public async Task <IReadOnlyDictionary <Guid, MediaThumbnail> > GetThumbnailsByMediaIdsAsync(
IEnumerable <Guid> mediaIds,
ThumbnailSizeName size,
CancellationToken cancellationToken)
{
FilterDefinition <Media> filter = Builders <Media> .Filter
.In(x => x.Id, mediaIds.ToList());
filter = filter & Builders <Media> .Filter.ElemMatch(x =>
x.Thumbnails,
Builders <MediaThumbnail> .Filter.Eq(t => t.Size, size));
List <Media> medias = await _mediaStoreContext.Medias.Find(filter)
.ToListAsync(cancellationToken);
var result = new Dictionary <Guid, MediaThumbnail>();
foreach (Media media in medias)
{
MediaThumbnail?thumb = media !.Thumbnails !.Where(x =>
x.Size == size &&
x.Format == "webp")
.FirstOrDefault();
if (thumb != null)
{
thumb.Data = await Thumbnails.GetAsync(thumb.Id, cancellationToken);
result.Add(media.Id, thumb);
}
}
return(result);
}
