feat: add translated and phonetic lyric previews

qq.go

@@ -2,6 +2,7 @@ package main
 
 import (
 	"bytes"
+	"encoding/base64"
 	"encoding/json"
 	"errors"
 	"fmt"
@@ -13,9 +14,10 @@ import (
 )
 
 const (
-	searchEndpoint   = "https://c.y.qq.com/soso/fcgi-bin/search_for_qq_cp"
-	lyricsEndpoint   = "https://c.y.qq.com/lyric/fcgi-bin/fcg_query_lyric_new.fcg"
-	maxUpstreamBytes = 4 << 20
+	searchEndpoint       = "https://c.y.qq.com/soso/fcgi-bin/search_for_qq_cp"
+	musicuEndpoint       = "https://u.y.qq.com/cgi-bin/musicu.fcg"
+	legacyLyricsEndpoint = "https://c.y.qq.com/lyric/fcgi-bin/fcg_query_lyric_new.fcg"
+	maxUpstreamBytes     = 4 << 20
 )
 
 type song struct {
@@ -29,6 +31,7 @@ type song struct {
 type lyricResult struct {
 	Lyric string `json:"lyric"`
 	Trans string `json:"trans"`
+	Roma  string `json:"roma"`
 	Code  int    `json:"code"`
 }
 
@@ -40,6 +43,7 @@ type qqAPI interface {
 type qqClient struct {
 	httpClient     *http.Client
 	searchEndpoint string
+	musicuEndpoint string
 	lyricsEndpoint string
 }
 
@@ -57,7 +61,8 @@ func newQQClient() *qqClient {
 			},
 		},
 		searchEndpoint: searchEndpoint,
-		lyricsEndpoint: lyricsEndpoint,
+		musicuEndpoint: musicuEndpoint,
+		lyricsEndpoint: legacyLyricsEndpoint,
 	}
 }
 
@@ -112,6 +117,54 @@ func (c *qqClient) Search(keyword string, limit int) ([]song, error) {
 }
 
 func (c *qqClient) Lyrics(mid string) (lyricResult, error) {
+	result, err := c.musicuLyrics(mid)
+	if err == nil {
+		return result, nil
+	}
+	return c.legacyLyrics(mid)
+}
+
+func (c *qqClient) musicuLyrics(mid string) (lyricResult, error) {
+	payload := map[string]any{
+		"comm": map[string]any{"ct": 24, "cv": 0, "format": "json", "platform": "yqq.json"},
+		"req_1": map[string]any{
+			"module": "music.musichallSong.PlayLyricInfo",
+			"method": "GetPlayLyricInfo",
+			"param": map[string]any{
+				"songMID": mid, "songID": 0, "crypt": 0, "qrc": 0, "trans": 1, "roma": 1,
+			},
+		},
+	}
+	var response struct {
+		Code    int `json:"code"`
+		Request struct {
+			Code int `json:"code"`
+			Data struct {
+				Lyric string `json:"lyric"`
+				Trans string `json:"trans"`
+				Roma  string `json:"roma"`
+			} `json:"data"`
+		} `json:"req_1"`
+	}
+	if err := c.postJSON(c.musicuEndpoint, payload, &response); err != nil {
+		return lyricResult{}, err
+	}
+	if response.Code != 0 || response.Request.Code != 0 {
+		return lyricResult{}, errors.New("QQ Music lyrics request failed")
+	}
+	lyric, err := decodeLyricBase64(response.Request.Data.Lyric)
+	if err != nil || strings.TrimSpace(lyric) == "" {
+		return lyricResult{}, errors.New("lyrics are not available for this track")
+	}
+	trans, _ := decodeLyricBase64(response.Request.Data.Trans)
+	roma := ""
+	if response.Request.Data.Roma != "" {
+		roma, _ = decryptQRCLyric(response.Request.Data.Roma)
+	}
+	return lyricResult{Lyric: lyric, Trans: trans, Roma: roma, Code: 0}, nil
+}
+
+func (c *qqClient) legacyLyrics(mid string) (lyricResult, error) {
 	query := url.Values{
 		"format": {"json"}, "songmid": {mid}, "outCharset": {"utf-8"}, "nobase64": {"1"},
 	}
@@ -125,11 +178,42 @@ func (c *qqClient) Lyrics(mid string) (lyricResult, error) {
 	return result, nil
 }
 
+func decodeLyricBase64(value string) (string, error) {
+	if value == "" {
+		return "", nil
+	}
+	decoded, err := base64.StdEncoding.DecodeString(value)
+	if err != nil {
+		return "", errors.New("QQ Music returned invalid lyric encoding")
+	}
+	if len(decoded) > maxUpstreamBytes {
+		return "", errors.New("decoded lyrics exceeded the safety limit")
+	}
+	return string(decoded), nil
+}
+
+func (c *qqClient) postJSON(endpoint string, payload, destination any) error {
+	body, err := json.Marshal(payload)
+	if err != nil {
+		return err
+	}
+	request, err := http.NewRequest(http.MethodPost, endpoint, bytes.NewReader(body))
+	if err != nil {
+		return err
+	}
+	request.Header.Set("Content-Type", "application/json")
+	return c.doJSON(request, destination)
+}
+
 func (c *qqClient) getJSON(endpoint string, query url.Values, destination any) error {
 	request, err := http.NewRequest(http.MethodGet, endpoint+"?"+query.Encode(), nil)
 	if err != nil {
 		return err
 	}
+	return c.doJSON(request, destination)
+}
+
+func (c *qqClient) doJSON(request *http.Request, destination any) error {
 	request.Header.Set("User-Agent", "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 Chrome/131 Safari/537.36")
 	request.Header.Set("Referer", "https://y.qq.com/")
 	request.Header.Set("Origin", "https://y.qq.com")