Support new YouTube HTML output

lib/api.mjs

@@ -1,23 +1,26 @@
 import debug from 'debug';
 import util from 'util';
 import fetch from 'node-fetch';
+import fs from 'fs';
 
 import { WATCH_BASE } from './util.mjs';
 import { retryable, exclusive } from './retry.mjs';
 import { TemporaryError } from './retry.mjs';
 
 const log = debug('youtube-maze:api');
-const PLAYER_RESP_REGEX = /window\["ytInitialPlayerResponse"\] = (\{.*?\});/;
-const PLAYER_CONFIG_REGEX = /ytplayer\.config = (\{.*?\});/;
+const METADATA_REGEXES = [
+    /window\["ytInitialPlayerResponse"\] = (\{.*?\});/,
+    /var ytInitialPlayerResponse = (\{.*?\});/,
+];
 
 /**
- * Fetch the `ytplayer.config` object for a YouTube video.
+ * Fetch metadata about a YouTube video.
  *
  * @async
  * @param String videoId Identifier of the video to fetch.
- * @return Object The player configuration object.
+ * @return Object The video metadata object.
  */
-const bareGetPlayerConfig = async (videoId) =>
+const bareGetMetadata = async (videoId) =>
 {
     const url = util.format(WATCH_BASE, encodeURIComponent(videoId));
     log(`Fetching ${videoId} (${url})`);
@@ -33,36 +36,24 @@ const bareGetPlayerConfig = async (videoId) =>
     }
 
     const body = await res.text();
+    const searchResults = METADATA_REGEXES.map(regex => body.match(regex));
+    const searchResult = searchResults.find(item => item !== null);
 
-    // Look for the initial player response object to check whether the
-    // video was found
-    const responseSearch = body.match(PLAYER_RESP_REGEX);
-
-    if (responseSearch === null)
+    if (searchResult === null)
     {
-        throw new TemporaryError(`Invalid YouTube response for video ${videoId}`);
+        throw new TemporaryError(`Incomplete YouTube response for video ${videoId}`);
     }
 
-    const response = JSON.parse(responseSearch[1]);
+    const metadata = JSON.parse(searchResult[1]);
 
-    if (response.playabilityStatus.status !== 'OK')
+    if (metadata.playabilityStatus.status !== 'OK')
     {
         throw new Error(`Video ${videoId} is not available; \
-status: ${response.playabilityStatus.status}; \
-reason: "${response.playabilityStatus.reason}"`);
+status: ${metadata.playabilityStatus.status}; \
+reason: "${metadata.playabilityStatus.reason}"`);
     }
 
-    // Look for the definition of ytplayer.config and unserialize it
-    const configSearch = body.match(PLAYER_CONFIG_REGEX);
-
-    if (configSearch === null)
-    {
-        throw new TemporaryError(`Unable to find player for video ${videoId}`);
-    }
-
-    const config = JSON.parse(configSearch[1]);
-    config.args.player_response = JSON.parse(config.args.player_response);
-    const actualId = config.args.player_response.videoDetails.videoId;
+    const actualId = metadata.videoDetails.videoId;
 
     if (videoId !== actualId)
     {
@@ -70,40 +61,36 @@ reason: "${response.playabilityStatus.reason}"`);
     }
 
     log(`Done fetching ${videoId}`);
-    return config;
+    return metadata;
 };
 
-export const getPlayerConfig = exclusive(retryable(bareGetPlayerConfig));
+export const getMetadata = exclusive(retryable(bareGetMetadata));
 
 /**
- * Get metadata about a YouTube video.
+ * Get video ID and title.
  *
- * @param config The `ytplayer.config` object corresponding to the source
- * YouTube video, as obtained from `getPlayerConfig`.
- * @return Object containing the video metadata.
+ * @param Object metadata The video metadata object from `getMetadata`.
+ * @return Object Containing the video ID and title.
  */
-export const getVideoMeta = config => ({
-    videoId: config.args.player_response.videoDetails.videoId,
-    title: config.args.player_response.videoDetails.title,
+export const getVideoInfo = metadata => ({
+    videoId: metadata.videoDetails.videoId,
+    title: metadata.videoDetails.title,
 });
 
 /**
  * Find videos linked from the endscreen of a YouTube video.
  *
- * @param config The `ytplayer.config` object corresponding to the source
- * YouTube video, as obtained from `getPlayerConfig`.
+ * @param Object metadata The video metadata object from `getMetadata`.
  * @return List of identifiers of linked videos.
  */
-export const getEndScreenVideos = config =>
+export const getEndScreenVideos = metadata =>
 {
-    const response = config.args.player_response;
-
-    if (!('endscreen' in response))
+    if (!('endscreen' in metadata))
     {
         return [];
     }
 
-    return response.endscreen.endscreenRenderer.elements
+    return metadata.endscreen.endscreenRenderer.elements
         .map(elt => elt.endscreenElementRenderer)
         .filter(rdr => 'watchEndpoint' in rdr.endpoint)
         .map(rdr => rdr.endpoint.watchEndpoint.videoId);
@@ -112,20 +99,17 @@ export const getEndScreenVideos = config =>
 /**
  * Find videos linked from as cards from a YouTube video.
  *
- * @param config The `ytplayer.config` object corresponding to the source
- * YouTube video, as obtained from `getPlayerConfig`.
+ * @param Object metadata The video metadata object from `getMetadata`.
  * @return List of identifiers of linked videos.
  */
-export const getCardVideos = config =>
+export const getCardVideos = metadata =>
 {
-    const response = config.args.player_response;
-
-    if (!('cards' in response))
+    if (!('cards' in metadata))
     {
         return [];
     }
 
-    return response.cards.cardCollectionRenderer.cards
+    return metadata.cards.cardCollectionRenderer.cards
         .map(card => card.cardRenderer.content)
         .filter(content => 'videoInfoCardContentRenderer' in content)
         .map(content => content.videoInfoCardContentRenderer)

lib/explore.mjs

@@ -31,19 +31,19 @@ export const exploreVideos = async (videoId, onUpdate) =>
 
         if (!(currentId in videosNodes))
         {
-            const config = await api.getPlayerConfig(currentId);
-            const meta = api.getVideoMeta(config);
+            const metadata = await api.getMetadata(currentId);
+            const info = api.getVideoInfo(metadata);
 
-            videosNodes[currentId] = meta;
+            videosNodes[currentId] = info;
             nextVideos[currentId] = new Set();
 
             // Add links between this video and the linked ones
-            api.getEndScreenVideos(config)
-                .forEach(nextId => nextVideos[meta.videoId].add(nextId));
-            api.getCardVideos(config)
-                .forEach(nextId => nextVideos[meta.videoId].add(nextId));
+            api.getEndScreenVideos(metadata)
+                .forEach(nextId => nextVideos[info.videoId].add(nextId));
+            api.getCardVideos(metadata)
+                .forEach(nextId => nextVideos[info.videoId].add(nextId));
 
-            for (let nextId of nextVideos[meta.videoId])
+            for (let nextId of nextVideos[info.videoId])
             {
                 queue.push(nextId);
             }