// Copyright (c) 2011 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "extensions/browser/file_reader.h"

#include "base/bind.h"
#include "base/callback_helpers.h"
#include "base/files/file_util.h"
#include "base/threading/thread_task_runner_handle.h"
#include "extensions/browser/extension_file_task_runner.h"

FileReader::FileReader(const extensions::ExtensionResource& resource,
                       OptionalFileSequenceTask optional_file_sequence_task,
                       DoneCallback done_callback)
    : resource_(resource),
      optional_file_sequence_task_(std::move(optional_file_sequence_task)),
      done_callback_(std::move(done_callback)),
      origin_task_runner_(base::ThreadTaskRunnerHandle::Get()) {}

void FileReader::Start() {
  extensions::GetExtensionFileTaskRunner()->PostTask(
      FROM_HERE, base::Bind(&FileReader::ReadFileOnFileSequence, this));
}

FileReader::~FileReader() {}

void FileReader::ReadFileOnFileSequence() {
  DCHECK(
      extensions::GetExtensionFileTaskRunner()->RunsTasksInCurrentSequence());

  std::unique_ptr<std::string> data(new std::string());
  bool success = base::ReadFileToString(resource_.GetFilePath(), data.get());

  if (optional_file_sequence_task_) {
    if (success)
      std::move(optional_file_sequence_task_).Run(data.get());
    else
      optional_file_sequence_task_.Reset();
  }

  origin_task_runner_->PostTask(
      FROM_HERE,
      base::BindOnce(std::move(done_callback_), success, std::move(data)));
}