exiv2/src/helper_functions.hpp

// SPDX-License-Identifier: GPL-2.0-or-later

#ifndef HELPER_FUNCTIONS_HPP
#define HELPER_FUNCTIONS_HPP

#include <string>
#include "basicio.hpp"
#include "types.hpp"
/*!
  @brief Convert a (potentially not null terminated) array into a
  std::string.

  Convert a C style string that may or may not be null terminated safely
  into a std::string. The string's termination is either set at the first \0
  or after data_length characters.

  @param[in] data  A c-string from which the std::string shall be
      constructed. Does not need to be null terminated.
  @param[in] data_length  An upper bound for the string length (must be at most
      the allocated length of `buffer`). If no null terminator is found in data,
      then the resulting std::string will be null terminated at `data_length`.

 */
std::string string_from_unterminated(const char* data, size_t data_length);

namespace Exiv2 {

static constexpr size_t BYTE = 0x1;
static constexpr size_t WCHAR = 0x2;
static constexpr size_t WORD = 0X2;
static constexpr size_t DWORD = 0x4;
static constexpr size_t QWORD = 0x8;
static constexpr size_t GUID = 0x10;

// @brief

/*!
    @brief The function utf16ToUtf8 takes a wide string wstr as input and converts it to a narrow string
    The conversion is performed using the std::wstring_convert class template and a std::codecvt_utf8 facet, which
    implements conversion between UTF-8 and wide characters.
    @param wstr : wide string
    @return Returns std::string object
*/
std::string utf16ToUtf8(const std::wstring& wstr);

[[nodiscard]] uint64_t readQWORDTag(Exiv2::BasicIo::UniquePtr& io);

[[nodiscard]] uint32_t readDWORDTag(Exiv2::BasicIo::UniquePtr& io);

[[nodiscard]] uint16_t readWORDTag(Exiv2::BasicIo::UniquePtr& io);

[[nodiscard]] std::string readStringWcharTag(Exiv2::BasicIo::UniquePtr& io, size_t length);

[[nodiscard]] std::string readStringTag(Exiv2::BasicIo::UniquePtr& io, size_t length = DWORD);

/*!
  @brief Calculates Aspect Ratio of a video
 */
[[nodiscard]] std::string getAspectRatio(size_t width, size_t height);

}  // namespace Exiv2
#endif  // HELPER_FUNCTIONS_HPP