// 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.

// Defines the Geolocation access token store, and associated factory function.
// An access token store is responsible for providing the API to persist
// access tokens, one at a time, and to load them back on mass.
// The API is a little more complex than one might wish, due to the need for
// prefs access to happen asynchronously on the UI thread.
// This API is provided as abstract base classes to allow mocking and testing
// of clients, without dependency on browser process singleton objects etc.

#ifndef CONTENT_BROWSER_GEOLOCATION_ACCESS_TOKEN_STORE_H_
#define CONTENT_BROWSER_GEOLOCATION_ACCESS_TOKEN_STORE_H_
#pragma once

#include <map>

#include "base/callback_old.h"
#include "base/memory/ref_counted.h"
#include "base/string16.h"
#include "content/browser/cancelable_request.h"
#include "content/common/content_export.h"
#include "googleurl/src/gurl.h"

class GURL;

namespace net {
class URLRequestContextGetter;
}

// Provides storage for the access token used in the network request.
class AccessTokenStore : public base::RefCountedThreadSafe<AccessTokenStore>,
                         public CancelableRequestProvider {
 public:

  // Map of server URLs to associated access token.
  typedef std::map<GURL, string16> AccessTokenSet;
  typedef Callback2<AccessTokenSet, net::URLRequestContextGetter*>::Type
      LoadAccessTokensCallbackType;
  // |callback| will be invoked once per LoadAccessTokens call, after existing
  // access tokens have been loaded from persistent store. As a convenience the
  // URLRequestContextGetter is also supplied as an argument in |callback|, as
  // in Chrome the call to obtain this must also be performed on the UI thread
  // so it is efficient to piggyback it onto this request.
  // Takes ownership of |callback|.
  // Returns a handle which can subsequently be used with CancelRequest().
  Handle LoadAccessTokens(CancelableRequestConsumerBase* consumer,
                          LoadAccessTokensCallbackType* callback);

  virtual void SaveAccessToken(
      const GURL& server_url, const string16& access_token) = 0;

 protected:
  friend class base::RefCountedThreadSafe<AccessTokenStore>;
  CONTENT_EXPORT AccessTokenStore();
  CONTENT_EXPORT virtual ~AccessTokenStore();

  virtual void DoLoadAccessTokens(
      scoped_refptr<CancelableRequest<LoadAccessTokensCallbackType> > req) = 0;

 private:
  DISALLOW_COPY_AND_ASSIGN(AccessTokenStore);
};

#endif  // CONTENT_BROWSER_GEOLOCATION_ACCESS_TOKEN_STORE_H_