org.mailster.smtp.core.commands.AbstractCommand Maven / Gradle / Ivy

package org.mailster.smtp.core.commands;

import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.StringTokenizer;
import java.util.regex.Pattern;

import org.apache.mina.core.session.IoSession;
import org.mailster.smtp.core.SMTPConnectionHandler;

/**
 * An abstract class which provides a minimal function set used
 * by SMTP commands implementations.
 *
 * @author De Oliveira Edouard <[email protected]>
 * @author Ian McFarland <[email protected]>
 * @author Jon Stevens
 */
abstract public class AbstractCommand implements Command {

    private static final String VALIDATE_EMAIL = "^[\\w!#$%&'*+/=?`{|}~^-]+(?:\\.[\\w!#$%&'*+/=?`{|}~^-]+)*@(localhost|(?:[a-zA-Z0-9-]+\\.)+[a-zA-Z]{2,6}$)";
    private static final Pattern EMAIL_PATTERN = Pattern.compile(VALIDATE_EMAIL);
    private static Map helpMessageMap = new HashMap<>();
    private String name;
    private CommandHandler handler;

    public AbstractCommand(String name, String help) {
        this.name = name;
        if (help != null) {
            setHelp(new HelpMessage(name, help));
        }
    }

    public AbstractCommand(String name, String help, String argumentDescription) {
        this.name = name;
        if (help != null) {
            setHelp(new HelpMessage(name, help, argumentDescription));
        }
    }

    protected static void getTokenizedString(StringBuilder sb, Collection items, String delim) {
        for (var it = items.iterator(); it.hasNext(); ) {
            sb.append(it.next());
            if (it.hasNext()) {
                sb.append(delim);
            }
        }
    }

    public CommandHandler getCommandHandler() {
        return handler;
    }

    public void setCommandHandler(CommandHandler handler) {
        this.handler = handler;
    }

    public HelpMessage getHelp(String commandName) throws CommandException {
        var msg = helpMessageMap.get(commandName.toUpperCase());
        if (msg == null) {
            throw new CommandException();
        }
        return msg;
    }

    protected Map getHelp() {
        return helpMessageMap;
    }

    private void setHelp(HelpMessage helpMessage) {
        helpMessageMap.put(helpMessage.getName().toUpperCase(), helpMessage);
    }

    protected String getArgPredicate(String commandString) {
        if (commandString == null || commandString.length() < 4) {
            return "";
        }

        return commandString.substring(4).trim();
    }

    @Override
    public String getName() {
        return name;
    }

    protected void sendResponse(IoSession session, String response) {
        SMTPConnectionHandler.sendResponse(session, response);
    }

    protected boolean isValidEmailAddress(String address) {
        if (address.length() == 0) {
            return false;
        }

        return EMAIL_PATTERN.matcher(address).matches();
    }

    protected String[] getArgs(String commandString) {
        List strings = new ArrayList<>();
        var st = new StringTokenizer(commandString);

        while (st.hasMoreTokens()) {
            strings.add(st.nextToken());
        }

        return strings.toArray(new String[0]);
    }

    protected String extractEmailAddress(String args, int subcommandOffset) {
        var address = args.substring(subcommandOffset).trim();
        if (address.indexOf('<') == 0) {
            address = address.substring(1, address.indexOf('>'));
        }

        return address;
    }

    @Override
    public boolean isAuthRequired() {
        return true;
    }
}