feat: make main live captions stream public

Reviewed-on: #5

index.js

@@ -29,6 +29,7 @@ const limiter = rateLimit({
     limit: 500, // Limit each IP to 100 requests per `window` (here, per 15 minutes).
     standardHeaders: 'draft-8', // draft-6: `RateLimit-*` headers; draft-7 & draft-8: combined `RateLimit` header
     legacyHeaders: false, // Disable the `X-RateLimit-*` headers.
+    skip: (req) => req.path.startsWith("/live-captions"),
     keyGenerator: (req) => {
         const forwarded = req.headers["x-forwarded-for"]?.split(",")[0]; // Take the first IP in the list
         const ip = forwarded || req.ip; // Fallback to req.ip

package.json

@@ -6,6 +6,7 @@
   "scripts": {
     "test": "npx mocha test/auth.test.js",
     "start": "node index.js",
+    "dev": "node --watch index.js",
     "live-captions:test-sender": "node scripts/liveCaptionsTestSender.js",
     "docker": "docker compose up -d",
     "docker_restore": "docker-compose exec mongo mongorestore --db EMI_SOCIAL /dump/EMI_SOCIAL/",

routes/liveCaptions.js

@@ -1,19 +1,36 @@
 var express = require('express');
 var router = express.Router();
+const { rateLimit } = require("express-rate-limit");
 
 const sessionChecker = require("../middleware/sessionChecker.js");
 
 const MAX_BUFFER_SIZE = 300;
 const DEFAULT_INITIAL_LIMIT = 40;
 const MAX_INITIAL_LIMIT = 120;
-const CAPTION_META_KEYS = new Set(["sequence", "createdAt", "original"]);
+const INACTIVITY_RESET_MS = 10 * 60 * 1000;
+const CAPTION_META_KEYS = new Set(["sequence", "createdAt", "original", "draft", "sourceLang", "lang", "isDraft", "status", "translations"]);
 
 const liveCaptionState = {
     startedAt: Date.now(),
+    lastIngestAt: 0,
     latestSequence: 0,
     captions: [],
 };
 
+const liveCaptionsLimiter = rateLimit({
+    windowMs: 10 * 60 * 1000,
+    limit: 6000,
+    standardHeaders: "draft-8",
+    legacyHeaders: false,
+    keyGenerator: (req) => {
+        const forwarded = req.headers["x-forwarded-for"]?.split(",")[0];
+        const ip = forwarded || req.ip || "";
+        return ip.includes(":") ? ip.split(":")[0] : ip;
+    },
+});
+
+router.use(liveCaptionsLimiter);
+
 const normalizeLang = (lang = "") => {
     const value = String(lang || "").trim().toLowerCase();
     if (!value) return "";
@@ -33,8 +50,23 @@ const normalizeTranslations = (translations) => {
     return normalized;
 };
 
+const readText = (value) => {
+    if (typeof value === "string") return value.trim();
+    return "";
+};
+
+const extractDraftText = (body = {}) => {
+    const directDraft = readText(body?.draft);
+    if (directDraft) return directDraft;
+    const nestedDraft = readText(body?.draft?.text);
+    if (nestedDraft) return nestedDraft;
+    const fallbackText = readText(body?.text);
+    if (fallbackText) return fallbackText;
+    return "";
+};
+
 const buildTranslationsFromFlatPayload = (payload) => {
-    const ignoredKeys = new Set(["original", "sourceLang", "translations"]);
+    const ignoredKeys = new Set(["original", "draft", "sourceLang", "lang", "isDraft", "status", "translations"]);
     const normalized = {};
     for (const [key, value] of Object.entries(payload || {})) {
         if (ignoredKeys.has(key)) continue;
@@ -67,8 +99,22 @@ const getAvailableLanguages = () => {
     return Array.from(langs).filter(Boolean).sort();
 };
 
-router.get("/stream", sessionChecker, async (req, res) => {
+const resetLiveCaptionState = () => {
+    liveCaptionState.startedAt = Date.now();
+    liveCaptionState.lastIngestAt = 0;
+    liveCaptionState.latestSequence = 0;
+    liveCaptionState.captions = [];
+};
+
+const maybeResetForInactivity = () => {
+    if (!liveCaptionState.lastIngestAt) return;
+    if ((Date.now() - liveCaptionState.lastIngestAt) < INACTIVITY_RESET_MS) return;
+    resetLiveCaptionState();
+};
+
+router.get("/stream", async (req, res) => {
     try {
+        maybeResetForInactivity();
         const sinceSequence = Number.parseInt(req.query?.sinceSequence, 10);
         const requestedLimit = Number.parseInt(req.query?.limit, 10);
         const initialLimit = Number.isFinite(requestedLimit)
@@ -103,16 +149,22 @@ router.get("/stream", sessionChecker, async (req, res) => {
 router.post("/ingest", async (req, res) => {
     try {
         // TODO: Add basic auth/API key validation before production roll-out.
-        const original = typeof req.body?.original === "string" ? req.body.original.trim() : "";
+        const draft = extractDraftText(req.body || {});
+        const originalFromPayload = readText(req.body?.original);
+        const original = originalFromPayload || draft;
+        const requestedLang = normalizeLang(req.body?.lang);
+        const sourceLangFromRequest = normalizeLang(req.body?.sourceLang || (requestedLang && requestedLang !== "draft" ? requestedLang : ""));
+        const isDraft = !!draft || requestedLang === "draft" || sourceLangFromRequest === "draft" || req.body?.isDraft === true || req.body?.status === "draft";
         const mapFromNested = normalizeTranslations(req.body?.translations);
         const mapFromFlat = buildTranslationsFromFlatPayload(req.body);
-        const translations = { ...mapFromNested, ...mapFromFlat };
+        const translations = isDraft ? {} : { ...mapFromNested, ...mapFromFlat };
-        const sourceLang = normalizeLang(req.body?.sourceLang || inferSourceLangFromTranslations(original, translations));
+        const inferredSource = inferSourceLangFromTranslations(original, translations);
+        const sourceLang = isDraft ? "" : (sourceLangFromRequest || inferredSource);
 
         if (!original) {
             return res.status(400).json({ status: "Original text is required" });
         }
-        if (sourceLang && sourceLang !== "original" && !translations[sourceLang]) {
+        if (sourceLang && sourceLang !== "original" && sourceLang !== "draft" && !translations[sourceLang]) {
             translations[sourceLang] = original;
         }
 
