///////////////////////////////////////////////////////////////////////////////
//                                                                           //
// Unicode.cpp                                                               //
// Copyright (C) Microsoft Corporation. All rights reserved.                 //
// This file is distributed under the University of Illinois Open Source     //
// License. See LICENSE.TXT for details.                                     //
//                                                                           //
// Provides utitlity functions to work with Unicode and other encodings.     //
//                                                                           //
///////////////////////////////////////////////////////////////////////////////

#include "dxc/Support/Global.h"
#include <specstrings.h>
#include "dxc/Support/Unicode.h"
#include <string>

#include "dxc/Support/WinIncludes.h"


namespace Unicode {

_Success_(return != false)
bool UTF16ToEncodedString(_In_z_ const wchar_t* text, DWORD cp, DWORD flags, _Inout_ std::string* pValue, _Out_opt_ bool* lossy) {
  BOOL usedDefaultChar;
  LPBOOL pUsedDefaultChar = (lossy == nullptr) ? nullptr : &usedDefaultChar;
  size_t cUTF16 = wcslen(text);
  if (lossy != nullptr) *lossy = false;

  // Handle zero-length as a special case; it's a special value to indicate errors in WideCharToMultiByte.
  if (cUTF16 == 0) {
    pValue->resize(0);
    DXASSERT(lossy == nullptr || *lossy == false, "otherwise earlier initialization in this function was updated");
    return true;
  }

  int cbUTF8 = ::WideCharToMultiByte(cp, flags, text, cUTF16, nullptr, 0, nullptr, pUsedDefaultChar);
  if (cbUTF8 == 0)
    return false;

  pValue->resize(cbUTF8);

  cbUTF8 = ::WideCharToMultiByte(cp, flags, text, cUTF16, &(*pValue)[0], pValue->size(), nullptr, pUsedDefaultChar);
  DXASSERT(cbUTF8 > 0, "otherwise contents have changed");
  DXASSERT((*pValue)[pValue->size()] == '\0', "otherwise string didn't null-terminate after resize() call");

  if (lossy != nullptr) *lossy = usedDefaultChar;
  return true;
}

_Use_decl_annotations_
bool UTF8ToUTF16String(const char *pUTF8, std::wstring *pUTF16) {
  size_t cbUTF8 = (pUTF8 == nullptr) ? 0 : strlen(pUTF8);
  return UTF8ToUTF16String(pUTF8, cbUTF8, pUTF16);
}

_Use_decl_annotations_
bool UTF8ToUTF16String(const char *pUTF8, size_t cbUTF8, std::wstring *pUTF16) {
  DXASSERT_NOMSG(pUTF16 != nullptr);

  // Handle zero-length as a special case; it's a special value to indicate
  // errors in MultiByteToWideChar.
  if (cbUTF8 == 0) {
    pUTF16->resize(0);
    return true;
  }

  int cUTF16 = ::MultiByteToWideChar(CP_UTF8, MB_ERR_INVALID_CHARS, pUTF8,
                                     cbUTF8, nullptr, 0);
  if (cUTF16 == 0)
    return false;

  pUTF16->resize(cUTF16);

  cUTF16 = ::MultiByteToWideChar(CP_UTF8, MB_ERR_INVALID_CHARS, pUTF8, cbUTF8,
                                 &(*pUTF16)[0], pUTF16->size());
  DXASSERT(cUTF16 > 0, "otherwise contents changed");
  DXASSERT((*pUTF16)[pUTF16->size()] == L'\0',
           "otherwise wstring didn't null-terminate after resize() call");
  return true;
}

std::wstring UTF8ToUTF16StringOrThrow(_In_z_ const char *pUTF8) {
  std::wstring result;
  if (!UTF8ToUTF16String(pUTF8, &result)) {
    throw hlsl::Exception(DXC_E_STRING_ENCODING_FAILED);
  }
  return result;
}

_Use_decl_annotations_
bool UTF8ToConsoleString(_In_z_ const char* text, _Inout_ std::string* pValue, _Out_opt_ bool* lossy) {
  DXASSERT_NOMSG(text != nullptr);
  DXASSERT_NOMSG(pValue != nullptr);
  std::wstring text16;
  if (lossy != nullptr) *lossy = false;
  if (!UTF8ToUTF16String(text, &text16)) {
    return false;
  }
  return UTF16ToConsoleString(text16.c_str(), pValue, lossy);
}

_Use_decl_annotations_
bool UTF16ToConsoleString(const wchar_t* text, std::string* pValue, bool* lossy) {
  DXASSERT_NOMSG(text != nullptr);
  DXASSERT_NOMSG(pValue != nullptr);
  UINT cp = GetConsoleOutputCP();
  return UTF16ToEncodedString(text, cp, 0, pValue, lossy);
}

