// SPDX-FileCopyrightText: (c) 2024 Ilya Andreev <bugdealer@icloud.com>

// SPDX-License-Identifier: MIT

#include "abi.hpp"

#include <filesystem>

#include <string_view>

#include <system_error>

#ifdef _WIN32

#define UNICODE

#include <Windows.h>

#include <array>

#include <cwchar>

#else

#include <cerrno>

#include <unistd.h>

#endif

namespace tmp::detail {

namespace {

namespace fs = std::filesystem;

/// Checks if the given prefix is valid to attach to a temporary directory name

/// @param prefix The prefix to check validity for

/// @returns `true` if the prefix is valid, `false` otherwise

bool is_prefix_valid(const fs::path& prefix) {

// We also need to check that the prefix does not contain a root path

// because of how path concatenation works in C++

return prefix.empty() || (++prefix.begin() == prefix.end() &&

prefix.is_relative() && !prefix.has_root_path());

}

#ifdef _WIN32

/// Creates a temporary path with the given prefix

/// @note prefix must be valid

/// @param prefix A prefix to attach to the path pattern

/// @returns A unique temporary path

fs::path make_path(std::string_view prefix) {

GUID guid;

CoCreateGuid(&guid);

constexpr static std::size_t CHARS_IN_GUID = 39;

std::array name = std::array<wchar_t, CHARS_IN_GUID>();

const wchar_t* format =

prefix.empty() ? L"%08X-%04X-%04X-%02X%02X-%02X%02X%02X%02X%02X%02X"

: L".%08X-%04X-%04X-%02X%02X-%02X%02X%02X%02X%02X%02X";

swprintf(name.data(), name.size(), format, guid.Data1, guid.Data2, guid.Data3,

guid.Data4[0], guid.Data4[1], guid.Data4[2], guid.Data4[3],

guid.Data4[4], guid.Data4[5], guid.Data4[6], guid.Data4[7]);

fs::path path = fs::temp_directory_path() / prefix;

path += name.data();

return path;

}

#endif

} // namespace

/// Creates a temporary directory in the current user's temporary directory

/// @param prefix A prefix to attach to the temporary directory name

/// @returns A path to the created temporary directory

/// @throws fs::filesystem_error if cannot create a temporary directory

/// @throws std::invalid_argument if the prefix contains a directory separator

fs::path create_directory(std::string_view prefix) {

if (!is_prefix_valid(prefix)) {

throw std::invalid_argument("Cannot create a temporary directory: "

"prefix cannot contain a directory separator");

}

std::error_code ec;

#ifdef _WIN32

fs::path path = make_path(prefix);

if (!CreateDirectory(path.c_str(), nullptr)) {

ec = std::error_code(GetLastError(), std::system_category());

}

#else

std::string path = fs::temp_directory_path() / prefix;

path += prefix.empty() ? "XXXXXX" : ".XXXXXX";

if (mkdtemp(path.data()) == nullptr) {

ec = std::error_code(errno, std::system_category());

}

#endif

if (ec) {

throw fs::filesystem_error("Cannot create a temporary directory", ec);

}

return fs::canonical(path);

}

} // namespace tmp::detail