/*
  Copyright:        Copyright (C) 2003-2018 SIL International.
  Authors:          mcdurdin
*/
#include "kmx_processor.h"

using namespace km::kbp;
using namespace kmx;

#if defined(_WIN32) || defined(_WIN64)
#include <share.h>
#endif

KMX_BOOL KMX_Processor::Load(km_kbp_path_name KeyboardName)
{
  if(!LoadKeyboard(KeyboardName, &m_keyboard.Keyboard)) return FALSE;   // I5136

  return TRUE;
}

const unsigned long CRCTable[256] = {
  0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419, 0x706af48f, 0xe963a535, 0x9e6495a3,
  0x0edb8832, 0x79dcb8a4, 0xe0d5e91e, 0x97d2d988, 0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, 0x90bf1d91,
  0x1db71064, 0x6ab020f2, 0xf3b97148, 0x84be41de, 0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7,
  0x136c9856, 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec, 0x14015c4f, 0x63066cd9, 0xfa0f3d63, 0x8d080df5,
  0x3b6e20c8, 0x4c69105e, 0xd56041e4, 0xa2677172, 0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b,
  0x35b5a8fa, 0x42b2986c, 0xdbbbc9d6, 0xacbcf940, 0x32d86ce3, 0x45df5c75, 0xdcd60dcf, 0xabd13d59,
  0x26d930ac, 0x51de003a, 0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423, 0xcfba9599, 0xb8bda50f,
  0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924, 0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d,
  0x76dc4190, 0x01db7106, 0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f, 0x9fbfe4a5, 0xe8b8d433,
  0x7807c9a2, 0x0f00f934, 0x9609a88e, 0xe10e9818, 0x7f6a0dbb, 0x086d3d2d, 0x91646c97, 0xe6635c01,
  0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e, 0x6c0695ed, 0x1b01a57b, 0x8208f4c1, 0xf50fc457,
  0x65b0d9c6, 0x12b7e950, 0x8bbeb8ea, 0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, 0xfbd44c65,
  0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2, 0x4adfa541, 0x3dd895d7, 0xa4d1c46d, 0xd3d6f4fb,
  0x4369e96a, 0x346ed9fc, 0xad678846, 0xda60b8d0, 0x44042d73, 0x33031de5, 0xaa0a4c5f, 0xdd0d7cc9,
  0x5005713c, 0x270241aa, 0xbe0b1010, 0xc90c2086, 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f,
  0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17, 0x2eb40d81, 0xb7bd5c3b, 0xc0ba6cad,
  0xedb88320, 0x9abfb3b6, 0x03b6e20c, 0x74b1d29a, 0xead54739, 0x9dd277af, 0x04db2615, 0x73dc1683,
  0xe3630b12, 0x94643b84, 0x0d6d6a3e, 0x7a6a5aa8, 0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1,
  0xf00f9344, 0x8708a3d2, 0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb, 0x196c3671, 0x6e6b06e7,
  0xfed41b76, 0x89d32be0, 0x10da7a5a, 0x67dd4acc, 0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5,
  0xd6d6a3e8, 0xa1d1937e, 0x38d8c2c4, 0x4fdff252, 0xd1bb67f1, 0xa6bc5767, 0x3fb506dd, 0x48b2364b,
  0xd80d2bda, 0xaf0a1b4c, 0x36034af6, 0x41047a60, 0xdf60efc3, 0xa867df55, 0x316e8eef, 0x4669be79,
  0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236, 0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f,
  0xc5ba3bbe, 0xb2bd0b28, 0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7, 0xb5d0cf31, 0x2cd99e8b, 0x5bdeae1d,
  0x9b64c2b0, 0xec63f226, 0x756aa39c, 0x026d930a, 0x9c0906a9, 0xeb0e363f, 0x72076785, 0x05005713,
  0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38, 0x92d28e9b, 0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21,
  0x86d3d2d4, 0xf1d4e242, 0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1, 0x18b74777,
  0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c, 0x8f659eff, 0xf862ae69, 0x616bffd3, 0x166ccf45,
  0xa00ae278, 0xd70dd2ee, 0x4e048354, 0x3903b3c2, 0xa7672661, 0xd06016f7, 0x4969474d, 0x3e6e77db,
  0xaed16a4a, 0xd9d65adc, 0x40df0b66, 0x37d83bf0, 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9,
  0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, 0xbad03605, 0xcdd70693, 0x54de5729, 0x23d967bf,
  0xb3667a2e, 0xc4614ab8, 0x5d681b02, 0x2a6f2b94, 0xb40bbe37, 0xc30c8ea1, 0x5a05df1b, 0x2d02ef8d
};

