// Copyright 2023 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "chrome/services/file_util/public/cpp/temporary_file_getter.h"

#include "build/build_config.h"

#include "base/files/file_util.h"
#include "base/task/thread_pool.h"

namespace {

constexpr int kMaxNumberOfFilesAllowed = 10;

base::File TemporaryFileGetterHelper(int num_files_requested) {
  if (num_files_requested > kMaxNumberOfFilesAllowed) {
    return base::File();
  }

  base::FilePath temp_dir;
  if (!base::GetTempDir(&temp_dir)) {
    return base::File();
  }

  base::FilePath temp_path;
  base::File temp_file = base::CreateAndOpenTemporaryFileInDir(
      temp_dir, &temp_path,
      base::File::FLAG_WIN_TEMPORARY | base::File::FLAG_DELETE_ON_CLOSE);
  if (!temp_file.IsValid()) {
    return base::File();
  }

#if !BUILDFLAG(IS_WIN)
  // CreateAndOpenTemporaryFileInDir delegates deletion to the caller on POSIX.
  // We unlink the file immediately after creation to ensure it is deleted even
  // if the process crashes, while keeping the file descriptor open for use.
  base::DeleteFile(temp_path);
#endif

  return temp_file;
}
}  // namespace

TemporaryFileGetter::TemporaryFileGetter() = default;

TemporaryFileGetter::~TemporaryFileGetter() = default;
void TemporaryFileGetter::RequestTemporaryFile(
    RequestTemporaryFileCallback callback) {
  num_files_requested_++;
  base::ThreadPool::PostTaskAndReplyWithResult(
      FROM_HERE, {base::MayBlock()},
      base::BindOnce(&TemporaryFileGetterHelper, num_files_requested_),
      std::move(callback));
}