/*
    CrossFire, A Multiplayer game for X-windows

    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>

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)
{
  {
    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 = IPTOS_LOWDELAY;

    if (setsockopt (fd, IPPROTO_IP, IP_TOS, &val, sizeof (val)))
      LOG (llevError, "IP_TOS: %s\n", strerror (errno));
  }

  {
    int val = 1;

    if (setsockopt (fd, IPPROTO_TCP, TCP_NODELAY, &val, sizeof (val)))
      LOG (llevError, "TCP_NODELAY: %s\n", strerror (errno));
  }

#ifdef __linux__
  {
     int val;

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

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

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

  faces_sent = salloc0<uint8> (nrofpixmaps);

  /* 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] = NS_FACESENT_FACE;

  // socket I/O is low priority
  // we prefer to have the server run instead of handling client requests
  socket_ev.prio (PE_PRIO_NORMAL + 1);
  socket_ev.fd (fd);
  socket_ev.poll (PE_R);

  // command handling is even lower priority
  // that way no client can monopolise the server
  cmd_ev.prio (PE_PRIO_NORMAL + 2);

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

#if 0//TODO
  socket_info.nconns++;
  if (socket_info.nconns > cst_tot.max_conn) cst_tot.max_conn = socket_info.nconns;
  if (socket_info.nconns > cst_lst.max_conn) cst_lst.max_conn = socket_info.nconns;
#endif
}

client::~client ()
{
  if (pl)
    {
      pl->save ();
      leave (pl, 1);
      pl->ns = 0;

      delete pl;
    }

  if (fd >= 0)
    close (fd);

  sfree<uint8> (faces_sent, nrofpixmaps);
  free (stats.range);
  free (stats.title);
  free (host);
}

void
client::destroy ()
{
  INVOKE_CLIENT (DESTROY, this);

  state = ST_DEAD;

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

/** 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");

  read_client_images ();
}


/*******************************************************************************
 *
 * 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)
{
  if (checkbanned (NULL, peername))
    {
      LOG (llevInfo, "Banned host tried to connect: [%s]\n", peername);
      return 0;
    }
  else
    {
      client *ns = new client (dup (fd), peername);
      clients.push_back (ns);

      ns->instantiate (); // effectively a nop right now

      INVOKE_CLIENT (CONNECT, ns);

      return ns;
    }
}