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)

DeepDrftPublic.Client/Clients/TrackMediaClient.cs

@@ -1,3 +1,6 @@
+using System.Net;
+using System.Net.Http.Json;
+using DeepDrftModels.DTOs;
 using Microsoft.Extensions.DependencyInjection;
 using NetBlocks.Models;
 
@@ -61,4 +64,36 @@ public class TrackMediaClient
             return ApiResult<TrackMediaResponse>.CreateFailResult(e.Message);
         }
     }
+
+    /// <summary>
+    /// Fetches a track's stored waveform loudness profile. A 404 means no profile is stored
+    /// (existing tracks predate profiling, or computation failed at upload); callers treat that
+    /// as "render a flat seekbar" rather than an error, so it surfaces as a fail result with a
+    /// stable message rather than throwing.
+    /// </summary>
+    public async Task<ApiResult<WaveformProfileDto>> GetWaveformProfileAsync(string trackId, CancellationToken cancellationToken = default)
+    {
+        try
+        {
+            var response = await _http.GetAsync($"api/track/{trackId}/waveform", cancellationToken);
+            if (response.StatusCode == HttpStatusCode.NotFound)
+            {
+                return ApiResult<WaveformProfileDto>.CreateFailResult("No waveform profile available");
+            }
+
+            response.EnsureSuccessStatusCode();
+
+            var profile = await response.Content.ReadFromJsonAsync<WaveformProfileDto>();
+            if (profile is null)
+            {
+                return ApiResult<WaveformProfileDto>.CreateFailResult("Waveform profile response was empty");
+            }
+
+            return ApiResult<WaveformProfileDto>.CreatePassResult(profile);
+        }
+        catch (Exception e)
+        {
+            return ApiResult<WaveformProfileDto>.CreateFailResult(e.Message);
+        }
+    }
 }

DeepDrftPublic/Controllers/TrackProxyController.cs

@@ -106,4 +106,38 @@ public class TrackProxyController : ControllerBase
         HttpContext.Response.RegisterForDispose(upstream);
         return File(stream, contentType, enableRangeProcessing: false);
     }
+
+    /// <summary>
+    /// Proxies a track's stored waveform profile (JSON) from DeepDrftAPI. Unauthenticated,
+    /// same posture as the audio stream forward. The profile is small JSON, so it is buffered
+    /// and relayed rather than streamed; a 404 from upstream (no profile stored) passes through.
+    /// </summary>
+    [HttpGet("{trackId}/waveform")]
+    public async Task<ActionResult> GetWaveform(string trackId, CancellationToken ct = default)
+    {
+        var path = $"api/track/{Uri.EscapeDataString(trackId)}/waveform";
+
+        HttpResponseMessage upstream;
+        try
+        {
+            upstream = await _upstream.GetAsync(path, HttpCompletionOption.ResponseHeadersRead, ct);
+        }
+        catch (Exception ex)
+        {
+            _logger.LogError(ex, "Upstream call to DeepDrftAPI track/{TrackId}/waveform failed", trackId);
+            return StatusCode(502, "Upstream unavailable");
+        }
+
+        using (upstream)
+        {
+            if (!upstream.IsSuccessStatusCode)
+            {
+                _logger.LogWarning("DeepDrftAPI track/{TrackId}/waveform returned {Status}", trackId, (int)upstream.StatusCode);
+                return StatusCode((int)upstream.StatusCode);
+            }
+
+            var json = await upstream.Content.ReadAsStringAsync(ct);
+            return Content(json, "application/json");
+        }
+    }
 }