api: add initial draft support for nicovideo

Author: wukko

api/src/processing/match.js

@@ -29,6 +29,7 @@ import loom from "./services/loom.js";
 import facebook from "./services/facebook.js";
 import bluesky from "./services/bluesky.js";
 import xiaohongshu from "./services/xiaohongshu.js";
+import nicovideo from "./services/nicovideo.js";
 
 let freebind;
 
@@ -268,6 +269,14 @@ export default async function({ host, patternMatch, params, authType }) {
                 });
                 break;
 
+            case "nicovideo":
+                r = await nicovideo({
+                    ...patternMatch,
+                    dispatcher,
+                    quality: params.videoQuality,
+                });
+                break;
+
             default:
                 return createResponse("error", {
                     code: "error.api.service.unsupported"

api/src/processing/service-config.js

@@ -60,6 +60,11 @@ export const services = {
     loom: {
         patterns: ["share/:id", "embed/:id"],
     },
+    nicovideo: {
+        patterns: ["watch/:id"],
+        tld: "jp",
+        subdomains: ["sp"],
+    },
     ok: {
         patterns: [
             "video/:id",

api/src/processing/service-patterns.js

@@ -79,4 +79,6 @@ export const testers = {
     "xiaohongshu": pattern =>
         pattern.id?.length <= 24 && pattern.token?.length <= 64
         || pattern.shareId?.length <= 24,
+
+    "nicovideo": pattern => pattern.id?.length <= 12,
 }

api/src/processing/services/nicovideo.js

@@ -0,0 +1,120 @@
+import { genericUserAgent } from "../../config.js";
+
+const genericHeaders = {
+    "user-agent": genericUserAgent,
+    "accept-language": "en-US,en;q=0.9",
+}
+
+const getVideoInfo = async (id, dispatcher, quality) => {
+    const html = await fetch(`https://www.nicovideo.jp/watch/${id}`, {
+        dispatcher,
+        headers: genericHeaders
+    }).then(r => r.text()).catch(() => {});
+
+    if (!(html.includes("accessRightKey")
+            || !(html.includes('<meta name="server-response" content="')))) {
+        return { error: "fetch.fail" };
+    }
+
+    const rawContent =
+        html.split('<meta name="server-response" content="')[1]
+        .split('" />')[0]
+        .replaceAll("&quot;", '"');
+
+    const data = JSON.parse(rawContent)?.data?.response;
+
+    if (!data) {
+        return { error: "fetch.fail" };
+    }
+
+    const audio = data.media?.domand?.audios.find(audio => audio.isAvailable);
+    const bestVideo = data.media?.domand?.videos.find(video => video.isAvailable);
+
+    const preferredVideo = data.media?.domand?.videos.find(video =>
+        video.isAvailable && video.label.split('p')[0] === quality
+    );
+
+    const video = preferredVideo || bestVideo;
+
+    return {
+        watchTrackId: data.client?.watchTrackId,
+        accessRightKey: data.media?.domand?.accessRightKey,
+
+        video,
+
+        outputs: [[video.id, audio.id]],
+
+        author: data.owner?.nickname,
+        title: data.video?.title,
+    }
+}
+
+const getHls = async (dispatcher, id, trackId, accessRightKey, outputs) => {
+    const response = await fetch(
+        `https://nvapi.nicovideo.jp/v1/watch/${id}/access-rights/hls?actionTrackId=${trackId}`,
+        {
+            method: "POST",
+            dispatcher,
+            headers: {
+                ...genericHeaders,
+                "content-type": "application/json",
+                "x-access-right-key": accessRightKey,
+                "x-frontend-id": "6",
+                "x-frontend-version": "0",
+                "x-request-with": "nicovideo",
+            },
+            body: JSON.stringify({
+                outputs,
+            })
+        }
+    ).then(r => r.json()).catch(() => {});
+
+    if (!response?.data?.contentUrl) return;
+    return response.data.contentUrl;
+}
+
+export default async function ({ id, dispatcher, quality }) {
+    const {
+        watchTrackId,
+        accessRightKey,
+        video,
+        outputs,
+        author,
+        title,
+        error
+    } = await getVideoInfo(id, dispatcher, quality);
+
+    if (error) {
+        return { error };
+    }
+
+    if (!watchTrackId || !accessRightKey || !outputs) {
+        return { error: "fetch.empty" };
+    }
+
+    const hlsUrl = await getHls(
+        dispatcher,
+        id,
+        watchTrackId,
+        accessRightKey,
+        outputs
+    );
+
+    if (!hlsUrl) {
+        return { error: "fetch.empty" };
+    }
+
+    return {
+        urls: hlsUrl,
+        isHLS: true,
+        filenameAttributes: {
+            service: "nicovideo",
+            id,
+            title,
+            author,
+            resolution: `${video.width}x${video.height}`,
+            qualityLabel: `${video.label}`,
+            extension: "mp4"
+        }
+    }
+}