package cornell.cs2046.examples;

import android.app.Activity;
import android.content.Context;
import android.hardware.Sensor;
import android.hardware.SensorEvent;
import android.hardware.SensorEventListener;
import android.hardware.SensorManager;
import android.os.Bundle;
import android.widget.Toast;

public class ShakeDetectorActivity extends Activity implements SensorEventListener {
    private SensorManager mSensorManager;
    private Sensor mSensor;
    private float lastX, lastY, lastZ;
    private long lastTimeMillis;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        mSensorManager = (SensorManager) getSystemService(Context.SENSOR_SERVICE);
    }

    @Override
    public void onResume() {
        super.onResume();
        mSensor = mSensorManager.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);
        if (mSensor != null) {
            mSensorManager.registerListener(this, mSensor, 
                SensorManager.SENSOR_DELAY_GAME);
        }
    }

    @Override
    public void onPause() {
        super.onPause();
        if (mSensor != null) {
            mSensorManager.unregisterListener(this, mSensor);
        }
    }

    @Override
    public void onAccuracyChanged(Sensor sensor, int accuracy) {
    }

    @Override
    public void onSensorChanged(SensorEvent event) {
        long timeMillis = event.timestamp / 1000000;
        if (lastTimeMillis == 0) {
            lastTimeMillis = timeMillis;
            lastX = event.values[0];
            lastY = event.values[1];
            lastZ = event.values[2];
        } else if (timeMillis - lastTimeMillis > 100) {
            float x = event.values[0];
            float y = event.values[1];
            float z = event.values[2];
            float disp = Math.abs(x+y+z-lastX-lastY-lastZ);
            float speed = disp / (timeMillis - lastTimeMillis) * 10000;
            if (speed > 800) {
                Toast.makeText(this, "Phone is shaking!", Toast.LENGTH_SHORT).show();
            }
            lastTimeMillis = timeMillis;
            lastX = x;
            lastY = y;
            lastZ = z;
        }

    }

}