firebase-ios-sdk/FirebaseAppDistribution/Sources/FIRAppDistributionAppDelegateInterceptor.m

// Copyright 2019 Google
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#import "FirebaseCore/Sources/Private/FirebaseCoreInternal.h"
#import "FIRAppDistributionAppDelegateInterceptor.h"
#import "FIRFADLogger+Private.h"

#import <AuthenticationServices/AuthenticationServices.h>
#import <SafariServices/SafariServices.h>
#import <UIKit/UIKit.h>

@implementation FIRAppDistributionAppDelegateInterceptor

API_AVAILABLE(ios(9.0))
SFSafariViewController *_safariVC;

API_AVAILABLE(ios(12.0))
ASWebAuthenticationSession *_webAuthenticationVC;

API_AVAILABLE(ios(11.0))
SFAuthenticationSession *_safariAuthenticationVC;

- (instancetype)init {
  self = [super init];

  self.safariHostingViewController = [[UIViewController alloc] init];

  return self;
}

+ (instancetype)sharedInstance {
  static dispatch_once_t once;
  static FIRAppDistributionAppDelegateInterceptor *sharedInstance;
  dispatch_once(&once, ^{
    sharedInstance = [[FIRAppDistributionAppDelegateInterceptor alloc] init];
  });

  return sharedInstance;
}

- (void)appDistributionRegistrationFlow:(NSURL *)URL
                         withCompletion:(void (^)(NSError *_Nullable error))completion {
  NSString *callbackURL = [NSString stringWithFormat:@"com.firebase.appdistribution.%@", [[FIRApp defaultApp] options].googleAppID];

  FIRFADInfoLog(@"Registration URL: %@", URL);
  FIRFADInfoLog(@"Callback URL: %@", callbackURL);

  if (@available(iOS 12.0, *)) {
    ASWebAuthenticationSession *authenticationVC = [[ASWebAuthenticationSession alloc]
              initWithURL:URL
        callbackURLScheme:callbackURL
        completionHandler:^(NSURL *_Nullable callbackURL, NSError *_Nullable error) {
          [self resetUIState];
          FIRFADInfoLog(@"Sign in complete using ASWebAuthenticationSession");
          // TODO (b/161538029): Map these errors to AppDistribution error codes

          completion(error);
        }];

    if (@available(iOS 13.0, *)) {
      authenticationVC.presentationContextProvider = self;
    }

    _webAuthenticationVC = authenticationVC;

    [authenticationVC start];
  } else if (@available(iOS 11.0, *)) {
    _safariAuthenticationVC = [[SFAuthenticationSession alloc]
              initWithURL:URL
        callbackURLScheme:callbackURL
        completionHandler:^(NSURL *_Nullable callbackURL, NSError *_Nullable error) {
          [self resetUIState];
          FIRFADInfoLog(@"Sign in complete using SFAuthenticationSession");
          // TODO (b/161538029): Map these errors to AppDistribution error codes

          completion(error);
        }];

    [_safariAuthenticationVC start];
  } else if (@available(iOS 9.0, *)){
    SFSafariViewController *safariVC = [[SFSafariViewController alloc] initWithURL:URL];

    safariVC.delegate = self;
    _safariVC = safariVC;
    [self->_safariHostingViewController presentViewController:safariVC animated:YES completion:nil];
    self.registrationFlowCompletion = completion;
  }
}

- (void)showUIAlert:(UIAlertController *)alertController {
  [self initializeUIState];
  [self.window.rootViewController presentViewController:alertController
                                               animated:YES
                                             completion:nil];
}

- (BOOL)application:(UIApplication *)application
            openURL:(NSURL *)URL
            options:(NSDictionary<NSString *, id> *)options {
  [self registrationFlowCompletion];
  [self resetUIState];
  return NO;
}

- (void)initializeUIState {
  if (self.window) {
    return;
  }
  // Create an empty window + viewController to host the Safari UI.
  self.window = [[UIWindow alloc] initWithFrame:[UIScreen mainScreen].bounds];
  self.window.rootViewController = self.safariHostingViewController;

  // Place it at the highest level within the stack.
  self.window.windowLevel = +CGFLOAT_MAX;

  // Run it.
  [self.window makeKeyAndVisible];
}

- (void)resetUIState {
  if (self.window) {
    self.window.hidden = YES;
    self.window = nil;
  }

  self.registrationFlowCompletion = nil;

  if (@available(iOS 11.0, *)) {
    _safariAuthenticationVC = nil;
  } else if (@available(iOS 12.0, *)) {
    _webAuthenticationVC = nil;
  } else if (@available(iOS 9.0, *)) {
    _safariVC = nil;
  }
}

- (void)safariViewControllerDidFinish:(SFSafariViewController *)controller NS_AVAILABLE_IOS(9.0) {
  [self resetUIState];
}

- (ASPresentationAnchor)presentationAnchorForWebAuthenticationSession:
    (ASWebAuthenticationSession *)session API_AVAILABLE(ios(13.0)) {
  return self.safariHostingViewController.view.window;
}

@end