Wire NowPlayingStats to live aggregates: add SQL track duration column, stats endpoint, and duration backfill

DeepDrftData/Repositories/TrackRepository.cs

@@ -3,6 +3,7 @@ using Data.Errors;
 using DeepDrftData.Data;
 using DeepDrftModels.DTOs;
 using DeepDrftModels.Entities;
+using DeepDrftModels.Enums;
 using Microsoft.EntityFrameworkCore;
 using Microsoft.Extensions.Logging;
 using Models.Common;
@@ -157,6 +158,57 @@ public class TrackRepository : Repository<DeepDrftContext, TrackEntity>
             .Select(g => new { ReleaseId = g.Key, Count = g.Count() })
             .ToDictionaryAsync(x => x.ReleaseId, x => x.Count, ct);
 
+    // Aggregate figures for the public home hero stat row, assembled in as few round-trips as is clean.
+    // All counts go through Query / the release set's !IsDeleted filter so soft-deleted rows never count.
+    // Mix runtime sums DurationSeconds with a null-coalesce to 0 so not-yet-backfilled rows contribute
+    // zero rather than throwing or skewing the total. The cut release-type breakdown is grouped here so
+    // a zero-count type is simply absent from the result (no present-with-zero row).
+    public async Task<HomeStatsDto> GetHomeStatsAsync(CancellationToken ct = default)
+    {
+        var releases = _context.Set<ReleaseEntity>().Where(r => !r.IsDeleted);
+
+        var cutTrackCount = await Query
+            .CountAsync(t => t.Release != null && t.Release.Medium == ReleaseMedium.Cut, ct);
+
+        var cutReleaseTypeCounts = await releases
+            .Where(r => r.Medium == ReleaseMedium.Cut)
+            .GroupBy(r => r.ReleaseType)
+            .Select(g => new CutReleaseTypeCount { ReleaseType = g.Key, Count = g.Count() })
+            .ToListAsync(ct);
+
+        var mixReleaseCount = await releases
+            .CountAsync(r => r.Medium == ReleaseMedium.Mix, ct);
+
+        var mixRuntimeSeconds = await Query
+            .Where(t => t.Release != null && t.Release.Medium == ReleaseMedium.Mix)
+            .SumAsync(t => t.DurationSeconds ?? 0d, ct);
+
+        return new HomeStatsDto
+        {
+            CutTrackCount = cutTrackCount,
+            CutReleaseTypeCounts = cutReleaseTypeCounts,
+            MixReleaseCount = mixReleaseCount,
+            MixRuntimeSeconds = mixRuntimeSeconds,
+        };
+    }
+
+    // EntryKey + stored duration for non-deleted tracks whose SQL duration is still null — the work list
+    // the one-time duration backfill iterates. The migration cannot read the vault, so duration is filled
+    // at runtime: this lists which rows still need it, the backfill reads each from the vault and writes
+    // it back via UpdateDurationAsync.
+    public async Task<List<TrackEntity>> GetTracksMissingDurationAsync(CancellationToken ct = default)
+        => await Query.Where(t => t.DurationSeconds == null).ToListAsync(ct);
+
+    // Set-based duration write for one track (no load round-trip), used by the backfill. The
+    // DurationSeconds == null guard keeps a re-run from re-stamping updated_at on an already-filled row
+    // and from clobbering a value the upload path may have set in the meantime.
+    public async Task<int> UpdateDurationAsync(long id, double durationSeconds, CancellationToken ct = default)
+        => await Query
+            .Where(t => t.Id == id && t.DurationSeconds == null)
+            .ExecuteUpdateAsync(s => s
+                .SetProperty(t => t.DurationSeconds, durationSeconds)
+                .SetProperty(t => t.UpdatedAt, DateTime.UtcNow), ct);
+
     // Resolve an existing release by its natural key (title + artist). Returns null when no match,
     // signalling the manager to create one. Soft-deleted releases never match.
     public async Task<ReleaseEntity?> GetReleaseByTitleAndArtistAsync(
@@ -211,6 +263,7 @@ public class TrackRepository : Repository<DeepDrftContext, TrackEntity>
         target.TrackName = source.TrackName;
         target.TrackNumber = source.TrackNumber;
         target.OriginalFileName = source.OriginalFileName;
+        target.DurationSeconds = source.DurationSeconds;
         target.ReleaseId = source.ReleaseId;
     }
 }