ActivationService

public class ActivationService extends Service {

    public static final String STATUS_NEW = "0";
    public static final String STATUS_IDLE = "1";
    public static final String STATUS_SERVICE_DESTROY = "2";
    public static final String STATUS_OK = "3";
    public static final String STATUS_EMERGENCY = "4";

    private DatabaseReference databaseReference;
    private static String loggedUserId;
    private Context context;
    private ValueEventListener valueEventListenerContatos;
    private Preferences preferences;

    public ActivationService() {
    }

    @Override
    public IBinder onBind(Intent intent) {
        return null;
    }

    @Override
    public void onCreate() {
        super.onCreate();
        Log.d("TAG", "onCreate - ActivationService");
        context = getApplicationContext();
        preferences = new Preferences(context);
        loggedUserId = preferences.getLoggedUserId();
        if (TextUtils.isEmpty(loggedUserId)) {
            stopSelf();
        }
    }

    @Override
    public int onStartCommand(final Intent intent, int flags, int startId) {
        Log.d("TAG", "onStartCommand - ActivationService");
        databaseReference = FirebaseConfig.getFirebaseReference();
        databaseReference = databaseReference.child("users");
        valueEventListenerContatos = new ValueEventListener() {
            @Override
            public void onDataChange(DataSnapshot dataSnapshot) {
                if (dataSnapshot.getValue() != null) {
                    for (DataSnapshot users : dataSnapshot.getChildren()) {
                        User user = users.getValue(User.class);
                        if (isActive(user)) {
                            pushEmergency(user);
                        } else if (isCurrentInEmergency(user)) {
                            pushSelfEmergency(user);
                        } else if (wasActive(user)) {
                            removeEmergency(user);
                        }
                    }
                }
            }

            private boolean isActive(User user) {
                return !isLoggedUser(user) && isInContats(user) &&
                        isInEmergency(user);
            }

            private boolean isCurrentInEmergency(User user) {
                return isLoggedUser(user) && isInEmergency(user);
            }

            private boolean wasActive(User user) {
                String emergencyUserId = preferences.getEmergencyUserId();
                return !TextUtils.isEmpty(emergencyUserId) && isEmergencyUser(emergencyUserId, user)
                        && isUserStatusOK(emergencyUserId) && !isLoggedUser(user);
            }

            @Override
            public void onCancelled(DatabaseError databaseError) {
            }
        };
        databaseReference.addValueEventListener(valueEventListenerContatos);
        return super.onStartCommand(intent, flags, startId);
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        Log.d("TAG", "onDestroy - ActivationService");
        if(!TextUtils.isEmpty(loggedUserId)){
            UserHelper.changeStatus(loggedUserId, STATUS_SERVICE_DESTROY);
        }
        if (databaseReference != null && valueEventListenerContatos != null) {
            databaseReference.removeEventListener(valueEventListenerContatos);
        }
        NotificationHelper.cancelNotification(context, NotificationHelper.NOTIFICATION_ID_ALARM);
        NotificationHelper.cancelNotification(context, NotificationHelper.NOTIFICATION_ID_EMERGENCY);
        NotificationHelper.cancelNotification(context, NotificationHelper.NOTIFICATION_ID_SELFEMERGENCY);
    }

    private void pushEmergency(User user) {
        Log.d("TAG", "pushEmergency " + user.getName());
        preferences.setEmergencyUserId(user.getId());
        preferences.setEmergencyUserName(user.getName());
        Intent intentEmergency = new Intent(context, NotificationEmergencyService.class);
        startService(intentEmergency);
    }

    private void removeEmergency(User user) {
        Log.d("TAG", "removeEmergency " + user.getName());
        preferences.setEmergencyUserId("");
        preferences.setEmergencyUserName("");
        Intent intentEmergency = new Intent(context, NotificationEmergencyService.class);
        stopService(intentEmergency);
        NotificationHelper.cancelNotification(context, NotificationHelper.NOTIFICATION_ID_EMERGENCY);
    }

    private void pushSelfEmergency(User user) {
        Log.d("TAG", "pushSelfEmergency " + user.getName());
        Intent intentSelfEmergency = new Intent(context, NotificationSelfEmergencyService.class);
        startService(intentSelfEmergency);
    }

    private boolean isLoggedUser(User user) {
        return !TextUtils.isEmpty(loggedUserId) && user.getId().equals(loggedUserId);
    }

    private boolean isInEmergency(User user) {
        return user.getStatus().equals(STATUS_EMERGENCY);
    }

    private boolean isInContats(User user) {
        ArrayList<Contat> contatsArray = ContatsHelper.getContats(context, user);
        for (Contat contat : contatsArray) {
            if (contat.getId().equals(user.getId())) {
                return true;
            }
        }
        return false;
    }

    private boolean isEmergencyUser(String id, User user) {
        return id.equals(user.getId());
    }

    private boolean isUserStatusOK(String userId) {
        String status = UserHelper.getStatus(userId);
        return status.equals(STATUS_OK)
                || status.equals(STATUS_IDLE)
                || status.equals(STATUS_SERVICE_DESTROY);
    }

}