public class LocationActivity extends AppCompatActivity
        implements LocationContract.View {

    private static final int REQ_CODE = 111;

    @BindView(R.id.latitudeTextView)
    TextView latitudeTextView;
    @BindView(R.id.longitudeTextView)
    TextView longitudeTextView;
    @BindView(R.id.softDenyTextView)
    TextView softDeniedWarningTextView;
    @BindView(R.id.hardDenyTextView)
    TextView hardDeniedWarningTextView;
    @BindViews({R.id.softDenyTextView, R.id.hardDenyTextView})
    List<TextView> deniedTextViews;

    private static ButterKnife.Action<View> VISIBLE =
            (v, index) -> v.setVisibility(View.VISIBLE);
    private static ButterKnife.Action<View> GONE =
            (v, index) -> v.setVisibility(View.GONE);

    @Inject
    LocationContract.Presenter presenter;

    private FusedLocationProviderClient fusedLocationProviderClient;

    public static Intent newIntent(Context context) {
        return new Intent(context, LocationActivity.class);
    }

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        AndroidInjection.inject(this);
        super.onCreate(savedInstanceState);
        setContentView(R.layout.location_activity);

        ButterKnife.bind(this);

        fusedLocationProviderClient = LocationServices.getFusedLocationProviderClient(this);
    }

    @Override
    protected void onStart() {
        super.onStart();
        if (ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION)
                == PackageManager.PERMISSION_GRANTED) {
            hidePermissionDeniedWarning();
            getLocation();
        } else {
            requestPermission();
        }
    }

    @Override
    public void showLatitude(String latitude) {
        latitudeTextView.setText(latitude);
    }

    @Override
    public void showLongitude(String longitude) {
        longitudeTextView.setText(longitude);
    }

    @RequiresPermission(Manifest.permission.ACCESS_FINE_LOCATION)
    @SuppressWarnings({"MissingPermission"})
    private void getLocation() {
        fusedLocationProviderClient.getLastLocation()
                .addOnSuccessListener(location -> {
                    if (location != null) {
                        presenter.onLocationAvailable(location.getLatitude(),
                                location.getLongitude());
                    } else {
                        Toast.makeText(LocationActivity.this,
                                R.string.error_accessing_location,
                                Toast.LENGTH_SHORT)
                                .show();
                        Log.w("LOCATION", "Are you using an emulator? " +
                                "Make sure you send a dummy location to the emulator " +
                                "through the emulator settings");
                    }
                });
    }

    private void requestPermission() {
        ActivityCompat.requestPermissions(this,
                new String[]{Manifest.permission.ACCESS_FINE_LOCATION},
                REQ_CODE);
    }

    @Override
    @SuppressWarnings({"MissingPermission"})
    public void onRequestPermissionsResult(int requestCode,
                                           @NonNull String[] permissions,
                                           @NonNull int[] grantResults) {
        if (requestCode == REQ_CODE) {
            if (grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                hidePermissionDeniedWarning();
                getLocation();
            } else {
                handlePermissionDenied();
            }
        } else {
            super.onRequestPermissionsResult(requestCode, permissions, grantResults);
        }
    }

    private void handlePermissionDenied() {
        if (ActivityCompat.shouldShowRequestPermissionRationale(this,
                Manifest.permission.ACCESS_FINE_LOCATION)) {
            showSoftPermissionDeniedWarning();
        } else {
            // user has checked the "Do not ask again" checkbox
            showHardPermissionDeniedWarning();
        }
    }

    private void hidePermissionDeniedWarning() {
        ButterKnife.apply(deniedTextViews, GONE);
    }

    private void showSoftPermissionDeniedWarning() {
        ButterKnife.apply(softDeniedWarningTextView, VISIBLE);
        ButterKnife.apply(hardDeniedWarningTextView, GONE);
    }

    private void showHardPermissionDeniedWarning() {
        ButterKnife.apply(hardDeniedWarningTextView, VISIBLE);
        ButterKnife.apply(softDeniedWarningTextView, GONE);
    }

    @OnClick(R.id.softDenyTextView)
    void softDenyTextViewClicked(View view) {
        requestPermission();
    }

    @OnClick(R.id.hardDenyTextView)
    void hardDenyTextViewClicked(View view) {
        Intent intent = new Intent();
        intent.setAction(Settings.ACTION_APPLICATION_DETAILS_SETTINGS);
        Uri uri = Uri.fromParts("package", getPackageName(), null);
        intent.setData(uri);
        startActivity(intent);
    }

}