Function GetTextfile

src/textfile_gui.cpp:939–984

* Search a textfile file next to the given content. * @param type The type of the textfile to search for. * @param dir The subdirectory to search in. * @param filename The filename of the content to look for. * @return The path to the textfile, \c nullptr otherwise. */

 * @return The path to the textfile, \c nullptr otherwise.
 */
std::optional<std::string> GetTextfile(TextfileType type, Subdirectory dir, std::string_view filename)
{
	static const std::string_view prefixes[] = {
		"readme",
		"changelog",
		"license",
	};
	static_assert(lengthof(prefixes) == TFT_CONTENT_END);

	/* Only the generic text file types allowed for this function */
	if (type >= TFT_CONTENT_END) return std::nullopt;

	std::string_view prefix = prefixes[type];

	if (filename.empty()) return std::nullopt;

	auto slash = filename.find_last_of(PATHSEPCHAR);
	if (slash == std::string::npos) return std::nullopt;

	std::string_view base_path = filename.substr(0, slash + 1);

	static const std::initializer_list<const std::string_view> extensions{
		"txt",
		"md",
#if defined(WITH_ZLIB)
		"txt.gz",
		"md.gz",
#endif
#if defined(WITH_LIBLZMA)
		"txt.xz",
		"md.xz",
#endif
	};

	for (auto &extension : extensions) {
		std::string file_path = fmt::format("{}{}_{}.{}", base_path, prefix, GetCurrentLanguageIsoCode(), extension);
		if (FioCheckFileExists(file_path, dir)) return file_path;

		file_path = fmt::format("{}{}_{:.2s}.{}", base_path, prefix, GetCurrentLanguageIsoCode(), extension);
		if (FioCheckFileExists(file_path, dir)) return file_path;

		file_path = fmt::format("{}{}.{}", base_path, prefix, extension);
		if (FioCheckFileExists(file_path, dir)) return file_path;
	}
	return std::nullopt;
}