ListenerRegistration

        override fun onEvent(snapshot: QuerySnapshot?, e: FirebaseFirestoreException?) {
            if (e == null) {
                if (!snapshot!!.metadata.isFromCache) {

SUPERCILEX

FirebaseFirestore.getInstance()
        .collection("teams")
        .addSnapshotListener { snapshot: QuerySnapshot?, e: FirebaseFirestoreException? ->
            if (e != null) {
                FirebaseCrash.report(e)
                return@addSnapshotListener
            }
            snapshot!! // The parameters follow a XOR pattern so this is perfectly safe

            // Do stuff

SUPERCILEX

/** Deletes all scouts for a team, including their `metrics` subcollection. */
fun Team.deleteAllScouts() {
    ref.collection("scouts").delete() // Kotlin's syntactic sugar
            .addOnSuccessListener { snapshots: List<DocumentSnapshot> ->
                for (snapshot in snapshots) deleteScout(snapshot.id)
            }
}

fun Team.deleteScout(id: String) {
    val scoutDoc = ref.collection("scouts").document(id)

SUPERCILEX

fun Team.addScout() {
    val scoutRef: DocumentReference = FirebaseFirestore.getInstance()
        .collection("teams")
        .document(id /* Field in Team */)
        .collection("scouts")
        .document() // Creating a document ref with a truly random id

    scoutRef.set(Scout(scoutRef.id, templateId))
    firestoreBatch {
        val metricsRef = scoutRef.collection("metrics")

SUPERCILEX

FirebaseFirestore.getInstance().collection("teams").add(team)

SUPERCILEX

{
  "teams": { // Collection
    "teamId1": { // Document
      "name": "SERT",
      "number": 2521,
      "owners": { // Object within document
        "uid1": 2521, // We sort our teams in ascending order by team number
        "uid2": { ... },
        "uid3": { ... }
      },

SUPERCILEX

{
  "team-indices": {
    "uid1": {
      "teamKey1": 2521, // We sort our teams in ascending order by team number
      "teamKey2": { ... },
      "teamKey3": { ... }
    },
    "uid2": { ... },
    "uid3": { ... }
  },