// 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.

#ifndef FLUTTER_FML_UNIQUE_FD_H_
#define FLUTTER_FML_UNIQUE_FD_H_

#include "flutter/fml/build_config.h"
#include "flutter/fml/unique_object.h"

#if OS_WIN
#include <windows.h>
#else  // OS_WIN
#include <dirent.h>
#include <unistd.h>
#endif  // OS_WIN

namespace fml {
namespace internal {

#if OS_WIN

namespace os_win {

struct UniqueFDTraits {
  static HANDLE InvalidValue() { return INVALID_HANDLE_VALUE; }
  static bool IsValid(HANDLE value) { return value != InvalidValue(); }
  static void Free(HANDLE fd);
};

}  // namespace os_win

#else  // OS_WIN

namespace os_unix {

struct UniqueFDTraits {
  static int InvalidValue() { return -1; }
  static bool IsValid(int value) { return value >= 0; }
  static void Free(int fd);
};

struct UniqueDirTraits {
  static DIR* InvalidValue() { return nullptr; }
  static bool IsValid(DIR* value) { return value != nullptr; }
  static void Free(DIR* dir);
};

}  // namespace os_unix

#endif  // OS_WIN

}  // namespace internal

#if OS_WIN

using UniqueFD = UniqueObject<HANDLE, internal::os_win::UniqueFDTraits>;

#else  // OS_WIN

using UniqueFD = UniqueObject<int, internal::os_unix::UniqueFDTraits>;
using UniqueDir = UniqueObject<DIR*, internal::os_unix::UniqueDirTraits>;

#endif  // OS_WIN

}  // namespace fml

#endif  // FLUTTER_FML_UNIQUE_FD_H_