<?php
/*
 * StatusNet - the distributed open-source microblogging tool
 * Copyright (C) 2008, 2009, StatusNet, Inc.
 *
 * This program 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.
 *
 * 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 Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

if (!defined('STATUSNET') && !defined('LACONICA')) { exit(1); }

require_once INSTALLDIR.'/lib/command.php';

class CommandInterpreter
{
    function handle_command($user, $text)
    {
        # XXX: localise

        $text = preg_replace('/\s+/', ' ', trim($text));
        list($cmd, $arg) = $this->split_arg($text);

        # We try to support all the same commands as Twitter, see
        # http://getsatisfaction.com/twitter/topics/what_are_the_twitter_commands
        # There are a few compatibility commands from earlier versions of
        # StatusNet

        switch(strtolower($cmd)) {
         case 'help':
            if ($arg) {
                return null;
            }
            return new HelpCommand($user);
         case 'login':
            if ($arg) {
                return null;
            } else {
                return new LoginCommand($user);
            }
         case 'lose':
            if ($arg) {
                list($other, $extra) = $this->split_arg($arg);
                if ($extra) {
                    return null;
                } else {
                    return new LoseCommand($user, $other);
                }
            } else {
              return null;
            }
         case 'subscribers':
            if ($arg) {
                return null;
            } else {
                return new SubscribersCommand($user);
            }
         case 'subscriptions':
            if ($arg) {
                return null;
            } else {
                return new SubscriptionsCommand($user);
            }
         case 'groups':
            if ($arg) {
                return null;
            } else {
                return new GroupsCommand($user);
            }
         case 'on':
            if ($arg) {
                list($other, $extra) = $this->split_arg($arg);
                if ($extra) {
                    return null;
                } else {
                    return new OnCommand($user, $other);
                }
            } else {
                return new OnCommand($user);
            }
         case 'off':
            if ($arg) {
                list($other, $extra) = $this->split_arg($arg);
                if ($extra) {
                    return null;
                } else {
                    return new OffCommand($user, $other);
                }
            } else {
                return new OffCommand($user);
            }
         case 'stop':
         case 'quit':
            if ($arg) {
                return null;
            } else {
                return new OffCommand($user);
            }
         case 'join':
             if (!$arg) {
                return null;
            }
            list($other, $extra) = $this->split_arg($arg);
            if ($extra) {
                return null;
            } else {
                return new JoinCommand($user, $other);
            }
         case 'drop':
            if (!$arg) {
                return null;
            }
            list($other, $extra) = $this->split_arg($arg);
            if ($extra) {
                return null;
            } else {
                return new DropCommand($user, $other);
            }
         case 'follow':
         case 'sub':
            if (!$arg) {
                return null;
            }
            list($other, $extra) = $this->split_arg($arg);
            if ($extra) {
                return null;
            } else {
                return new SubCommand($user, $other);
            }
         case 'leave':
         case 'unsub':
            if (!$arg) {
                return null;
            }
            list($other, $extra) = $this->split_arg($arg);
            if ($extra) {
                return null;
            } else {
                return new UnsubCommand($user, $other);
            }
         case 'get':
         case 'last':
            if (!$arg) {
                return null;
            }
            list($other, $extra) = $this->split_arg($arg);
            if ($extra) {
                return null;
            } else {
                return new GetCommand($user, $other);
            }
         case 'd':
         case 'dm':
            if (!$arg) {
                return null;
            }
            list($other, $extra) = $this->split_arg($arg);
            if (!$extra) {
                return null;
            } else {
                return new MessageCommand($user, $other, $extra);
            }
         case 'r':
         case 'reply':
            if (!$arg) {
                return null;
            }
            list($other, $extra) = $this->split_arg($arg);
            if (!$extra) {
                return null;
            } else {
                return new ReplyCommand($user, $other, $extra);
            }
         case 'repeat':
         case 'rp':
         case 'rt':
         case 'rd':
            if (!$arg) {
                return null;
            }
            list($other, $extra) = $this->split_arg($arg);
            if ($extra) {
                return null;
            } else {
                return new RepeatCommand($user, $other);
            }
         case 'whois':
            if (!$arg) {
                return null;
            }
            list($other, $extra) = $this->split_arg($arg);
            if ($extra) {
                return null;
            } else {
                return new WhoisCommand($user, $other);
            }
         case 'fav':
            if (!$arg) {
                return null;
            }
            list($other, $extra) = $this->split_arg($arg);
            if ($extra) {
                return null;
            } else {
                return new FavCommand($user, $other);
            }
         case 'nudge':
            if (!$arg) {
                return null;
            }
            list($other, $extra) = $this->split_arg($arg);
            if ($extra) {
                return null;
            } else {
                return new NudgeCommand($user, $other);
            }
         case 'stats':
            if ($arg) {
                return null;
            }
            return new StatsCommand($user);
         case 'invite':
            if (!$arg) {
                return null;
            }
            list($other, $extra) = $this->split_arg($arg);
            if ($extra) {
                return null;
            } else {
                return new InviteCommand($user, $other);
            }
         case 'track':
            if (!$arg) {
                return null;
            }
            list($word, $extra) = $this->split_arg($arg);
            if ($extra) {
                return null;
            } else if ($word == 'off') {
                return new TrackOffCommand($user);
            } else {
                return new TrackCommand($user, $word);
            }
         case 'untrack':
            if (!$arg) {
                return null;
            }
            list($word, $extra) = $this->split_arg($arg);
            if ($extra) {
                return null;
            } else if ($word == 'all') {
                return new TrackOffCommand($user);
            } else {
                return new UntrackCommand($user, $word);
            }
         case 'tracks':
         case 'tracking':
            if ($arg) {
                return null;
            }
            return new TrackingCommand($user);
         default:
            return false;
        }
    }

    /**
     * Split arguments without triggering a PHP notice warning
     */
    function split_arg($text)
    {
        $pieces = explode(' ', $text, 2);
        if (count($pieces) == 1) {
            $pieces[] = null;
        }
        return $pieces;
    }
}