Fix large CMS upload timeout with idle heartbeat and add per-file progress meter

Replace the 100s default HttpClient timeout (set Timeout=Infinite) with an idle/heartbeat
deadline driven by a ProgressStreamContent wrapper that reports bytes-on-the-wire. Each tick
resets the idle window and advances a MudProgressLinear per upload row. Idle window is
configurable via Upload:IdleTimeoutSeconds (default 90s).

DeepDrftManager/Services/CmsTrackService.cs

@@ -20,19 +20,29 @@ public class CmsTrackService : ICmsTrackService
     private const string ContentCmsClientName = "DeepDrft.Content.Cms";
     private const string UploadPath = "api/track/upload";
 
+    // Idle/heartbeat window: abort an upload only after this long with zero bytes written to the wire.
+    // The window resets on every progress tick, so a slow-but-moving half-gig upload never trips it;
+    // a genuinely stalled socket does. Operator-tunable via Upload:IdleTimeoutSeconds.
+    private const int DefaultIdleTimeoutSeconds = 90;
+
     private readonly IHttpClientFactory _httpClientFactory;
     private readonly ILogger<CmsTrackService> _logger;
+    private readonly TimeSpan _uploadIdleTimeout;
 
     public CmsTrackService(
         IHttpClientFactory httpClientFactory,
+        IConfiguration configuration,
         ILogger<CmsTrackService> logger)
     {
         _httpClientFactory = httpClientFactory;
         _logger = logger;
+        var seconds = configuration.GetValue<int?>("Upload:IdleTimeoutSeconds") ?? DefaultIdleTimeoutSeconds;
+        _uploadIdleTimeout = TimeSpan.FromSeconds(seconds > 0 ? seconds : DefaultIdleTimeoutSeconds);
     }
 
     public async Task<ResultContainer<TrackDto>> UploadTrackAsync(
         Stream wavStream,
+        long contentLength,
         string fileName,
         string contentType,
         string trackName,
@@ -46,12 +56,25 @@ public class CmsTrackService : ICmsTrackService
         ReleaseType releaseType,
         int trackNumber,
         ReleaseMedium medium = ReleaseMedium.Cut,
+        IProgress<long>? progress = null,
         CancellationToken ct = default)
     {
+        // Idle/heartbeat cancellation: HttpClient.Timeout is a whole-request cap and cannot express
+        // "no bytes for N seconds", so the named client runs with InfiniteTimeSpan and the deadline
+        // lives here. Each ProgressStreamContent tick resets CancelAfter(idle); a stalled socket lets
+        // the window elapse and cancels the send. Linked to the caller's ct so a page cancel still wins.
+        using var idleCts = CancellationTokenSource.CreateLinkedTokenSource(ct);
+        idleCts.CancelAfter(_uploadIdleTimeout);
+
         // Rebuild the multipart container so the boundary is owned by HttpClient and the
         // caller-supplied stream (already buffered by the SignalR upload) is the source.
         using var multipart = new MultipartFormDataContent();
-        var wavContent = new StreamContent(wavStream);
+        var wavContent = new ProgressStreamContent(wavStream, contentLength, written =>
+        {
+            // One mechanism, two consumers: advance the UI meter and reset the idle heartbeat.
+            progress?.Report(written);
+            idleCts.CancelAfter(_uploadIdleTimeout);
+        });
         wavContent.Headers.ContentType = new MediaTypeHeaderValue(
             string.IsNullOrWhiteSpace(contentType) ? "audio/wav" : contentType);
         multipart.Add(wavContent, "audioFile", fileName);
@@ -76,7 +99,15 @@ public class CmsTrackService : ICmsTrackService
         HttpResponseMessage response;
         try
         {
-            response = await client.SendAsync(request, HttpCompletionOption.ResponseHeadersRead, ct);
+            response = await client.SendAsync(request, HttpCompletionOption.ResponseHeadersRead, idleCts.Token);
+        }
+        catch (OperationCanceledException) when (idleCts.IsCancellationRequested && !ct.IsCancellationRequested)
+        {
+            // Idle window elapsed with no bytes moving — a stalled connection, not a caller cancel.
+            _logger.LogWarning("Upload of {TrackName} stalled — no progress for {IdleSeconds}s; aborting.",
+                trackName, _uploadIdleTimeout.TotalSeconds);
+            return ResultContainer<TrackDto>.CreateFailResult(
+                $"Upload stalled — no data transferred for {_uploadIdleTimeout.TotalSeconds:0}s. Please retry.");
         }
         catch (Exception ex)
         {

