[CRD iOS] Refactor an interface for RemotingAuthorization

remoting/ios/facade/remoting_authentication.mm

-// Copyright 2017 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.
-
-#if !defined(__has_feature) || !__has_feature(objc_arc)
-#error "This file requires ARC support."
-#endif
-
-#import "remoting/ios/facade/remoting_authentication.h"
-
-#import <Foundation/Foundation.h>
-#import <Security/Security.h>
-
-#import "base/mac/bind_objc_block.h"
-#import "remoting/ios/facade/host_info.h"
-#import "remoting/ios/facade/host_list_fetcher.h"
-#import "remoting/ios/facade/ios_client_runtime_delegate.h"
-#import "remoting/ios/facade/remoting_service.h"
-#import "remoting/ios/keychain_wrapper.h"
-
-#include "base/logging.h"
-#include "base/strings/sys_string_conversions.h"
-#include "net/url_request/url_request_context_getter.h"
-#include "remoting/base/oauth_token_getter.h"
-#include "remoting/base/oauth_token_getter_impl.h"
-
-static NSString* const kCRDAuthenticatedUserEmailKey =
-    @"kCRDAuthenticatedUserEmailKey";
-
-const char kOauthRedirectUrl[] =
-    "https://chromoting-oauth.talkgadget."
-    "google.com/talkgadget/oauth/chrome-remote-desktop/dev";
-
-std::unique_ptr<remoting::OAuthTokenGetter>
-CreateOAuthTokenGetterWithAuthorizationCode(
-    const std::string& auth_code,
-    const remoting::OAuthTokenGetter::CredentialsUpdatedCallback&
-        on_credentials_update) {
-  std::unique_ptr<remoting::OAuthTokenGetter::OAuthIntermediateCredentials>
-      oauth_credentials(
-          new remoting::OAuthTokenGetter::OAuthIntermediateCredentials(
-              auth_code, /*is_service_account=*/false));
-  oauth_credentials->oauth_redirect_uri = kOauthRedirectUrl;
-
-  std::unique_ptr<remoting::OAuthTokenGetter> oauth_tokenGetter(
-      new remoting::OAuthTokenGetterImpl(
-          std::move(oauth_credentials), on_credentials_update,
-          [RemotingService SharedInstance].runtime->url_requester(),
-          /*auto_refresh=*/true));
-  return oauth_tokenGetter;
-}
-
-std::unique_ptr<remoting::OAuthTokenGetter> CreateOAuthTokenWithRefreshToken(
-    const std::string& refresh_token,
-    const std::string& email) {
-  std::unique_ptr<remoting::OAuthTokenGetter::OAuthAuthorizationCredentials>
-      oauth_credentials(
-          new remoting::OAuthTokenGetter::OAuthAuthorizationCredentials(
-              email, refresh_token, /*is_service_account=*/false));
-
-  std::unique_ptr<remoting::OAuthTokenGetter> oauth_tokenGetter(
-      new remoting::OAuthTokenGetterImpl(
-          std::move(oauth_credentials),
-          [RemotingService SharedInstance].runtime->url_requester(),
-          /*auto_refresh=*/true));
-  return oauth_tokenGetter;
-}
-
-@interface RemotingAuthentication () {
-  std::unique_ptr<remoting::OAuthTokenGetter> _tokenGetter;
-  KeychainWrapper* _keychainWrapper;
-  BOOL _firstLoadUserAttempt;
-}
-@end
-
-@implementation RemotingAuthentication
-
-@synthesize user = _user;
-@synthesize delegate = _delegate;
-
-- (instancetype)init {
-  self = [super init];
-  if (self) {
-    _keychainWrapper = [[KeychainWrapper alloc] init];
-    _user = nil;
-    _firstLoadUserAttempt = YES;
-  }
-  return self;
-}
-
-#pragma mark - Property Overrides
-
-- (UserInfo*)user {
-  if (_firstLoadUserAttempt && _user == nil) {
-    _firstLoadUserAttempt = NO;
-    [self setUser:[self loadUserInfo]];
-  }
-  return _user;
-}
-
-- (void)setUser:(UserInfo*)user {
-  _user = user;
-  [self storeUserInfo:_user];
-  [_delegate userDidUpdate:_user];
-}
-
-#pragma mark - Class Implementation
-
-- (void)authenticateWithAuthorizationCode:(NSString*)authorizationCode {
-  __weak RemotingAuthentication* weakSelf = self;
-  _tokenGetter = CreateOAuthTokenGetterWithAuthorizationCode(
-      std::string(base::SysNSStringToUTF8(authorizationCode)),
-      base::BindBlockArc(
-          ^(const std::string& user_email, const std::string& refresh_token) {
-            // TODO(nicholss): Do something with these new creds.
