/*
 * This file is part of Crossfire TRT, the Roguelike Realtime MORPG.
 * 
 * Copyright (©) 2005,2006,2007 Marc Alexander Lehmann / Robin Redeker / the Crossfire TRT team
 * Copyright (©) 2001,2007 Mark Wedel
 * Copyright (©) 1992,2007 Frank Tore Johansen
 * 
 * Crossfire TRT 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.
 * 
 * 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, see <http://www.gnu.org/licenses/>.
 * 
 * The authors can be reached via e-mail to <crossfire@schmorp.de>
 */

/** \file
 * Image related communication
 *
 *  \date 2003-12-02
 *
 * This file deals with the image related communication to the
 * client.  I've located all the functions in this file - this
 * localizes it more, and means that we don't need to declare
 * things like all the structures as globals.
 */

#include <global.h>
#include <sproto.h>

#include "crc.h"

#define MAX_IMAGE_SIZE 10000

/**
 * Client tells us what type of faces it wants.  Also sets
 * the caching attribute.
 *
 */
void
SetFaceMode (char *buf, int len, client *ns)
{
  int mask = (atoi (buf) & CF_FACE_CACHE), mode = (atoi (buf) & ~CF_FACE_CACHE);

  if (mode == CF_FACE_NONE)
    ns->facecache = 1;
  else if (mode != CF_FACE_PNG)
    ns->send_packet_printf ("drawinfo %d %s", NDI_RED, "Warning - send unsupported face mode.  Will use Png");

  if (mask)
    ns->facecache = 1;
}

/**
 * client requested an image. send it rate-limited
 * before flushing.
 */
void
AskFaceCmd (char *buf, int len, client *ns)
{
  int idx = 0, pri = 0;

  sscanf (buf, "%d %d", &idx, &pri);

  //TODO: somehow fetch default priority from send_fx here

  const facedata *d = face_data (idx, ns->faceset);

  if (!d)
    return; // doh

  client::ixsend ix;

  ix.pri = pri;
  ix.idx = idx;
  ix.ofs = d->data.size ();

  auto (pos, ns->ixface.end ());

  if (ns->fxix < 2)
    {
      // gcfclient does not support prioritising, older cfplus versions
      // do not support interleaved transfers.
      if (!ns->ixface.empty ())
        pos = ns->ixface.end () - 1;
    }
  else
    {
      // the by far most common case will be to insert
      // near the end, so little looping.
      while (pos != ns->ixface.begin ())
        {
          --pos;

          // sort within 2k bins, to slightly prefer smaller images
          if (pri > pos->pri || (pri == pos->pri && (ix.ofs >> 11) <= (pos->ofs >> 11)))
            {
              ++pos;
              break;
            }
        }
    }

  ns->ixface.insert (pos, ix);

#if 0
  for (auto (i, ns->ixface.begin ()); i != ns->ixface.end (); ++i)
    fprintf (stderr, "<%d,%d> ",  i->pri, i->ofs);
  fprintf (stderr, "\n");
#endif
}

/**
 * Tells client the picture it has to use 
 * to smooth a picture number given as argument.
 */
void
AskSmooth (char *buf, int len, client *ns)
{
  ns->send_face (atoi (buf), -100);
  ns->flush_fx ();
}

// how lame
static void print_facename (packet &sl, const facedata &d)
{
  for (int i = 0; i < CHKSUM_SIZE; ++i)
    sl.printf ("%02x", d.chksum [i]);
}

// gcfclient uses the server-provided checksum for comparison, but always
// writes a broken checksum to its cache file, so we have to provide
// gcfclient with the same broken (and useless) checksum just to have it
// cache the image despite its bugs.
static uint32 gcfclient_checksum (const facedata *d)
{
  uint32 csum = 0;

  for (std::string::const_iterator i = d->data.begin ();
       i != d->data.end ();
       ++i)
    {
      csum = rotate_right (csum);
      csum += *(uint8 *)&*i;
    }

  return csum;
}

/**
 * Sends a face to a client if they are in pixmap mode
 * nothing gets sent in bitmap mode. 
 * If nocache is true (nonzero), ignore the cache setting from the client -
 * this is needed for the askface, in which we really do want to send the
 * face (and askface is the only place that should be setting it).  Otherwise,
 * we look at the facecache, and if set, send the image name.
 */
void
client::send_face (faceidx facenum, int pri)
{
  // never send face 0. ever. it does not exist.
  if (!facenum)
    return;

  faceinfo *f = face_info (facenum);

  if (!f)
    {
      LOG (llevError | logBacktrace, "client::send_face (%d) out of bounds??\n", facenum);
      return;
    }

  // refuse to send non-image faces
  if (!fx_want [f->type])
    return;

  if (faces_sent [facenum])
    return;

  faces_sent[facenum] = true;

  // if for some reason we let a client without face caching connect,
  // we better support that decision here and implement it.
  if (!facecache)
    return send_image (facenum);

  if (fxix)
    {
      fxface.push_back (facenum);
      return;
    }

  const facedata *d = f->data (faceset);

  packet sl;

  if (force_face0)
    sl << "face "  << uint16 (facenum);
  else if (image2)
    sl << "face2 " << uint16 (facenum) << uint8 (0) << uint32 (force_bad_checksum ? gcfclient_checksum (d) : 0);
  else
    sl << "face1 " << uint16 (facenum) << uint32 (force_bad_checksum ? gcfclient_checksum (d) : 0);

