Mobile_Application_Development_lab/AirKoality/app/src/main/java/at/fhj/airkoality/ui/activity/MainActivity.java

package at.fhj.airkoality.ui.activity;

import android.app.ProgressDialog;
import android.content.Intent;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.preference.PreferenceManager;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;
import android.support.design.widget.BottomNavigationView;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentTransaction;
import android.support.v7.app.AppCompatActivity;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;


import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import java.util.ArrayList;
import java.util.List;

import at.fhj.airkoality.R;
import at.fhj.airkoality.db.room.AirKoalityDB;
import at.fhj.airkoality.model.Location;
import at.fhj.airkoality.network.HttpsGetTask;
import at.fhj.airkoality.network.RequestCallback;
import at.fhj.airkoality.service.LocationService;
import at.fhj.airkoality.ui.fragment.LocationListFragment;
import at.fhj.airkoality.ui.fragment.MapFragment;

public class MainActivity extends AppCompatActivity implements RequestCallback {

    private LocationListFragment locationListFragment;
    private MapFragment mapFragment;

    private static final  String LOCATION_LIST = "location_list";
    private static final  String MAP = "map";
    private static final  String FRAGMENT_PREF_KEY = "last_fragment";

    private ProgressDialog progressDialog;

    private AirKoalityDB database;



    private BottomNavigationView bottomNavigationView;

    private SharedPreferences sharedPreferences;


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

        locationListFragment = new LocationListFragment();
        mapFragment = new MapFragment();

        bottomNavigationView = findViewById(R.id.bnvMain);

        progressDialog = new ProgressDialog(this);

        database = AirKoalityDB.getDatabase(this);

        sharedPreferences = PreferenceManager.getDefaultSharedPreferences(this);

        FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
        transaction.add(R.id.flFragmentContainer, locationListFragment);
        transaction.add(R.id.flFragmentContainer, mapFragment);

        transaction.commit();

        bottomNavigationView.setOnNavigationItemSelectedListener(menuItem ->  {

                    switch (menuItem.getItemId()){
                    case R.id.action_location:
                        setSelectedFragment(LOCATION_LIST);
                        sharedPreferences.edit()
                                .putString(FRAGMENT_PREF_KEY, LOCATION_LIST)
                                .commit();

                        break;
                    case R.id.action_map:
                        setSelectedFragment(MAP);
                        sharedPreferences.edit()
                                .putString(FRAGMENT_PREF_KEY, MAP)
                                .commit();
                        break;
                }
                return true;

        });
        setSelectedFragment(sharedPreferences.getString("last_fragment", LOCATION_LIST));
        fetchLocations();

    }


    private void fetchLocations(){
        HttpsGetTask httpsGetTask = new HttpsGetTask(this);
        httpsGetTask.execute("https://api.openaq.org/v1/locations?country=AT&limit=200");
    }



    private void setSelectedFragment(String fragmentName){
        FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
        switch (fragmentName) {
            case LOCATION_LIST:
                transaction.hide(mapFragment);
                transaction.show(locationListFragment);
                break;
            case MAP:
                transaction.hide(locationListFragment);
                transaction.show(mapFragment);
                break;
        }
        transaction.commit();
    }

    @Override
    public void onRequestStart() {
        progressDialog.setMessage("Fetching...");
        progressDialog.show();
    }

    @Override
    public void onResult(String result) {
        new Thread(()->{

            List<Location> locations;
            //parse result
            if(result == null){
                System.out.println("no locations");
            }else {
//write to db
                try {
                    locations = parseLocations(result);
                    database.locationDAO().clear();
                    database.locationDAO().addAll(locations);
                }catch (JSONException e){
                    e.printStackTrace();
                }


            }

            //notify fragments
            dismissProgressDialog();
            updateFragments();

        }).start();


    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {


        MenuInflater inflater = getMenuInflater();
        inflater.inflate(R.menu.main_menue, menu);
        return true;

    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {

        switch (item.getItemId()){
            case R.id.action_service_on:
                startLocationService();
                return true;
            case R.id.action_service_off:
                stopLocationService();
                return true;
            default:
                return false;
        }


    }

    private void startLocationService(){
        Intent intent = new Intent(this, LocationService.class);
        startService(intent);

}

    private void stopLocationService(){

            Intent intent = new Intent(this, LocationService.class);
            stopService(intent);

    }

    private void updateFragments() {
        runOnUiThread(() -> {
            locationListFragment.refresh();
            mapFragment.refresh();
        });
    }

    private void dismissProgressDialog() {
       runOnUiThread(()-> progressDialog.dismiss());
    }

    private List<Location> parseLocations(String json) throws JSONException {
        List<Location> locations = new ArrayList<>();
        JSONObject jsonObject = new JSONObject(json);
        JSONArray results = jsonObject.getJSONArray("results");

        for (int i = 0; i < results.length(); i++){
            JSONObject locationResult = results.getJSONObject(i);
            String locationName = locationResult.getString("location");
            String city = locationResult.getString("city");
            String country = locationResult.getString("country");

            Location location = new Location(locationName, city, country);
            locations.add(location);
        }
        return locations;
    }
}