/*
    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>
#ifndef __CEXTRACT__
# include <sproto.h>
# include <sockproto.h>
#endif

#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, NewSocket *);

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

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+ */
  {NULL, NULL, 0}               /* terminator */
};

/** Face-related commands */
static struct NsCmdMapping nscommands[] = {
  {"addme", AddMeCmd},
  {"askface", SendFaceCmd},     /* Added: phil */
  {"requestinfo", RequestInfo},
  {"setfacemode", SetFaceMode},
  {"setsound", SetSound},
  {"setup", SetUp},
  {"version", VersionCmd},
  {"toggleextendedinfos", ToggleExtendedInfos}, /*Added: tchize */
  {"toggleextendedtext", ToggleExtendedText},   /*Added: tchize */
  {"asksmooth", AskSmooth},     /*Added: tchize (smoothing technologies) */
  {NULL, NULL}                  /* 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, NewSocket * 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
    Write_String_To_Socket (ns, 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 (NewSocket * ns, player *pl)
{
  int len = 0, i, cnt;
  char *data;

  /* Loop through this - maybe we have several complete packets here. */
  // limit to a few commands only, though, as to not monopolise the server
  for (cnt = 16; cnt--;)
    {
      /* 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 != NULL && pl->ob->speed_left < 0)
        {
          return;
        }

      i = SockList_ReadPacket (ns->fd, &ns->inbuf, MAXSOCKBUF - 1);

      if (i < 0)
        {
#ifdef ESRV_DEBUG
          LOG (llevDebug, "HandleClient: Read error on connection player %s\n", (pl ? pl->ob->name : "None"));
#endif
          /* Caller will take care of cleaning this up */
          ns->status = Ns_Dead;
          return;
        }
      /* Still dont have a full packet */
      if (i == 0)
        return;

//        //D//TODO//temporarily log long commands
//        if (ns->inbuf.len >= 40 && pl && pl->ob)
//          LOG (llevDebug, "HandleClient: long comamnd from <%s,%s> %d<%s>\n", pl->ob->name, ns->host, ns->inbuf.len, ns->inbuf.buf + 2);

      /* 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.
       */
      data = (char *) strchr ((char *) ns->inbuf.buf + 2, ' ');
      if (data)
        {
          *data = '\0';
          data++;
          len = ns->inbuf.len - (data - (char *) ns->inbuf.buf);
        }
      else
        len = 0;

      ns->inbuf.buf[ns->inbuf.len] = '\0';      /* Terminate buffer - useful for string data */
      for (i = 0; nscommands[i].cmdname != NULL; i++)
        {
          if (strcmp ((char *) ns->inbuf.buf + 2, nscommands[i].cmdname) == 0)
            {
              nscommands[i].cmdproc ((char *) data, len, ns);
              ns->inbuf.len = 0;
              return;           //D// not doing this causes random memory corruption
              goto next_packet;
            }
        }
      /* 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 (i = 0; plcommands[i].cmdname != NULL; i++)
          {
            if (strcmp ((char *) ns->inbuf.buf + 2, plcommands[i].cmdname) == 0)
              {
                if (pl->state == ST_PLAYING || !(plcommands[i].flag & 1))
                  plcommands[i].cmdproc ((char *) data, len, pl);
                ns->inbuf.len = 0;
                //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.buf + 2);
    next_packet:
      ;
    }
}


/*****************************************************************************
 *
 * Low level socket looping - select calls and watchdog udp packet
 * sending.
 *
 ******************************************************************************/

#ifdef WATCHDOG

/**
 * Tell watchdog that we are still alive
 *
 * I put the function here since we should hopefully already be getting
 * all the needed include files for socket support 
 */

void
watchdog (void)
{
  static int fd = -1;
  static struct sockaddr_in insock;

  if (fd == -1)
    {
      struct protoent *protoent;

      if ((protoent = getprotobyname ("udp")) == NULL || (fd = socket (PF_INET, SOCK_DGRAM, protoent->p_proto)) == -1)
        {
          return;
        }
      insock.sin_family = AF_INET;
      insock.sin_port = htons ((unsigned short) 13325);
      insock.sin_addr.s_addr = inet_addr ("127.0.0.1");
    }
  sendto (fd, (void *) &fd, 1, 0, (struct sockaddr *) &insock, sizeof (insock));
}
#endif

void
flush_sockets (void)
{
  player *pl;

  for (pl = first_player; pl != NULL; pl = pl->next)
    if (pl->socket.status != Ns_Dead)
      Socket_Flush (&pl->socket);
}

/**
 * This checks the sockets for input and exceptions, 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, tmp_exceptions, tmp_write;
  struct sockaddr_in addr;
  socklen_t addrlen = sizeof (struct sockaddr);
  player *pl, *next;

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

  FD_ZERO (&tmp_read);
  FD_ZERO (&tmp_write);
  FD_ZERO (&tmp_exceptions);

  for (i = 0; i < socket_info.allocated_sockets; i++)
    {
      if (init_sockets[i].status == Ns_Dead)
        {
          free_newsocket (&init_sockets[i]);
          init_sockets[i].status = Ns_Avail;
          socket_info.nconns--;
        }
      else if (init_sockets[i].status != Ns_Avail)
        {
          FD_SET ((uint32) init_sockets[i].fd, &tmp_read);
          FD_SET ((uint32) init_sockets[i].fd, &tmp_write);
          FD_SET ((uint32) init_sockets[i].fd, &tmp_exceptions);
        }
    }

