/*

 *   SONEWS News Server

 *   see AUTHORS for the list of contributors

 *

 *   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 org.sonews.daemon.command;

import java.io.IOException;

import java.util.Set;

import org.sonews.daemon.CommandSelector;

import org.sonews.daemon.NNTPConnection;

import org.sonews.util.io.Resource;

/**

 * This command provides a short summary of the commands that are

 * understood by this implementation of the server. The help text will

 * be presented as a multi-line data block following the 100 response

 * code (taken from RFC).

 * @author Christian Lins

 * @since sonews/0.5.0

 */

public class HelpCommand implements Command

{

	@Override

	public boolean hasFinished()

	{

		return true;

	}

	@Override

	public String impliedCapability()

	{

		return null;

	}

	@Override

	public boolean isStateful()

	{

		return true;

	}

	@Override

	public String[] getSupportedCommandStrings()

	{

		return new String[] {"HELP"};

	}

	@Override

	public void processLine(NNTPConnection conn, final String line, byte[] raw)

		throws IOException

	{

		final String[] command = line.split(" ");

		conn.println("100 help text follows");

		if (line.length() <= 1) {

			final String[] help = Resource.getAsString("helpers/helptext", true).split("\n");

			for (String hstr : help) {

				conn.println(hstr);

			}

			Set<String> commandNames = CommandSelector.getCommandNames();

			for (String cmdName : commandNames) {

				conn.println(cmdName);

			}

		} else {

			Command cmd = CommandSelector.getInstance().get(command[1]);

			if (cmd instanceof HelpfulCommand) {

				conn.println(((HelpfulCommand) cmd).getHelpString());

			} else {

				conn.println("No further help information available.");

			}

		}

		conn.println(".");

	}

}