From cd45c3f40a9163e7265b8159ec9dce8967ea1746 Mon Sep 17 00:00:00 2001
From: Mathis Maquenne <124215603+mathismqn@users.noreply.github.com>
Date: Sun, 1 Mar 2026 21:29:02 +0100
Subject: [PATCH] perf(downloader): fetch metadata concurrently with stream
 download

---
 internal/downloader/client.go | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/internal/downloader/client.go b/internal/downloader/client.go
index d3c34ec..830a7b2 100644
--- a/internal/downloader/client.go
+++ b/internal/downloader/client.go
@@ -167,8 +167,11 @@ func (c *Client) downloadSong(ctx context.Context, resource deezer.Resource, son
 	}
 
 	metadataFetcher := newMetadataFetcher(c.deezerClient.Session.HttpClient)
-	metadataResult := metadataFetcher.fetch(ctx, song, opts)
-	warnings = append(warnings, metadataResult.warnings...)
+	metadataChan := make(chan metadataResult, 1)
+	go func() {
+		metadataResult := metadataFetcher.fetch(ctx, song, opts)
+		metadataChan <- metadataResult
+	}()
 
 	stream, err := c.deezerClient.GetMediaStream(ctx, media, song.ID)
 	if err != nil {
@@ -196,6 +199,9 @@ func (c *Client) downloadSong(ctx context.Context, resource deezer.Resource, son
 		warnings = append(warnings, fmt.Sprintf("failed to fetch cover image: %v", err))
 	}
 
+	metadataResult := <-metadataChan
+	warnings = append(warnings, metadataResult.warnings...)
+
 	finalizeWarnings := c.finalizeDownload(resource, song, outputPath, mediaFormat, metadataResult.genre, cover, metadataResult.bpmKey)
 	warnings = append(warnings, finalizeWarnings...)