/*
    CrossFire, A Multiplayer game for X-windows

    Copyright (C) 2002-2003 Mark Wedel & The Crossfire Development Team
    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
 * Main client/server loops.
 *
 * \date 2003-12-02
 *
 * loop.c 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 <sockproto.h>

#include <sys/types.h>
#include <sys/time.h>
#include <sys/socket.h>
#include <netinet/in.h>
#include <netdb.h>

#ifdef HAVE_UNISTD_H
# include <unistd.h>
#endif

#ifdef HAVE_ARPA_INET_H
# include <arpa/inet.h>
#endif

#include <loader.h>
#include <newserver.h>

/*****************************************************************************
 * Start of command dispatch area.
 * The commands here are protocol commands. 
 ****************************************************************************/

/* Either keep this near the start or end of the file so it is
 * at least reasonablye easy to find.
 * There are really 2 commands - those which are sent/received
 * before player joins, and those happen after the player has joined.
 * As such, we have function types that might be called, so
 * we end up having 2 tables.
 */

typedef void (*func_uint8_int_ns) (char *, int, client_socket *);

struct NsCmdMapping
{
  const char *cmdname;
  func_uint8_int_ns cmdproc;
  uint8 flag;
};

typedef void (*func_uint8_int_pl) (char *, int, player *);
struct PlCmdMapping
{
  const char *cmdname;
  func_uint8_int_pl cmdproc;
  uint8 flag;
};

/**
 * Dispatch table for the server.
 *
 * CmdMapping is the dispatch table for the server, used in HandleClient,
 * which gets called when the client has input.  All commands called here 
 * use the same parameter form (char* data, int len, int clientnum.
 * We do implicit casts, because the data that is being passed is
 * unsigned (pretty much needs to be for binary data), however, most
 * of these treat it only as strings, so it makes things easier
 * to cast it here instead of a bunch of times in the function itself.
 * flag is 1 if the player must be in the playing state to issue the
 * command, 0 if they can issue it at any time.
 */
static struct PlCmdMapping plcommands[] = {
  {"examine", ExamineCmd, 1},
  {"apply", ApplyCmd, 1},
  {"move", MoveCmd, 1},
  {"reply", ReplyCmd, 0},
  {"command", PlayerCmd, 1},
  {"ncom", (func_uint8_int_pl) NewPlayerCmd, 1},
  {"lookat", LookAt, 1},
  {"lock", (func_uint8_int_pl) LockItem, 1},
  {"mark", (func_uint8_int_pl) MarkItem, 1},
  {"mapredraw", MapRedrawCmd, 0},       /* Added: phil */
  {"mapinfo", MapInfoCmd, 2},   /* CF+ */
  {"ext", ExtCmd, 2},           /* CF+ */
  { 0 }               /* terminator */
};

/** Face-related commands */
static struct NsCmdMapping nscommands[] = {
  {"addme", AddMeCmd, 2},
  {"askface", SendFaceCmd},     /* Added: phil */
  {"requestinfo", RequestInfo},
  {"setfacemode", SetFaceMode, 2},
  {"setsound", SetSound, 2},
  {"setup", SetUp, 2},
  {"version", VersionCmd, 2},
  {"toggleextendedinfos", ToggleExtendedInfos, 2}, /*Added: tchize */
  {"toggleextendedtext", ToggleExtendedText, 2},   /*Added: tchize */
  {"asksmooth", AskSmooth},     /*Added: tchize (smoothing technologies) */
  { 0 }                  /* terminator (I, II & III) */
};

/**
 * RequestInfo is sort of a meta command. There is some specific
 * request of information, but we call other functions to provide
 * that information.
 */
void
RequestInfo (char *buf, int len, client_socket * ns)
{
  char *params = NULL, *cp;

  /* No match */
  char bigbuf[MAX_BUF];
  int slen;

  /* Set up replyinfo before we modify any of the buffers - this is used
   * if we don't find a match.
   */
  strcpy (bigbuf, "replyinfo ");
  slen = strlen (bigbuf);
  safe_strcat (bigbuf, buf, &slen, MAX_BUF);

  /* find the first space, make it null, and update the
   * params pointer.
   */
  for (cp = buf; *cp != '\0'; cp++)
    if (*cp == ' ')
      {
        *cp = '\0';
        params = cp + 1;
        break;
      }

  if (!strcmp (buf, "image_info"))
    send_image_info (ns, params);
  else if (!strcmp (buf, "image_sums"))
    send_image_sums (ns, params);
  else if (!strcmp (buf, "skill_info"))
    send_skill_info (ns, params);
  else if (!strcmp (buf, "spell_paths"))
    send_spell_paths (ns, params);
  else
    ns->send_packet (bigbuf, len);
}

/**
 * Handle client input.
 *
 * HandleClient is actually not named really well - we only get here once
 * there is input, so we don't do exception or other stuff here.
 * sock is the output socket information.  pl is the player associated
 * with this socket, null if no player (one of the init_sockets for just
 * starting a connection)
 */

void
HandleClient (client_socket *ns, player *pl)
{
  /* Loop through this - maybe we have several complete packets here. */
  // limit to a few commands only, though, as to not monopolise the server
  for (int repeat = 16; repeat--;)
    {
      /* If it is a player, and they don't have any speed left, we
       * return, and will read in the data when they do have time.
       */
      if (pl && pl->state == ST_PLAYING && pl->ob && pl->ob->speed_left < 0)
        return;

      int pkt_len = ns->read_packet ();

      if (pkt_len < 0)
        {
          LOG (llevError, "read error on player %s\n", &pl->ob->name);
          /* Caller will take care of cleaning this up */
          ns->status = Ns_Dead;
          return;
        }
      else if (pkt_len == 0)
        /* Still dont have a full packet */
        return;

