public async Task AddOrUpdateAsync(IEnumerable <Tag> tags)
{
var allTags = await _tagRepository.BrowseAsync(new BrowseTags
{
Results = int.MaxValue
});
var newTags = new List <Tag>();
foreach (var tag in tags)
{
var existingTag = allTags.Value.Items.SingleOrDefault(x => x.Name == tag.Name);
if (existingTag != null)
{
continue;
}
if (newTags.Any(x => x.Name == tag.Name))
{
continue;
}
newTags.Add(tag);
}
await _tagRepository.AddManyAsync(newTags);
}