feat: add nuance, riva, ibm

lib/utils.js

@@ -1,4 +1,14 @@
 const crypto = require('crypto');
+const {SynthesizerClient} = require('../stubs/nuance/synthesizer_grpc_pb');
+const {RivaSpeechSynthesisClient} = require('../stubs/riva/proto/riva_tts_grpc_pb');
+const {Pool} = require('undici');
+const pool = new Pool('https://auth.crt.nuance.com');
+const HTTP_TIMEOUT = 5000;
+const NUANCE_AUTH_ENDPOINT = 'tts.api.nuance.com:443';
+const grpc = require('@grpc/grpc-js');
+const formurlencoded = require('form-urlencoded');
+
+const debug = require('debug')('jambonz:realtimedb-helpers');
 /**
  * Future TODO: cache recently used connections to providers
  * to avoid connection overhead during a call.
@@ -18,8 +28,87 @@ const noopLogger = {
   error: () => {}
 };
 
+const toBase64 = (str) => Buffer.from(str || '', 'utf8').toString('base64');
+
+function makeBasicAuthHeader(username, password) {
+  if (!username || !password) return {};
+  const creds = `${encodeURIComponent(username)}:${password || ''}`;
+  const header = `Basic ${toBase64(creds)}`;
+  return {Authorization: header};
+}
+
+function makeIbmKey(apiKey) {
+  const hash = crypto.createHash('sha1');
+  hash.update(apiKey);
+  return `ibm:${hash.digest('hex')}`;
+}
+
+function makeNuanceKey(clientId, secret, scope) {
+  const hash = crypto.createHash('sha1');
+  hash.update(`${clientId}:${secret}:${scope}`);
+  return `nuance:${hash.digest('hex')}`;
+}
+
+const getNuanceAccessToken = async(clientId, secret, scope = 'asr tts') => {
+  const payload = {
+    grant_type: 'client_credentials',
+    scope
+  };
+  const auth = makeBasicAuthHeader(clientId, secret);
+  const {statusCode, headers, body} =  await pool.request({
+    path: '/oauth2/token',
+    method: 'POST',
+    headers: {
+      ...auth,
+      'Content-Type': 'application/x-www-form-urlencoded'
+    },
+    body: formurlencoded(payload),
+    timeout: HTTP_TIMEOUT,
+    followRedirects: false
+  });
+
+  if (200 !== statusCode) {
+    debug({statusCode, headers, body: body.text()}, 'error fetching access token from Nuance');
+    const err = new Error();
+    err.statusCode = statusCode;
+    throw err;
+  }
+  const json = await body.json();
+  return json.access_token;
+};
+
+const createNuanceClient = async(access_token) => {
+
+  //if (nuanceClientMap.has(access_token)) return nuanceClientMap.get(access_token);
+
+  const generateMetadata = (params, callback) => {
+    var metadata = new grpc.Metadata();
+    metadata.add('authorization', `Bearer ${access_token}`);
+    callback(null, metadata);
+  };
+
+  const sslCreds = grpc.credentials.createSsl();
+  const authCreds = grpc.credentials.createFromMetadataGenerator(generateMetadata);
+  const combined_creds = grpc.credentials.combineChannelCredentials(sslCreds, authCreds);
+  const client = new SynthesizerClient(NUANCE_AUTH_ENDPOINT, combined_creds);
+
+  //if (process.env.NUANCE_CACHE_TTS_CONNECTIONS) nuanceClientMap.set(access_token, client);
+  return client;
+};
+
+const createRivaClient = async(rivaUri) => {
+  const client = new RivaSpeechSynthesisClient(rivaUri, grpc.credentials.createInsecure());
+  return client;
+};
+
 
 module.exports = {
   makeSynthKey,
+  makeNuanceKey,
+  makeIbmKey,
+  getNuanceAccessToken,
+  createNuanceClient,
+  createRivaClient,
+  NUANCE_AUTH_ENDPOINT,
   noopLogger
 };