/*

 * Copyright (C) 2020, University of the Basque Country (UPV/EHU)

 *  Contact for licensing options: <licensing-mcpttclient(at)mcopenplatform(dot)com>
 *
 * The original file was part of Open Source IMSDROID
 *  Copyright (C) 2010-2011, Mamadou Diop.
 *  Copyright (C) 2011, Doubango Telecom.
 *
 *
 * Contact: Mamadou Diop <diopmamadou(at)doubango(dot)org>
 *
 * This file is part of Open Source Doubango Framework.
 *
 * This is free software: you can redistribute it and/or modify it under the terms of
 * the GNU General Public License as published by the Free Software Foundation, either version 3
 * of the License, or (at your option) any later version.
 *
 * This is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
 * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 * See the GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */
 package org.doubango.ngn.services.impl;
 
 import android.util.Log;
 
 import org.doubango.ngn.NgnEngine;
 import org.doubango.ngn.model.NgnHistoryEvent;
 import org.doubango.ngn.model.NgnHistoryList;
 import org.doubango.ngn.services.INgnHistoryService;
 import org.doubango.ngn.utils.NgnObservableList;
 import org.doubango.ngn.utils.NgnPredicate;
 import org.doubango.utils.Utils;
 import org.simpleframework.xml.Serializer;
 import org.simpleframework.xml.core.Persister;
 
 import java.io.File;
 import java.io.IOException;
 import java.util.List;
 
 
 public class NgnHistoryService extends NgnBaseService implements INgnHistoryService {
 	private final static String TAG = Utils.getTAG(NgnHistoryService.class.getCanonicalName());
 	private final static String HISTORY_FILE = "history.xml";
 	
 	private File mHistoryFile;
 	private NgnHistoryList mEventsList;
 	private final Serializer mSerializer;
 	private boolean mLoadingHistory;
 	
 	public NgnHistoryService(){
 		super();
 		
 		mSerializer = new Persister();
 		mEventsList = new NgnHistoryList();
 	}
 	
 	@Override
 	public boolean start() {
 		Log.d(TAG, "Starting...");
 		boolean result = true;
 		
 		/*	http://code.google.com/p/dalvik/wiki/JavaxPackages
 	     * Ensure the factory implementation is loaded from the application
 	     * classpath (which contains the implementation classes), rather than the
 	     * system classpath (which doesn't).
 	     */
 		Thread.currentThread().setContextClassLoader(getClass().getClassLoader());
 		

 		mHistoryFile = new File(NgnEngine.getInstance().getStorageService().getCurrentDir(), NgnHistoryService.HISTORY_FILE);

 		if(!mHistoryFile.exists()){
 			try {
 				mHistoryFile.createNewFile();
 				result = compute(); /* to create an empty but valid document */
 			} catch (IOException e) {
 				Log.e(TAG, e.toString());
 				mHistoryFile = null;
 				result =  false;
 			}
 		}
 		
 		return result;
 	}
 
 	@Override
 	public boolean stop() {
 		Log.d(TAG, "Stopping");
 		return true;
 	}
 
 	@Override
 	public boolean load(){
 		boolean result = true;
 		
 		try {
 			mLoadingHistory = true;
 			Log.d(TAG, "Loading history.");
 			mEventsList = mSerializer.read(mEventsList.getClass(), mHistoryFile);
 			Log.d(TAG, "History loaded.");
 		} catch (Exception ex) {
 			ex.printStackTrace();
 			result = false;
 		}
 		mLoadingHistory = false;
 		return result;
 	}
 	
 	@Override
 	public boolean isLoading() {
 		return mLoadingHistory;
 	}
 
 	@Override
 	public void addEvent(NgnHistoryEvent event) {
 		mEventsList.addEvent(event);
 		new Thread(new Runnable(){
 			@Override
 			public void run() {
 				compute();
 			}
 		}).start();
 	}
 
 	@Override
 	public void updateEvent(NgnHistoryEvent event) {
 		Log.e(TAG, "Not implemented.");
 		//throw new Exception("Not implemented");
 	}
 
 	@Override
 	public void deleteEvent(NgnHistoryEvent event) {
 		mEventsList.removeEvent(event);
 		new Thread(new Runnable(){
 			@Override
 			public void run() {
 				compute();
 			}
 		}).start();
 	}
 
 	@Override
 	public void deleteEvent(int location) {
 		mEventsList.removeEvent(location);
 		new Thread(new Runnable(){
 			@Override
 			public void run() {
 				compute();
 			}
 		}).start();
 	}
 	
 	@Override
 	public void deleteEvents(NgnPredicate<NgnHistoryEvent> predicate){
 		mEventsList.removeEvents(predicate);
 		new Thread(new Runnable(){
 			@Override
 			public void run() {
 				compute();
 			}
 		}).start();
 	}
 
 	@Override
 	public void clear() {
 		mEventsList.clear();
 		new Thread(new Runnable(){
 			@Override
 			public void run() {
 				compute();
 			}
 		}).start();
 	}
 
 	@Override
 	public List<NgnHistoryEvent> getEvents() {
 		return mEventsList.getList().getList();
 	}
 	
 	@Override
 	public NgnObservableList<NgnHistoryEvent> getObservableEvents() {
 		return mEventsList.getList();
 	}
 	
 	private synchronized boolean compute(){
 		synchronized(this){
 			if(mHistoryFile == null || mSerializer == null){
 				Log.e(TAG, "Invalid arguments.");
 				return false;
 			}
 			try{
 				mSerializer.write(mEventsList, mHistoryFile);
 			}
 			catch (Exception e) {
 				e.printStackTrace();
 				return false;
 			}
 			return true;
 		}
 	}
 	@Override
 	public boolean clearService(){
 		return true;
 	}
 }