ExistsFunc.java

/*
 * 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 YANModPack.util.htmltmpls.funcs;

import java.util.Map;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import com.l2jserver.gameserver.model.actor.instance.L2PcInstance;

import YANModPack.util.htmltmpls.HTMLTemplateFunc;
import YANModPack.util.htmltmpls.HTMLTemplatePlaceholder;
import YANModPack.util.htmltmpls.HTMLTemplateUtils;

/**
 * @author FBIagent
 */
public final class ExistsFunc extends HTMLTemplateFunc
{
	public static final ExistsFunc INSTANCE = new ExistsFunc();
	
	private static final Pattern _NEGATE_PATTERN = Pattern.compile("\\s*!\\s*");
	private static final Pattern _PLACEHOLDER_PATTERN = Pattern.compile("[a-zA-Z_][a-zA-Z0-9_]*(\\.[a-zA-Z_][a-zA-Z0-9_]*)*\\s*,");
	
	private ExistsFunc()
	{
		super("EXISTS", "ENDEXISTS", false);
	}
	
	private static Matcher _getMatcher(Pattern pattern, StringBuilder content, int findIndex) throws Exception
	{
		Matcher m = pattern.matcher(content);
		if (!m.find(findIndex) || m.start() > findIndex)
			throw new Exception();
		
		return m;
	}
	
	@Override
	public Map<String, HTMLTemplatePlaceholder> handle(StringBuilder content, L2PcInstance player, Map<String, HTMLTemplatePlaceholder> placeholders, HTMLTemplateFunc[] funcs)
	{
		try
		{
			boolean negate = false;
			Matcher m = null;

			try
			{
				m = _getMatcher(_NEGATE_PATTERN, content, 0);
				negate = true;
			}
			catch (Exception e)
			{
				// ignore this exception, negate is optional
			}

			if (m != null)
				m = _getMatcher(_PLACEHOLDER_PATTERN, content, m.end());
			else
				m = _getMatcher(_PLACEHOLDER_PATTERN, content, 0);

			HTMLTemplatePlaceholder placeholder = HTMLTemplateUtils.getPlaceholder(m.group().substring(0, m.group().length() - 1).trim(), placeholders);
			if ((placeholder == null && !negate) || (placeholder != null && negate))
			{
				content.setLength(0);
				return null;
			}
			
			content.delete(0, m.end());
		}
		catch (Exception e)
		{
			content.setLength(0);
		}
		
		return null;
	}
	
}