/*
 * This routine calculates the CRC for a block of data using the
 * table lookup method. It accepts an original value for the crc,
 * and returns the updated value.
 */

unsigned long CalculateBufferCRC(unsigned long count, KMX_BYTE *p)
{
  unsigned long temp1;
  unsigned long temp2;
  unsigned long crc = 0xFFFFFFFFL;

  while (count-- != 0)
  {
    temp1 = ( crc >> 8 ) & 0x00FFFFFFL;
    temp2 = CRCTable[((int) crc ^ *p++) & 0xff];
    crc = temp1 ^ temp2;
  }

  return crc;
}

KMX_BOOL KMX_Processor::LoadKeyboard(km_kbp_path_name fileName, LPKEYBOARD *lpKeyboard)
{
  PKMX_BYTE buf;
  FILE *fp;
  LPKEYBOARD kbp;
  PKMX_BYTE filebase;

  DebugLog("Loading file %ws", fileName);
  if(!fileName || !lpKeyboard)
  {
    DebugLog("Bad Filename");
    return FALSE;
  }

#if defined(_WIN32) || defined(_WIN64)
  fp = _wfsopen(fileName, L"rb", _SH_DENYWR);
#else
  fp = fopen(fileName, "rb");
#endif
  if(fp == NULL)
  {
    DebugLog("Could not open file");
    return FALSE;
  }

  if (fseek(fp, 0, SEEK_END) != 0) {
    fclose(fp);
    DebugLog("Could not fseek file");
    return FALSE;
  }

  auto sz = ftell(fp);
  if (sz < 0) {
    fclose(fp);
    return FALSE;
  }

  if (fseek(fp, 0, SEEK_SET) != 0) {
    fclose(fp);
    DebugLog("Could not fseek(set) file");
    return FALSE;
  }

#ifdef KMX_64BIT
  buf = new KMX_BYTE[sz*3];
#else
  buf = new KMX_BYTE[sz];
#endif

  if(!buf)
  {
    fclose(fp);
    DebugLog("Not allocmem");
    return FALSE;
  }
#ifdef KMX_64BIT
  filebase = buf + sz*2;
#else
  filebase = buf;
#endif

  if (fread(filebase, 1, sz, fp) < (size_t) sz) {
    fclose(fp);
    DebugLog("Could not read file");
    return FALSE;
  }

  fclose(fp);

  if(*PKMX_DWORD(filebase) != KMX_DWORD(FILEID_COMPILED))
  {
    delete buf;
    DebugLog("Invalid file - signature is invalid");
    return FALSE;
  }

  if(!VerifyKeyboard(filebase, sz)) return FALSE;

#ifdef KMX_64BIT
  kbp = CopyKeyboard(buf, filebase);
#else
  kbp = FixupKeyboard(buf, filebase, sz);
#endif

  if(!kbp) return FALSE;

  if(kbp->dwIdentifier != FILEID_COMPILED) { delete buf; DebugLog("errNotFileID"); return FALSE; }

  *lpKeyboard = kbp;

  return TRUE;
}

PKMX_WCHAR KMX_Processor::StringOffset(PKMX_BYTE base, KMX_DWORD offset)
{
  if(offset == 0) return NULL;
  return (PKMX_WCHAR)(base + offset);
}

#ifdef KMX_64BIT

/**
  CopyKeyboard will copy the data read into bufp from x86-sized structures into x64-sized structures starting at base
  * We know the base is dwFileSize * 3
  * After this function finishes, we still need to keep the original data
*/
LPKEYBOARD KMX_Processor::CopyKeyboard(PKMX_BYTE bufp, PKMX_BYTE base)
{
  PCOMP_KEYBOARD ckbp = (PCOMP_KEYBOARD) base;

  /* Copy keyboard structure */

  LPKEYBOARD kbp = (LPKEYBOARD) bufp;
  bufp += sizeof(KEYBOARD);

  kbp->dwIdentifier = ckbp->dwIdentifier;
  kbp->dwFileVersion = ckbp->dwFileVersion;
  kbp->dwCheckSum = ckbp->dwCheckSum;
  kbp->xxkbdlayout = ckbp->KeyboardID;
  kbp->IsRegistered = ckbp->IsRegistered;
  kbp->version = ckbp->version;
  kbp->cxStoreArray = ckbp->cxStoreArray;
  kbp->cxGroupArray = ckbp->cxGroupArray;
  kbp->StartGroup[0] = ckbp->StartGroup[0];
  kbp->StartGroup[1] = ckbp->StartGroup[1];
  kbp->dwFlags = ckbp->dwFlags;
  kbp->dwHotKey = ckbp->dwHotKey;

  kbp->dpStoreArray = (LPSTORE) bufp;
  bufp += sizeof(STORE) * kbp->cxStoreArray;

  kbp->dpGroupArray = (LPGROUP) bufp;
  bufp += sizeof(GROUP) * kbp->cxGroupArray;

  PCOMP_STORE csp;
  LPSTORE sp;
  KMX_DWORD i;

  for(
    csp = (PCOMP_STORE)(base + ckbp->dpStoreArray), sp = kbp->dpStoreArray, i = 0;
    i < kbp->cxStoreArray;
    i++, sp++, csp++)
  {
    sp->dwSystemID = csp->dwSystemID;
    sp->dpName = StringOffset(base, csp->dpName);
    sp->dpString = StringOffset(base, csp->dpString);
  }

