public async Task <List <ImageThumbnailGeneratingResult> > GenerateThumbnails(string imageId, string partitionKey)
{
var imageMetadataList = await _metadataStorage.GetMetadata(new List <string> {
imageId
}, partitionKey, CancellationToken.None);
if (imageMetadataList == null || !imageMetadataList.Any())
{
_logger.LogInformation(ImageNotFound, imageId);
return(null);
}
var imageMetadata = imageMetadataList[0];
imageMetadata.Thumbnails = new List <ImageThumbnail>();
_logger.LogDebug(MetadataReceived, imageMetadata.Id, imageMetadata.Width, imageMetadata.Height);
if (imageMetadata.Width <= _thumbnailTargetWidth.Last())
{
_logger.LogInformation(ImageSmallerThanTargetWidth, imageMetadata.Id, imageMetadata.Width);
return(new List <ImageThumbnailGeneratingResult>(0));
}
using var originalImageStream = await _blobStorage.DownloadImage(imageMetadata.Name, ImageSizeType.Original, CancellationToken.None);
_logger.LogDebug(ImageDownloaded, imageMetadata.Id);
StorageImageType imageType = imageMetadata.ImageType;
string mimeType = imageMetadata.MimeType;
string fileExtension = imageMetadata.FileExtension;
if (imageType == StorageImageType.BMP)
{
imageType = StorageImageType.PNG;
mimeType = PngMimeType;
fileExtension = PngFileExtension;
}
var imageStream = originalImageStream;
foreach (var targetWidth in _thumbnailTargetWidth)
{
if (targetWidth >= imageMetadata.Width)
{
continue;
}
var resizingResult = _imageResizing.Resize(imageStream, (ImageType)imageType, targetWidth);
_logger.LogDebug(ImageResized, imageMetadata.Id, resizingResult.Size);
var thumbnailImageId = _imageIdentifierProvider.GenerateUniqueId();
var thumbnailImageName = _imageIdentifierProvider.GetImageName(thumbnailImageId, fileExtension);
var uploadedBlob = await _blobStorage.UploadImage(thumbnailImageName, resizingResult.Image, ImageSizeType.Thumbnail, mimeType, CancellationToken.None);
imageMetadata.Thumbnails.Add(new ImageThumbnail
{
Id = thumbnailImageId,
Name = thumbnailImageName,
MD5Hash = uploadedBlob.MD5Hash,
DateAddedUtc = uploadedBlob.DateAdded.DateTime,
MimeType = mimeType,
Height = resizingResult.Size.Height,
Width = resizingResult.Size.Width,
SizeBytes = resizingResult.Size.Bytes
});
imageStream = resizingResult.Image;
}
imageStream.Dispose();
imageMetadata.Thumbnails.Reverse();
await _metadataStorage.SetMetadata(imageMetadata, CancellationToken.None);
_logger.LogInformation(ThumbnailsGenerated, imageMetadata.Thumbnails.Count, imageId);
return(imageMetadata.Thumbnails.Select(x => new ImageThumbnailGeneratingResult
{
Id = x.Id,
Width = x.Width,
Height = x.Height,
MimeType = x.MimeType
}).ToList());
}
private async Task <ImageMetadata> UploadImage(string imagePath, int width, int height, string contentType, ImageType imageType, string partitionKey)
{
string extension = "";
switch (imageType)
{
case ImageType.BMP:
extension = ".bmp";
break;
case ImageType.JPEG:
extension = ".jpeg";
break;
case ImageType.PNG:
extension = ".png";
break;
case ImageType.GIF:
extension = ".gif";
break;
}
await using FileStream file = OpenFileForReading(imagePath);
string imageId = Guid.NewGuid().ToString();
string imageName = imageId + extension;
var uploadImageResult = await _blobStorage.UploadImage(imageName, file, ImageSizeType.Original, contentType, CancellationToken.None);
var imageMetadata = new ImageMetadata
{
Id = imageId,
Name = imageName,
DateAddedUtc = uploadImageResult.DateAdded.DateTime,
Height = height,
Width = width,
MD5Hash = uploadImageResult.MD5Hash,
SizeBytes = file.Length,
MimeType = contentType,
ImageType = imageType,
PartitionKey = partitionKey
};
await _metadataStorage.SetMetadata(imageMetadata, CancellationToken.None);
return(imageMetadata);
}