Add experimental YouTube caption integration that doesn't really work

app/api/routes/channels/index.js

@@ -1,6 +1,7 @@
 const channels = require('express').Router();
 
 channels.use('/zoom', require('./zoom'));
+channels.use('/youtube', require('./youtube'));
 
 const iconPrefix = '/static/channel-icons';
 const configPatePathPrefix = '/captioner/settings/channels/new?type=';
@@ -55,12 +56,32 @@ const channelsList = [
     iconPath: `${iconPrefix}/youtube.png`,
     limit: 1,
     configPagePath: `${configPatePathPrefix}youtube`,
+    requiredExperiment: 'youtube',
   },
 ];
 
 channels.get('/', async (req, res, next) => {
-  // Sort alphabetically by name
-  res.send(channelsList.sort((a, b) => a.name.localeCompare(b.name)));
+  let { experiments } = req.query;
+  experiments = experiments ? String(experiments).split(',') : [];
+
+  let channelsToReturn = [
+    ...channelsList.sort((a, b) =>
+      // Sort alphabetically by name
+      a.name.localeCompare(b.name)
+    ),
+  ].map((c) => ({ ...c })); // clone
+
+  // Filter out any channels that require experiments
+  // to be enabled, unless those experiments are enabled
+  channelsToReturn = channelsToReturn.filter(
+    (channel) =>
+      !channel.requiredExperiment ||
+      experiments.includes(channel.requiredExperiment)
+  );
+
+  channelsToReturn.forEach((channel) => delete channel.requiredExperiment);
+
+  res.send(channelsToReturn);
 });
 
 channels.get('/:id', async (req, res, next) => {

app/api/routes/channels/youtube/index.js

@@ -0,0 +1,76 @@
+const youtube = require('express').Router();
+const axios = require('axios');
+const rateLimit = require('express-rate-limit');
+
+const rateLimitWindowMinutes = 5;
+const requestsAllowedPerSecond = 1; // Frontend limits to one request per second
+const rateLimitLeeway = 10;
+const rateLimiter = rateLimit({
+  windowMs: rateLimitWindowMinutes * 60 * 1000,
+  max: rateLimitWindowMinutes * requestsAllowedPerSecond * 60 + rateLimitLeeway,
+});
+
+youtube.use('/', rateLimiter);
+
+youtube.post('/', async (req, res) => {
+  const { apiPath, transcript } = req.body;
+  if (!apiPath || !transcript) {
+    return res.sendStatus(400);
+  }
+
+  try {
+    // Verify this is actually a URL and a YouTube closed caption URL
+    const url = new URL(apiPath);
+    if (
+      url.origin !== 'http://upload.youtube.com' ||
+      url.pathname !== '/closedcaption'
+    ) {
+      throw new Error();
+    }
+  } catch (e) {
+    return res.sendStatus(400);
+  }
+
+  // At one point I thought doing this might improve caption delay
+  // in YouTube but I don't think so
+  const offsetTimestampSeconds = 0;
+
+  const body = `${
+    new Date(new Date().getTime() - 1000 * offsetTimestampSeconds)
+      .toISOString()
+      .split('Z')[0]
+  }\n${transcript}\n`;
+
+  axios
+    .post(apiPath, body, {
+      headers: {
+        'Content-Type': 'text/plain',
+      },
+    })
+    .then(() => {
+      // We got a successful response
+      res.sendStatus(200);
+    })
+    .catch((e) => {
+      if (e.code === 'ENOTFOUND') {
+        return res.sendStatus(404);
+      } else {
+        const errorCode =
+          e && e.response && e.response.status ? e.response.status : undefined;
+        switch (errorCode) {
+          case 400:
+            return res
+              .status(400)
+              .send(
+                `Error: The Zoom meeting has not started yet or it has already ended.`
+              );
+          default:
+            return res
+              .status(520)
+              .send(`Something went wrong. (${errorCode || 'Unknown error'})`);
+        }
+      }
+    });
+});
+
+module.exports = youtube;

app/api/routes/channels/zoom/index.js

@@ -12,7 +12,7 @@ const zoomRateLimiter = rateLimit({
 
 zoom.use('/', zoomRateLimiter);
 