DeepDrftManager/Services/ICmsTrackService.cs

@@ -21,9 +21,14 @@ public interface ICmsTrackService
     /// <paramref name="medium"/> sets the parent release's <see cref="ReleaseMedium"/> when this upload
     /// creates the release. The medium is authoritative only on creation — adding a track to an existing
     /// release never changes its medium (that is the edit path, <see cref="UpdateAsync"/>).
+    /// <paramref name="contentLength"/> is the total payload size (the browser file's <c>Size</c>); it
+    /// sets Content-Length and is the denominator for <paramref name="progress"/>, which reports cumulative
+    /// bytes pushed to the wire. Each progress tick also resets the idle/heartbeat upload timeout, so a
+    /// stalled connection aborts without a fixed total-duration cap.
     /// </summary>
     Task<ResultContainer<TrackDto>> UploadTrackAsync(
         Stream wavStream,
+        long contentLength,
         string fileName,
         string contentType,
         string trackName,
@@ -37,6 +42,7 @@ public interface ICmsTrackService
         ReleaseType releaseType,
         int trackNumber,
         ReleaseMedium medium = ReleaseMedium.Cut,
+        IProgress<long>? progress = null,
         CancellationToken ct = default);
 
     /// <summary>

DeepDrftManager/Services/ProgressStreamContent.cs

@@ -0,0 +1,64 @@
+using System.Net;
+
+namespace DeepDrftManager.Services;
+
+/// <summary>
+/// An <see cref="HttpContent"/> that streams a source stream to the wire while reporting cumulative
+/// bytes written after each chunk. This is the single source of truth for both the upload progress
+/// meter and the idle/heartbeat timeout: every reported tick advances the UI <em>and</em> resets the
+/// idle deadline, so one mechanism feeds both concerns.
+/// </summary>
+/// <remarks>
+/// Wrap the audio payload (not the whole multipart container) so <see cref="TryComputeLength"/>
+/// returns the file length and the reported byte counts map directly onto "bytes of this file".
+/// </remarks>
+public sealed class ProgressStreamContent : HttpContent
+{
+    // 80 KB: large enough to keep the socket fed on a healthy link, small enough that a stalled
+    // connection trips the idle window without a multi-MB write swallowing the whole heartbeat budget.
+    private const int CopyBufferSize = 81_920;
+
+    private readonly Stream _source;
+    private readonly long _length;
+    private readonly Action<long> _onBytesWritten;
+
+    /// <param name="source">The payload stream. Read once, sequentially — not seekable-rewound.</param>
+    /// <param name="length">Total bytes the source will yield; sets Content-Length and the meter denominator.</param>
+    /// <param name="onBytesWritten">Invoked after each chunk with the cumulative bytes written so far.</param>
+    public ProgressStreamContent(Stream source, long length, Action<long> onBytesWritten)
+    {
+        _source = source;
+        _length = length;
+        _onBytesWritten = onBytesWritten;
+    }
+
+    // Token-aware overload (.NET 5+): HttpClient calls this on the send path and passes the request's
+    // CancellationToken, so the idle-heartbeat CTS aborts an in-flight read/write promptly — not just
+    // between chunks. The parameterless base override delegates here with CancellationToken.None.
+    protected override Task SerializeToStreamAsync(Stream stream, TransportContext? context, CancellationToken cancellationToken)
+        => CopyAsync(stream, cancellationToken);
+
+    protected override Task SerializeToStreamAsync(Stream stream, TransportContext? context)
+        => CopyAsync(stream, CancellationToken.None);
+
+    private async Task CopyAsync(Stream stream, CancellationToken cancellationToken)
+    {
+        var buffer = new byte[CopyBufferSize];
+        long written = 0;
+        int read;
+        while ((read = await _source.ReadAsync(buffer, cancellationToken)) > 0)
+        {
+            await stream.WriteAsync(buffer.AsMemory(0, read), cancellationToken);
+            written += read;
+            // Report after the bytes are on the wire — a tick means real forward progress, which is
+            // exactly the signal the idle heartbeat must reset on.
+            _onBytesWritten(written);
+        }
+    }
+
+    protected override bool TryComputeLength(out long length)
+    {
+        length = _length;
+        return true;
+    }
+}