package com.example.wakeup;

import android.annotation.SuppressLint;

import android.app.Activity;

import android.content.BroadcastReceiver;

import android.content.Context;

import android.content.Intent;

import android.content.IntentFilter;

import android.hardware.Sensor;

import android.hardware.SensorEvent;

import android.hardware.SensorEventListener;

import android.hardware.SensorManager;

import android.os.Bundle;

import android.os.Handler;

import android.os.PowerManager;

import android.util.Log;

import android.widget.TextView;

public class MainActivity extends Activity implements SensorEventListener{

	private static final String TAG = "MainActivity";

	private static final String WAKE_LOCK_TAG = "LightTag";

	private PowerManager pm ;

	private PowerManager.WakeLock wl;

	private TextView tv;

	private StringBuilder mBuilder = new StringBuilder(2048);

	private SensorManager mSensorManager;

	private Sensor mLight;

	private Handler handler =new Handler();

	@Override

	protected void onCreate(Bundle savedInstanceState) {

		super.onCreate(savedInstanceState);

		setContentView(R.layout.activity_main);

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

		mSensorManager = (SensorManager)getSystemService(SENSOR_SERVICE);

		mLight = mSensorManager.getDefaultSensor(Sensor.TYPE_LIGHT);

	}

	@Override

	protected void onResume() {

		super.onResume();

		pm = (PowerManager) getSystemService(Context.POWER_SERVICE);

		wl = pm.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, WAKE_LOCK_TAG);

		wl.acquire();

	}

	@Override

	protected void onStart() {

		super.onStart();

		mSensorManager.registerListener(this, mLight, SensorManager.SENSOR_DELAY_FASTEST);

		//register broadcasts receiver

		IntentFilter filter = new IntentFilter(Intent.ACTION_SCREEN_OFF);

		registerReceiver(mReceiver, filter);  

	}

	@Override

	protected void onPause() {

		super.onPause();

		//release lock

		if (wl!=null) {

			wl.release();

			wl=null;

		}

	}

	@Override

	protected void onDestroy() {

		super.onDestroy();

		mSensorManager.unregisterListener(this);

		unregisterReceiver(mReceiver);  

	}

	@Override

	public void onAccuracyChanged(Sensor sensor, int accuracy) {

	}

	@Override

	public void onSensorChanged(SensorEvent event) {

		Log.i(TAG, "Light Values :"+ event.values[0]);

		mBuilder.insert(0,  event.values[0]+"\n");

		tv.setText(mBuilder.toString());

		tv.invalidate();

	}

	private BroadcastReceiver mReceiver =  new BroadcastReceiver() {

		@Override

		public void onReceive(Context context, Intent intent) {

			if (Intent.ACTION_SCREEN_OFF.equalsIgnoreCase(intent.getAction())) {

				handler.post(new Runnable() {

					@SuppressLint("Wakelock")

					public void run() {

						if (wl != null) {

							wl.release();

							wl=null;

						}

						try {

							System.out.println("Sleeping ...");

							Thread.sleep (3000);

						} catch (InterruptedException e) {

							e.printStackTrace();

						}

						wl = pm.newWakeLock(

								PowerManager.PARTIAL_WAKE_LOCK

								,

								WAKE_LOCK_TAG);

						wl.acquire();

					}

				});

			}

		}

	};

}