Implement Track Management Skill

Plan and implement Stage 5 Track Management for NovaTune: CRUD endpoints, soft-delete semantics, lifecycle worker, and observability.

Overview

Stage 5 implements user library management with:

• GET /tracks - List tracks with search, filter, sort, cursor-based pagination
• GET /tracks/{trackId} - Get track details
• PATCH /tracks/{trackId} - Update track metadata (merge policy)
• DELETE /tracks/{trackId} - Soft-delete with grace period
• POST /tracks/{trackId}/restore - Restore within grace period
• Lifecycle Worker - Physical deletion after grace period

Implementation Plan

Phase 1: Models and Configuration

1. Extend Track Model (ApiService/Models/Track.cs)

   • Add soft-delete fields: DeletedAt, ScheduledDeletionAt, StatusBeforeDeletion

2. Add Configuration (ApiService/Configuration/TrackManagementOptions.cs)

   • DeletionGracePeriod (default: 30 days)
   • MaxPageSize (default: 100)
   • DefaultPageSize (default: 20)

3. Add DTOs (ApiService/Models/)

   • TrackListQuery, TrackListQueryParams
   • TrackListItem, TrackDetails
   • UpdateTrackRequest
   • PagedResult<T>, TrackListCursor

Phase 2: RavenDB Indexes

1. Tracks_ByUserForSearch (ApiService/Infrastructure/Indexes/)

   csharpCopy

   Map = tracks => from track in tracks
                   where track.Status != TrackStatus.Unknown
                   select new
                   {
                       track.UserId,
                       track.Status,
                       track.Title,
                       track.Artist,
                       track.CreatedAt,
                       track.UpdatedAt,
                       track.Duration,
                       SearchText = new[] { track.Title, track.Artist }
                   };
   Index("SearchText", FieldIndexing.Search);
   

2. Tracks_ByScheduledDeletion (ApiService/Infrastructure/Indexes/)

   csharpCopy

   Map = tracks => from track in tracks
                   where track.Status == TrackStatus.Deleted
                      && track.ScheduledDeletionAt != null
                   select new { track.Status, track.ScheduledDeletionAt };
   

Phase 3: Service Layer

1. ITrackManagementService (ApiService/Services/)

   • ListTracksAsync(userId, query, ct)
   • GetTrackAsync(trackId, userId, ct)
   • UpdateTrackAsync(trackId, userId, request, ct)
   • DeleteTrackAsync(trackId, userId, ct)
   • RestoreTrackAsync(trackId, userId, ct)

2. Custom Exceptions (ApiService/Infrastructure/Exceptions/)

   • TrackNotFoundException
   • TrackAccessDeniedException
   • TrackDeletedException
   • RestorationExpiredException

Phase 4: API Endpoints

1. TrackEndpoints.cs (ApiService/Endpoints/)

   csharpCopy

   group.MapGet("/", HandleListTracks).RequireRateLimiting("track-list");
   group.MapGet("/{trackId}", HandleGetTrack);
   group.MapPatch("/{trackId}", HandleUpdateTrack).RequireRateLimiting("track-update");
   group.MapDelete("/{trackId}", HandleDeleteTrack).RequireRateLimiting("track-delete");
   group.MapPost("/{trackId}/restore", HandleRestoreTrack);
   

2. Rate Limiting Policies

   • track-list: 60 req/min
   • track-update: 30 req/min
   • track-delete: 10 req/min

Phase 5: Event Publishing

1. TrackDeletedEvent (ApiService/Infrastructure/Messaging/Messages/)

   • Migrate from Guid to ULID strings
   • Include ObjectKey, WaveformObjectKey, FileSizeBytes

2. Outbox Pattern

   • Write event to OutboxMessages collection in same transaction
   • Outbox processor publishes to {prefix}-track-deletions topic

Phase 6: Lifecycle Worker

1. Create Worker Project (Workers.Lifecycle/)

   • Use add-aspire-worker-project skill

2. TrackDeletedHandler - Kafka consumer for immediate cache invalidation

3. PhysicalDeletionService - Background service polling for expired tracks

   • Delete MinIO objects (audio + waveform)
   • Delete RavenDB document
   • Update user quota

Phase 7: Observability

1. Metrics (ApiService/Infrastructure/Observability/)

   • track_list_requests_total
   • track_get_requests_total
   • track_update_requests_total
   • track_delete_requests_total
   • track_physical_deletions_total

2. Logging

   • Track operations with TrackId, UserId, CorrelationId
   • Never log object keys in production

Phase 8: Testing

1. Unit Tests

   • TrackManagementServiceTests
   • Pagination cursor encoding/decoding
   • Soft-delete state transitions

2. Integration Tests

   • End-to-end CRUD flow
   • Soft-delete → restore → delete cycle
   • Physical deletion via lifecycle worker

Files to Create/Modify

New Files

Modified Files

Related Skills

• add-ravendb-index - For creating RavenDB indexes
• add-rate-limiting - For rate limiting policies
• add-background-service - For physical deletion service
• add-kafka-consumer - For TrackDeletedHandler
• add-aspire-worker-project - For lifecycle worker project
• add-observability - For metrics and tracing

Validation Checklist

• All CRUD endpoints return RFC 7807 problem details on error
• Rate limiting enforced on mutation endpoints
• Soft-delete preserves StatusBeforeDeletion for restore
• Physical deletion only after grace period
• Cache invalidated immediately on soft-delete
• Quota updated only after physical deletion
• All operations logged with correlation ID
• Optimistic concurrency on updates