NotesRepository.kt

package com.vferreirati.noteskotlinmvvm.repository

import android.content.Context
import android.os.AsyncTask
import com.vferreirati.noteskotlinmvvm.data.Note
import com.vferreirati.noteskotlinmvvm.data.NoteDao
import com.vferreirati.noteskotlinmvvm.data.NoteDatabase

class NotesRepository(context: Context) {

    private val noteDao: NoteDao? = NoteDatabase.getInstance(context)?.noteDao()
    val allNotes = noteDao?.getAll()

    fun insert(note: Note) {
        InsertTask(noteDao).execute(note)
    }

    fun deleteAll() {
        DeleteAllTask(noteDao).execute()
    }

    fun delete(note: Note) {
        DeleteOneTask(noteDao).execute(note)
    }

    class InsertTask(private val noteDao: NoteDao?) : AsyncTask<Note, Unit, Unit>() {

        override fun doInBackground(vararg params: Note) {
            noteDao?.insert(params[0])
        }
    }

    class DeleteAllTask(private val noteDao: NoteDao?) : AsyncTask<Unit, Unit, Unit>() {
        override fun doInBackground(vararg params: Unit?) {
            noteDao?.deleteAll()
        }
    }

    class DeleteOneTask(private val noteDao: NoteDao?) : AsyncTask<Note, Unit, Unit>() {

        override fun doInBackground(vararg params: Note) {
                noteDao?.delete(params[0])
        }
    }
}