package dk.thoerup.traininfo;

import java.util.List;

import android.content.Context;
import android.location.GpsSatellite;
import android.location.GpsStatus;
import android.location.Location;
import android.location.LocationListener;
import android.location.LocationManager;
import android.os.Bundle;
import android.util.Log;


public class LocationLookup implements LocationListener, GpsStatus.Listener {
	
	public enum LookupStates {
		GOTLOCATION,
		NOPROVIDER,
		STARTED,
		IDLE
	}

	private LocationManager locManager;
	private Context cntx;

	private Location lastKnownLocation = null;
	private Location savedLocation = null;
	private int satCount;
	
	private boolean hasGps;
	
	private LookupStates state;
	
	private long startTime;

	public LocationLookup(Context c) {
		state = LookupStates.IDLE;
		cntx = c;
	}
	
	
	public boolean hasLocation() {
		return savedLocation != null;
	}
	
	public Location getLocation()
	{
		return savedLocation;
	}
	
	public boolean hasGps() {
		return hasGps;
	}
	
	public int getSatCount() {
		return satCount;
	}
	
	public LookupStates getState() {
		return state;
	}
	
	public Location getLastKnownLocation() {
		return lastKnownLocation;
	}
	
	public long elapsedTime() {
		long now = android.os.SystemClock.elapsedRealtime();
		
		return now - startTime;
	}

	public void locateStations() {
		
		state = LookupStates.STARTED;
		
		hasGps = false;
		locManager = (LocationManager) cntx.getSystemService(Context.LOCATION_SERVICE);
		satCount = 0;
		
		startTime = android.os.SystemClock.elapsedRealtime(); 

		List<String> providers = locManager.getProviders(true);		
		
		if (providers.size() > 0) {
			for(String provider : providers) {
				Log.i("Provider", ""+provider);
				if (provider.equalsIgnoreCase("gps")) {
					locManager.addGpsStatusListener(this);
					hasGps = true;					
				}

				locManager.requestLocationUpdates(provider, 0, 0, this);
				Location tmpLastKnown = locManager.getLastKnownLocation(provider);
				if (tmpLastKnown != null) {
					saveLastKnownLocation(tmpLastKnown);
				}
			}
		} else {
			// message that no suitable provider was found
			//hndl.sendEmptyMessage(StationList.NOPROVIDER);
			state = LookupStates.NOPROVIDER;
			
		}
	}
	@Override
	public void onLocationChanged(Location location) {		
		Log.i("Location", "Got location fix " + location.getLatitude() + ", " + location.getLongitude() + " accuracy=" + location.getAccuracy() + " provider=" +location.getProvider());
		

		if (savedLocation == null || location.getAccuracy() < savedLocation.getAccuracy())
			savedLocation = new Location(location); //save a copy
		
		if (hasGps) {
			if (!location.getProvider().equals("gps")) {
				return; // at least give the gps a chance
			} else if (location.getAccuracy() > 512) {
				return; //if we have a gps provider lets wait for a more precise fix
			}

		}
		stopSearch();
		state = LookupStates.GOTLOCATION;

	}
	
	private void saveLastKnownLocation(Location loc) {
		if (lastKnownLocation == null) { 
			lastKnownLocation = loc; 
		} else {
			if (loc.getTime() > lastKnownLocation.getTime()) {//if loc is more recent than saved
				lastKnownLocation = loc;
			}
		}
	}
	
	public void stopSearch()
	{
		if (state == LookupStates.STARTED) {
			state = LookupStates.IDLE;
			locManager.removeGpsStatusListener(this);
			locManager.removeUpdates(this);
		}
	}


	@Override
	public void onProviderDisabled(String provider) {
	}


	@Override
	public void onProviderEnabled(String provider) {
	}


	@Override
	public void onStatusChanged(String provider, int status, Bundle extras) {
		// TODO Auto-generated method stub

	}


	@Override //GpsStatus.Listener
	public void onGpsStatusChanged(int event) {
		if (event == GpsStatus.GPS_EVENT_SATELLITE_STATUS) {
			int count = 0;
			GpsStatus status =  locManager.getGpsStatus(null);
			for (GpsSatellite sat : status.getSatellites()) {
				count ++;
			}			
			
			satCount = count;
		}
		
	}
}