public class CourseSendingContentNotificationHandler : INotificationHandler<SendingContentNotification>
{
    private readonly IContentService _contentService;
    private readonly IPublishedContentQuery _publishedContentQuery;

    public CourseSendingContentNotificationHandler(IContentService contentService, IPublishedContentQuery publishedContentQuery)
    {
        _contentService = contentService;
        _publishedContentQuery = publishedContentQuery;
    }

    public void Handle(SendingContentNotification notification)
    {
        var content = notification.Content as ContentItemDisplay;

        if (content == null)
            return;

        if (content.ContentTypeAlias == "course")
        {
            var settingsContent = _contentService.GetById(GetSettingsContentId());

            if (settingsContent != null)
            {
                var masterCoursePublished = _publishedContentQuery.ContentAtRoot().FirstOrDefault(x => x.ContentType.Alias == "settings")?.DescendantOfType("courseMaster");

                if (masterCoursePublished != null)
                {
                    var masterCourse = _contentService.GetById(masterCoursePublished.Id);

                    if (masterCourse != null)
                    {

                        foreach (var variant in notification.Content.Variants)
                        {
                            // Check if variant is a 'new variant'
                            // we only want to set the default value when the content item is first created
                            if (variant.State == ContentSavedState.NotCreated)
                            {
                                // each variant has an IEnumerable of 'Tabs' (property groupings)
                                // and each of these contain an IEnumerable of `ContentPropertyDisplay` properties
                                // find the first property with alias 'publishDate'
                                var blockList = variant.Tabs.SelectMany(f => f.Properties)
                                    .FirstOrDefault(f => f.Alias.InvariantEquals("content"));
                                if (blockList is not null)
                                {
                                    var masterBlockList = masterCourse.GetValue<string>("content");

                                    BlockValue blockValue = JsonConvert.DeserializeObject<BlockValue>(masterBlockList);

                                    // set default value of the publish date property if it exists
                                    blockList.Value = masterBlockList;
                                }
                            }
                        }
                    }
                }
            }
        }
    }

    private int GetSettingsContentId()
    {
        return 1071;
    }
}