private static async Task <Uri> GetImageUriAsync(HttpClient client, ScreenshotID screenshotID, CancellationToken cancellationToken = default)
{
Uri metadataUri = new Uri($"https://prnt.sc/{screenshotID}");
using (HttpResponseMessage metadataResponse = await client.GetAsync(metadataUri, cancellationToken))
{
metadataResponse.EnsureSuccessStatusCode();
HtmlDocument html = new HtmlDocument();
html.Load(await metadataResponse.Content.ReadAsStreamAsync());
// first attempt to get image from og:image meta tag
string metaImageUrl = html.DocumentNode.SelectSingleNode("//meta[@property='og:image']").GetAttributeValue("content", null);
// if null, try twitter:image:src
if (string.IsNullOrWhiteSpace(metaImageUrl))
{
metaImageUrl = html.DocumentNode.SelectSingleNode("//meta[@name='twitter:image:src']").GetAttributeValue("content", null);
}
// if failed, throw
if (string.IsNullOrWhiteSpace(metaImageUrl))
{
throw new KeyNotFoundException("No raw image URL found in Prnt.sc's response");
}
if (metaImageUrl.StartsWith("//"))
{
metaImageUrl = metaImageUrl.Insert(0, "https:");
}
return(new Uri(metaImageUrl));
}
}
public Screenshot(ScreenshotID id, byte[] data, string directUrl)
{
if (data?.Any() != true)
{
throw new ArgumentException("Screenshot byte data is required", nameof(data));
}
if (string.IsNullOrWhiteSpace(directUrl))
{
throw new ArgumentException("Screenshot URL is required", nameof(directUrl));
}
this.ID = id;
this.Data = data;
this.DirectURL = directUrl;
}
public static async Task <Stream> DownloadScreenshotStreamAsync(this HttpClient client, ScreenshotID screenshotID, CancellationToken cancellationToken = default)
{
Uri screenshotUri = await GetImageUriAsync(client, screenshotID, cancellationToken);
using (HttpResponseMessage screenshotResponse = await client.GetAsync(screenshotUri, cancellationToken))
return(await screenshotResponse.Content.ReadAsStreamAsync());
}
public static async Task <Screenshot> DownloadScreenshotAsync(this HttpClient client, ScreenshotID screenshotID, CancellationToken cancellationToken = default)
{
Uri screenshotUri = await GetImageUriAsync(client, screenshotID, cancellationToken);
using (HttpResponseMessage screenshotResponse = await client.GetAsync(screenshotUri, cancellationToken))
{
byte[] bytes = await screenshotResponse.Content.ReadAsByteArrayAsync();
return(new Screenshot(screenshotID, bytes, screenshotUri.ToString()));
}
}
