// Copyright (c) 2012 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.

#ifndef CHROME_BROWSER_EXTENSIONS_API_API_FUNCTION_H_
#define CHROME_BROWSER_EXTENSIONS_API_API_FUNCTION_H_
#pragma once

#include "chrome/browser/extensions/extension_function.h"
#include "chrome/browser/extensions/api/api_resource.h"

namespace extensions {

class APIResourceController;
class APIResourceEventNotifier;

// AsyncIOAPIFunction provides convenient thread management for APIs that
// need to do essentially all their work on the IO thread.
class AsyncIOAPIFunction : public AsyncExtensionFunction {
 protected:
  // Set up for work (e.g., validate arguments). Guaranteed to happen on UI
  // thread.
  virtual bool Prepare() = 0;

  // Do actual work. Guaranteed to happen on IO thread.
  virtual void Work() = 0;

  // Respond. Guaranteed to happen on UI thread.
  virtual bool Respond() = 0;

  // Looks for a kSrcId key that might have been added to a create method's
  // options object.
  int ExtractSrcId(size_t argument_position);

  // Utility.
  APIResourceEventNotifier* CreateEventNotifier(int src_id);

  // Access to the controller singleton.
  APIResourceController* controller();

  virtual bool RunImpl() OVERRIDE;

 private:
  void WorkOnIOThread();
  void RespondOnUIThread();
};

}  // namespace extensions

#endif  // CHROME_BROWSER_EXTENSIONS_API_API_FUNCTION_H_