      /* First, break out beginning word.  There are at least
       * a few commands that do not have any paremeters.  If
       * we get such a command, don't worry about trying
       * to break it up.
       */
      int datalen;
      char *data = strchr ((char *)ns->inbuf + 2, ' ');

      if (data)
        {
          *data++ = 0;
          datalen = pkt_len - (data - (char *)ns->inbuf);
        }
      else
        {
          data = (char *)ns->inbuf + 2; // better read garbage than segfault
          datalen = 0;
        }

      ns->inbuf [pkt_len] = 0;      /* Terminate buffer - useful for string data */

      for (int i = 0; nscommands[i].cmdname; i++)
        {
          if (!strcmp ((char *)ns->inbuf + 2, nscommands[i].cmdname))
            {
              nscommands[i].cmdproc (data, datalen, ns);
              ns->skip_packet (pkt_len);
              //D// not doing this causes random memory corruption
              if (nscommands[i].flag & 2)
                goto next_packet;
              return;
            }
        }

      /* Player must be in the playing state or the flag on the
       * the command must be zero for the user to use the command -
       * otherwise, a player cam save, be in the play_again state, and
       * the map they were on gets swapped out, yet things that try to look
       * at the map causes a crash.  If the command is valid, but
       * one they can't use, we still swallow it up.
       */
      if (pl)
        for (int i = 0; plcommands[i].cmdname; i++)
          {
            if (!strcmp ((char *)ns->inbuf + 2, plcommands[i].cmdname))
              {
                if (pl->state == ST_PLAYING || !(plcommands[i].flag & 1))
                  plcommands[i].cmdproc ((char *) data, datalen, pl);

                ns->skip_packet (pkt_len);
                //D// not doing this causes random memory corruption
                if (plcommands[i].flag & 2)
                  goto next_packet;

                return;
              }
          }

      /* If we get here, we didn't find a valid command.  Logging
       * this might be questionable, because a broken client/malicious
       * user could certainly send a whole bunch of invalid commands.
       */
      LOG (llevDebug, "Bad command from client (%s)\n", ns->inbuf + 2);
      ns->skip_packet (pkt_len);
    next_packet:
      ;
    }
}

void
flush_sockets (void)
{
  for (sockvec::iterator i = client_sockets.begin (); i != client_sockets.end (); ++i)
    if ((*i)->status != Ns_Dead)
      (*i)->flush ();
}

/**
 * This checks the sockets for input, does the right thing.
 *
 * A bit of this code is grabbed out of socket.c
 * There are 2 lists we need to look through - init_sockets is a list
 * 
 */
void
doeric_server (void)
{
  int i, pollret;
  fd_set tmp_read;
  struct sockaddr_in addr;
  socklen_t addrlen = sizeof (struct sockaddr);
  player *pl, *next;
  int maxfd = 0;

#ifdef CS_LOGSTATS
  if ((time (NULL) - cst_lst.time_start) >= CS_LOGTIME)
    write_cs_stats ();
#endif

  /* Go through the players.  Let the loop set the next pl value,
   * since we may remove some
   */
  //TODO: must be handled cleanly elsewhere
  for (pl = first_player; pl; )
    {
      player *npl = pl->next;

      //TODO: must be handled cleanly elsewhere
      if (pl->socket->status == Ns_Dead)
        {
          save_player (pl->ob, 0);

          if (!QUERY_FLAG (pl->ob, FLAG_REMOVED))
            {
              terminate_all_pets (pl->ob);
              pl->ob->remove ();
            }

          leave (pl, 1);
          final_free_player (pl);
        }

      pl = npl;
    }

  FD_ZERO (&tmp_read);

  for (sockvec::iterator i = client_sockets.begin (); i != client_sockets.end (); )
    {
      client_socket *s = *i;

      if (s->status == Ns_Dead)
        {
          client_sockets.erase (i);
          delete s;
        }
      else
        {
          if (s->fd > maxfd) maxfd = s->fd;

          FD_SET (s->fd, &tmp_read);

          ++i;
        }
    }

  struct timeval timeout;

  timeout.tv_sec  = 0;
  timeout.tv_usec = 0;

  pollret = select (maxfd + 1,
                    &tmp_read, 0, 0,
                    &timeout);

  if (pollret == -1)
    {
      LOG (llevError, "select failed: %s\n", strerror (errno));
      return;
    }

  /* We need to do some of the processing below regardless */

  /* Check for any input on the sockets */
  for (sockvec::iterator i = client_sockets.begin (); i != client_sockets.end (); ++i)
    {
      client_socket *s = *i;
      player *pl = s->pl;

      //TODO: disassociate handleclient from socket readin
      if (s->inbuf_len || FD_ISSET (s->fd, &tmp_read))
        HandleClient (s, pl);

      //TODO: should not be done here, either
      if (s->status != Ns_Dead && pl)
        {
          /* Update the players stats once per tick.  More efficient than
           * sending them whenever they change, and probably just as useful
           */
          esrv_update_stats (pl);
          if (pl->last_weight != -1 && pl->last_weight != WEIGHT (pl->ob))
            {
              esrv_update_item (UPD_WEIGHT, pl->ob, pl->ob);
              if (pl->last_weight != WEIGHT (pl->ob))
                LOG (llevError, "esrv_update_item(UPD_WEIGHT) did not set player weight: is %lu, should be %lu\n",
                     (unsigned long) pl->last_weight, WEIGHT (pl->ob));
            }

          /* draw_client_map does sanity checking that map is
           * valid, so don't do it here.
           */
          draw_client_map (pl->ob);
          if (s->update_look)
            esrv_draw_look (pl->ob);
        }
    }
}