private async Task <(Stream stream, bool fromStorage)> GetContextStreamAsync(
TournamentBracketRequest request,
TournamentBracketContent content,
CompositeDisposable disposables,
CancellationToken cancellationToken
)
{
// Validate parameters.
if (request == null)
{
throw new ArgumentNullException(nameof(request));
}
if (disposables == null)
{
throw new ArgumentNullException(nameof(disposables));
}
// The algorithm is this:
// If there is content, use that.
// If there is not content, then try to get from challonge.
// If there is no content, try to get from persistence
// If it can't be retrieved, throw.
// Check the request for content.
if (content != null &&
content.MediaType.Type == "text" &&
content.MediaType.SubTypeWithoutSuffix == "html"
)
{
// Return a streamreader.
return(content.Content, false);
}
// Try and get it from challonge.
Stream stream = await GetStreamFromChallongeAsync(
request, disposables, cancellationToken
)
.ConfigureAwait(false);
// If not null, return.
if (stream != null)
{
return(stream, false);
}
// Get the reader from storage.
stream = await GetStreamFromStorageAsync(
request, disposables, cancellationToken
).ConfigureAwait(false);
// If there is no stream at this point, throw.
if (stream == null)
{
throw new InvalidOperationException(
$"Could not retrieve content for URL \"{request.Url}\" from user-sumbmitted content, Challonge, or storage.");
}
// Return the reader.
return(stream, true);
}
public async Task <TournamentBracketResponse> GetTournamentBracketAsync(
TournamentBracketRequest request,
TournamentBracketContent content,
CancellationToken cancellationToken)
{
// Validate parameters.
// Note: The content parameter can be null.
if (request == null)
{
throw new ArgumentNullException(nameof(request));
}
// If the url is null, throw.
if (request.Url == null)
{
throw new InvalidOperationException(
$"The {nameof(request.Url)} property on the {nameof(request)} parameter cannot be null.");
}
// The disposables.
using var disposables = new CompositeDisposable();
// The page content.
TournamentBracketPage page;
// Get the content stream.
(Stream rawStream, bool fromStorage) = await GetContextStreamAsync(
request, content, disposables, cancellationToken
).ConfigureAwait(false);
// Add the raw stream to the disposables.
disposables.Add(rawStream);
// If there is no stream, copy it.
if (!(rawStream is MemoryStream stream))
{
// Create a new one.
stream = new MemoryStream();
// Copy.
await rawStream.CopyToAsync(stream, 4096, cancellationToken)
.ConfigureAwait(false);
}
// Add the stream to the disposables.
disposables.Add(stream);
// Set the position of the stream back.
stream.Position = 0;
// Create a reader.
using TextReader reader = new StreamReader(stream);
// Parse.
page = await _parser.ParseTournamentBracketPageAsync(reader, cancellationToken)
.ConfigureAwait(false);
// Everything was successful at this point, reset the stream and persist.
stream.Position = 0;
// Persist if this wasn't from storage to begin with.
if (!fromStorage)
{
await PersistContentAsync(request, stream, cancellationToken)
.ConfigureAwait(false);
}
// Return.
return(new TournamentBracketResponse {
Request = request,
PageContent = page.PageContent,
Bracket = page.Bracket,
TargetingKeyValues = page.TargetingKeyValues,
MetaList = page.MetaList
});
}