public static MainFragment newInstance() {
    return new MainFragment();
}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {
    View rootView = inflater.inflate(R.layout.fragment_main, container, false);
    weatherList = new ArrayList<>();
    recyclerView = (RecyclerView) rootView.findViewById(R.id.list);
    swipeRefreshLayout = (SwipeRefreshLayout) rootView.findViewById(R.id.swipe_refresh_layout);
    recyclerView.setHasFixedSize(true);
    recyclerView.setLayoutManager(
            new LinearLayoutManager(getContext(), LinearLayoutManager.VERTICAL, false));
    cityListAdapter = new CityListAdapter(getActivity(), weatherList);
    recyclerView.setAdapter(cityListAdapter);
    swipeRefreshLayout.setOnRefreshListener(this);
    swipeRefreshLayout.post(new Runnable() {
        @Override
        public void run() {
            swipeRefreshLayout.setRefreshing(true);
            getCityTemp();
        }
    });
    return rootView;
}

@Override
public void onRefresh() {
    swipeRefreshLayout.setRefreshing(true);
    getCityTemp();
}

private void getCityTemp() {
    weatherList.clear();
    swipeRefreshLayout.setRefreshing(true);
    MyApplication.getInstance().getDb().getAllCityAsync(new DataBaseHelper.DatabaseHand<List<Weather>>() {
        @Override
        public void onComplete(boolean success, final List<Weather> result) {
            if (success) {
                for (final Weather cn : result) {
                    String url = CITY_TEMP_URL + cn.location.getCity() + LANG + METRIC + API_KEY;
                    JsonObjectRequest request = new JsonObjectRequest(url, null,
                            new Response.Listener<JSONObject>() {
                                @Override
                                public void onResponse(JSONObject jsonObject) {
                                    try {
                                        MyApplication.getInstance().setWeather(
                                                JSONWeatherParser.getWeather(jsonObject.toString(), cn.getCityID()));
                                        weatherList.add(MyApplication.getInstance().getWeather());
                                        cityListAdapter.notifyDataSetChanged();
                                    } catch (JSONException e) {
                                        e.printStackTrace();
                                    }
                                }
                            }, new Response.ErrorListener() {
                        @Override
                        public void onErrorResponse(VolleyError volleyError) {
                        }
                    });
                    MyApplication.getInstance().addToRequestQueue(request);
                }
            }
            MyApplication.getInstance().getDb().close();
        }
    });
    swipeRefreshLayout.setRefreshing(false);
}

@Override
public void onPause() {
    super.onPause();
    saveData();
}

private void read() {
    MyApplication.getInstance().getDb().getAllCityAsync(new DataBaseHelper.DatabaseHand<List<Weather>>() {
        @Override
        public void onComplete(boolean success, List<Weather> result) {
            if (success) {
                for (Weather cn : result) {
                    String log =
                            "Id: " + cn.getCityID() + "n" +
                                    " , name_city: " + cn.location.getCity() + "n" +
                                    " , lon: " + cn.location.getLongitude() + "n" +
                                    " , lat: " + cn.location.getLatitude() + "n" +
                                    " , country: " + cn.location.getCountry() + "n" +
                                    " , sunrise: " + cn.location.getSunrise() + "n" +
                                    " , sunset: " + cn.location.getSunset() + "n" +
                                    " , weather_id: " + cn.currentCondition.getWeatherId() + "n" +
                                    " , description: " + cn.currentCondition.getDescr() + "n" +
                                    " , main: " + cn.currentCondition.getCondition() + "n" +
                                    " , icon: " + cn.currentCondition.getIcon() + "n" +
                                    " , humidity: " + cn.currentCondition.getHumidity() + "n" +
                                    " , pressure: " + cn.currentCondition.getPressure() + "n" +
                                    " , temp_max: " + cn.temperature.getMaxTemp() + "n" +
                                    " , temp_min: " + cn.temperature.getMinTemp() + "n" +
                                    " , speed: " + cn.wind.getSpeed() + "n" +
                                    " , deg: " + cn.wind.getDeg() + "n" +
                                    " , all: " + cn.clouds.getPerc() + "n" +
                                    " , icon_array: " + Arrays.toString(cn.getIconArray()) + "n";
                    Log.d("TAG", log);
                }
            }
            MyApplication.getInstance().getDb().close();
        }
    });
}

public void saveData() {
    for (Weather weather : weatherList) {
        MyApplication.getInstance().getDb().updateCityAsync(weather,
                new DataBaseHelper.DatabaseHand<Integer>() {
                    @Override
                    public void onComplete(boolean success, Integer result) {
                        if (success) {

                        }
                    }
                });
    }
    read();
}

public class CityListAdapter extends RecyclerView.Adapter<CityListAdapter.ViewHolder> {

private List<Weather> data;
Context context;

public CityListAdapter(Context context, List<Weather> data) {
    this.context = context;
    this.data = data;
}

@Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
    View itemView = LayoutInflater.from(parent.getContext())
            .inflate(R.layout.custom_list_item, parent, false);
    return new ViewHolder(itemView);
}

