#include <colorer/strings/legacy/CString.h>
#include <colorer/strings/legacy/Encodings.h>
#include <colorer/strings/legacy/StringExceptions.h>
#include <colorer/strings/legacy/x_encodings.h>
#include <cstring>

#ifndef WIN32
#define STRCMP strcasecmp
#else
#define STRCMP _stricmp
#endif

const int Encodings::ENC_UTF8_BOM    = 0xBFBBEF;
const int Encodings::ENC_UTF16_BOM   = 0xFEFF;
const int Encodings::ENC_UTF16BE_BOM = 0xFFFE;
const int Encodings::ENC_UTF32_BOM   = 0x0000FEFF;
const int Encodings::ENC_UTF32BE_BOM = 0xFFFE0000;

const int Encodings::ENC_UTF32BE = (-6);
const int Encodings::ENC_UTF32   = (-5);
const int Encodings::ENC_UTF16BE = (-4);
const int Encodings::ENC_UTF16   = (-3);
const int Encodings::ENC_UTF8    = (-2);


#define ENC_UTF8_BOM    ((byte*)&Encodings::ENC_UTF8_BOM)
#define ENC_UTF16_BOM   ((byte*)&Encodings::ENC_UTF16_BOM)
#define ENC_UTF16BE_BOM ((byte*)&Encodings::ENC_UTF16BE_BOM)
#define ENC_UTF32_BOM   ((byte*)&Encodings::ENC_UTF32_BOM)
#define ENC_UTF32BE_BOM ((byte*)&Encodings::ENC_UTF32BE_BOM)
static byte* bomArray[5] = { ENC_UTF8_BOM, ENC_UTF16_BOM, ENC_UTF16BE_BOM, ENC_UTF32_BOM, ENC_UTF32BE_BOM };
static int bomArraySize[5] = { 3, 2, 2, 4, 4 };

byte* Encodings::getEncodingBOM(int encoding)
{
  if (encoding >= -1 || encoding < -6) throw UnsupportedEncodingException("getEncodingBOM was called for bad encoding");
  return bomArray[-encoding - 2];
}

int Encodings::getEncodingBOMSize(int encoding)
{
  if (encoding >= -1 || encoding < -6) throw UnsupportedEncodingException("getEncodingBOM was called for bad encoding");
  return bomArraySize[-encoding - 2];
}

int Encodings::isMultibyteEncoding(int encoding)
{
  return (encoding < -1);
}

int Encodings::getEncodingIndex(const char* enc)
{
  if (!enc) return -1;
  for (auto & arr_idxEncoding : arr_idxEncodings)
    if (!STRCMP(arr_idxEncoding.name, enc)) {
      return arr_idxEncoding.pos;
    }
  return -1;
}

const char* Encodings::getEncodingName(int enc)
{
  if (enc >= encNamesNum || enc < -6 || enc == -1) return nullptr;
  for (auto & arr_idxEncoding : arr_idxEncodings)
    if (arr_idxEncoding.pos == enc)
      return arr_idxEncoding.name;
  return nullptr;
}

int Encodings::getEncodingNamesNum()
{
  return encNamesNum;
}

int Encodings::getDefaultEncodingIndex()
{
  return defEncodingIdx;
}

const char* Encodings::getDefaultEncodingName()
{
  return defEncoding;
}

int Encodings::toUTF8Bytes(wchar wc, byte* dest)
{
  return toBytes(ENC_UTF8,wc,dest);
}

int Encodings::toBytes(int encoding, wchar wc, byte* dest)
{
  if (encoding < -6 || encoding == -1 || encoding >= encNamesNum)
    throw UnsupportedEncodingException(UnicodeString(encoding));
  if (encoding >= 0) {
    dest[0] = TO_CHAR(encoding, wc);
    return 1;
  }
  if (encoding == ENC_UTF8) {
    int dpos = 0;
    if (wc <= 0x7F) {
      dest[dpos] = wc & 0x7F;
    }
    if (wc > 0x7F && wc <= 0x7FF) {
      dest[dpos] =(byte)(0xC0 + (wc >> 6));
      dpos++;
      dest[dpos] = 0x80 + (wc & 0x3F);
    }
    if (wc > 0x7FF && wc <= 0xFFFF) {
      dest[dpos] = 0xE0 + (wc >> 12);
      dpos++;
      dest[dpos] = 0x80 + ((wc >> 6) & 0x3F);
      dpos++;
      dest[dpos] = 0x80 + (wc & 0x3F);
    }
    if (wc > 0xFFFF) {
      dest[dpos] = 0xF0 + (wc >> 14);
      dpos++;
      dest[dpos] = 0x80 + ((wc >> 12) & 0x3F);
      dpos++;
      dest[dpos] = 0x80 + ((wc >> 6) & 0x3F);
      dpos++;
      dest[dpos] = 0x80 + (wc & 0x3F);
    }
    return dpos + 1;
  }
  if (encoding == ENC_UTF16) {
    dest[0] = wc & 0xFF;
    dest[1] = (wc >> 8) & 0xFF;
    return 2;
  }
  if (encoding == ENC_UTF16BE) {
    dest[1] = wc & 0xFF;
    dest[0] = (wc >> 8) & 0xFF;
    return 2;
  }
#if (__WCHAR_MAX__ > 0xffff) // impossible for 16-bit wchar
  if (encoding == ENC_UTF32) {
    dest[0] = wc & 0xFF;
    dest[1] = (wc >> 8) & 0xFF;
    dest[2] = (wc >> 16) & 0xFF;
    dest[3] = (wc >> 14) & 0xFF;
    return 4;
  }

  if (encoding == ENC_UTF32BE) {
    dest[3] = wc & 0xFF;
    dest[2] = (wc >> 8) & 0xFF;
    dest[1] = (wc >> 16) & 0xFF;
    dest[0] = (wc >> 14) & 0xFF;
    return 4;
  }
#endif
  throw UnsupportedEncodingException(UnicodeString(encoding));
}

// no checks for encoding index validness!!!!
char Encodings::toChar(int eidx, wchar c)
{
//  if (eidx < 0 || eidx >= encNamesNum) throw UnsupportedEncodingException(SString(eidx));
  return TO_CHAR(eidx, c);
}

wchar Encodings::toWChar(int eidx, char c)
{
//  if (eidx < 0 || eidx >= encNamesNum) throw UnsupportedEncodingException(SString(eidx));
  return TO_WCHAR(eidx, c);
}

uUnicodeString Encodings::toUnicodeString(char* data, int32_t len)
{
  // TODO change ENC_UTF8 to detect
  return std::make_unique<UnicodeString>(data, len, Encodings::ENC_UTF8);
}

uUnicodeString Encodings::fromUTF8(char* data, int32_t len)
{
  return std::make_unique<UnicodeString>(data, len, Encodings::ENC_UTF8);
}


