From 5fafda1544332dee80c21af740041c2c74fd589c Mon Sep 17 00:00:00 2001
From: ranokay <github@ranokay.com>
Date: Wed, 26 Aug 2026 12:04:02 +0300
Subject: [PATCH] fix(ui): match ISO 639 lyric languages

---
 ui/src/audioplayer/lyrics.js      | 12 ++++++++++--
 ui/src/audioplayer/lyrics.test.js | 15 +++++++++++++++
 2 files changed, 25 insertions(+), 2 deletions(-)

diff --git a/ui/src/audioplayer/lyrics.js b/ui/src/audioplayer/lyrics.js
index ec93cc6f0..05193d271 100644
--- a/ui/src/audioplayer/lyrics.js
+++ b/ui/src/audioplayer/lyrics.js
@@ -1,5 +1,13 @@
-const normalizeLanguageTag = (language) =>
-  (language || '').toLowerCase().replace(/_/g, '-')
+const normalizeLanguageTag = (language) => {
+  const normalized = (language || '').trim().replace(/_/g, '-')
+  if (!normalized) return ''
+
+  try {
+    return Intl.getCanonicalLocales(normalized)[0].toLowerCase()
+  } catch {
+    return normalized.toLowerCase()
+  }
+}
 
 const LYRIC_KIND_MAIN = 'main'
 const LYRIC_KIND_TRANSLATION = 'translation'
diff --git a/ui/src/audioplayer/lyrics.test.js b/ui/src/audioplayer/lyrics.test.js
index c5ef6d736..208d82ac6 100644
--- a/ui/src/audioplayer/lyrics.test.js
+++ b/ui/src/audioplayer/lyrics.test.js
@@ -101,6 +101,21 @@ describe('lyrics helpers', () => {
     expect(layers.main.line[0].value).toBe('繁體')
   })
 
+  it('matches ISO 639-2 lyric languages to regional browser locales', () => {
+    const lyrics = [
+      structured('main', 'spa', 'Español'),
+      structured('main', 'eng', 'English'),
+      structured('main', 'por', 'Português'),
+    ]
+
+    expect(selectLyricLayers(lyrics, 'en-US').main.line[0].value).toBe(
+      'English',
+    )
+    expect(selectLyricLayers(lyrics, 'pt-BR').main.line[0].value).toBe(
+      'Português',
+    )
+  })
+
   it('resolves UTF-8 byte ranges without confusing repeated words', () => {
     const text = 'caf\u00e9 caf\u00e9'