package se.nekotronic.simplegpstest;

import android.Manifest;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.TextView;

import java.util.Date;
import java.text.SimpleDateFormat;

import android.util.Log;
import android.location.Location;
import android.location.LocationManager;
import android.location.LocationListener;
import android.content.Context;
import java.text.DecimalFormat;

public class MainActivity extends AppCompatActivity {
    private TextView texten = null;
    private LocationManager locationManager;
    MyLocationListener locationListener;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        // Acquire a reference to the TextView we print in
        texten = (TextView) findViewById(R.id.textView1);
        texten.setText("");
        print("onCreate");

        // Acquire a reference to the system Location Manager
        locationManager = (LocationManager) this.getSystemService(Context.LOCATION_SERVICE);
        locationListener = new MyLocationListener();

        Location location = getLatestKnownLocation();
        if (location == null)
            print("No latest known location.");
        else {
            double latitude = location.getLatitude();
            double longitude = location.getLongitude();
            double accuracy = location.getAccuracy();
            double altitude = location.getAltitude();
            print("Latest known location from " + dateFormat.format(location.getTime()) +
                    ": Long " + decimalFormat.format(longitude) +
                    ", lat " + decimalFormat.format(latitude) +
                    ", accuracy " + decimalFormat.format(accuracy) +
                    ", alt " + decimalFormat.format(altitude));
        }
    } // onCreate

    @Override
    protected void onPause() {
        super.onPause();
        print("onPause");
        // Here in onPause, we cancel the subscription to location updates
        locationManager.removeUpdates(locationListener);
    }

    @Override
    protected void onResume() {
        super.onResume();
        print("onResume");
        // Here in onResume, we subscribe to location updates

        if (android.os.Build.VERSION.SDK_INT >= 23) {
            print("Detta är en nyare Android (API " + android.os.Build.VERSION.SDK_INT + "), så appen måste begära GPS-rättigheter av användaren.");
            int hasPermission = this.checkSelfPermission(Manifest.permission.ACCESS_FINE_LOCATION);
            if (hasPermission == android.content.pm.PackageManager.PERMISSION_GRANTED)
                print("Har redan GPS-rättigheter.");
            else
                this.requestPermissions((new String[]{Manifest.permission.ACCESS_FINE_LOCATION}), 4711);
        }
        else {
            print("Detta är en äldre Android (API " + android.os.Build.VERSION.SDK_INT + "), så GPS-rättigheterna i AndroidManifest.xml räcker.");
        }

        try {
            // Register the listener with the Location Manager to receive location updates
            locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, locationListener);
        } catch (SecurityException e) {
            print("requestLocationUpdates failed because missing permissions: " + e.getMessage());
        }
    }

    private SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSS");

    private void print(String message) {
        Date now = new Date();
        String nowString = dateFormat.format(now);
        String line = nowString + ": " + message;
        texten.setText(texten.getText() + line + "\n");
        Log.d("**************", line);
        texten.invalidate();
        texten.postInvalidate();
    }

    private DecimalFormat decimalFormat = new DecimalFormat("0.0000");

    // Define a listener that responds to location updates
    private class MyLocationListener implements LocationListener {
        // Called when a new location is found by the network location provider
        public void onLocationChanged(Location location) {
            double latitude = location.getLatitude();
            double longitude = location.getLongitude();
            double accuracy = location.getAccuracy();
            double altitude= location.getAltitude();
            print("Received a GPS location: Long " + decimalFormat.format(longitude) +
                  ", lat " + decimalFormat.format(latitude) +
                  ", accuracy " + decimalFormat.format(accuracy) +
                  ", alt " + decimalFormat.format(altitude));
        }

        public void onStatusChanged(String provider, int status, Bundle extras) {
            print("GPS provider status changed to " + status);
        }

        public void onProviderEnabled(String provider) {
            print("GPS provider enabled");
        }

        public void onProviderDisabled(String provider) {
            print("GPS provider disabled");
        }
    } // MyLocationListener


    // Find the latest known location
    private Location getLatestKnownLocation() {
        try {
            Location locationFromGPS = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);
            Location locationFromNetwork = locationManager.getLastKnownLocation(LocationManager.NETWORK_PROVIDER);
            long GPSLocationTime = 0;
            if (locationFromGPS == null)
                return locationFromNetwork;
            else if (locationFromNetwork == null)
                return locationFromGPS;
            else if (locationFromNetwork.getTime() > locationFromGPS.getTime())
                return locationFromNetwork;
            else
                return locationFromGPS;
        } catch (SecurityException e) {
            print("getLastKnownLocation failed because missing permissions: " + e.getMessage());
            return null;
        }
    } // getLatestKnownLocation

} // MainActivity