feat: 完善后端启动，打二进制文件防止因为网络无法运行

backend-deno/modules/lyrics.ts

@@ -5,6 +5,9 @@
 
 import { MusicStatus } from "./apple_music.ts";
 import { DatabaseSync } from 'node:sqlite'
+const userDataDir = Deno.env.get("USER_DATA_DIR") ?? ".";
+// 将 DB_PATH 设为 `${userDataDir}/lyrics.db`
+const DB_PATH = `${userDataDir}/lyrics.db`;
 
 export interface LyricsData {
   current_lyric_time: number | null;
@@ -37,7 +40,6 @@ let lyricsCache: LyricsCache = {
   deleted: false,
 };
 
-const DB_PATH = "./lyrics.db";
 const db = new DatabaseSync(DB_PATH);
 
 /**
@@ -80,12 +82,12 @@ export function clearLyricsCache(): void {
 async function loadLyricsFromDB(
   trackName: string,
   artist: string
-): Promise<string | null> {
+): Promise<string> {
   try {
     const content = db.prepare(`SELECT lyrics_text FROM lyrics WHERE track_name = ? AND artist = ?`).get(trackName, artist);
-    return content.lyrics_text;
+    return String(content?.lyrics_text ?? '');
   } catch (error) {
-    return null;
+    return '';
   }
 }
 
@@ -101,8 +103,8 @@ export async function saveLyrics(
   try {
     db.prepare(`DELETE FROM lyrics WHERE track_name = ? AND artist = ?`).run(trackName, artist);
     db.prepare(`INSERT INTO lyrics (track_name, artist, lyrics_text, source) VALUES (?, ?, ?, ?)`).run(trackName, artist, lyricsText, source);
-    lyricsCache.track_name = trackName;
-    lyricsCache.artist = artist;
+    lyricsCache.track_name = trackName ?? null;
+    lyricsCache.artist = artist ?? null;
     lyricsCache.lyrics_text = lyricsText;
     lyricsCache.source = source;
     console.log(`保存歌词成功: ${trackName} - ${artist}`);
@@ -117,7 +119,7 @@ export async function saveLyrics(
 export async function searchLyrics(
   trackName: string,
   artistName: string
-): Promise<string | null> {
+): Promise<string> {
   try {
     const searchVariants = [
       { title: trackName, artist: artistName },
@@ -155,10 +157,10 @@ export async function searchLyrics(
       }
     }
 
-    return null;
+    return '';
   } catch (error) {
     console.error(`搜索歌词时出错: ${error}`);
-    return null;
+    return '';
   }
 }
 
@@ -283,8 +285,8 @@ export async function getLyricsData(status: MusicStatus): Promise<LyricsData> {
     console.log(`歌曲切换，重新获取歌词: ${trackName} - ${artist}`);
 
     // 清空缓存
-    lyricsCache.track_name = trackName;
-    lyricsCache.artist = artist;
+    lyricsCache.track_name = trackName ?? null;
+    lyricsCache.artist = artist ?? null;
     lyricsCache.lyrics_text = null;
     lyricsCache.deleted = false;