/// <summary>
/// Method to add news to multiple tags
/// </summary>
/// <param name="newsId">news id</param>
/// <param name="tags">list of tag names</param>
/// <returns></returns>
public async Task AddToTagsAsync(Guid newsId, IEnumerable <string> tags)
{
if (tags == null)
{
throw new ArgumentNullException(nameof(tags));
}
var news = await newsRepository.GetAsync(newsId);
if (news == null)
{
throw new InvalidOperationException($"UserId not found. No user with this id found {newsId}.");
}
var newsTags = await newsRepository.GetTagsAsync(news);
foreach (var tag in tags)
{
if (newsTags.Contains(tag))
{
throw new ArgumentException("News already has tag. Error when a news is already has a tag");
}
await newsRepository.AddToTagAsync(news, tag);
}
await newsRepository.EditAsync(news);
}