/*
 *  Copyright (C) 2012 maartenl
 *
 * 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 mmud.commands.items;

import java.util.logging.Level;
import java.util.logging.Logger;
import mmud.commands.Command;
import mmud.database.entities.characters.User;
import mmud.database.entities.game.DisplayInterface;
import mmud.exceptions.MudException;

/**
 * An abstract class for the most normal commands.
 *
 * @author maartenl
 */
public abstract class ItemCommand implements Command
{

    private static final Logger itsLog = Logger.getLogger(ItemCommand.class.getName());
    /**
     * the regular expression the command structure must follow
     */
    private final String theRegExpr;

    @Override
    public String getRegExpr()
    {
        return theRegExpr;
    }

    /**
     * Constructor.
     *
     * @param aRegExpr
     * a regular expression to which the command should follow. For
     * example "give [A..Za..z]*1-4 to [A..Za..z]*". %me is a
     * parameter that can be used when the name of the character
     * playing is requested.
     */
    public ItemCommand(String aRegExpr)
    {
        theRegExpr = aRegExpr;
    }

    /**
     * Starts the command, this method is used for default behaviour that needs
     * to take place before the run command is issued. This method starts the
     * run command.
     *
     * @param command the command entered by the user
     * @param aUser
     * the user that executed the command
     * @return DisplayInterface for providing to the user, or null if the
     * statement was not executed for some different reason.
     * @throws MudException
     * when anything goes wrong.
     */
    DisplayInterface start(String command, User aUser) throws MudException
    {
        itsLog.log(Level.FINER, "{0}({1}) : {2}", new Object[]
        {
            aUser.getName(), this.getClass().getName(), command
        });
        String myregexpr = theRegExpr.replaceAll("%s", aUser.getName());
        boolean result;
        if (myregexpr.endsWith(".+") && command.indexOf('\n') != -1)
        {
            String stuff = command.substring(0, command.indexOf('\n'));
            result = stuff.matches(myregexpr);
        } else
        {
            result = (command.matches(myregexpr));
        }
        if (!result)
        {
            /** didn't match the case, exiting */
            return null;
        }
        /** continue with the actual command */
        DisplayInterface displayInterface = run(command, aUser);
        aUser.setNow();
        return displayInterface;
    }

    @Override
    public abstract DisplayInterface run(String command, User aUser) throws MudException;

    /**
     * split up the command into different words.
     *
     * @param aCommand
     * String containing the command
     * @return String array where each String contains a word from the command.
     */
    protected static String[] parseCommand(String aCommand)
    {
        return aCommand.split("( )+", 50);
    }

    /**
     * split up the command into different words.<p/>
     * For example:
     * <p/>
     * <tt>parseCommand("bow to Marvin evilly", 4)</tt> returns array
     * <tt>["bow","to","Marvin", "evilly"]</tt><p/>
     * <tt>parseCommand("say to Marvin Greetings this morning.", 4)</tt>
     * returns array <tt>["say","to","Marvin", "Greetings this morning."]</tt>
     *
     * @param limit the result threshold, example 3 means the array holds
     * three, the first two words and the rest in the third array element.
     * @param aCommand
     * String containing the command
     * @return String array where each String contains a word from the command.
     * @see String#split(java.lang.String, int)
     */
    protected static String[] parseCommand(String aCommand, int limit)
    {
        return aCommand.split("( )+", limit);
    }
}