/*
 * CrossFire, A Multiplayer game
 *
 * 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
 * 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_FACE_SETS	20  /**< Maximum number of image sets the program will handle */

/** Information about one image */
typedef struct FaceInfo
{
  uint8 *data;              /**< image data */
  uint16 datalen;           /**< length of the xpm data */
  uint32 checksum;          /**< Checksum of face data */
} FaceInfo;

/** Information about one face set */
typedef struct
{
  char *prefix;         /**< */
  char *fullname;

  uint8 fallback;       /**< faceset to use when an image is not found in this faceset */
  char *size;
  char *extension;
  char *comment;

  FaceInfo *faces;      /**< images in this faceset */
} FaceSets;

static FaceSets facesets[MAX_FACE_SETS];    /**< All facesets */

/**
 * Checks specified faceset is valid
 * \param fsn faceset number
 */
int
is_valid_faceset (int fsn)
{
  if (fsn >= 0 && fsn < MAX_FACE_SETS && facesets[fsn].prefix)
    return TRUE;
  return FALSE;
}

/**
 * Frees all faceset information
 */
void
free_socket_images (void)
{
  int num, q;

  for (num = 0; num < MAX_FACE_SETS; num++)
    {
      if (facesets[num].prefix)
        {
          for (q = 0; q < faces.size (); q++)
            if (facesets[num].faces[q].data)
              free (facesets[num].faces[q].data);

          free (facesets[num].prefix);
          free (facesets[num].fullname);
          free (facesets[num].size);
          free (facesets[num].extension);
          free (facesets[num].comment);
          free (facesets[num].faces);
        }
    }
}

/**
 * This returns the set we will actually use when sending
 * a face.  This is used because the image files may be sparse.
 * This function is recursive.  imageno is the face number we are
 * trying to send
 *
 * If face is not found in specified faceset, tries with 'fallback' faceset.
 *
 * \param faceset faceset to check
 * \param imageno image number
 *
 */
static int
get_face_fallback (int faceset, int imageno)
{
  /* faceset 0 is supposed to have every image, so just return.  Doing
   * so also prevents infinite loops in the case if it not having
   * the face, but in that case, we are likely to crash when we try
   * to access the data, but that is probably preferable to an infinite
   * loop.
   */
  if (faceset == 0)
    return 0;

  if (!facesets[faceset].prefix)
    {
      LOG (llevError, "get_face_fallback called with unused set (%d)?\n", faceset);
      return 0;                 /* use default set */
    }

  if (facesets[faceset].faces[imageno].data)
    return faceset;

  return get_face_fallback (facesets[faceset].fallback, imageno);
}

/**
 * Checks fallback are correctly defined.
 * This is a simple recursive function that makes sure the fallbacks
 * are all proper (eg, the fall back to defined sets, and also
 * eventually fall back to 0).  At the top level, togo is set to MAX_FACE_SETS,
 * if togo gets to zero, it means we have a loop.
 * This is only run when we first load the facesets.
 */
static void
check_faceset_fallback (int faceset, int togo)
{
  int fallback = facesets[faceset].fallback;

  /* proper case - falls back to base set */
  if (fallback == 0)
    return;

  if (!facesets[fallback].prefix)
    {
      LOG (llevError, "Face set %d falls to non set faceset %d\n", faceset, fallback);
      abort ();
    }

  togo--;
  if (togo == 0)
    {
      LOG (llevError, "Infinite loop found in facesets. aborting.\n");
      abort ();
    }

  check_faceset_fallback (fallback, togo);
}

#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 has requested pixmap that it somehow missed getting.
 * This will be called often if the client is
 * caching images.
 */
void
SendFaceCmd (char *buf, int len, client *ns)
{
  ns->send_image (atoi (buf));
}

// 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)
{
  // never send face 0. ever. it does not exist.
  if (!facenum)
    return;

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

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

  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)
    {
      faceinfo *f = face_info (facenum);

      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");

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

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

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

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

                  if (f->smooth)
                    {
                      send_face (f->smooth);
                      sx << ber32 (facenum)
                         << ber32 (f->smooth)
                         << ber32 (f->smoothlevel);
                    }
                }
            }
        }
      while (!fxface.empty ()
             && fx.room () > ber32::size + CHKSUM_SIZE + 1
             && 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);

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

  faces_sent[facenum] = true;

  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);

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

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

/**
 * 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 > num_animations)
    {
      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]);
      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++)
    {
      ns->faces_sent[i] = true;

      const facedata *d = face_data (i, 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);
}