AcManager.Tools.Helpers.Loaders.FlexibleLoader.LoadAsyncTo C# (CSharp) Method

        public static async Task<string> LoadAsyncTo(string argument, string destination, IProgress<AsyncProgressEntry> progress = null,
                CancellationToken cancellation = default(CancellationToken)) {
            var loader = CreateLoader(argument);

            try {
                // TODO: Timeout?
                using (var client = new CookieAwareWebClient {
                    Headers = {
                        [HttpRequestHeader.UserAgent] = CmApiProvider.UserAgent
                    }
                }) {
                    progress?.Report(AsyncProgressEntry.Indetermitate);

                    cancellation.ThrowIfCancellationRequested();
                    cancellation.Register(client.CancelAsync);

                    if (!await loader.PrepareAsync(client, cancellation) ||
                            cancellation.IsCancellationRequested) return null;

                    var skipEvent = 0;
                    client.DownloadProgressChanged += (sender, args) => {
                        if (++skipEvent > 50) {
                            skipEvent = 0;
                        } else {
                            return;
                        }

                        var total = args.TotalBytesToReceive;
                        if (total == -1 && loader.TotalSize != -1) {
                            total = Math.Max(loader.TotalSize, args.BytesReceived);
                        }

                        // ReSharper disable once AccessToDisposedClosure
                        progress?.Report(AsyncProgressEntry.CreateDownloading(args.BytesReceived, total));
                    };

                    await loader.DownloadAsync(client, destination, cancellation);
                    if (cancellation.IsCancellationRequested) return null;

                    Logging.Debug("Loaded: " + destination);
                }

                return destination;
            } catch (TaskCanceledException) {
                return null;
            } catch (Exception e) {
                NonfatalError.Notify(ToolsStrings.Common_CannotDownloadFile, ToolsStrings.Common_CannotDownloadFile_Commentary, e);
                return null;
            }
        }
    }