// Copyright 2013 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "flutter/shell/platform/windows/string_conversion.h"

#include <Windows.h>

namespace flutter {

std::string Utf8FromUtf16(const std::wstring_view utf16_string) {
  if (utf16_string.empty()) {
    return std::string();
  }
  int target_length = ::WideCharToMultiByte(
      CP_UTF8, WC_ERR_INVALID_CHARS, utf16_string.data(),
      static_cast<int>(utf16_string.length()), nullptr, 0, nullptr, nullptr);
  if (target_length == 0) {
    return std::string();
  }
  std::string utf8_string;
  utf8_string.resize(target_length);
  int converted_length = ::WideCharToMultiByte(
      CP_UTF8, WC_ERR_INVALID_CHARS, utf16_string.data(),
      static_cast<int>(utf16_string.length()), utf8_string.data(),
      target_length, nullptr, nullptr);
  if (converted_length == 0) {
    return std::string();
  }
  return utf8_string;
}

std::wstring Utf16FromUtf8(const std::string_view utf8_string) {
  if (utf8_string.empty()) {
    return std::wstring();
  }
  int target_length =
      ::MultiByteToWideChar(CP_UTF8, MB_ERR_INVALID_CHARS, utf8_string.data(),
                            static_cast<int>(utf8_string.length()), nullptr, 0);
  if (target_length == 0) {
    return std::wstring();
  }
  std::wstring utf16_string;
  utf16_string.resize(target_length);
  int converted_length =
      ::MultiByteToWideChar(CP_UTF8, MB_ERR_INVALID_CHARS, utf8_string.data(),
                            static_cast<int>(utf8_string.length()),
                            utf16_string.data(), target_length);
  if (converted_length == 0) {
    return std::wstring();
  }
  return utf16_string;
}

}  // namespace flutter