Auto update YT Descriptions using the YouTube API

.gitignore

@@ -4,3 +4,4 @@ public
 .DS_Store
 _descriptions
 .netlify
+google-credentials

node-scripts/update-yt.mjs

@@ -0,0 +1,245 @@
+// npm run update-yt
+// Updates YouTube video descriptions according to description generated by from json data.
+
+// ===========================================================
+// HOW TO SETUP GOOGLE OAuth2 CREDENTIALS
+// ===========================================================
+// 1. Go to https://console.developers.google.com/
+// 2. Click on the dropdown on the top left. Create a new project / select an existing project.
+// 3. Enable YouTube Data API v3 in this project by going to APIs & Services > Enable APIs and Services > Search for 'YouTube Data API v3' > Click Enable.
+// 4. Go to Credentials > Create Credentials > OAuth client ID. Here you might be asked to CONFIGURE CONSENT SCREEN. (If not, skip to step 5). Click on this button
+//    and fill in the required fields. (User type: 'External', App name, User support email, Developer contact information as required)
+//    Scopes: Add 'https://www.googleapis.com/auth/youtube'. On the summary page, scroll below to "Test Users" and add your email address. (This must be a Google account
+//    which has write access to the Coding Train YouTube channel.)
+// 5. Go to Credentials > Create Credentials > OAuth client ID > Application type: Desktop app > Create. Here, click on "DOWNLOAD JSON" to download the credentials file.
+//    Save this file as `google-credentials/client_secret.json` in this repo.
+// ===========================================================
+//
+//
+// ===========================================================
+// RUNNING THE SCRIPT
+// ===========================================================
+// 1. Run `npm run update-yt`
+// 2. If running the script for the first time, you will be asked to visit a URL to authenticate the app. Open this URL in your browser,
+//    and login with the Google account which has write access to the Coding Train YouTube channel. You will be asked to grant permissions to the app.
+//    After granting permissions, you will be redirected to a localhost page. Copy the `code` query param from the URL and paste it in the terminal.
+//    This will store the auth token and a refresh token in `google-credentials/credentials.json`, which will be used for subsequent runs.
+// 3. For updating the description of a video, it is required to first generate the descriptions using the `yt-desc` script.
+// ===========================================================
+
+import fs from 'fs';
+import { createInterface } from 'readline';
+import { google, youtube_v3 } from 'googleapis';
+import inquirer from 'inquirer';
+
+const SCOPES = ['https://www.googleapis.com/auth/youtube'];
+const TOKEN_DIR = 'google-credentials/';
+const TOKEN_PATH = TOKEN_DIR + 'credentials.json';
+const CLIENT_PATH = TOKEN_DIR + 'client_secret.json';
+const OAuth2 = google.auth.OAuth2;
+
+/**
+ * Create an OAuth2 client with the given credentials.
+ *
+ * @param {Object} credentials The authorization client credentials.
+ */
+async function authorize(credentials) {
+  const clientSecret = credentials.installed.client_secret;
+  const clientId = credentials.installed.client_id;
+  const redirectUrl = credentials.installed.redirect_uris[0];
+  const oauth2Client = new OAuth2(clientId, clientSecret, redirectUrl);
+
+  // Check if we have previously stored a token.
+  try {
+    const token = await fs.promises.readFile(TOKEN_PATH);
+    oauth2Client.credentials = JSON.parse(token);
+  } catch (err) {
+    await getNewToken(oauth2Client);
+  }
+
+  return oauth2Client;
+}
+
+/**
+ * Get and store new token after prompting for user authorization.
+ *
+ * @param {google.auth.OAuth2} oauth2Client The OAuth2 client to get token for.
+ */
+async function getNewToken(oauth2Client) {
+  const authUrl = oauth2Client.generateAuthUrl({
+    access_type: 'offline',
+    scope: SCOPES
+  });
+  console.log('Authorize this app by visiting this url: ', authUrl);
+  const rl = createInterface({
+    input: process.stdin,
+    output: process.stdout
+  });
+
+  return new Promise((res, rej) => {
+    rl.question('Enter the code from that page here: ', function (code) {
+      rl.close();
+      oauth2Client.getToken(code, function (err, token) {
+        if (err) {
+          console.log('Error while trying to retrieve access token', err);
+          return rej();
+        }
+        oauth2Client.credentials = token;
+        storeToken(token, res);
+      });
+    });
+  });
+}
+
+function storeToken(token, callback) {
+  try {
+    fs.mkdirSync(TOKEN_DIR);
+  } catch (err) {
+    if (err.code != 'EEXIST') {
+      throw err;
+    }
+  }
+  fs.writeFile(TOKEN_PATH, JSON.stringify(token), (err) => {
+    if (err) throw err;
+    console.log('Token stored to ' + TOKEN_PATH);
+    callback();
+  });
+}
+
+/**
+ * Updates the description of a YouTube video.
+ * @param {string} videoId youtube video id
+ * @param {string} newDescription new description to update
+ * @param {youtube_v3.Youtube} service youtube service
+ */
+async function updateYTDesc(videoId, newDescription, service) {
+  // YouTube Data API v3:
+  // videos.update
+  // ⚠️ Quota impact: A call to this method has a quota cost of 50 units.
+
+  try {
+    const res = await service.videos.list({
+      part: ['snippet'],
+      id: videoId
+    });
+    const video = res.data.items[0];
+
+    // diff old and new description
+    const oldDescription = video.snippet.description;
+    if (oldDescription === newDescription) {
+      console.log('Description is already up to date.');
+      return;
+    }
+
+    const res2 = await service.videos.update({
+      part: ['snippet'],
+      requestBody: {
+        id: videoId,
+        snippet: {
+          title: video.snippet.title,
+          description: newDescription,
+          categoryId: video.snippet.categoryId
+        }
+      }
+    });
+
+    console.log('Updated video description.');
+  } catch (err) {
+    console.error('The API returned an error: ' + err);
+  }
+}
+
+// Load client secrets from a local file.
+async function main() {
+  let credentials;
+  try {
+    credentials = await fs.promises.readFile(CLIENT_PATH);
+  } catch (err) {
+    console.log('Error loading client secret file: ' + err);
+    return;
+  }
+  const auth = await authorize(JSON.parse(credentials));
+
+  const service = google.youtube({
+    version: 'v3',
+    auth
+  });
+
+  if (
+    !fs.existsSync('_descriptions') ||
+    fs.readdirSync('_descriptions').length === 0
+  ) {
+    console.log(
+      'No generated descriptions available. Try generating them first by using the yt-desc script.'
+    );
+    return;
+  }
+
+  const videoIds = fs
+    .readdirSync('_descriptions')
+    .filter((f) => !f.endsWith('json'))
+    .map((f) => f.split('.')[0].split('_').slice(1).join('_'));
+  const metadata = JSON.parse(
+    fs.readFileSync('_descriptions/metadata.json', 'utf8')
+  );
+
+  const videos = metadata.videos.filter((x) => videoIds.includes(x.videoId));
+  const tracks = metadata.tracks
+    .map((track) => {
+      track.videos = videos.filter(
+        (video) => video.canonicalTrack === track.slug
+      );
+      return track;
+    })
+    .filter((track) => track.videos.length > 0);
+  const challengeVideos = videos.filter((video) =>
+    video.canonicalURL.startsWith('challenges')
+  );
+  if (challengeVideos.length > 0) {
+    tracks.push({
+      slug: 'challenges',
+      title: 'Coding Challenges',
+      videos: challengeVideos
+    });
+  }
+
+  const { trackSlug } = await inquirer.prompt([
+    {
+      type: 'list',
+      name: 'trackSlug',
+      message: 'Select a track to update:',
+      choices: tracks.map((track) => ({
+        name: track.title,
+        value: track.slug
+      }))
+    }
+  ]);
+  const track = tracks.find((x) => x.slug === trackSlug);
+  const { videoId } = await inquirer.prompt([
+    {
+      type: 'list',
+      name: 'videoId',
+      message: 'Select a video to update:',
+      choices: track.videos.map((video) => ({
+        name: video.title + ' (' + video.videoId + ')',
+        value: video.videoId
+      }))
+    }
+  ]);
+  const video = track.videos.find((video) => video.videoId === videoId);
+
+  console.log(
+    'Updating description for video...',
+    video.title,
+    `(${video.videoId})`
+  );
+
+  let newDescription = fs.readFileSync(
+    `_descriptions/${video.slug}_${video.videoId}.txt`,
+    'utf8'
+  );
+
+  updateYTDesc(video.videoId, newDescription, service);
+}
+
+main();