-            VLOG(1) << "New Creds: " << user_email << " " << refresh_token;
-            UserInfo* user = [[UserInfo alloc] init];
-            user.userEmail = base::SysUTF8ToNSString(user_email);
-            user.refreshToken = base::SysUTF8ToNSString(refresh_token);
-            [weakSelf setUser:user];
-          }));
-  // Stimulate the oAuth Token Getter to fetch and access token, this forces it
-  // to convert the authorization code into a refresh token, and saving the
-  // refresh token will happen automaticly in the above block.
-  [self callbackWithAccessToken:base::BindBlockArc(^(
-                                    remoting::OAuthTokenGetter::Status status,
-                                    const std::string& user_email,
-                                    const std::string& access_token) {
-          if (status == remoting::OAuthTokenGetter::Status::SUCCESS) {
-            VLOG(1) << "Success fetching access token from authorization code.";
-          } else {
-            LOG(ERROR)
-                << "Failed to fetch access token from authorization code. ("
-                << status << ")";
-            // TODO(nicholss): Deal with the sad path for a bad auth token.
-          }
-        })];
-}
-
-#pragma mark - Private
-
-// Provide the |refreshToken| and |email| to authenticate a user as a returning
-// user of the application.
-- (void)authenticateWithRefreshToken:(NSString*)refreshToken
-                               email:(NSString*)email {
-  _tokenGetter = CreateOAuthTokenWithRefreshToken(
-      std::string(base::SysNSStringToUTF8(refreshToken)),
-      base::SysNSStringToUTF8(email));
-}
-
-- (void)callbackWithAccessToken:
-    (const remoting::OAuthTokenGetter::TokenCallback&)onAccessToken {
-  // TODO(nicholss): Be careful here since a failure to reset onAccessToken
-  // will end up with retain cycle and memory leakage.
-  if (_tokenGetter) {
-    _tokenGetter->CallWithToken(onAccessToken);
-  }
-}
-
-- (void)logout {
-  [self storeUserInfo:nil];
-  [self setUser:nil];
-}
-
-#pragma mark - Persistence
-
-- (void)storeUserInfo:(UserInfo*)user {
-  NSUserDefaults* defaults = [NSUserDefaults standardUserDefaults];
-  if (user) {
-    [defaults setObject:user.userEmail forKey:kCRDAuthenticatedUserEmailKey];
-    // TODO(nicholss): Need to match the token with the email.
-    [_keychainWrapper setRefreshToken:user.refreshToken];
-  } else {
-    [defaults removeObjectForKey:kCRDAuthenticatedUserEmailKey];
-    [_keychainWrapper resetKeychainItem];
-  }
-  [defaults synchronize];
-}
-
-- (UserInfo*)loadUserInfo {
-  UserInfo* user = [[UserInfo alloc] init];
-  NSUserDefaults* defaults = [NSUserDefaults standardUserDefaults];
-  user.userEmail = [defaults objectForKey:kCRDAuthenticatedUserEmailKey];
-  // TODO(nicholss): Need to match the token with the email.
-  user.refreshToken = [_keychainWrapper refreshToken];
-
-  if (!user || ![user isAuthenticated]) {
-    user = nil;
-  } else {
-    [self authenticateWithRefreshToken:user.refreshToken email:user.userEmail];
-  }
-  return user;
-}
-
-@end