  PCOMP_GROUP cgp;
  LPGROUP gp;

  for(
    cgp = (PCOMP_GROUP)(base + ckbp->dpGroupArray), gp = kbp->dpGroupArray, i = 0;
    i < kbp->cxGroupArray;
    i++, gp++, cgp++)
  {
    gp->dpName = (PKMX_WCHAR)(base + cgp->dpName);
    gp->dpKeyArray = (LPKEY) bufp;
    gp->cxKeyArray = cgp->cxKeyArray;
    bufp += sizeof(KEY) * gp->cxKeyArray;
    gp->dpMatch = StringOffset(base, cgp->dpMatch);
    gp->dpNoMatch = StringOffset(base, cgp->dpNoMatch);
    gp->fUsingKeys = cgp->fUsingKeys;

    PCOMP_KEY ckp;
    LPKEY kp;
    KMX_DWORD j;

    for(
      ckp = (PCOMP_KEY)(base + cgp->dpKeyArray), kp = gp->dpKeyArray, j = 0;
      j < gp->cxKeyArray;
      j++, kp++, ckp++)
    {
      kp->Key = ckp->Key;
      kp->Line = ckp->Line;
      kp->ShiftFlags = ckp->ShiftFlags;
      kp->dpOutput = StringOffset(base, ckp->dpOutput);
      kp->dpContext = StringOffset(base, ckp->dpContext);
    }
  }

  return kbp;
}

#else

LPKEYBOARD KMX_Processor::FixupKeyboard(PKMX_BYTE bufp, PKMX_BYTE base, KMX_DWORD dwFileSize)
{
  KMX_DWORD i, j;
  PCOMP_KEYBOARD ckbp = (PCOMP_KEYBOARD) base;
  PCOMP_GROUP cgp;
  PCOMP_STORE csp;
  PCOMP_KEY ckp;
  LPKEYBOARD kbp = (LPKEYBOARD) bufp;
  LPSTORE sp;
  LPGROUP gp;
  LPKEY kp;

  kbp->dpStoreArray = (LPSTORE) (base + ckbp->dpStoreArray);
  kbp->dpGroupArray = (LPGROUP) (base + ckbp->dpGroupArray);

  for(sp = kbp->dpStoreArray, csp = (PCOMP_STORE) sp, i = 0; i < kbp->cxStoreArray; i++, sp++, csp++)
  {
    sp->dpName = StringOffset(base, csp->dpName);
    sp->dpString = StringOffset(base, csp->dpString);
  }

  for(gp = kbp->dpGroupArray, cgp = (PCOMP_GROUP) gp, i = 0; i < kbp->cxGroupArray; i++, gp++, cgp++)
  {
    gp->dpName = StringOffset(base, cgp->dpName);
    gp->dpKeyArray = (LPKEY) (base + cgp->dpKeyArray);
    if(cgp->dpMatch != NULL) gp->dpMatch = (PKMX_WCHAR) (base + cgp->dpMatch);
    if(cgp->dpNoMatch != NULL) gp->dpNoMatch = (PKMX_WCHAR) (base + cgp->dpNoMatch);

    for(kp = gp->dpKeyArray, ckp = (PCOMP_KEY) kp, j = 0; j < gp->cxKeyArray; j++, kp++, ckp++)
    {
      kp->dpOutput = (PKMX_WCHAR) (base + ckp->dpOutput);
      kp->dpContext = (PKMX_WCHAR) (base + ckp->dpContext);
    }
  }

  return kbp;
}

#endif

KMX_BOOL KMX_Processor::VerifyChecksum(PKMX_BYTE buf, size_t sz)
{
  KMX_DWORD tempcs;
  PCOMP_KEYBOARD ckbp;

  ckbp = (PCOMP_KEYBOARD) buf;

  tempcs = ckbp->dwCheckSum;
  ckbp->dwCheckSum = 0;

  return tempcs == CalculateBufferCRC(sz, buf);
}

KMX_BOOL KMX_Processor::VerifyKeyboard(PKMX_BYTE filebase, size_t sz)
{
  KMX_DWORD i;
  PCOMP_KEYBOARD ckbp = (PCOMP_KEYBOARD) filebase;
  PCOMP_STORE csp;

  /* Check file version */

  if(ckbp->dwFileVersion < VERSION_MIN ||
     ckbp->dwFileVersion > VERSION_MAX)
  {
    /* Old or new version -- identify the desired program version */
    if(VerifyChecksum(filebase, sz))
    {
      for(csp = (PCOMP_STORE)(filebase + ckbp->dpStoreArray), i = 0; i < ckbp->cxStoreArray; i++, csp++)
        if(csp->dwSystemID == TSS_COMPILEDVERSION)
        {
          if(csp->dpString == 0)
            DebugLog("errWrongFileVersion:NULL");
          else
            DebugLog("errWrongFileVersion:%10.10ls", StringOffset(filebase, csp->dpString));
          return FALSE;
        }
    }
    DebugLog("errWrongFileVersion");
    return FALSE;
  }

  if(!VerifyChecksum(filebase, sz)) { DebugLog("errBadChecksum"); return FALSE; }

  return TRUE;
}