package com.rxjava2.android.samples.ui.operators;

import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

import com.rxjava2.android.samples.R;
import com.rxjava2.android.samples.utils.AppConstant;

import java.util.Random;
import java.util.concurrent.TimeUnit;

import androidx.annotation.Nullable;
import androidx.appcompat.app.AppCompatActivity;
import io.reactivex.Observable;
import io.reactivex.ObservableSource;
import io.reactivex.Observer;
import io.reactivex.android.schedulers.AndroidSchedulers;
import io.reactivex.disposables.Disposable;
import io.reactivex.functions.Function;
import io.reactivex.schedulers.Schedulers;

/**
 * Created by thanhtuan on 26/04/18.
 */
public class SwitchMapExampleActivity extends AppCompatActivity {

    private static final String TAG = SwitchMapExampleActivity.class.getSimpleName();
    Button btn;
    TextView textView;

    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_example);

        btn = findViewById(R.id.btn);
        textView = findViewById(R.id.textView);

        btn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                doSomeWork();
            }
        });
    }

    /* whenever a new item is emitted by the source Observable, it will unsubscribe to and stop
     * mirroring the Observable that was generated from the previously-emitted item,
     * and begin only mirroring the current one.
     *
     * Result: 5x
     */
    private void doSomeWork() {
        getObservable()
                .switchMap(new Function<Integer, ObservableSource<String>>() {
                    @Override
                    public ObservableSource<String> apply(Integer integer) {
                        int delay = new Random().nextInt(2);

                        return Observable.just(integer.toString() + "x")
                                .delay(delay, TimeUnit.SECONDS, Schedulers.io());
                    }
                })
                .subscribeOn(Schedulers.io())
                .observeOn(AndroidSchedulers.mainThread())
                .subscribe(getObserver());
    }

    private Observable<Integer> getObservable() {
        return Observable.just(1, 2, 3, 4, 5);
    }

    private Observer<String> getObserver() {
        return new Observer<String>() {
            @Override
            public void onSubscribe(Disposable d) {
                Log.d(TAG, " onSubscribe : " + d.isDisposed());
            }

            @Override
            public void onNext(String value) {
                textView.append(" onNext : value : " + value);
                textView.append(AppConstant.LINE_SEPARATOR);
                Log.d(TAG, " onNext value : " + value);
            }

            @Override
            public void onError(Throwable e) {
                textView.append(" onError : " + e.getMessage());
                textView.append(AppConstant.LINE_SEPARATOR);
                Log.d(TAG, " onError : " + e.getMessage());
            }

            @Override
            public void onComplete() {
                textView.append(" onComplete");
                textView.append(AppConstant.LINE_SEPARATOR);
                Log.d(TAG, " onComplete");
            }
        };
    }
}