package ru.chulakov.ris.utils;

import android.app.Service;
import android.content.Context;
import android.content.Intent;
import android.location.Location;
import android.location.LocationManager;
import android.os.Bundle;
import android.os.IBinder;

/**
 * Service to getting user location.
 */
public class GPSTracker extends Service
{
    private LocationManager mLocationManager = null;
    private static final int LOCATION_INTERVAL = 1000 * 10;
    private static final int LOCATION_DISTANCE = 100;

    public final static int ACCURACY = 25;

    /** Constant to transmission latitude through broadcast. */
    public static final String LATITUDE = "latitude";
    /** Constant to transmission longitude through broadcast. */
    public static final String LONGITUDE = "longitude";
    /** Intent action for work with broadcast. */
    public static final String INTENT_ACTION = "GPSLocationUpdates";

    private boolean isUsedGPS;

    /**
     * Sends location to activity via broadcast.
     *
     * @param location Location passed to Activity.
     */
    private void sendMessageToActivity(Location location) {
        Intent intent = new Intent(INTENT_ACTION);
        Bundle b = new Bundle();
        b.putDouble(LATITUDE, location.getLatitude());
        b.putDouble(LONGITUDE, location.getLongitude());
        intent.putExtras(b);

        sendBroadcast(intent);
    }

    private class LocationListener implements android.location.LocationListener{
        @Override
        public void onLocationChanged(Location location) {
            sendMessageToActivity(location);
            if (isUsedGPS && location.getAccuracy() < ACCURACY)
                disableGPS();
        }

        @Override
        public void onProviderDisabled(String provider) {}

        @Override
        public void onProviderEnabled(String provider) {}

        @Override
        public void onStatusChanged(String provider, int status, Bundle extras) {}
    }

    final LocationListener mLocationListenerNetwork = new LocationListener();
    final LocationListener mLocationListenerGPS = new LocationListener();

    @Override
    public IBinder onBind(Intent arg0) {
        return null;
    }

    private static final String TAG = GPSTracker.class.getSimpleName();
    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        super.onStartCommand(intent, flags, startId);

        if (PermissionUtils.appHasAccessFineLocationPermission(getApplicationContext())) {
            requestUpdatesIfAvailable(LocationManager.NETWORK_PROVIDER,
                                      LOCATION_INTERVAL,
                                      LOCATION_DISTANCE,
                                      mLocationListenerNetwork);

            if (isUsedGPS)
                requestUpdatesIfAvailable(LocationManager.GPS_PROVIDER,
                                          LOCATION_INTERVAL,
                                          LOCATION_DISTANCE,
                                          mLocationListenerGPS);
        }

        return START_STICKY;
    }

    @Override
    public void onCreate() {
        isUsedGPS = true;
        initializeLocationManager();
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        //noinspection MissingPermission
        if (mLocationManager != null) {
            mLocationManager.removeUpdates(mLocationListenerGPS);
            mLocationManager.removeUpdates(mLocationListenerNetwork);
        }

    }

    private void disableGPS() {
        isUsedGPS = false;
        mLocationManager.removeUpdates(mLocationListenerGPS);
    }

    private void initializeLocationManager() {
        if (mLocationManager == null)
            mLocationManager = (LocationManager) getApplicationContext()
                    .getSystemService(Context.LOCATION_SERVICE);
    }

    /**
     * Requests location updates if provider is available.
     *
     * @param provider Location provider.
     * @param locationInterval Interval between updates.
     * @param locationDistance Distance between updates.
     * @param locationListener Callback function.
     */
    private void requestUpdatesIfAvailable(String provider,
                                           int locationInterval,
                                           int locationDistance,
                                           LocationListener locationListener)
    {
        if (!mLocationManager.isProviderEnabled(provider))
            return;
        //noinspection MissingPermission
        mLocationManager.requestLocationUpdates(provider,
                                                locationInterval,
                                                locationDistance,
                                                locationListener);
    }
}