  // how lame
  print_facename (sl, *d);
  send_packet (sl);

  if (EMI_smooth)
    {
      if (f->smooth)
        {
          send_face (f->smooth);

          packet sl ("smooth");

          sl << uint16 (facenum)
             << uint16 (f->smooth);

          send_packet (sl);
        }
    }
}

void client::flush_fx ()
{
  while (!fxface.empty ())
    {
      packet fx ("fx");
      packet sx ("sx");
      int type = 0;

      do
        {
          faceidx facenum = fxface.back (); fxface.pop_back ();

          if (const faceinfo *f = face_info (facenum))
            {
              if (f->type != type)
                {
                  type = f->type;

                  fx << ber32 (0)
                     << uint8 (1) << uint8 (type);
                }

              const facedata *d = f->data (faceset);

              fx << ber32 (facenum)
                 << data8 (d->chksum, CHKSUM_SIZE);

              if (smoothing)
                {
                  faceinfo *f = face_info (facenum);

                  if (f->smooth)
                    {
                      send_face (f->smooth, -110);

                      sx << ber32 (facenum)
                         << ber32 (f->smooth)
                         << ber32 (f->smoothlevel);
                    }
                }
            }
        }
      while (!fxface.empty ()
             && fx.room () > ber32::size + CHKSUM_SIZE + 1 + 3 /* type switch */
             && sx.room () > ber32::size * 3);

      send_packet (fx);
      if (sx.length () > 3) send_packet (sx);
    }
}

void
client::send_image (faceidx facenum)
{
  // never send face 0. ever. it does not exist.
  if (!facenum)
    return;

  const facedata *d = face_data (facenum, faceset);

  faces_sent[facenum] = true;

  if (!d)
    {
      LOG (llevError, "client::send_image (%d) out of bounds??\n", facenum);
      return;
    }
  
  if (force_image_newmap)
    force_newmap = true;

  packet sl;

  sl << (image2 ? "image2 " : "image ")
     << uint32 (facenum);

  if (image2)
    sl << uint8 (0);

  sl << uint32 (d->data.size ())
     << data (d->data.data (), d->data.size ());

  send_packet (sl);
}

// send all faces of this object to the client
// this uses more bandwidth initially, but makes
// animations look much smoother, and every client
// is supposed to do client-side caching anyways.
void
client::send_faces (object *ob)
{
  send_face (ob->face, 10);

  if (ob->animation_id)
    {
      animation &anim = animations [ob->animation_id];

      for (int i = 0; i < anim.num_animations; i++)
        send_face (anim.faces [i], -10);
    }
}

/**
 * Need to send an animation sequence to the client.
 * We will send appropriate face commands to the client if we haven't
 * sent them the face yet (this can become quite costly in terms of
 * how much we are sending - on the other hand, this should only happen
 * when the player logs in and picks stuff up.
 */
void
client::send_animation (short anim_num)
{
  /* Do some checking on the anim_num we got.  Note that the animations
   * are added in contigous order, so if the number is in the valid
   * range, it must be a valid animation.
   */
  if (anim_num < 0 || anim_num >= animations.size ())
    {
      LOG (llevError, "esrv_send_anim (%d) out of bounds??\n", anim_num);
      return;
    }

  packet sl ("anim");

  sl << uint16 (anim_num)
     << uint16 (0); /* flags - not used right now */

  /* Build up the list of faces.  Also, send any information (ie, the
   * the face itself) down to the client.
   */
  for (int i = 0; i < animations[anim_num].num_animations; i++)
    {
      send_face (animations[anim_num].faces[i], -20);
      sl << uint16 (animations[anim_num].faces[i]);   /* flags - not used right now */
    }

  send_packet (sl);

  anims_sent[anim_num] = 1;
}

/**
 * Sends the number of images, checksum of the face file,
 * and the image_info file information.  See the doc/Developers/protocol
 * if you want further detail.
 */
void
send_image_info (client *ns, char *params)
{
  packet sl;

  //TODO: second parameter is a checksum, but it makes no sense in this current framework
  sl.printf ("replyinfo image_info\n%d\n%u\n", MAX_FACES, 0);

  sl << "0:base:standard:0:32x32:none:The old 32x32 faceset.\n";

  ns->send_packet (sl);
}

/**
 * Sends requested face information.
 * \param ns socket to send to
 * \param params contains first and last index of face
 *
 * For each image in [start..stop] sends
 *  - checksum
 *  - name
 */
void
send_image_sums (client *ns, char *params)
{
  int start, stop;
  char *cp;

  packet sl;

  start = atoi (params);
  for (cp = params; *cp != '\0'; cp++)
    if (*cp == ' ')
      break;

  stop = atoi (cp);
  if (stop < start || *cp == '\0' || (stop - start) > 1000 || stop >= MAX_FACES)
    {
      sl.printf ("replyinfo image_sums %d %d", start, stop);
      ns->send_packet (sl);
      sl.reset ();
      return;
    }

  sl.printf ("replyinfo image_sums %d %d ", start, stop);

  for (int i = start; i <= stop && i < faces.size (); i++)
    if (const faceinfo *f = face_info (i))
      if (ns->fx_want [f->type])
        {
          ns->faces_sent[i] = true;

          const facedata *d = f->data (ns->faceset);

          if (sl.room () < 2 + 4 + 1 + d->data.size () + 1)
            break;

          sl << uint16 (i)
             << uint32 (0) // checksum
             << uint8  (ns->faceset);

          print_facename (sl, *d); sl << uint8 (0);
        }

  /* It would make more sense to catch this pre-emptively in the code above.
   * however, if this really happens, we probably just want to cut down the
   * size to less than 1000, since that is what we claim the protocol would
   * support.
   */
  //TODO: taken care of above, should simply abort or make sure the above code is correct
  if (sl.length () > MAXSOCKBUF)
    {
      LOG (llevError, "send_image_send: buffer overrun, %d > %d\n", sl.length (), MAXSOCKBUF);
      abort ();
    }

  ns->send_packet (sl);
}