import io.reactivex.ObservableTransformer

import io.reactivex.ObservableTransformer

object RxUtil {

    private val LOADING_MESSAGE = "Loading"

    fun <T> applyUIDefaults(rxFragment: RxFragment): ObservableTransformer<T, T> {
        return { upstream ->
            upstream
                .compose(RxUtil.addToCompositeDisposable<Any>(rxFragment))
                .compose(RxUtil.applySchedulers<Any>())
                .compose(RxUtil.applyRequestStatus<Any>(rxFragment))
                .compose(RxUtil.showLoadingDialog<Any>(rxFragment))
        }
    }

    private fun <T> applyRequestStatus(rxFragment: RxFragment): ObservableTransformer<T, T> {
        return { upstream ->
            upstream.doOnSubscribe({ disposable -> rxFragment.setRequestInProgress(true) })
                .doOnTerminate({ rxFragment.setRequestInProgress(false) })
        }
    }

    private fun <T> applySchedulers(): ObservableTransformer<T, T> {
        return schedulersTransformer as ObservableTransformer<T, T>
    }

    private fun <T> addToCompositeDisposable(rxFragment: RxFragment): ObservableTransformer<T, T> {
        return { upstream -> upstream.doOnSubscribe({ disposable -> rxFragment.getCompositeDisposable().add(disposable) }) }
    }

    private fun <T> showLoadingDialog(rxFragment: RxFragment): ObservableTransformer<T, T> {
        return { observable ->
            observable
                .doOnSubscribe({ disposable -> DialogUtils.showProgressDialog(rxFragment.getFragmentManager(), LOADING_MESSAGE) })
                .doOnTerminate({ DialogUtils.hideProgressDialog(rxFragment.getFragmentManager()) })
        }
    }
}