rewrite na js bo rust jest zjebany

src/util/downloader.ts

@@ -0,0 +1,51 @@
+import { spawn } from "node:child_process";
+
+export async function get_audio(url: string): Promise<string> {
+  const ytDlpBin = process.env.YT_DLP_BIN_PATH! ?? "yt-dlp";
+  const dataDir = "./data";
+
+  const idMatch = /[?&]v=([a-zA-Z0-9_-]{11})/.exec(url);
+  if (!idMatch) throw new Error("Cannot extract video ID");
+
+  const id = idMatch[1];
+  console.log(`ID: ${id}`);
+
+  // ---- run yt-dlp ----
+  await new Promise<void>((resolve, reject) => {
+    const p = spawn(ytDlpBin, [
+      "-x",
+      "--audio-format", "opus",
+      "--audio-quality", "0",
+      "--no-playlist",
+      "--paths", dataDir,
+      url,
+    ]);
+
+    p.stderr.on("data", d => process.stderr.write(d));
+    p.on("close", code => code === 0 ? resolve() : reject(new Error("yt-dlp failed")));
+  });
+
+  // ---- find the file ----
+  return await new Promise<string>((resolve, reject) => {
+    const find = spawn("find", [
+      dataDir,
+      "-type", "f",
+      "-iname", `*${id}*.opus`,
+      "-exec", "readlink", "-f", "{}", ";",
+    ]);
+
+    let out = "";
+
+    find.stdout.on("data", d => out += d.toString());
+    find.stderr.on("data", d => process.stderr.write(d));
+
+    find.on("close", code => {
+      if (code !== 0 || !out.trim()) {
+        reject(new Error("Audio file not found"));
+      } else {
+        resolve(out.trim());
+      }
+    });
+  });
+}
+