@GET(PREFIX + "{userId}/repos")
    fun getRepos(@Path("userId") userId: String,
                 @Query("page") page: Int,
                 @Query("per_page") perPage : Int
    ): Single<Response<List<ReposDto>>>

class ReposDataSource(var user : String) : BaseDataSource<Repos>() {
    val manager : ReposManager = ReposManager()

    @SuppressLint("CheckResult")
    override fun loadInitialData(params: LoadInitialParams<Int>, callback: LoadInitialCallback<Int, Repos>) {
        // in the initial load, we will start at page 0, and retrieve the number of pages in the params.requestLoadSize
        manager.getListOfRepos(user, 0, params.requestedLoadSize)
                .subscribeOn(Schedulers.io())
                .observeOn(AndroidSchedulers.mainThread())
                .subscribe(
                        { items -> submitInitialData(items, params, callback) },
                        { error -> submitInitialError(error) }
                )
    }

    @SuppressLint("CheckResult")
    override fun loadAditionalData(params: LoadParams<Int>, callback: LoadCallback<Int, Repos>) {
        manager.getListOfRepos(user, params.key, params.requestedLoadSize)
                .subscribeOn(Schedulers.io())
                .observeOn(AndroidSchedulers.mainThread())
                .subscribe(
                        { items -> submitData(items, params, callback) },
                        { error -> submitError(error) }
                )
    }
}

class ReposDataSourceFactory(var loading: OnDataSourceLoading,
                             var user: String?) : DataSource.Factory<Int, Repos>() {
    lateinit var source : ReposDataSource

    override fun create(): DataSource<Int, Repos>? {
        // invalidate the previous data source, if available
        if (::source.isInitialized && source != null) source.invalidate()
        // if we have a user, then create a data source
        if (user != null) {
            source = ReposDataSource(user!!)
            source.onDataSourceLoading = loading
            return source
        }
        return null
    }
}

override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): RecyclerView.ViewHolder {
        if (viewType == VIEW_TYPE_NORMAL) {
            return MainViewHolder(LayoutInflater.from(parent.context)
                    .inflate(R.layout.item_repo, parent, false)
            )
        } else {
            return LoadingViewHolder(LayoutInflater.from(parent.context)
                    .inflate(R.layout.item_loading, parent, false)
            )
        }
    }

class MainViewModel : BasePaginationViewModel<ReposDataSourceFactory, Repos>() {
    init {
        dataSourceFactory = ReposDataSourceFactory(getListener(), null)
    }

    override fun getPageSize(): Int {
        return 3
    }
}

        // Toast for API Errors
viewModel.errorToastEvent.observe(this,
        Observer { Toast.makeText(this, getString(R.string.err_search), Toast.LENGTH_LONG) }
)

// Clearing the data of the adapter when doing a new search
viewModel.clearDataEvents.observe(this,
        Observer {
            viewModel.clearDataSource()
            submitItems()
            adapter.notifyDataSetChanged()
        }
)

// Showing an empty view on the screen
viewModel.emptyVisibilityEvents.observe(this,
        Observer { show ->
            if(show != null) {
                var visibility = if (show.peek()) View.VISIBLE else View.GONE
                this.empty_view_imageView.visibility = visibility
            }
        }
)

// Display the recyclerview loading item
viewModel.recyclerViewLoadingEvents.observe(this,
        Observer { show ->
            if(show != null) {
                adapter.loading = show.peek()
            }
        })})

fun newSearch(user : String) {
    // set a new value for the dataSource internal variable
    dataSourceFactory.user = user
    clearData()
}     

fun clearData() {
        this.clearDataEvents.postValue(Event(Unit))
    }

// Clearing the data of the adapter when doing a new search
        viewModel.clearDataEvents.observe(this,
                Observer {
                    viewModel.clearDataSource()
                    submitItems()
                    adapter.notifyDataSetChanged()
                }
        )