From 93d53773c5a9665322b628f2a221559be1b9b197 Mon Sep 17 00:00:00 2001
From: syeopite <syeopite@syeopite.dev>
Date: Thu, 26 Dec 2024 22:24:10 -0800
Subject: [PATCH] Add Invidious's download endpoint

---
 src/routes/index.ts                     |  3 ++
 src/routes/invidious_routes/download.ts | 64 +++++++++++++++++++++++++
 2 files changed, 67 insertions(+)
 create mode 100644 src/routes/invidious_routes/download.ts

diff --git a/src/routes/index.ts b/src/routes/index.ts
index 5ad9258..f4ec8c1 100644
--- a/src/routes/index.ts
+++ b/src/routes/index.ts
@@ -6,6 +6,7 @@ import { bearerAuth } from "hono/bearer-auth";
 import youtubeApiPlayer from "./youtube_api_routes/player.ts";
 import invidiousRouteLatestVersion from "./invidious_routes/latestVersion.ts";
 import invidiousRouteDashManifest from "./invidious_routes/dashManifest.ts";
+import {getDownloadHandler} from "./invidious_routes/download.ts";
 import videoPlaybackProxy from "./videoPlaybackProxy.ts";
 import health from "./health.ts";
 
@@ -21,6 +22,8 @@ export const routes = (app: Hono, konfigStore: Store<Record<string, unknown>>) =
 
   app.route("/youtubei/v1", youtubeApiPlayer);
   app.route("/latest_version", invidiousRouteLatestVersion);
+  // Needs app for app.request in order to call /latest_version endpoint
+  app.post("/download", getDownloadHandler(app));
   app.route("/api/manifest/dash/id", invidiousRouteDashManifest);
   app.route("/videoplayback", videoPlaybackProxy);
   app.route("/healthz", health);
diff --git a/src/routes/invidious_routes/download.ts b/src/routes/invidious_routes/download.ts
new file mode 100644
index 0000000..50a86db
--- /dev/null
+++ b/src/routes/invidious_routes/download.ts
@@ -0,0 +1,64 @@
+import { HTTPException } from "hono/http-exception";
+import { Store } from "@willsoto/node-konfig-core";
+import {
+    verifyRequest
+} from "../../lib/helpers/verifyRequest.ts";
+
+export function getDownloadHandler(app) {
+    async function handler(c) {
+        const body = await c.req.formData();
+
+        const videoId = body.get("id");
+
+        const konfigStore = await c.get("konfigStore") as Store<
+            Record<string, unknown>
+        >;
+
+        const check = c.req.query("check");
+
+        if (konfigStore.get("server.verify_requests") && check == undefined) {
+            throw new HTTPException(400, {
+                res: new Response("No check ID."),
+            });
+        } else if (konfigStore.get("server.verify_requests") && check) {
+            if (verifyRequest(check, videoId, konfigStore) === false) {
+                throw new HTTPException(400, {
+                    res: new Response("ID incorrect."),
+                });
+            }
+        }
+
+        const title = body.get("title");
+
+        let downloadWidgetData : { itag: number; ext: string; label: string};
+
+        try {
+            downloadWidgetData = JSON.parse(body.get("download_widget"));
+        } catch (error) {
+            throw new HTTPException(400, {res: new Response("Invalid download_widget json"), });
+        }
+
+        if (!(title || videoId || (downloadWidgetData.itag && downloadWidgetData.ext))) {
+            throw new HTTPException(400, {res: new Response("Invalid form data"), });
+        }
+        const itag = Number(downloadWidgetData.itag);
+        const {ext, label} = downloadWidgetData;
+
+        const filename = `${title}-${videoId}.${ext || ''}`;
+
+        if (label) {
+        } else if (itag) {
+            const urlQueriesForLatestVersion = new URLSearchParams();
+            urlQueriesForLatestVersion.set("id", videoId);
+            urlQueriesForLatestVersion.set("itag", itag.toString());
+            urlQueriesForLatestVersion.set("title", filename);
+            urlQueriesForLatestVersion.set("local", "true");
+
+            return await app.request(`/latest_version?${urlQueriesForLatestVersion.toString()}`);
+        } else {
+            throw new HTTPException(400, {res: new Response("Invalid label or itag"), });
+        }
+    }
+
+    return handler
+}