/// <summary>
/// Gets a stream for downloading an image
/// </summary>
/// <param name="image">The image to download</param>
/// <param name="cancellationToken">The cancellation token</param>
/// <param name="progress">The progress of the image download</param>
/// <exception cref="FlurlHttpException">Thrown when the image fails to download</exception>
/// <returns>A stream for downloading an image</returns>
protected async Task <Stream> GetDownloadStream(IPhilomenaImage image, CancellationToken cancellationToken, IProgress <StreamProgressInfo>?progress, bool isSvgVersion = false)
{
string? imageUrl = isSvgVersion ? image.ShortSvgViewUrl : image.ShortViewUrl;
IFlurlResponse response = await imageUrl.GetAsync(cancellationToken, HttpCompletionOption.ResponseHeadersRead);
// Attempt to read the length of the stream from the header
long?length = null;
if (response.Headers.TryGetFirst("Content-Length", out string lengthString))
{
if (long.TryParse(lengthString, out long parsedLength))
{
length = parsedLength;
}
}
// Open the image stream
Stream downloadStream = await response.GetStreamAsync();
_logger.LogDebug("Opened download stream for image {ImageId} with size {DownloadSize}: {DownloadUrl}", image.Id, length, image.ShortViewUrl);
// Create progress stream wrapper for reporting download progress
return(new StreamProgressReporter(downloadStream, progress, length));
}
