package de.tudarmstadt.informatik.hostage;

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.Socket;
import java.security.SecureRandom;
import java.util.ArrayList;
import java.util.LinkedList;
import java.util.List;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
import org.apache.http.util.EntityUtils;
import org.json.JSONObject;

import android.app.NotificationManager;
import android.app.PendingIntent;
import android.app.Service;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.content.SharedPreferences;
import android.content.SharedPreferences.Editor;
import android.net.ConnectivityManager;
import android.net.Uri;
import android.os.AsyncTask;
import android.os.Binder;
import android.os.IBinder;
import android.preference.PreferenceManager;
import android.support.v4.app.NotificationCompat;
import android.support.v4.app.TaskStackBuilder;
import android.support.v4.content.LocalBroadcastManager;
import android.util.Log;
import android.widget.Toast;
import de.tudarmstadt.informatik.hostage.commons.HelperUtils;
import de.tudarmstadt.informatik.hostage.logging.MyLocationManager;
import de.tudarmstadt.informatik.hostage.logging.UglyDbHelper;
import de.tudarmstadt.informatik.hostage.protocol.HTTP;
import de.tudarmstadt.informatik.hostage.protocol.Protocol;
import de.tudarmstadt.informatik.hostage.ui.MainActivity;

/**
 * Background service running as long as at least one protocol is active.
 * Service controls start and stop of protocol listener. Notifies GUI about
 * events happening in the background. Creates Notifications to inform the user
 * what it happening.
 * 
 * @author Mihai Plasoianu
 * @author Lars Pandikow
 * @author Wulf Pfeiffer
 */
public class HoneyService extends Service {

	private static Context context;

	/**
	 * Returns the application context.
	 * 
	 * @return context.
	 */
	public static Context getContext() {
		return HoneyService.context;
	}

	private LinkedList<Protocol> implementedProtocols;
	private ArrayList<HoneyListener> listeners = new ArrayList<HoneyListener>();
	private NotificationCompat.Builder builder;
	private SharedPreferences connectionInfo;
	private Editor connectionInfoEditor;

	public List<HoneyListener> getListeners() {
		return listeners;
	}

	private final IBinder mBinder = new LocalBinder();

	public class LocalBinder extends Binder {
		public HoneyService getService() {
			return HoneyService.this;
		}
	}

	@Override
	public IBinder onBind(Intent intent) {
		return mBinder;
	}

	@Override
	public void onCreate() {
		super.onCreate();
		HoneyService.context = getApplicationContext();
		implementedProtocols = getImplementedProtocols();
		connectionInfo = getSharedPreferences(getString(R.string.connection_info), Context.MODE_PRIVATE);
		connectionInfoEditor = connectionInfo.edit();
		createNotification();
		registerNetReceiver();
		updateConnectionInfo();
		getLocationData();
		
		String sharedPreferencePath = getString(R.string.shared_preference_path);
		boolean useQotd = getSharedPreferences(sharedPreferencePath , MODE_PRIVATE).getBoolean("useQotd", true);
		if(useQotd) {
			new QotdTask().execute(new String[] {});
		}
	}

	@Override
	public int onStartCommand(Intent intent, int flags, int startId) {
		// We want this service to continue running until it is explicitly
		// stopped, so return sticky.
		return START_STICKY;
	}

	@Override
	public void onDestroy() {
		cancelNotification();
		unregisterNetReceiver();
		super.onDestroy();
	}

	/**
	 * Starts an Instance of MyLocationManager to set the location within this
	 * class.
	 */
	private void getLocationData() {
		MyLocationManager locationManager = new MyLocationManager(this);
		locationManager.getUpdates(60 * 1000, 3);
	}

	/**
	 * Deletes all session related data.
	 */
	private void deleteConnectionData() {
		connectionInfoEditor.clear();
		connectionInfoEditor.commit();
	}

	/**
	 * Register broadcast receiver for connectivity changes
	 */
	private void registerNetReceiver() {
		// register BroadcastReceiver on network state changes
		IntentFilter intent = new IntentFilter();
		intent.addAction(ConnectivityManager.CONNECTIVITY_ACTION); // "android.net.conn.CONNECTIVITY_CHANGE"
		registerReceiver(netReceiver, intent);
	}

	/**
	 * Unregister broadcast receiver for connectivity changes
	 */
	private void unregisterNetReceiver() {
		unregisterReceiver(netReceiver);
	}

	/**
	 * Receiver for connectivity change broadcast.
	 * 
	 * @see MainActivity#BROADCAST
	 */
	private BroadcastReceiver netReceiver = new BroadcastReceiver() {
		@Override
		public void onReceive(Context context, Intent intent) {
			String bssid_old = connectionInfo.getString(getString(R.string.connection_info_bssid), "");
			String bssid_new = HelperUtils.getBSSID(context);
			if (bssid_new == null || !bssid_new.equals(bssid_old)) {
				deleteConnectionData();
				updateConnectionInfo();
				getLocationData();
				notifyUI(this.getClass().getName(), new String[]{getString(R.string.broadcast_connectivity)});
			}
		}
	};
	

