/*
 * CrossFire, A Multiplayer game for X-windows
 * 
 * Copyright (C) 2005, 2006, 2007 Marc Lehmann & Crossfire+ Development Team
 * Copyright (C) 2001 Mark Wedel
 * Copyright (C) 1992 Frank Tore Johansen
 * 
 * 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 2 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, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 * The author can be reached via e-mail to <crossfire@schmorp.de>
 */

/**
 * \file
 * Socket general functions
 *
 * \date 2003-12-02
 *
 * Mainly deals with initialization and higher level socket
 * maintenance (checking for lost connections and if data has arrived.)
 * The reading of data is handled in ericserver.c
 */

#include <global.h>
#include <sproto.h>
#include <sys/types.h>
#include <sys/time.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netinet/tcp.h>
#include <netinet/ip.h>
#include <netdb.h>

#include <unistd.h>
#include <arpa/inet.h>

#include <algorithm>

sockvec clients;

/**
 * Initializes a connection. Really, it just sets up the data structure,
 * socket setup is handled elsewhere.  We do send a version to the
 * client.
 */
client::client (int fd, const char *peername)
: fd (fd), host (strdup (peername)),
  socket_ev (this, &client::socket_cb),
  cmd_ev    (this, &client::cmd_cb),
  cc_inv (this), cc_other (this)
{
  refcnt_inc (); // the socket is an external reference

  mss = 1500 - 66; // 1500 typical ethernet frame, 66 typical tcp header overhead

  {
    struct linger linger_opt;

    linger_opt.l_onoff = 0;
    linger_opt.l_linger = 0;

    if (setsockopt (fd, SOL_SOCKET, SO_LINGER, &linger_opt, sizeof (struct linger)))
      LOG (llevError, "SO_LINGER: %s\n", strerror (errno));
  }

  {
    int val;

#ifdef IP_TOS
    val = IPTOS_LOWDELAY;
    if (setsockopt (fd, IPPROTO_IP, IP_TOS, &val, sizeof (val)))
      LOG (llevError, "IP_TOS: %s\n", strerror (errno));
#endif

#ifdef TCP_NODELAY
    val = 1;
    if (setsockopt (fd, IPPROTO_TCP, TCP_NODELAY, &val, sizeof (val)))
      LOG (llevError, "TCP_NODELAY: %s\n", strerror (errno));
#endif

    // set some very aggressive keepalive parameters
#ifdef TCP_KEEPIDLE
    val = 10;
    if (setsockopt (fd, IPPROTO_TCP, TCP_KEEPIDLE, &val, sizeof (val)))
      LOG (llevError, "TCP_KEEPIDLE: %s\n", strerror (errno));
#endif

#ifdef TCP_KEEPCNT
    val = 5;
    if (setsockopt (fd, IPPROTO_TCP, TCP_KEEPCNT, &val, sizeof (val)))
      LOG (llevError, "TCP_KEEPCNT: %s\n", strerror (errno));
#endif

#ifdef TCP_KEEPINTVL
    val = 1;
    if (setsockopt (fd, IPPROTO_TCP, TCP_KEEPINTVL, &val, sizeof (val)))
      LOG (llevError, "TCP_KEEPINTVL: %s\n", strerror (errno));
#endif

    // try to find the mss value in use
#ifdef TCP_MAXSEG
    socklen_t sl = sizeof (val);
    if (!getsockopt (fd, IPPROTO_TCP, TCP_MAXSEG, &val, &sl) && sl == sizeof (val))
      mss = val;
#endif
  }

  {
    int bufsize = 65535;          /*Supposed absolute upper limit */
    int oldbufsize;
    int buflen = sizeof (int);

    if (fcntl (fd, F_SETFL, O_NONBLOCK) == -1)
      LOG (llevError, "InitConnection:  Error on fcntl.\n");

    if (getsockopt (fd, SOL_SOCKET, SO_SNDBUF, (char *) &oldbufsize, (socklen_t *) & buflen) == -1)
      oldbufsize = 0;

    if (oldbufsize < bufsize)
      if (setsockopt (fd, SOL_SOCKET, SO_SNDBUF, (char *) &bufsize, sizeof (&bufsize)))
        LOG (llevError, "InitConnection: setsockopt unable to set output buf size to %d\n", bufsize);

    buflen = sizeof (oldbufsize);
    getsockopt (fd, SOL_SOCKET, SO_SNDBUF, (char *) &oldbufsize, (socklen_t *) & buflen);
  }

  state = ST_SETUP;
  mapmode = Map0Cmd;
  darkness = 1;
  mapx = 11;
  mapy = 11;
  itemcmd = 1;              /* Default is version item1 command */
  max_rate = 100000 / (1000000 / MAX_TIME); // ~1mbit is assumed per default

  /* Do this so we don't send a face command for the client for
   * this face.  Face 0 is sent to the client to say clear
   * face information.
   */
  faces_sent[0] = true;

  socket_ev.prio (PE_PRIO_NORMAL);
  socket_ev.fd (fd);
  socket_ev.poll (PE_R);

  cmd_ev.prio (PE_PRIO_NORMAL);

  // initialisation done, kick it!
  send_packet_printf ("version %d %d %s\n", VERSION_CS, VERSION_SC, VERSION_INFO);
  flush ();

  reset_stats ();

  clients.insert (this);
}

client::~client ()
{
  clients.erase (this);

  free (stats.range);
  free (stats.title);
  free (host);
}

void
client::do_destroy ()
{
  attachable::do_destroy ();

  if (pl)
    pl->disconnect ();

  if (fd >= 0)
    {
      send_packet ("goodbye");
      flush ();

      close (fd);
    }

  state = ST_DEAD;

  socket_ev.suspend ();
  cmd_ev.suspend ();

  refcnt_dec (); // socket no longer open
}

void
client::reset_stats ()
{
  /* we need to clear these to -1 and not zero - otherwise,
   * if a player quits and starts a new character, we wont
   * send new values to the client, as things like exp start
   * at zero.
   */
  for (int i = 0; i < NUM_SKILLS; i++)
    last_skill_exp[i] = -1;

  for (int i = 0; i < NROFATTACKS; i++)
    last_resist[i] = -1;

  last_weapon_sp = -1;
  last_level = -1;
  last_stats.exp = -1;
  last_weight = (uint32) - 1;
  last_flags = 0;
  last_weight = 0;
  last_weight_limit = 0;
  last_path_attuned = 0;
  last_path_repelled = 0;
  last_path_denied = 0;
  last_speed = 0;
  flags = 0;

  static living zero_living;
  last_stats = zero_living;
}

/** This sets up the socket and reads all the image information into memory. */
void
init_ericserver (void)
{
  cst_tot.time_start = time (NULL);
  cst_lst.time_start = time (NULL);

  LOG (llevDebug, "Initialize new client/server data\n");
}


/*******************************************************************************
 *
 * Start of functions dealing with freeing of the data.
 *
 ******************************************************************************/

/** Free's all the memory that ericserver allocates. */
void
free_all_newserver (void)
{
  LOG (llevDebug, "Freeing all new client/server information.\n");
  free_socket_images ();
}

client *
client::create (int fd, const char *peername)
{
  client *ns = new client (dup (fd), peername);
  ns->instantiate (); // effectively a nop right now
  INVOKE_CLIENT (CONNECT, ns);
  return ns;
}