node-scripts/yt-description.mjs

@@ -4,8 +4,8 @@
 // npm run yt-desc
 // npm run yt-desc https://thecodingtrain.com/path/to/video/page
 // npm run yt-desc https://youtube.com/watch?v=videoId
-// npm run yt-desc ./path/to/index.json
-// npm run yt-desc ./path/to/index.json -- -c # copy to clipboard
+// npm run yt-desc path/to/index.json # path starts with content/videos
+// npm run yt-desc path/to/index.json -- -c # copy to clipboard
 
 // Output files are saved to `./_descriptions` directory
 
@@ -63,7 +63,6 @@ class Video {
 /**
  * Searches for `index.json` files in a given directory and returns an array of parsed files.
  * @param {string} dir Name of directory to search for files
- * @param {?any[]} arrayOfFiles Array to store the parsed JSON files
  * @returns {any[]}
  */
 function findContentFilesRecursive(dir) {
@@ -661,5 +660,22 @@ const allTracks = [...mainTracks, ...sideTracks];
   } else {
     videos.forEach(writeDescription);
   }
+  const metadata = {
+    videos: videos.map((v) => ({
+      title: v.data.title,
+      videoId: v.data.videoId,
+      slug: v.slug,
+      canonicalTrack: v.canonicalTrack,
+      canonicalURL: v.canonicalURL
+    })),
+    tracks: allTracks.map((t) => ({
+      slug: t.trackName,
+      title: t.data.title
+    }))
+  };
+  fs.writeFileSync(
+    './_descriptions/metadata.json',
+    JSON.stringify(metadata, null, 2)
+  );
   console.log('\n✅ Wrote descriptions to  ./_descriptions/');
 })();