feat(genius): load song metadata, lyrics, and artwork

Search hits omit album covers and artist images. The worker now reads the full song and artist, stores the description, and leaves Genius image URLs unchanged on mobile.

Co-authored-by: Cursor <cursoragent@cursor.com>

services/api/internal/genius/client_test.go

@@ -0,0 +1,92 @@
+package genius
+
+import (
+	"context"
+	"errors"
+	"io"
+	"net/http"
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+type transportFunc func(*http.Request) (*http.Response, error)
+
+func (f transportFunc) RoundTrip(r *http.Request) (*http.Response, error) { return f(r) }
+
+func TestLyricsFormatting(t *testing.T) {
+	text, err := parseLyrics([]byte(`<header>Not lyrics</header><div data-lyrics-container="true"><div class="LyricsHeader-x">Title</div>[Куплет 1]<br>Привет &amp; <a href="/annotation">мир</a><br><br>Next <b>line</b><span data-exclude-from-selection="true">Embed</span><script>bad()</script></div><div data-lyrics-container="true">[Припев]<br>Again<button>Share</button></div>`))
+	require.NoError(t, err)
+	require.Equal(t, "[Куплет 1]\nПривет & мир\n\nNext line\n\n[Припев]\nAgain", text)
+}
+
+func TestUnavailable(t *testing.T) {
+	for _, page := range []string{`<h1>Just a moment</h1>`, `<div data-lyrics-container="true"> </div>`, `<script>window.__PRELOADED_STATE__ = JSON.parse('broken')</script>`} {
+		_, err := parseLyrics([]byte(page))
+		require.ErrorIs(t, err, ErrLyricsUnavailable)
+	}
+}
+
+func TestEmbeddedLyrics(t *testing.T) {
+	text, err := parseLyrics([]byte(`<script>window.__PRELOADED_STATE__ = JSON.parse('{"songPage":{"lyricsData":{"body":{"html":"<p>[Verse]<br>It\'s \\"fine\\" &amp; good<br>Привет</p>"}}}}')</script>`))
+	require.NoError(t, err)
+	require.Equal(t, "[Verse]\nIt's \"fine\" & good\nПривет", text)
+}
+
+func TestURLValidation(t *testing.T) {
+	c := New("secret")
+	c.http.Transport = transportFunc(func(*http.Request) (*http.Response, error) { t.Fatal("unexpected network call"); return nil, nil })
+	for _, u := range []string{"https://evil.test/song-lyrics", "http://genius.com/song-lyrics", "https://genius.com:443/song-lyrics", "https://secret@genius.com/song-lyrics", "https://genius.com/artists/test"} {
+		_, err := c.FetchLyrics(context.Background(), u)
+		require.Error(t, err)
+	}
+}
+
+func TestRequests(t *testing.T) {
+	c := New("secret")
+	c.http.Transport = transportFunc(func(r *http.Request) (*http.Response, error) {
+		body := `<div data-lyrics-container="true">Synthetic test text</div>`
+		if r.URL.Host == "api.genius.com" {
+			require.Equal(t, "Bearer secret", r.Header.Get("Authorization"))
+			require.Equal(t, "artist & title", r.URL.Query().Get("q"))
+			body = `{"response":{"hits":[{"type":"song","result":{"id":12,"title":"Example","url":"https://genius.com/example-lyrics","primary_artist":{"name":"Artist"}}}]}}`
+		} else {
+			require.Empty(t, r.Header.Get("Authorization"))
+			require.Empty(t, r.URL.RawQuery)
+		}
+		return &http.Response{StatusCode: 200, Body: io.NopCloser(strings.NewReader(body)), Header: make(http.Header)}, nil
+	})
+	songs, err := c.Search(context.Background(), "artist & title")
+	require.NoError(t, err)
+	require.Len(t, songs, 1)
+	lyrics, err := c.FetchLyrics(context.Background(), songs[0].URL+"?tracking=1")
+	require.NoError(t, err)
+	require.Equal(t, "Synthetic test text", lyrics.Text)
+	require.Equal(t, songs[0].URL, lyrics.SourceURL)
+	require.False(t, lyrics.FetchedAt.IsZero())
+}
+
+func TestHTTPFailures(t *testing.T) {
+	for _, status := range []int{401, 403, 404, 429, 500} {
+		c := New("secret")
+		c.http.Transport = transportFunc(func(*http.Request) (*http.Response, error) {
+			return &http.Response{StatusCode: status, Header: http.Header{"Retry-After": {"60"}}, Body: io.NopCloser(strings.NewReader("private upstream body"))}, nil
+		})
+		_, err := c.Search(context.Background(), "test")
+		var httpErr *HTTPError
+		require.True(t, errors.As(err, &httpErr))
+		require.Equal(t, status, httpErr.StatusCode)
+		require.Equal(t, "60", httpErr.RetryAfter)
+		require.NotContains(t, err.Error(), "private")
+	}
+}
+
+func TestRedirects(t *testing.T) {
+	c := New("secret")
+	first, _ := http.NewRequest("GET", "https://api.genius.com/search", nil)
+	for _, endpoint := range []string{"http://api.genius.com/search", "https://genius.com/song-lyrics", "https://evil.test/"} {
+		req, _ := http.NewRequest("GET", endpoint, nil)
+		require.Error(t, c.http.CheckRedirect(req, []*http.Request{first}))
+	}
+}