	/**
	 * Notifies the GUI about a event.
	 * 
	 * @param sender
	 *            Source where the event took place.
	 * @param key
	 *            Detailed information about the event.
	 */
	public void notifyUI(String sender, String[] values) {
		createNotification();
		// Send Notification
		if (sender.equals(HoneyHandler.class.getName()) && values[0].equals(R.string.broadcast_started)) {
			attackNotification();
		}
		// Inform UI of Preference Change
		Intent intent = new Intent(getString(R.string.broadcast));
		intent.putExtra("SENDER", sender);
		intent.putExtra("VALUES", values);
		Log.i("Sender" ,sender);
		LocalBroadcastManager.getInstance(this).sendBroadcast(intent);
	}
	


	/**
	 * Returns an LinkedList<String> with the names of all implemented protocols.
	 * 
	 * @return ArrayList of
	 *         {@link de.tudarmstadt.informatik.hostage.protocol.Protocol
	 *         Protocol}
	 */
	private LinkedList<Protocol> getImplementedProtocols() {
		String[] protocols = getResources().getStringArray(R.array.protocols);
		String packageName = Protocol.class.getPackage().getName();
		LinkedList<Protocol> implementedProtocols = new LinkedList<Protocol>();

		for (String protocol : protocols) {
			try {
				implementedProtocols.add((Protocol) Class.forName(String.format("%s.%s", packageName, protocol)).newInstance());
			} catch (Exception e) {
				e.printStackTrace();
			}
		}
		return implementedProtocols;
	}
	
	/**
	 * Returns the default port number, if the protocol is implemented.
	 * @param protocolName The name of the protocol
	 * @return Returns the default port number, if the protocol is implemented. Else returns -1.
	 */
	private int getDefaultPort(String protocolName){
		for (Protocol protocol : implementedProtocols) {
			if(protocolName.equals(protocol.toString())){
				return protocol.getDefaultPort();
			}
		}
		return -1;
	}

	/**
	 * Determines if there any listener is currently running.
	 * 
	 * @return True if there is a running listener, else false.
	 */
	public boolean hasRunningListeners() {
		for (HoneyListener listener : listeners) {
			if (listener.isRunning())
				return true;
		}
		return false;
	}
	
	/**
	 * Determines if a protocol with the given name is running on its default port.
	 * @param protocolName The protocol name
	 * @return True if protocol is running, else false.
	 */
	public boolean isRunning(String protocolName){
		int port = getDefaultPort(protocolName);
		return isRunning(protocolName, port);
	}
	
	/**
	 * Determines if a protocol with the given name is running on the given port.
	 * @param protocolName The protocol name
	 * @param port Specific port
	 * @return True if protocol is running, else false.
	 */
	public boolean isRunning(String protocolName, int port){
		for (HoneyListener listener : listeners) {
			if (listener.getProtocolName().equals(protocolName) && listener.getPort() == port) {
				return listener.isRunning();
			}
		}	
		return false;
	}
	
	/**
	 * Determines the number of active connections for a protocol running on its default port.
	 * @param protocolName The protocol name
	 * @return Number of active connections
	 */
	public int getNumberOfActiveConnections(String protocolName){
		int port = getDefaultPort(protocolName);
		return getNumberOfActiveConnections(protocolName, port);
	}
	
	/**
	 * Determines the number of active connections for a protocol running on the given port.
	 * @param protocolName The protocol name
	 * @param port Specific port
	 * @return Number of active connections
	 */
	public int getNumberOfActiveConnections(String protocolName, int port){
		for (HoneyListener listener : listeners) {
			if (listener.getProtocolName().equals(protocolName) && listener.getPort() == port) {
				return listener.getHandlerCount();
			}
		}	
		return 0;
	}

	/**
	 * Creates a Listener for a given protocol on a specific port. 
	 * After creation the Listener is not started.
	 * Checks if the protocol is implemented first.
	 * 
	 * @param protocolName Name of the protocol
	 * @param port Port on which to start the Listener
	 * @return Returns the created HoneyListener, if creation failed returns null.
	 */
	private HoneyListener createListener(String protocolName, int port){
		for(Protocol protocol : implementedProtocols){
			if(protocolName.equals(protocol.toString())){
				HoneyListener listener = new HoneyListener(this, protocol, port);
				listeners.add(listener);
				return listener;
			} 
		}
		return null;
	}

