Add waveform profile HTTP transport: API endpoint, public proxy, content client method

DeepDrftAPI/Controllers/TrackController.cs

@@ -5,7 +5,9 @@ using DeepDrftContent.Audio;
 using DeepDrftContent.Constants;
 using DeepDrftContent.FileDatabase.Services;
 using DeepDrftContent.FileDatabase.Models;
+using DeepDrftContent.Processors;
 using DeepDrftData;
+using DeepDrftModels.DTOs;
 using Microsoft.AspNetCore.Mvc;
 
 namespace DeepDrftAPI.Controllers;
@@ -18,6 +20,7 @@ public class TrackController : ControllerBase
     private readonly WavOffsetService _wavOffsetService;
     private readonly UnifiedTrackService _unifiedService;
     private readonly ITrackService _sqlTrackService;
+    private readonly WaveformProfileService _waveformProfileService;
     private readonly ILogger<TrackController> _logger;
 
     // FileDatabase is injected directly for PutTrack because that endpoint receives a pre-processed
@@ -32,6 +35,7 @@ public class TrackController : ControllerBase
         WavOffsetService wavOffsetService,
         UnifiedTrackService unifiedService,
         ITrackService sqlTrackService,
+        WaveformProfileService waveformProfileService,
         ILogger<TrackController> logger)
     {
         _trackContentService = trackContentService;
@@ -39,6 +43,7 @@ public class TrackController : ControllerBase
         _wavOffsetService = wavOffsetService;
         _unifiedService = unifiedService;
         _sqlTrackService = sqlTrackService;
+        _waveformProfileService = waveformProfileService;
         _logger = logger;
     }
 
@@ -348,6 +353,28 @@ public class TrackController : ControllerBase
         }
     }
 
+    // GET api/track/{trackId}/waveform (unauthenticated)
+    // Returns the stored waveform loudness profile for a track, base64-encoded. Public listener
+    // data, same auth posture as GET api/track/{trackId} streaming. 404 when no profile is stored
+    // (existing tracks predate profiling, or computation failed at upload — the frontend falls back
+    // to a flat seekbar). The "waveform" literal suffix keeps this distinct from the audio route.
+    [HttpGet("{trackId}/waveform")]
+    public async Task<ActionResult> GetWaveform(string trackId)
+    {
+        var bytes = await _waveformProfileService.GetProfileAsync(trackId);
+        if (bytes is null)
+        {
+            _logger.LogInformation("No waveform profile for track: {TrackId}", trackId);
+            return NotFound();
+        }
+
+        return Ok(new WaveformProfileDto
+        {
+            BucketCount = bytes.Length,
+            Data = Convert.ToBase64String(bytes),
+        });
+    }
+
     [ApiKeyAuthorize]
     [HttpPut("{trackId}")]
     public async Task<ActionResult> PutTrack(string trackId, [FromBody] AudioBinaryDto track)