fix(playback): preserve Apple stream quality on startup

allstarr.Tests/Providers/AppleDownloadCapabilityAdapterTests.cs

@@ -148,7 +148,7 @@ public sealed class AppleDownloadCapabilityAdapterTests : IDisposable
             "apple/track 1");
 
         var lease = (await adapter.GetStreamLeaseAsync(
-            Context(tenant, user), new(track))).RequireValue();
+            Context(tenant, user), new(track, ProviderAudioQuality.HighResolution))).RequireValue();
         using var request = new HttpRequestMessage(HttpMethod.Get, lease.ProtectedSourceUri);
         using var response = await lease.ProtectedResponseFactory!(request, CancellationToken.None);
 
@@ -162,7 +162,7 @@ public sealed class AppleDownloadCapabilityAdapterTests : IDisposable
         Assert.Equal(HttpStatusCode.OK, response.StatusCode);
         Assert.Equal(audio, await response.Content.ReadAsByteArrayAsync());
         Assert.Contains(gateway.Requests, uri =>
-            uri.PathAndQuery == "/api/stream/apple%2Ftrack%201?quality=aac-320");
+            uri.PathAndQuery == "/api/stream/apple%2Ftrack%201?quality=alac-24-96");
     }
 
     [Fact]

allstarr/Core/Providers/AppleDownload/AppleDownloadStreamingCapabilityAdapter.cs

@@ -47,12 +47,7 @@ public sealed class AppleDownloadStreamingCapabilityAdapter : IProviderStreaming
                 return ProviderOutcome<ProviderStreamLease>.Failure(new(ErrorFor(snapshot.State)));
             if (!OutboundRequestGuard.TryCreateConfiguredServiceUri(settings.BaseUrl, out var baseUri, out _))
                 return ProviderOutcome<ProviderStreamLease>.Failure(new(ProviderErrorKind.AccountNeedsConfiguration));
-            // Cold lossless preparation can outlast music-client startup timeouts.
-            // Keep configured lossless quality for downloads; default playback starts at AAC 320.
-            var playbackQuality = request.RequestedQuality == ProviderAudioQuality.Any
-                ? ProviderAudioQuality.Lossy
-                : request.RequestedQuality;
-            var quality = AppleDownloadCapabilityAdapter.Quality(playbackQuality, settings.Quality);
+            var quality = AppleDownloadCapabilityAdapter.Quality(request.RequestedQuality, settings.Quality);
             var source = new Uri(baseUri!,
                 $"api/stream/{Uri.EscapeDataString(request.TrackId.Value)}?quality={Uri.EscapeDataString(quality)}");
             return ProviderOutcome<ProviderStreamLease>.Success(new(

sidecars/apple-gateway/apple_gateway/app.py

@@ -5,7 +5,7 @@ import shutil
 import uuid
 from contextlib import asynccontextmanager
 from pathlib import Path
-from typing import Any
+from typing import Any, AsyncIterator
 
 import httpx
 from fastapi import FastAPI, HTTPException, Query
@@ -274,12 +274,24 @@ def create_app(
 
     @application.get("/api/stream/{song_id}")
     async def stream_song(song_id: str, quality: str = "alac-16-44") -> StreamingResponse:
-        root, source = await prepare_song(song_id, quality, "aac-web")
+        async def content() -> AsyncIterator[bytes]:
+            root: Path | None = None
+            try:
+                root, source = await prepare_song(song_id, quality, "aac-web")
+                async for chunk in process_runner.stream_flac(source):
+                    yield chunk
+            finally:
+                if root is not None:
+                    shutil.rmtree(root, ignore_errors=True)
+
         return StreamingResponse(
-            process_runner.stream_flac(source),
+            content(),
             media_type="audio/flac",
-            headers={"Content-Disposition": f'inline; filename="{song_id}.flac"'},
-            background=BackgroundTask(shutil.rmtree, root, ignore_errors=True),
+            headers={
+                "Content-Disposition": f'inline; filename="{song_id}.flac"',
+                "Cache-Control": "no-store",
+                "X-Accel-Buffering": "no",
+            },
         )
 
     @application.head("/api/stream/{song_id}")

sidecars/apple-gateway/tests/test_gateway.py

@@ -10,6 +10,7 @@ from typing import Any
 import httpx
 import pytest
 from fastapi.testclient import TestClient
+from fastapi.responses import StreamingResponse
 
 from apple_gateway.app import API_VERSION, create_app
 from apple_gateway.catalog import CatalogClient
@@ -247,6 +248,22 @@ def test_song_stream_head_reports_only_known_facts_without_preparing_media(clien
     assert client[0].head("/api/stream/102", params={"quality": "made-up"}).status_code == 400
 
 
+@pytest.mark.asyncio
+async def test_song_stream_opens_before_preparing_configured_quality(settings: Settings):
+    runner = FakeRunner()
+    app = create_app(settings, FakeWrapper(), FakeCatalog(), runner)
+    route = next(route for route in app.routes if getattr(route, "path", None) == "/api/stream/{song_id}")
+
+    response = await route.endpoint("102", "alac-16-44")
+
+    assert isinstance(response, StreamingResponse)
+    assert response.headers["cache-control"] == "no-store"
+    assert response.headers["x-accel-buffering"] == "no"
+    assert runner.calls == []
+    assert b"".join([chunk async for chunk in response.body_iterator]) == b"fLaCfixture"
+    assert runner.calls[-1][1] == "alac"
+
+
 def test_song_stream_falls_back_to_web_aac_when_lossless_is_unavailable(settings):
     class FallbackRunner(FakeRunner):
         async def download(self, url: str, quality: str, output: Path, temporary: Path) -> list[Path]: