/**
 * Copyright (C) 2018-2021 Christian Pierre MOMON <cmomon@april.org>
 *
 * This file is part of (April) Hebdobot.
 *
 * Hebdobot is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * Hebdobot 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 Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with Hebdobot.  If not, see <http://www.gnu.org/licenses/>
 */
package org.april.hebdobot.bot.hooks;

import java.util.regex.Matcher;
import java.util.regex.Pattern;

import org.apache.commons.lang3.StringUtils;
import org.april.hebdobot.HebdobotException;
import org.april.hebdobot.bot.Hebdobot;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import fr.devinsy.strings.StringList;
import fr.devinsy.strings.StringsUtils;

/**
 * The Class HelpHook.
 */
public class HelpHook extends Hook
{
    private static final Pattern COMMAND_HELP_PATTERN = Pattern.compile("^!(aide|help)\\s+(?<token>\\S+)$");

    private static final Logger logger = LoggerFactory.getLogger(HelpHook.class);

    /* (non-Javadoc)
     * @see org.april.hebdobot.bot.hooks.Hook#attemptHelp(java.lang.String)
     */
    @Override
    public StringList attemptHelp(final String token) throws HebdobotException
    {
        StringList result;

        if (StringsUtils.equalsAnyIgnoreCase(token, "aide", "help"))
        {
            result = new StringList();
            result.append("!aide, !help, !aide hebdobot, !help hebdobot : afficher l'aide générale");
            result.append("!aide commande, !help commande : afficher l'aide de la commande !commande");
        }
        else
        {
            result = null;
        }

        //
        return result;
    }

    /* (non-Javadoc)
     * @see org.april.hebdobot.bot.hooks.Hook#attemptProcess(org.april.hebdobot.bot.Hebdobot, java.lang.String, java.lang.String, java.lang.String, java.lang.String, java.lang.String)
     */
    @Override
    public boolean attemptProcess(final Hebdobot bot, final String channel, final String sender, final String login, final String hostname,
            final String message) throws HebdobotException
    {
        boolean result;

        if (StringUtils.equalsAnyIgnoreCase(message, "!aide", "!help", "!aide hebdobot", "!help hebdobot"))
        {
            logger.info("!help caught.");

            // Help.
            bot.sendMessage(sender,
                    String.format("Bienvenue %s. Je suis %s, le robot de gestion des revues hebdomadaires de l'April.", sender, bot.getName()));
            bot.sendMessage(sender, "Voici les commandes que je comprends :");
            bot.sendMessage(sender, " ");
            bot.sendMessage(sender, "  !aide,!help    : afficher cette aide");
            bot.sendMessage(sender, "  !aide commande : afficher l'aide de la commande !commande");
            bot.sendMessage(sender, "  !début         : commencer une nouvelle revue");
            bot.sendMessage(sender, "  % message      : traiter comme un commentaire");
            bot.sendMessage(sender, "  # titre        : démarrer un sujet individuel");
            bot.sendMessage(sender, "  ## titre       : démarrer un sujet collectif");
            bot.sendMessage(sender, "  !oups          : annuler la dernière entrée dans un point de revue");
            bot.sendMessage(sender, "  !courant       : afficher le sujet en cours");
            bot.sendMessage(sender, "  !fin           : terminer la revue en cours");
            bot.sendMessage(sender, "  !stop          : abandonner la revue en cours");
            bot.sendMessage(sender, " ");
            bot.sendMessage(sender,
                    "Autres commandes : !anniv, !bonjour, !chrono, !date, !hello, !licence, !manquants, !merci, !record, !salut, !stats, !status, !version");

            result = true;
        }
        else
        {
            String token = extractTargetHelp(message);

            if (token == null)
            {
                result = false;
            }
            else
            {
                StringList help = bot.getHelp(token);
                if (help == null)
                {
                    bot.sendMessage("aide indisponible pour la commande " + token);
                }
                else
                {
                    for (String line : help)
                    {
                        bot.sendMessage(line);
                    }
                }

                result = true;
            }
        }

        //
        return result;
    }

    /**
     * Extract target help.
     *
     * @return the string
     */
    private String extractTargetHelp(final String message)
    {
        String result;

        Matcher matcher = COMMAND_HELP_PATTERN.matcher(message);
        if (matcher.find())
        {
            result = matcher.group("token");

            if (StringUtils.startsWith(result, "!"))
            {
                result = result.substring(1);
            }
        }
        else
        {
            result = null;
        }

        //
        return result;
    }

}