public async Task <EmoteFetchResult> FetchEmoteAsync(string url)
{
// Get headers
var request = await _httpClient.SendAsync(new HttpRequestMessage(HttpMethod.Head, url));
// Workaround if server doesn't support HEAD requests
if (request.StatusCode == HttpStatusCode.MethodNotAllowed)
{
request = await _httpClient.GetAsync(url, HttpCompletionOption.ResponseHeadersRead);
}
// Check media type
string mediaType;
if (request.Content.Headers.ContentType != null)
{
mediaType = request.Content.Headers.ContentType.MediaType;
if (!Global.ValidMediaTypes.Contains(mediaType))
{
return(new EmoteFetchResult.Failed("The provided file format is not supported."));
}
}
else
{
return(new EmoteFetchResult.Failed("The server responded with invalid headers."));
}
// Check file size
int maxSize = Global.MaxFileSize;
if (request.Content.Headers.ContentLength.HasValue)
{
var val = request.Content.Headers.ContentLength.Value;
if (val <= Global.MaxFileSize)
{
// val will always be an int here
maxSize = (int)val;
}
else
{
return(new EmoteFetchResult.Failed("Content length exceeds the 16MiB limit."));
}
}
// Fetch file
const int bufferSize = 4096;
var ms = new MemoryStream();
await using (var stream = await _httpClient.GetStreamAsync(url))
{
byte[] buffer = new byte[bufferSize];
int count;
int size = 0;
while ((count = await stream.ReadAsync(buffer, 0, buffer.Length)) != 0)
{
size += count;
if (size > maxSize)
{
return(new EmoteFetchResult.Failed("File size exceeds the 16MiB limit."));
}
await ms.WriteAsync(buffer, 0, count);
}
}
var fileType = _fileTypeGuesser.GuessFileType(ms);
if (fileType.MediaType != mediaType)
{
return(new EmoteFetchResult.Failed("The server provided incorrect headers."));
}
if (mediaType == "application/zip")
{
var extractedFiles = new List <EmoteFile>();
using (var archive = new ZipArchive(ms))
{
var fileCount = 0;
foreach (var entry in archive.Entries)
{
// 50 is max that can be added at a time due to discord ratelimits.
if (fileCount == 50)
{
break;
}
var ext = Global.ValidExtensions.FirstOrDefault(x => entry.Name.EndsWith($".{x}"));
if (ext == null)
{
continue;
}
var extractedFile = new MemoryStream();
await using (var extracted = entry.Open())
{
byte[] buffer = new byte[bufferSize];
int count;
int size = 0;
while ((count = await extracted.ReadAsync(buffer, 0, buffer.Length)) != 0)
{
size += count;
if (size > Global.MaxFileSize)
{
_logger.LogDebug($"Skipping {entry.Name}: File too large.");
continue;
}
await extractedFile.WriteAsync(buffer, 0, count);
}
}
var extractedFileType = _fileTypeGuesser.GuessFileType(extractedFile);
if (extractedFileType.Extension != "zip" && extractedFileType.Extension != "unknown")
{
var isGif = extractedFileType.Extension == "gif";
extractedFiles.Add(
new EmoteFile(await ResizeToEmoteAsync(extractedFile, isGif),
extractedFileType.MediaType, Utils.FormatEmoteName(entry.Name)));
fileCount++;
}
else
{
_logger.LogDebug($"Skipping {entry.Name}: Not a valid or supported image.");
}
}
}
return(new EmoteFetchResult.Multiple(extractedFiles.ToArray()));
}
var file = new EmoteFile(await ResizeToEmoteAsync(ms, fileType.Extension == "gif"), mediaType);
return(new EmoteFetchResult.Single(file));
}
public Single(EmoteFile file)
{
File = file;
}
