Announcements Npc instance.

/*
 * This program 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 program 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, see <http://www.gnu.org/licenses/>.
 */
package net.sf.l2j.gameserver.model.actor.instance;

import java.io.File;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.LineNumberReader;
import java.util.ArrayList;
import java.util.List;
import java.util.StringTokenizer;
import java.util.logging.Level;
import java.util.logging.Logger;

import net.sf.l2j.gameserver.Announcements;
import net.sf.l2j.gameserver.network.serverpackets.NpcHtmlMessage;
import net.sf.l2j.gameserver.templates.chars.L2NpcTemplate;

/**
 * @author Debian
 *
 */
public class L2AnnouncementsInstance extends L2NpcInstance
{
	public L2AnnouncementsInstance(int objectId, L2NpcTemplate template)
	{
		super(objectId, template);
	}

	private static Logger _log = Logger.getLogger(Announcements.class.getName());

	private static Announcements _instance;
	private final List<String> _announcements = new ArrayList<>();

	@SuppressWarnings("unused")
	private void Announcements()
	{
		loadAnnouncements();
	}

	public static Announcements getInstance()
	{
		if (_instance == null)
			_instance = new Announcements();

		return _instance;
	}

	public void loadAnnouncements()
	{
		_announcements.clear();
		File file = new File("./data/custom/messages.txt");
		if (file.exists())
			readFromDisk(file);
		else
			_log.config("The messages file (normally located to 'data/custom/messages.txt') doesn't exist.");
	}

	public void showAnnouncements(L2PcInstance player)
	{
		for (int i = 0; i < _announcements.size(); i++)
		{
			NpcHtmlMessage nhm = new NpcHtmlMessage(5);
			StringBuilder tb = new StringBuilder("");

			tb.append("<html><head><title>Announcements</title></head><body>");
			tb.append("<center>");
			tb.append("<table width=\"250\" cellpadding=\"5\" bgcolor=\"000000\">");
			tb.append("<tr>");
			tb.append("<td width=\"45\" valign=\"top\" align=\"center\"><img src=\"L2ui_ch3.menubutton4\" width=\"38\" height=\"38\"></td>");
			tb.append("<td valign=\"top\"><font color=\"FF6600\">Announcements</font>");
			tb.append("<br1><font color=\"00FF00\">"+player.getName()+"</font>, use this interface to check server's announcements.<br1></td>");
			tb.append("</tr>");
			tb.append("</table>");
			tb.append("</center>");
			tb.append("<center>");
			tb.append("<table width=\"200\" border=\"1\" bgcolor=\"FFFFFF\">");
			tb.append("<tr><td align=\"center\"></td><td>"+ _announcements +  "</td></tr>");
			tb.append("</center>");
			tb.append("</body></html>");

			nhm.setHtml(tb.toString());
			player.sendPacket(nhm);
		}
	}

	public void addAnnouncement(String text)
	{
		_announcements.add(text);
		saveToDisk();
	}

	public void delAnnouncement(int line)
	{
		_announcements.remove(line);
		saveToDisk();
	}

	private void readFromDisk(File file)
	{
		try (LineNumberReader lnr = new LineNumberReader(new FileReader(file)))
		{
			int i = 0;
			String line = null;
			while ((line = lnr.readLine()) != null)
			{
				StringTokenizer st = new StringTokenizer(line, "\n\r");
				if (st.hasMoreTokens())
				{
					String announcement = st.nextToken();
					_announcements.add(announcement);

					i++;
				}
			}
			_log.config("Announcements: Loaded " + i + " Announcements.");
		}
		catch (IOException e1)
		{
			_log.log(Level.SEVERE, "Error reading announcements", e1);
		}
	}

	private void saveToDisk()
	{
		final File file = new File("data/custom/messages.txt");
		try (FileWriter save = new FileWriter(file))
		{
			for (int i = 0; i < _announcements.size(); i++)
			{
				save.write(_announcements.get(i));
				save.write("\r\n");
			}
		}
		catch (IOException e)
		{
			_log.warning("saving the announcements file has failed: " + e);
		}
	}
}