root/nntp/last.cc

/*  This file is part of Alue, the multiprotocol Internet discussion daemon

    Copyright © 2009, 2010 Antti-Juhani Kaijanaho

    Alue 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.

    Alue 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 Alue.  If not, see <http://www.gnu.org/licenses/>.

 */

#include "connection.hh"

#include "../db/group.hh"
#include "../db/msg.hh"

namespace nntp
{
        class last : public connection::command
        {
        public:
                last(const char *s) {
                        connection::register_command(s, this);
                }

                connection::continuation::ptr
                perform(connection::cb, const std::string [],  size_t) const;
        };

        connection::continuation::ptr
        last::perform(connection::cb c, const std::string[], size_t nargs) const
        {
                if (nargs > 0) {
                        c.send_line("501 syntax error");
                        return c.dispatch();
                }
                if (!c.current_group()) {
                        c.send_line("412 no group selected");
                        return c.dispatch();
                }
                db::group::number low = c.current_group()->low_mark();
                if (c.current_article() < low ||
                    c.current_article() > c.current_group()->high_mark()) {
                        c.send_line("420 no current article");
                        return c.dispatch();
                }
                
                db::group::number n = c.current_article();
                do --n; while (n >= low && !c.current_group()->is_article(n));

                if (!c.current_group()->is_article(n)) {
                        c.send_line("422 already at the first article");
                        return c.dispatch();
                }
                std::ostringstream ss;
                ss << "223 "
                   << n
                   << ' '
                   << c.current_group()->get_article(n)->msgid()
                   << " selected";
                c.current_article() = n;
                c.send_line(ss.str());
                return c.dispatch();
        }
}
namespace {
        nntp::last last("last");
}