@@ -121,10 +173,15 @@ router.post("/ingest", async (req, res) => {
             sequence,
             createdAt: new Date().toISOString(),
             original,
+            sourceLang: sourceLang || undefined,
+            lang: isDraft ? "draft" : (sourceLang || undefined),
+            isDraft,
+            status: isDraft ? "draft" : "final",
             ...translations,
         };
 
         liveCaptionState.latestSequence = sequence;
+        liveCaptionState.lastIngestAt = Date.now();
         liveCaptionState.captions.push(caption);
         if (liveCaptionState.captions.length > MAX_BUFFER_SIZE) {
             liveCaptionState.captions.splice(0, liveCaptionState.captions.length - MAX_BUFFER_SIZE);
@@ -145,9 +202,7 @@ router.post("/ingest", async (req, res) => {
 router.post("/reset", async (_, res) => {
     try {
         // TODO: Add admin authorization before exposing this endpoint.
-        liveCaptionState.startedAt = Date.now();
+        resetLiveCaptionState();
-        liveCaptionState.latestSequence = 0;
-        liveCaptionState.captions = [];
         return res.json({ status: "ok" });
     } catch (error) {
         console.error("Error resetting live captions state", error);
@@ -155,4 +210,38 @@ router.post("/reset", async (_, res) => {
     }
 });
 
+router.get("/public/stream", async (req, res) => {
+    try {
+        maybeResetForInactivity();
+        const sinceSequence = Number.parseInt(req.query?.sinceSequence, 10);
+        const requestedLimit = Number.parseInt(req.query?.limit, 10);
+        const initialLimit = Number.isFinite(requestedLimit)
+            ? Math.max(1, Math.min(requestedLimit, MAX_INITIAL_LIMIT))
+            : DEFAULT_INITIAL_LIMIT;
+
+        let captions = [];
+        if (Number.isFinite(sinceSequence) && sinceSequence >= 0) {
+            captions = liveCaptionState.captions.filter((item) => item.sequence > sinceSequence);
+        } else {
+            captions = liveCaptionState.captions.slice(-initialLimit);
+        }
+
+        return res.json({
+            status: "ok",
+            latestSequence: liveCaptionState.latestSequence,
+            startedAt: new Date(liveCaptionState.startedAt).toISOString(),
+            availableLanguages: getAvailableLanguages(),
+            captions,
+        });
+    } catch (error) {
+        console.error("Error getting public live captions stream", error);
+        return res.status(500).json({
+            status: "Internal server error",
+            latestSequence: liveCaptionState.latestSequence,
+            captions: [],
+            availableLanguages: [],
+        });
+    }
+});
+
 module.exports = router;

scripts/liveCaptionsTestSender.js

@@ -5,7 +5,7 @@ const axios = require("axios");
 
 const baseUrl = (process.env.CAPTION_TEST_BASE_URL || process.env.BASE_URL || "http://localhost:3000").replace(/\/+$/, "");
 const ingestUrl = `${baseUrl}/live-captions/ingest`;
-const intervalMs = 5000;
+const intervalMs = 6000;
 
 const samples = [
     {
@@ -37,9 +37,8 @@ const samples = [
 let sampleIndex = 0;
 let timer = null;
 
-const sendNextSample = async () => {
+const postPayload = async (payload) => {
-    const payload = samples[sampleIndex];
+    const kind = payload?.draft ? "draft" : "final";
-    sampleIndex = (sampleIndex + 1) % samples.length;
 
     try {
         const response = await axios.post(ingestUrl, payload, {
@@ -47,7 +46,8 @@ const sendNextSample = async () => {
             timeout: 10000,
         });
         const seq = response?.data?.caption?.sequence || response?.data?.latestSequence || "?";
-        console.log(`[live-captions:test-sender] sent sequence=${seq} original="${payload.original}"`);
+        const text = payload?.draft || payload?.original || "";
+        console.log(`[live-captions:test-sender] sent ${kind} sequence=${seq} text="${text}"`);
     } catch (error) {
         const status = error?.response?.status;
         const body = error?.response?.data;
@@ -56,6 +56,21 @@ const sendNextSample = async () => {
     }
 };
 
+const sendNextSample = async () => {
+    const payload = samples[sampleIndex];
+
+    const draftWords = String(payload?.original || "").split(" ").filter(Boolean);
+    if (draftWords.length > 2) {
+        await postPayload({ draft: draftWords.slice(0, 2).join(" ") });
+        await new Promise((resolve) => setTimeout(resolve, 550));
+        await postPayload({ draft: draftWords.slice(0, 4).join(" ") });
+        await new Promise((resolve) => setTimeout(resolve, 550));
+    }
+
+    await postPayload(payload);
+    sampleIndex = (sampleIndex + 1) % samples.length;
+};
+
 const start = async () => {
     console.log(`[live-captions:test-sender] posting to ${ingestUrl} every ${intervalMs / 1000}s`);
     await sendNextSample();