	/**
	 * Starts all listeners which are not already running.
	 */
	public void startListeners() {
		for (HoneyListener listener : listeners) {
			if (!listener.isRunning()) {
				listener.start();
			}
		}
		Toast.makeText(getApplicationContext(), "SERVICES STARTED!",
				Toast.LENGTH_SHORT).show();
	}

	/**
	 * Stops all running listeners.
	 */
	public void stopListeners() {
		for (HoneyListener listener : listeners) {
			if (listener.isRunning()) {
				listener.stop();
			}
		}
		Toast.makeText(getApplicationContext(), "SERVICES STOPPED!",
				Toast.LENGTH_SHORT).show();
	}

	/**
	 * Starts the listener for the specified protocol. 
	 * Creates a new HoneyService if no matching HoneyListener is found.
	 * 
	 * @param protocolName
	 *            Name of the protocol that should be started.
	 */
	public boolean startListener(String protocolName) {
		return startListener(protocolName, getDefaultPort(protocolName));
	}
	
	/**
	 * Starts the listener for the specified protocol and port.
	 * Creates a new HoneyService if no matching HoneyListener is found.
	 * 
	 * @param protocolName
	 *            Name of the protocol that should be started.
	 * @param port The port number in which the listener should run.
	 */
	public boolean startListener(String protocolName, int port) {
		for (HoneyListener listener : listeners) {
			if (listener.getProtocolName().equals(protocolName) && listener.getPort() == port) {
				if (!listener.isRunning()) {
					if(listener.start()){
						Toast.makeText(getApplicationContext(),protocolName + " SERVICE STARTED!", Toast.LENGTH_SHORT).show();
						return true;
					}
					Toast.makeText(getApplicationContext(),protocolName + " SERVICE COULD NOT BE STARTED!", Toast.LENGTH_SHORT).show();
					return false;
				}
				
			}
		}
		HoneyListener listener = createListener(protocolName, port);
		if(listener != null){
			if(listener.start()){
				Toast.makeText(getApplicationContext(), protocolName + " SERVICE STARTED!", Toast.LENGTH_SHORT).show();
				return true;
			}
		}	
		Toast.makeText(getApplicationContext(),protocolName + " SERVICE COULD NOT BE STARTED!", Toast.LENGTH_SHORT).show();
		return false;
	}

	/**
	 * Stops the listener for the specified protocol.
	 * 
	 * @param protocolName
	 *            Name of the protocol that should be stopped.
	 */
	public void stopListener(String protocolName) {
		stopListener(protocolName, getDefaultPort(protocolName));
	}
	
	/**
	 * Stops the listener for the specified protocol.
	 * 
	 * @param protocolName
	 *            Name of the protocol that should be stopped.
	 * @param port The port number in which the listener is running.
	 */
	public void stopListener(String protocolName, int port) {
		for (HoneyListener listener : listeners) {
			if (listener.getProtocolName().equals(protocolName) && listener.getPort() == port) {
				if (listener.isRunning()) {
					listener.stop();
				}
			}
		}
		Toast.makeText(getApplicationContext(), protocolName + " SERVICE STOPPED!", Toast.LENGTH_SHORT).show();
	}

	/**
	 * Task for accuiring a qotd from one of four possible servers.
	 * 
	 * @author Wulf Pfeiffer
	 */
	private class QotdTask extends AsyncTask<String, Void, String> {
		@Override
		protected String doInBackground(String... unused) {
			String[] sources = new String[] { "djxmmx.net", "ota.iambic.com",
					"alpha.mike-r.com", "electricbiscuit.org" };
			SecureRandom rndm = new SecureRandom();
			StringBuffer sb = new StringBuffer();
			try {
				Socket client = new Socket(sources[rndm.nextInt(4)], 17);
				BufferedReader in = new BufferedReader(new InputStreamReader(
						client.getInputStream()));
				while (!in.ready())
					;
				while (in.ready()) {
					sb.append(in.readLine());
				}
				in.close();
				client.close();
			} catch (Exception e) {
				e.printStackTrace();
			}
			return sb.toString();
		}

		@Override
		protected void onPostExecute(String result) {
			if (result != null)
				HTTP.setHtmlDocumentContent(result);
		}
	};
	
	/**
	 * Updates the connection info and saves them in the the SharedPreferences
	 * for session data.
	 * 
	 * @param context
	 *            Needs a context to get system recourses.
	 * @see MainActivity#CONNECTION_INFO
	 */
	private void updateConnectionInfo() {
		SharedPreferences pref = context.getSharedPreferences(
				getString(R.string.connection_info), Context.MODE_PRIVATE);
		Editor editor = pref.edit();
		editor.putString(getString(R.string.connection_info_ssid), HelperUtils.getSSID(context));
		editor.putString(getString(R.string.connection_info_bssid), HelperUtils.getBSSID(context));
		editor.putString(getString(R.string.connection_info_internal_ip),
				HelperUtils.getInternalIP(context));
		editor.commit();
		SetExternalIPTask async = new SetExternalIPTask();
		async.execute(new String[] { "http://ip2country.sourceforge.net/ip2c.php?format=JSON" });
	}
	
