downlederigoೃ

src/downloader/index.ts

@@ -0,0 +1,50 @@
+import { config } from "../config.js";
+import { spawn } from "node:child_process";
+import path from "node:path";
+import { addToCache, isCached } from "../cache.js";
+
+// TODO: make this have a return type
+export async function downloadSong(streamUrl: string, decryptionKey: string): Promise<void> {
+    const baseOutputName = streamUrl.split("/").at(-1)?.split("?").at(0)?.split(".").splice(0, 1).join(".")?.trim();
+    if (!baseOutputName) { throw "could not get base output name from stream url"; }
+    const encryptedName = baseOutputName + "_enc.mp4";
+    const encryptedPath = path.join(config.downloader.cache.directory, encryptedName);
+    const decryptedName = baseOutputName + ".mp4";
+    const decryptedPath = path.join(config.downloader.cache.directory, decryptedName);
+
+    if ( // TODO: remove check for encrypted file/cache for encrypted?
+        isCached(encryptedName) &&
+        isCached(decryptedName)
+    ) { return; }
+
+    await new Promise<void>((res, rej) => {
+        const child = spawn(config.downloader.ytdlp_path, [
+            "--quiet",
+            "--no-warnings",
+            "--allow-unplayable-formats",
+            "--fixup", "never",
+            "--paths", config.downloader.cache.directory,
+            "--output", encryptedName,
+            streamUrl
+        ]).on("error", (err) => { rej(err); });
+        child.stderr.on("data", (chunk) => { rej(chunk); });
+        child.on("exit", () => { res(); });
+    });
+
+    await new Promise<void>((res, rej) => {
+        const child = spawn(config.downloader.ffmpeg_path, [
+            "-loglevel", "error",
+            "-y",
+            "-decryption_key", decryptionKey,
+            "-i", encryptedPath,
+            "-c", "copy",
+            "-movflags", "+faststart",
+            decryptedPath
+        ]).on("error", (err) => { rej(err); });
+        child.stderr.on("data", (chunk) => { rej(chunk); });
+        child.on("exit", () => { res(); } );
+    });
+
+    addToCache(encryptedName);
+    addToCache(decryptedName);
+}