/**
 * xrdp: A Remote Desktop Protocol server.
 *
 * Copyright (C) Jay Sorg 2012
 * Copyright (C) Kevin Zhou 2012
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include "libxrdp.h"

/*****************************************************************************/
struct xrdp_fastpath* APP_CC
xrdp_fastpath_create(struct xrdp_session* session)
{
  struct xrdp_fastpath* self;

  self = (struct xrdp_fastpath*)g_malloc(sizeof(struct xrdp_fastpath), 1);
  self->tcp_layer =
    ((struct xrdp_rdp*)session->rdp)->sec_layer->
                          mcs_layer->iso_layer->tcp_layer;
  make_stream(self->out_s);
  init_stream(self->out_s, FASTPATH_MAX_PACKET_SIZE);
  return self;
}

/*****************************************************************************/
void APP_CC
xrdp_fastpath_delete(struct xrdp_fastpath* self)
{
  if (self == 0)
  {
    return;
  }
  free_stream(self->out_s);
  g_free(self);
}

/*****************************************************************************/
/* returns error */
int APP_CC
xrdp_fastpath_reset(struct xrdp_fastpath* self)
{
  return 0;
}

int APP_CC
xrdp_fastpath_init(struct xrdp_fastpath* self)
{
  return 0;
}

/*****************************************************************************/
int APP_CC
xrdp_fastpath_send_update_pdu(struct xrdp_fastpath* self, tui8 updateCode,
                              struct stream* s)
{
  tui16 len;
  tui16 maxLen;
  tui32 payloadLeft;
  tui8 fragment;
  struct stream* s_send;
  int compression;
  int i;
  int i32;

  compression = 0;
  s_send = self->out_s;
  maxLen = FASTPATH_MAX_PACKET_SIZE - 6; /* 6 bytes for header */
  payloadLeft = (s->end - s->data);
  for (i = 0; payloadLeft > 0; i++)
  {
    if (payloadLeft > maxLen)
    {
      len = maxLen;
    }
    else
    {
      len = payloadLeft;
    }
    payloadLeft -= len;
    if (payloadLeft == 0)
    {
      fragment = i ? FASTPATH_FRAGMENT_LAST : FASTPATH_FRAGMENT_SINGLE;
    }
    else
    {
      fragment = i ? FASTPATH_FRAGMENT_NEXT : FASTPATH_FRAGMENT_FIRST;
    }
    init_stream(s_send, 0);
    out_uint8(s_send, 0); /* fOutputHeader */
    i32 = ((len + 6) >> 8) | 0x80;
    out_uint8(s_send, i32); /* use 2 bytes for length even length < 128 ??? */
    i32 = (len + 6) & 0xff;
    out_uint8(s_send, i32);
    i32 = (updateCode & 0x0f) | ((fragment & 0x03) << 4) |
          ((compression & 0x03) << 6);
    out_uint8(s_send, i32);
    out_uint16_le(s_send, len);
    s_copy(s_send, s, len);
    s_mark_end(s_send);
    if (xrdp_tcp_send(self->tcp_layer, s_send) != 0)
    {
      return 1;
    }
  }
  return 0;
}

/*****************************************************************************/
int
xrdp_fastpath_process_update(struct xrdp_fastpath* self, tui8 updateCode,
                                tui32 size, struct stream* s)
{
  switch (updateCode)
  {
    case FASTPATH_UPDATETYPE_ORDERS:
    case FASTPATH_UPDATETYPE_BITMAP:
    case FASTPATH_UPDATETYPE_PALETTE:
    case FASTPATH_UPDATETYPE_SYNCHRONIZE:
    case FASTPATH_UPDATETYPE_SURFCMDS:
    case FASTPATH_UPDATETYPE_PTR_NULL:
    case FASTPATH_UPDATETYPE_PTR_DEFAULT:
    case FASTPATH_UPDATETYPE_PTR_POSITION:
    case FASTPATH_UPDATETYPE_COLOR:
    case FASTPATH_UPDATETYPE_CACHED:
    case FASTPATH_UPDATETYPE_POINTER:
      break;
    default:
      g_writeln("xrdp_fastpath_process_update: unknown updateCode 0x%X",
                updateCode);
      break;
  }

  return 0;
}

/*****************************************************************************/
int APP_CC
xrdp_fastpath_process_data(struct xrdp_fastpath* self, struct stream* s,
                           tui8 header)
{
  tui8 encryptionFlags;
  tui8 numberEvents;
  tui8 length2;
  tui8 updateHeader;
  tui8 updateCode;
  tui8 updateFrag;
  tui8 updateComp;
  tui16 length;
  tui32 size;

  encryptionFlags = (header & 0xc0) >> 6;
  numberEvents = (header & 0x3c) >> 2;
  xrdp_tcp_recv(self->tcp_layer, s, 1);
  in_uint8(s, length);
  if (length & 0x80)
  {
    xrdp_tcp_recv(self->tcp_layer, s, 1);
    in_uint8(s, length2);
    length = (length & 0x7f) << 8 + length2 - 3;
  }
  else
  {
    length -= 2;
  }
  xrdp_tcp_recv(self->tcp_layer, s, length);
  if (encryptionFlags != 0)
  {
    /* TODO decryption ...*/
  }
  /* parse updateHeader */
  in_uint8(s, updateHeader);
  updateCode = (updateHeader & 0x0f);
  updateFrag = (updateHeader & 0x30) >> 4;
  updateComp = (updateHeader & 0xc0) >> 6;
  if (updateFrag && updateComp)
  {
    /* TODO */
    g_writeln("xrdp_fastpath_process_data: updateFrag=%d, updateComp=%d",
              updateFrag,updateComp);
    return 1;
  }
  in_uint16_le(s, size);
  return xrdp_fastpath_process_update(self, updateCode, size, s);
}