_Use_decl_annotations_
bool UTF16ToUTF8String(const wchar_t *pUTF16, std::string *pUTF8) {
  DXASSERT_NOMSG(pUTF16 != nullptr);
  DXASSERT_NOMSG(pUTF8 != nullptr);
  return UTF16ToEncodedString(pUTF16, CP_UTF8, 0, pUTF8, nullptr);
}

std::string UTF16ToUTF8StringOrThrow(_In_z_ const wchar_t *pUTF16) {
  std::string result;
  if (!UTF16ToUTF8String(pUTF16, &result)) {
    throw hlsl::Exception(DXC_E_STRING_ENCODING_FAILED);
  }
  return result;
}

_Use_decl_annotations_
bool UTF8BufferToUTF16Buffer(const char *pUTF8, int cbUTF8, wchar_t **ppUTF16, size_t *pcUTF16) throw() {
  *ppUTF16 = nullptr;
  *pcUTF16 = 0;

  if (cbUTF8 == 0 || (cbUTF8 == -1 && *pUTF8 == '\0')) {
    *ppUTF16 = new (std::nothrow) wchar_t[1];
    if (*ppUTF16 == nullptr)
      return false;
    (*ppUTF16)[0] = L'\0';
    *pcUTF16 = 1;
    return true;
  }

  int c = ::MultiByteToWideChar(CP_UTF8, MB_ERR_INVALID_CHARS, pUTF8, cbUTF8, nullptr, 0);
  if (c == 0)
    return false;

  // add space for null-terminator if we're not accounting for it
  if (cbUTF8 != -1)
    c += 1;

  wchar_t *p = new (std::nothrow) wchar_t[c];

  if (p == nullptr)
    return false;

  int converted = ::MultiByteToWideChar(CP_UTF8, MB_ERR_INVALID_CHARS,
                            pUTF8, cbUTF8,
                            p, c);
  (void)converted;
  DXASSERT(converted > 0, "otherwise contents have changed");
  p[c - 1] = L'\0';

  *ppUTF16 = p;
  *pcUTF16 = c;

  return true;
}

_Use_decl_annotations_
bool UTF16BufferToUTF8Buffer(const wchar_t *pUTF16, int cUTF16, char **ppUTF8, size_t *pcUTF8) throw() {
  *ppUTF8 = nullptr;
  *pcUTF8 = 0;

  if (cUTF16 == 0 || (cUTF16 == -1 && *pUTF16 == '\0')) {
    *ppUTF8 = new (std::nothrow) char[1];
    if (*ppUTF8 == nullptr)
      return false;
    (*ppUTF8)[0] = '\0';
    *pcUTF8 = 1;
    return true;
  }

  int c1 = ::WideCharToMultiByte(CP_UTF8, // code page
                                 0,       // flags
                                 pUTF16,  // string to convert
                                 cUTF16,  // size, in chars, of string to convert
                                 nullptr, // output buffer
                                 0,       // size of output buffer
                                 nullptr, nullptr);
  if (c1 == 0)
    return false;

  // add space for null-terminator if we're not accounting for it
  if (cUTF16 != -1)
    c1 += 1;

  char *p = new (std::nothrow) char[c1];
  if (p == nullptr)
    return false;

  int converted = ::WideCharToMultiByte(CP_UTF8, 0,
                            pUTF16, cUTF16,
                            p, c1,
                            nullptr, nullptr);
  (void)converted;
  DXASSERT(converted > 0, "otherwise contents have changed");
  p[c1 - 1] = '\0';

  *ppUTF8 = p;
  *pcUTF8 = c1;

  return true;
}

template<typename TChar>
static
bool IsStarMatchT(const TChar *pMask, size_t maskLen, const TChar *pName, size_t nameLen, TChar star) {
  if (maskLen == 0 && nameLen == 0) {
    return true;
  }
  if (maskLen == 0 || nameLen == 0) {
    return false;
  }

  if (pMask[maskLen - 1] == star) {
    // Prefix match.
    if (maskLen == 1) { // For just '*', everything is a match.
      return true;
    }
    --maskLen;
    if (maskLen > nameLen) { // Mask is longer than name, can't be a match.
      return false;
    }
    return 0 == memcmp(pMask, pName, sizeof(TChar) * maskLen);
  }
  else {
    // Exact match.
    if (nameLen != maskLen) {
      return false;
    }
    return 0 == memcmp(pMask, pName, sizeof(TChar) * nameLen);
  }
}

_Use_decl_annotations_
bool IsStarMatchUTF8(const char *pMask, size_t maskLen, const char *pName, size_t nameLen) {
  return IsStarMatchT<char>(pMask, maskLen, pName, nameLen, '*');
}

_Use_decl_annotations_
bool IsStarMatchUTF16(const wchar_t *pMask, size_t maskLen, const wchar_t *pName, size_t nameLen) {
  return IsStarMatchT<wchar_t>(pMask, maskLen, pName, nameLen, L'*');
}


}  // namespace Unicode