Arakne / Araknemu

 * This file is part of Araknemu.

 *

 * Araknemu 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 3 of the License, or

 * (at your option) any later version.

 *

 * Araknemu 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 Araknemu.  If not, see <https://www.gnu.org/licenses/>.

 *

 * Copyright (c) 2017-2021 Vincent Quatrevieux

 */

package fr.quatrevieux.araknemu.game.admin.exception.handler;

import fr.quatrevieux.araknemu.game.admin.AdminPerformer;

import fr.quatrevieux.araknemu.game.admin.Command;

import fr.quatrevieux.araknemu.game.admin.CommandParser;

import fr.quatrevieux.araknemu.game.admin.exception.CommandNotFoundException;

import fr.quatrevieux.araknemu.game.admin.exception.ExceptionHandler;

import fr.quatrevieux.araknemu.game.admin.formatter.Link;

import org.apache.commons.text.similarity.LevenshteinDistance;

import java.util.Comparator;

import java.util.Optional;

/**

 * Handler for command not found

 * This handler will try to found the nearest command name on the current context

 */

public final class CommandNotFoundExceptionHandler implements ExceptionHandler.Function<CommandNotFoundException> {

    @Override

    public void handle(AdminPerformer performer, CommandNotFoundException error, CommandParser.Arguments arguments) {

        performer.error("Command '{}' is not found", error.command());

        if (arguments == null) {

            return;

        }

        nearestCommandName(arguments).ifPresent(commandName -> performer.error(

            "Did you mean {} ? (See {})",

            new Link().text(commandName).command(rebuildCommand(arguments, commandName)),

            new Link().text("help").execute(arguments.contextPath() + " help " + commandName)

        ));

    }

    /**

     * Found the nearest command name from the contexts

     *

     * @param arguments The parsed arguments

     *

     * @return The command name

     */

    private Optional<String> nearestCommandName(CommandParser.Arguments arguments) {

        return arguments.context().commands().stream()

            .map(Command::name)

            .min(Comparator.comparingInt(name -> LevenshteinDistance.getDefaultInstance().apply(arguments.command(), name)))

        ;

    }

    /**

     * Change the command name from the current command line

     *

     * @param arguments The parsed arguments

     * @param newName The expected command name

     *

     * @return The new command line

     */

}