Firestore Delete elements from a nested map kotlin

Question

I have a collection, I want to delete 2 documents from this collection Paradas collection and delete it from the nested map too Nested map like in SQL, when you delete it from a table to delete it from elsewhere too.

I tried

fun deleteNestedParadas(lista: ArrayList<Parada> )  {
            try {
               val refrutas=Firebase.firestore.collection("rutas")
                refrutas.get().addOnSuccessListener { taskruta ->
                    for (ruta in taskruta.documents) {
                        val rutaa = ruta.toObject(Ruta::class.java)
                        if (rutaa != null) {
                            for (parada in lista) {
                                if (rutaa.paradasruta!!.contains(parada.id)) {
                                    refrutas.document(rutaa.id)
                                        .update("paradasruta",{parada.id to delete()})
                                        .addOnSuccessListener {
                                            Log.e("DeleteNestedParada",
                                                "Se han borrado las paradas correctamente")
                                        }
                                        .addOnFailureListener {
                                            Log.e("DeleteNestedParada", it.message.toString())
                                        }
                                }
                            }
                        }
                    }

                }
        } catch (e: Exception){
            Log.e("Nested Collection", e.message.toString())
        }
    }

Edit: The error that appears is this: After i execute the code, the whole map changes to this: "arity:0" and appears this android error

it doesn't make sense

Answer 1

I found the answer. Thanks to RogelioMonter and Alex Mamo for your help. Saw a few posts before like how to do it but it didn't work, I wasn't simply passing the mapOf to update by doing that now it works.

fun deleteNestedParadas(lista: ArrayList<Parada> )  {
        try {
           val refrutas=Firebase.firestore.collection("rutas")
            refrutas.get().addOnSuccessListener { taskruta ->
                for (ruta in taskruta.documents) {
                    val rutaa = ruta.toObject(Ruta::class.java)
                    if (rutaa != null) {
                        for (parada in lista) {
                            if (rutaa.paradasruta!!.contains(parada.id)) {
                                refrutas.document(rutaa.id)
                                    .update("paradasruta",mapOf{parada.id to FieldValue.delete()})
                                    .addOnSuccessListener {
                                        Log.e("DeleteNestedParada",
                                            "Se han borrado las paradas correctamente")
                                    }
                                    .addOnFailureListener {
                                        Log.e("DeleteNestedParada", it.message.toString())
                                    }
                            }
                        }
                    }
                }

            }
    } catch (e: Exception){
        Log.e("Nested Collection", e.message.toString())
    }
}