	/**
	 * Task to find out the external IP.
	 * 
	 * @author Lars Pandikow
	 */
	private class SetExternalIPTask extends AsyncTask<String, Void, String> {
		@Override
		protected String doInBackground(String... url) {
			String ipAddress = null;
			try {
				HttpClient httpclient = new DefaultHttpClient();
				HttpGet httpget = new HttpGet(url[0]);
				HttpResponse response;

				response = httpclient.execute(httpget);

				HttpEntity entity = response.getEntity();
				entity.getContentLength();
				String str = EntityUtils.toString(entity);
				JSONObject json_data = new JSONObject(str);
				ipAddress = json_data.getString("ip");
			} catch (Exception e) {
				e.printStackTrace();
			}
			return ipAddress;
		}

		@Override
		protected void onPostExecute(String result) {
			connectionInfoEditor.putString(getString(R.string.connection_info_external_ip), result);
			connectionInfoEditor.commit();
			notifyUI(this.getClass().getName(), new String[]{getString(R.string.broadcast_connectivity)});
		}
	};
	
	// Notifications
	
	/**
	 * Creates a Notification in the notification bar.
	 */
	private void createNotification() {
		UglyDbHelper dbh = new UglyDbHelper(this);
		boolean activeHandlers = false;
		boolean bssidSeen = false;
		boolean listening = false;

		for (HoneyListener listener : listeners) {
			if(listener.isRunning())
				listening = true;
			if (listener.getHandlerCount() > 0) {
				activeHandlers = true;
			}
			if (dbh.bssidSeen(listener.getProtocolName(), HelperUtils.getBSSID(getApplicationContext()))) {
				bssidSeen = true;
			}
		}
		builder = new NotificationCompat.Builder(this).setContentTitle(
				getString(R.string.app_name)).setWhen(
				System.currentTimeMillis());
		if(!listening){
			builder.setSmallIcon(R.drawable.ic_launcher);
			builder.setContentText("HosTaGe is not active.");
		} else if (activeHandlers) {
			builder.setSmallIcon(R.drawable.ic_service_red);
			builder.setContentText("Network is infected!");
		} else if (bssidSeen) {
			builder.setSmallIcon(R.drawable.ic_service_yellow);
			builder.setContentText("Network has been infected in previous session!");
		} else{
			builder.setSmallIcon(R.drawable.ic_service_green);
			builder.setContentText("Everything looks fine!");
		} 
		TaskStackBuilder stackBuilder = TaskStackBuilder.create(this);
		stackBuilder.addParentStack(MainActivity.class);
		stackBuilder.addNextIntent(new Intent(this, MainActivity.class));
		PendingIntent resultPendingIntent = stackBuilder.getPendingIntent(0,
				PendingIntent.FLAG_UPDATE_CURRENT);
		builder.setContentIntent(resultPendingIntent);
		builder.setOngoing(true);
		NotificationManager mNotificationManager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
		mNotificationManager.notify(1, builder.build());
	}

	/**
	 * Updates the notification when a attack is registered.
	 */
	private void attackNotification() {
		SharedPreferences defaultPref = PreferenceManager
				.getDefaultSharedPreferences(this);
		String strRingtonePreference = defaultPref.getString(
				"pref_notification_sound",
				"content://settings/system/notification_sound");
		builder = new NotificationCompat.Builder(this)
				.setContentTitle(getString(R.string.app_name))
				.setTicker("Honeypot under attack!")
				.setContentText("Honeypot under attack!")
				.setSmallIcon(R.drawable.ic_service_red).setAutoCancel(true)
				.setWhen(System.currentTimeMillis())
				.setSound(Uri.parse(strRingtonePreference));
		TaskStackBuilder stackBuilder = TaskStackBuilder.create(this);
		stackBuilder.addParentStack(MainActivity.class);
		stackBuilder.addNextIntent(new Intent(this, MainActivity.class));
		PendingIntent resultPendingIntent = stackBuilder.getPendingIntent(0,
				PendingIntent.FLAG_UPDATE_CURRENT);
		builder.setContentIntent(resultPendingIntent);
		if (defaultPref.getBoolean("pref_vibration", false)) {
			builder.setVibrate(new long[] { 100, 200, 100, 200 });
		}

		NotificationManager mNotificationManager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
		mNotificationManager.notify(2, builder.build());
	}

	/**
	 * Cancels the Notification
	 */
	private void cancelNotification() {
		NotificationManager mNotificationManager = (NotificationManager) getSystemService(Context.NOTIFICATION_SERVICE);
		mNotificationManager.cancel(1);
	}

}