-zoom.post('/api', async (req, res) => {
+zoom.post('/', async (req, res) => {
   const { apiPath, transcript } = req.body;
   if (!apiPath || !transcript) {
     return res.sendStatus(400);

app/components/channels/ChannelsPopup.vue

@@ -72,8 +72,8 @@ export default {
       channels: [],
     };
   },
-  async mounted() {
-    this.channels = await this.$axios.$get('/api/channels');
+  async created() {
+    this.channels = await this.$store.dispatch('channels/GET_CHANNELS');
   },
   methods: {
     toggleChannel(channelId, onOrOff) {

app/components/channels/editors/youtube.vue

@@ -0,0 +1,87 @@
+<template>
+  <div>
+    <img
+      :src="channel.iconPath"
+      class="w-100 col-6 d-block mx-auto mt-2 mb-3"
+      alt="YouTube"
+    />
+    <p class="lead text-center">
+      Send real-time captions to a YouTube live stream.
+    </p>
+    <hr />
+    <ol>
+      <li>
+        In YouTube Studio, set up a live stream. Go to stream settings and
+        enable closed captions.
+      </li>
+      <li>
+        Select "Post captions to URL."
+      </li>
+      <li>
+        Copy the captions ingestion URL and paste it here.
+      </li>
+    </ol>
+    <div class="card card-body">
+      <div
+        v-if="savedChannel && savedChannel.error"
+        class="alert alert-warning small"
+      >
+        <strong class="text-danger">
+          <fa icon="exclamation-triangle" /> Error:
+        </strong>
+        {{ savedChannel.error }}
+      </div>
+      <label for="url" class="small">
+        YouTube captions ingestion URL
+      </label>
+      <input
+        id="url"
+        name="url"
+        v-model="url"
+        autofocus
+        class="form-control"
+        type="url"
+        placeholder="YouTube captions ingestion URL"
+      />
+    </div>
+  </div>
+</template>
+
+<script>
+export default {
+  props: {
+    channel: {
+      required: true,
+      type: Object,
+    },
+    savedChannel: {
+      required: false,
+      type: Object,
+    },
+  },
+  mounted() {
+    this.url = this.savedChannel?.parameters?.url;
+  },
+  data() {
+    return {
+      url: null,
+    };
+  },
+  watch: {
+    url: {
+      immediate: true,
+      handler(url) {
+        this.$emit('parametersUpdated', {
+          url,
+        });
+
+        if (this.url) {
+          this.$emit('formValid');
+        } else {
+          this.$emit('formInvalid');
+        }
+      },
+    },
+  },
+};
+</script>

app/pages/captioner/settings/channels.vue

@@ -141,11 +141,23 @@ export default {
       channels: [],
     };
   },
-  async asyncData({ $axios }) {
-    const channels = await $axios.$get('/api/channels');
-    return {
-      channels,
-    };
+  async created() {
+    // Wait until settings are loaded
+    if (!this.$store.state.settingsLoaded) {
+      await new Promise((resolve) => {
+        this.$store.watch(
+          (state) => {
+            return state.settingsLoaded;
+          },
+          (loaded) => {
+            if (loaded) {
+              resolve();
+            }
+          }
+        );
+      });
+    }
+    this.channels = await this.$store.dispatch('channels/GET_CHANNELS');
   },
   methods: {
     channelInfo(id) {

app/pages/captioner/settings/channels/_channelId.vue

@@ -67,7 +67,7 @@ export default {
   },
   async beforeCreate() {
     try {
-      const channels = await this.$axios.$get('/api/channels');
+      const channels = await this.$store.dispatch('channels/GET_CHANNELS');
 
       await this.settingsLoaded();
 

app/pages/captioner/settings/experiments/index.vue

@@ -222,6 +222,12 @@ export default {
           description:
             'After speech is converted to text, convert the text back to speech using speech synthesis.',
         },
+        {
+          id: 'youtube',
+          name: 'YouTube integration',
+          description:
+            'Add an experimental YouTube live closed captions integration. Go to the Channels page to set it up.',
+        },
       ],
 
       experimentIdToAdd: '',