org.mailster.smtp.core.commands.impl.HelpCommand Maven / Gradle / Ivy

package org.mailster.smtp.core.commands.impl;

import java.io.IOException;
import java.util.Set;
import java.util.TreeSet;

import org.apache.mina.core.session.IoSession;
import org.mailster.smtp.SMTPServerConfig;
import org.mailster.smtp.core.SMTPContext;
import org.mailster.smtp.core.commands.AbstractCommand;
import org.mailster.smtp.core.commands.CommandException;

/**
 * The HELP command implementation.
 *
 * @author Ian McFarland <[email protected]>
 * @author Jon Stevens
 * @author De Oliveira Edouard <[email protected]>
 */
public class HelpCommand extends AbstractCommand {

    public HelpCommand() {
        super("HELP",
              "The HELP command gives help info about the topic specified.\r\n" + "For a list of topics, type HELP by itself.\r\n",
              "[]\n topic = the topic we want help info about\n");
    }

    @Override
    public void execute(String commandString, IoSession ioSession, SMTPContext ctx) throws IOException {
        var args = getArgPredicate(commandString);
        if ("".equals(args)) {
            sendResponse(ioSession, getCommandMessage(ctx.getSMTPServerConfig()));
            return;
        }

        try {
            sendResponse(ioSession, getHelp(args).toString());
        } catch (CommandException e) {
            sendResponse(ioSession, "504 HELP topic \"" + args + "\" unknown");
        }
    }

    private String getCommandMessage(SMTPServerConfig cfg) {
        var response = new StringBuilder();
        response.append("214-This is ");
        response.append(cfg.getNameVersion());
        response.append(" server running on ");
        response.append(cfg.getHostName());
        response.append("\r\n");
        response.append("214-Available commands:\r\n");
        getFormattedCommandsList(response);
        response.append("214-For more info use \"HELP \".\r\n");
        response.append("214-For more information about this server, visit:\r\n");
        response.append("214-    http://tedorg.free.fr/projects/projects.php?projects_section=3\r\n");
        response.append("214-To report bugs in the implementation, send email to:\r\n");
        response.append("214-    [email protected]\r\n");
        response.append("214-For local information send email to Postmaster at your site.\r\n");
        response.append("214 End of HELP info");

        return response.toString();
    }

    private void getFormattedCommandsList(StringBuilder sb) {
        Set set = new TreeSet<>(super.getHelp().keySet());

        for (var key : set) {
            sb.append("214-  ");
            sb.append(key);
            sb.append("\r\n");
        }
    }
}