  /* Go through the players.  Let the loop set the next pl value,
   * since we may remove some
   */
  for (pl = first_player; pl != NULL;)
    {
      if (pl->socket.status == Ns_Dead)
        {
          player *npl = pl->next;

          save_player (pl->ob, 0);
          if (!QUERY_FLAG (pl->ob, FLAG_REMOVED))
            {
              terminate_all_pets (pl->ob);
              remove_ob (pl->ob);
            }
          leave (pl, 1);
          final_free_player (pl);
          pl = npl;
        }
      else
        {
          FD_SET ((uint32) pl->socket.fd, &tmp_read);
          FD_SET ((uint32) pl->socket.fd, &tmp_write);
          FD_SET ((uint32) pl->socket.fd, &tmp_exceptions);
          pl = pl->next;
        }
    }

  /* Reset timeout each time, since some OS's will change the values on
   * the return from select.
   */
  socket_info.timeout.tv_sec = 0;
  socket_info.timeout.tv_usec = 0;

  pollret = select (socket_info.max_filedescriptor, &tmp_read, &tmp_write, &tmp_exceptions, &socket_info.timeout);

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

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

/*    if (!pollret) return;*/

  /* Following adds a new connection */
  if (pollret && FD_ISSET (init_sockets[0].fd, &tmp_read))
    {
      int newsocknum = 0;

#ifdef ESRV_DEBUG
      LOG (llevDebug, "doeric_server: New Connection\n");
#endif
      /* If this is the case, all sockets currently in used */
      if (socket_info.allocated_sockets <= socket_info.nconns)
        {
          init_sockets = (NewSocket *) realloc (init_sockets, sizeof (NewSocket) * (socket_info.nconns + 1));
          if (!init_sockets)
            fatal (OUT_OF_MEMORY);
          newsocknum = socket_info.allocated_sockets;
          socket_info.allocated_sockets++;
          init_sockets[newsocknum].faces_sent_len = nrofpixmaps;
          init_sockets[newsocknum].faces_sent = (uint8 *) malloc (nrofpixmaps * sizeof (*init_sockets[newsocknum].faces_sent));
          if (!init_sockets[newsocknum].faces_sent)
            fatal (OUT_OF_MEMORY);
          init_sockets[newsocknum].status = Ns_Avail;
        }
      else
        {
          int j;

          for (j = 1; j < socket_info.allocated_sockets; j++)
            if (init_sockets[j].status == Ns_Avail)
              {
                newsocknum = j;
                break;
              }
        }
      init_sockets[newsocknum].fd = accept (init_sockets[0].fd, (struct sockaddr *) &addr, &addrlen);
      if (init_sockets[newsocknum].fd == -1)
        {
          LOG (llevError, "accept failed: %s\n", strerror (errno));
        }
      else
        {
          char buf[MAX_BUF];
          long ip;
          NewSocket *ns;

          ns = &init_sockets[newsocknum];

          ip = ntohl (addr.sin_addr.s_addr);
          sprintf (buf, "%ld.%ld.%ld.%ld", (ip >> 24) & 255, (ip >> 16) & 255, (ip >> 8) & 255, ip & 255);

          if (checkbanned (NULL, buf))
            {
              LOG (llevInfo, "Banned host tried to connect: [%s]\n", buf);
              close (init_sockets[newsocknum].fd);
              init_sockets[newsocknum].fd = -1;
            }
          else
            {
              InitConnection (ns, buf);
              socket_info.nconns++;
            }
        }
    }

  /* Check for any exceptions/input on the sockets */
  if (pollret)
    for (i = 1; i < socket_info.allocated_sockets; i++)
      {
        if (init_sockets[i].status == Ns_Avail)
          continue;
        if (FD_ISSET (init_sockets[i].fd, &tmp_exceptions))
          {
            free_newsocket (&init_sockets[i]);
            init_sockets[i].status = Ns_Avail;
            socket_info.nconns--;
            continue;
          }
        if (FD_ISSET (init_sockets[i].fd, &tmp_read))
          {
            HandleClient (&init_sockets[i], NULL);
          }
        if (FD_ISSET (init_sockets[i].fd, &tmp_write))
          {
            init_sockets[i].can_write = 1;
          }
      }

  /* This does roughly the same thing, but for the players now */
  for (pl = first_player; pl != NULL; pl = next)
    {

      next = pl->next;
      if (pl->socket.status == Ns_Dead)
        continue;

      if (FD_ISSET (pl->socket.fd, &tmp_write))
        {
          if (!pl->socket.can_write)
            {
#if 0
              LOG (llevDebug, "Player %s socket now write enabled\n", pl->ob->name);
#endif
              pl->socket.can_write = 1;
              write_socket_buffer (&pl->socket);
            }
          /* if we get an error on the write_socket buffer, no reason to
           * continue on this socket.
           */
          if (pl->socket.status == Ns_Dead)
            continue;
        }
      else
        pl->socket.can_write = 0;

      if (FD_ISSET (pl->socket.fd, &tmp_exceptions))
        {
          save_player (pl->ob, 0);
          if (!QUERY_FLAG (pl->ob, FLAG_REMOVED))
            {
              terminate_all_pets (pl->ob);
              remove_ob (pl->ob);
            }
          leave (pl, 1);
          final_free_player (pl);
        }
      else
        {
          HandleClient (&pl->socket, pl);
          /* If the player has left the game, then the socket status
           * will be set to this be the leave function.  We don't
           * need to call leave again, as it has already been called
           * once.
           */
          if (pl->socket.status == Ns_Dead)
            {
              save_player (pl->ob, 0);
              if (!QUERY_FLAG (pl->ob, FLAG_REMOVED))
                {
                  terminate_all_pets (pl->ob);
                  remove_ob (pl->ob);
                }
              leave (pl, 1);
              final_free_player (pl);
            }
          else
            {

              /* 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 (pl->socket.update_look)
                esrv_draw_look (pl->ob);
            }
        }
    }
}