@Override
public void onBindViewHolder(ViewHolder holder, int position) {
    Weather weather = data.get(position);
    holder.name_city.setText(weather.location.getCity());
    holder.name_city.setTag(weather.getCityID());
    holder.temperature_city.setText(MessageFormat.format("{0}℃",
            Math.round(weather.temperature.getTemp())));
}

@Override
public int getItemCount() {
    return data.size();
}

class ViewHolder extends RecyclerView.ViewHolder
        implements View.OnClickListener {
    private TextView name_city, temperature_city;

    public ViewHolder(View itemView) {
        super(itemView);
        name_city = (TextView) itemView.findViewById(R.id.name_city);
        temperature_city = (TextView) itemView.findViewById(R.id.temperature_city);
        name_city.setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        Integer pos = (int) (long) v.getTag();
        read(pos);
    }
}

public void nextFragment() {
    FragmentManager manager = ((AppCompatActivity) context).getSupportFragmentManager();
    FragmentTransaction ft = manager.beginTransaction();
    ft.replace(R.id.container, new DetailFragment());
    ft.addToBackStack("detail");
    ft.commit();
}

private void read(long pos) {
    MyApplication.getInstance().getDb().getCityAsync(pos, new DataBaseHelper.DatabaseHand<Weather>() {
        @Override
        public void onComplete(boolean success, Weather result) {
            if (success) {
                MyApplication.getInstance().setWeather(result);
                nextFragment();
            }
            MyApplication.getInstance().getDb().close();
        }
    });
}

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
    View v = inflater.inflate(
            R.layout.detail_fragment, container, false);
    init(v);
    setDataView();
    return v;
}

public void setDataView() {
    tvLocation.setText(String.format("%s,%s", getInstance().getWeather().location.getCity(),
            getInstance().getWeather().location.getCountry()));
    tvTemperature.setText(String.valueOf(Math.round(getInstance().getWeather().temperature.getTemp())));
    tvTempMin.setText(String.valueOf(Math.round(getInstance().getWeather().temperature.getMinTemp())));
    tvTempMax.setText(String.valueOf(Math.round(getInstance().getWeather().temperature.getMaxTemp())));
    tvWindSpeed.setText(String.valueOf(Math.round(getInstance().getWeather().wind.getSpeed())));
    tvWindDeg.setText(String.valueOf(Math.round(getInstance().getWeather().wind.getDeg())));
    tvHum.setText(String.valueOf(Math.round(getInstance().getWeather().currentCondition.getHumidity())));
    tvPress.setText(String.valueOf(Math.round(getInstance().getWeather().currentCondition.getPressure())));
    tvSunrise.setText(convertTime(getInstance().getWeather().location.getSunrise()));
    tvSunset.setText(convertTime(getInstance().getWeather().location.getSunset()));
    int resId = getResource(getInstance().getWeather().temperature.getTemp());
    lineTxt.setBackgroundResource(resId);
    tvTempUnit.setText("°C");
    tvDescrWeather.setText(getInstance().getWeather().currentCondition.getDescr());
}

public void init(View v) {
    requestQueue = Volley.newRequestQueue(getActivity().getApplicationContext());
    tvDescrWeather = (TextView) v.findViewById(R.id.descrWeather);
    lineTxt = (TextView) v.findViewById(R.id.lineTxt);
    tvLocation = (TextView) v.findViewById(R.id.location);
    tvTemperature = (TextView) v.findViewById(R.id.temp);
    tvTempUnit = (TextView) v.findViewById(R.id.tempUnit);
    tvTempMin = (TextView) v.findViewById(R.id.tempMin);
    tvTempMax = (TextView) v.findViewById(R.id.tempMax);
    tvHum = (TextView) v.findViewById(R.id.humidity);
    tvWindSpeed = (TextView) v.findViewById(R.id.windSpeed);
    tvWindDeg = (TextView) v.findViewById(R.id.windDeg);
    tvPress = (TextView) v.findViewById(R.id.pressure);
    weatherImage = (ImageView) v.findViewById(R.id.imgWeather);
    tvSunrise = (TextView) v.findViewById(R.id.sunrise);
    tvSunset = (TextView) v.findViewById(R.id.sunset);
}

public String convertTime(long time) {
    long javaTimestamp = time * 1000L;
    Date date = new Date(javaTimestamp);
    return new SimpleDateFormat("hh:mm", Locale.ENGLISH).format(date);
}

private int getResource(float temp) {
    int resId = 0;
    if (temp < 10)
        resId = R.drawable.line_shape_blue;
    else if (temp >= 10 && temp <= 24)
        resId = R.drawable.line_shape_green;
    else if (temp > 25)
        resId = R.drawable.line_shape_red;
    return resId;
}

public class MyApplication extends Application {

public static final String TAG = MyApplication.class
        .getSimpleName();
private Weather weather;
private DataBaseHelper db;

private RequestQueue mRequestQueue;
private static MyApplication mInstance;
RequestQueue.RequestFinishedListener requestFinishedListener;

@Override
public void onCreate() {
    super.onCreate();
    mInstance = this;
    db = new DataBaseHelper(this);
    weather = new Weather();
}

public static synchronized MyApplication getInstance() {
    return mInstance;
}