MainViewModel

package com.cinderellaman.live.ui.viewmodel

import android.app.Application
import androidx.lifecycle.AndroidViewModel
import androidx.lifecycle.LiveData
import androidx.lifecycle.Transformations
import androidx.paging.LivePagedListBuilder
import androidx.paging.PagedList
import com.cinderellaman.live.youtubeapi.search.State
import com.cinderellaman.live.youtubeapi.search.datasource.SearchDataSource
import com.cinderellaman.live.youtubeapi.search.datasource.SearchDataSourceFactory
import com.cinderellaman.live.youtubeapi.search.network.NetworkService
import com.cinderellaman.live.youtubeapi.search.response.Item
import io.reactivex.disposables.CompositeDisposable

class MainViewModel(application: Application) : AndroidViewModel(application) {


    //paging
    private val networkService = NetworkService.getService()
    var searchList: LiveData<PagedList<Item>>
    private val compositeDisposable = CompositeDisposable()
    private val pageSize = 50
    private val searchDataSourceFactory: SearchDataSourceFactory

    init {

        //paging
        searchDataSourceFactory = SearchDataSourceFactory(compositeDisposable, networkService)
        val config = PagedList.Config.Builder()
            .setPageSize(pageSize)
            .setInitialLoadSizeHint(pageSize)
            .setEnablePlaceholders(false)
            .build()
        searchList = LivePagedListBuilder<String, Item>(searchDataSourceFactory, config).build()
    }

    fun getState(): LiveData<State> = Transformations.switchMap<SearchDataSource,
            State>(searchDataSourceFactory.searchDataSourceLiveData,SearchDataSource::state)

    fun retry() {
        searchDataSourceFactory.searchDataSourceLiveData.value?.retry()
    }

    fun setQuery(query: String){
        searchList.value?.dataSource?.invalidate()
    }
    override fun onCleared() {
        super.onCleared()
        compositeDisposable.dispose()
    }

    fun listIsEmpty(): Boolean {
        return searchList.value?.isEmpty() ?: true
    }
}