/*
 * Copyright (c) 2009 Mark Jeffries <motorviper@users.sourceforge.net>
 *
 * This program is free software; you can redistribute it and/or modify it under
 * the terms of the GNU Lesser General Public License as published by the Free
 * Software Foundation; either version 2.1 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 Lesser General Public License for more
 * details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this library; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
 */
package pcgen.rules.persistence.token;

import java.util.logging.Level;

import pcgen.rules.context.LoadContext;
import pcgen.util.Logging;

/**
 * Interface to provide feedback on parsing operations.
 * @author Mark
 */
public interface ParseResult
{
	/**
	 * Object to be returned from parsing operations that succeeded with no messages.
	 */
	public static Pass SUCCESS = new Pass();
	
	/*
	 * Temporary object for reporting errors that should be investigated further.
	 * See plugin.lsttokens.race.FeatToken.
	 */
	public static Fail INTERNAL_ERROR = new Fail("Internal error.");
	
	/**
	 * State of the parse operation.
	 * @return True if the parse was successful.
	 */
	public boolean passed();

	/**
	 * Log any messages associated with the operation.
	 */
	public void printMessages();

	/*
	 * Temporary method for aiding conversion to use of ParseResult.
	 * See pcgen.rules.persistence.token.ErrorParsingWrapper for use.
	 */
	public void addMessagesToLog();

	/**
	 * Class representing a message from the parser.
	 */
	public static class QueuedMessage
	{
		public final Level level;
		public final String message;
		public final StackTraceElement[] stackTrace;

		public QueuedMessage(Level lvl, String msg)
		{
			level = lvl;
			message = msg;
			stackTrace = Thread.currentThread().getStackTrace();
		}
	}

	/**
	 * This is the class of the SUCCESS object.
	 * Under normal use it should only be used for constructing this object.
	 */
	public class Pass implements ParseResult
	{
		@Override
		public boolean passed()
		{
			return true;
		}

		@Override
		public void addMessagesToLog()
		{
			//No messages because we passed
		}

		@Override
		public void printMessages()
		{
			//No messages because we passed
		}
	}

	/**
	 * Simple class to handle feedback from parse operations that fail.
	 */
	public class Fail implements ParseResult
	{
		private final QueuedMessage error;

		public Fail(String error)
		{
			this.error = new QueuedMessage(Logging.LST_ERROR, error);
		}

		public Fail(String error, LoadContext context)
		{
			if (context == null || context.getSourceURI() == null)
			{
				this.error = new QueuedMessage(Logging.LST_ERROR, error);
			}
			else
			{
				this.error =
						new QueuedMessage(Logging.LST_ERROR, error
							+ " (Source: "
							+ context.getSourceURI() + " )");
			}
		}

		@Override
		public boolean passed()
		{
			return false;
		}

		public QueuedMessage getError()
		{
			return error;
		}

		@Override
		public void addMessagesToLog()
		{
			Logging.addParseMessage(error.level, error.message,
				error.stackTrace);
		}

		@Override
		public void printMessages()
		{
			Logging.log(error.level, error.message, error.stackTrace);
		}

		@Override
		public String toString()
		{
			return error.message;
		}
	}
}