package com.google.marvin.there;



import com.google.tts.TTS;



import android.app.Activity;

import android.content.Context;

import android.content.Intent;

import android.location.Location;

import android.location.LocationListener;

import android.location.LocationManager;

import android.location.LocationProvider;

import android.os.Bundle;

import android.util.Log;

import android.view.KeyEvent;

import android.widget.TextView;



public class NavigationActivity extends Activity {



  private LocationManager locationManager;

  private Location currentLocation;

  private LocationListener gpsLocationListener = new LocationListener() {

    public void onLocationChanged(Location arg0) {

      currentLocation = arg0;

      distanceTextView.setText(Double.toString(currentLocation.getAccuracy()));

    }



    public void onProviderDisabled(String arg0) {

      currentLocation = null;

    }



    public void onProviderEnabled(String arg0) {

    }



    public void onStatusChanged(String arg0, int arg1, Bundle arg2) {

      if (arg1 != LocationProvider.AVAILABLE) {

        currentLocation = null;

        distanceTextView.setText("GPS Unavailable");

      }

    }

  };





  public TTS tts;

  private TTS.InitListener ttsInitListener = new TTS.InitListener() {

    public void onInit(int arg0) {

      tts.speak("Navigation started. Acquiring GPS.", 0, null);

    }

  };



  private Place destination;

  private TextView distanceTextView;

  private Compass compass;



  /** Called when the activity is first created. */

  @Override

  public void onCreate(Bundle savedInstanceState) {

    super.onCreate(savedInstanceState);



    Intent startingIntent = getIntent();

    String placeName = startingIntent.getStringExtra("DESTINATION");



    DbManager db = new DbManager(this);



    destination = db.get(placeName);



    if (destination == null) {

      finish();

    }



    compass = new Compass(this);



    locationManager = (LocationManager) getSystemService(Context.LOCATION_SERVICE);

    locationManager.requestLocationUpdates(LocationManager.GPS_PROVIDER, 0, 0, gpsLocationListener);



    setContentView(R.layout.main);

    distanceTextView = (TextView) findViewById(R.id.distanceTextView);



    tts = new TTS(this, ttsInitListener, true);

  }





  @Override

  protected void onDestroy() {

    compass.shutdown();

    locationManager.removeUpdates(gpsLocationListener);

    tts.shutdown();

    super.onDestroy();

  }



  // Distance returned is in m

  private double distanceFromDestination(Location startLocation) {

    if (startLocation == null) {

      return -1;

    }

    double lat1 = startLocation.getLatitude();

    double lon1 = startLocation.getLongitude();

    double lat2 = Double.parseDouble(destination.lat);

    double lon2 = Double.parseDouble(destination.lon);



    double R = 6371; // earth's mean radius in km

    double dLat = (lat2 - lat1) * Math.PI / 180.0;

    double dLon = (lon2 - lon1) * Math.PI / 180.0;





    lat1 = lat1 * Math.PI / 180.0;

    lat2 = lat2 * Math.PI / 180.0;



    double a =

        Math.sin(dLat / 2) * Math.sin(dLat / 2) + Math.cos(lat1) * Math.cos(lat2)

            * Math.sin(dLon / 2) * Math.sin(dLon / 2);

    double c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1 - a));

    double d = R * c;

    return d * 1000;

  }





  private double getBearingToDestination(Location startLocation) {

    if (startLocation == null) {

      return -1;

    }

    double lat1 = startLocation.getLatitude();

    double lon1 = startLocation.getLongitude();

    double lat2 = Double.parseDouble(destination.lat);

    double lon2 = Double.parseDouble(destination.lon);

    lat1 = lat1 * Math.PI / 180.0;

    lat2 = lat2 * Math.PI / 180.0;

    double dLon = (lon2 - lon1) * Math.PI / 180.0;



    double y = Math.sin(dLon) * Math.cos(lat2);

    double x = Math.cos(lat1) * Math.sin(lat2) - Math.sin(lat1) * Math.cos(lat2) * Math.cos(dLon);

    return ((Math.atan2(y, x) * 180 / Math.PI) + 360) % 360;

  }



  private void speakSimpleDirections() {

    if (tts == null) {

      return;

    }

    boolean closeToDest = false;

    Location myLocation = currentLocation;

    if (myLocation == null) {

      tts.speak("GPS unavailable, please retry later.", 0, null);

      return;

    }

    double distance = distanceFromDestination(myLocation);

    double accuracy = currentLocation.getAccuracy();

    if (accuracy > 50) {

      tts.speak("GPS signal weak.", 0, null);

    } else {

      if (distance < accuracy) {

        closeToDest = true;

        tts.speak("You are near your destination.", 0, null);

      } else {

        long roundedDistance = Math.round(distance);

        tts.speak("You are about " + roundedDistance + " meters away from your destination.", 0, null);        

      }

    }

    if (!closeToDest) {

      double currentHeading = compass.getCurrentHeadingValue();

      if (currentHeading == -1) {

        tts.speak("Please calibrate the compass by shaking your handset.", 1, null);

        return;

      }

      double bearingToDest = getBearingToDestination(myLocation);

      double headingDiff = bearingToDest - currentHeading;

      if (headingDiff < 0) {

        headingDiff = headingDiff + 360;

      }

      int index = (int) ((headingDiff * 100 + 1125) / 2250);

      tts.speak(HEADING_NAMES[index], 1, null);

    }



  }





  /** Called when a key is pressed down */

  @Override

  public boolean onKeyDown(int keyCode, KeyEvent event) {

    Log.i("Nav activity", "key down");

    if (keyCode == KeyEvent.KEYCODE_DPAD_CENTER) {

      Log.i("Nav activity", "center key");

      speakSimpleDirections();

    } else {

      super.onKeyDown(keyCode, event);

    }

    return false;

  }



  private static final String[] HEADING_NAMES =

      {"straight ahead", "ahead and a bit to the right", "ahead and to the right",

          "to the right and a bit ahead", "to the right", "to the right",

          "turn around, then to the left", "turn around, then a bit to the left", "turn around",

          "turn around, then a bit to the right", "turn around, then to the right", "to the left",

          "to the left", "to the left and a bit ahead", "ahead and to the left",

          "ahead and a bit to the left", "ahead"};



}