std::string ReadTextInput()

in auth/testapp/src/ios/ios_main.mm [120:165]
38 lines of code
4 McCabe index (conditional complexity)

std::string ReadTextInput(const char *title, const char *message, const char *placeholder) {
  assert(g_view_controller);
  // This should only be called from a background thread, as it blocks, which will mess up the main
  // thread.
  assert(![NSThread isMainThread]);

  g_view_controller.textEntryResult = nil;

  dispatch_async(dispatch_get_main_queue(), ^{
    UIAlertController *alertController =
        [UIAlertController alertControllerWithTitle:@(title)
                                            message:@(message)
                                     preferredStyle:UIAlertControllerStyleAlert];
    [alertController addTextFieldWithConfigurationHandler:^(UITextField *_Nonnull textField) {
      textField.placeholder = @(placeholder);
    }];
    UIAlertAction *confirmAction = [UIAlertAction
        actionWithTitle:@"OK"
                  style:UIAlertActionStyleDefault
                handler:^(UIAlertAction *_Nonnull action) {
                  g_view_controller.textEntryResult = alertController.textFields.firstObject.text;
                }];
    [alertController addAction:confirmAction];
    UIAlertAction *cancelAction = [UIAlertAction actionWithTitle:@"Cancel"
                                                           style:UIAlertActionStyleCancel
                                                         handler:^(UIAlertAction *_Nonnull action) {
                                                           g_view_controller.textEntryResult = @"";
                                                         }];
    [alertController addAction:cancelAction];
    [g_view_controller presentViewController:alertController animated:YES completion:nil];
  });

  while (true) {
    // Pause a second, waiting for the user to enter text.
    if (ProcessEvents(1000)) {
      // If this returns true, an exit was requested.
      return "";
    }
    if (g_view_controller.textEntryResult != nil) {
      // textEntryResult will be set to non-nil when a dialog button is clicked.
      std::string result = g_view_controller.textEntryResult.UTF8String;
      g_view_controller.textEntryResult = nil;  // Consume the result.
      return result;
    }
  }
}