botlib/dialogflow_session_client.js

/**
 * Copyright 2019 Google Inc. All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/**
 * @fileoverview Contacts dialogflow and returns response.
 */
const dialogflow = require('dialogflow');
const jsonToProto = require('./json_to_proto')
module.exports = class DialogflowSessionClient {

  constructor(projectId){
    this.sessionClient = new dialogflow.SessionsClient();
    this.projectId = projectId;
  }

  constructRequest(text, sessionPath, payload) {
    return {
      session: sessionPath,
      queryInput: {
        text: {
          text: text,
          languageCode: 'en'
        }
      },
      queryParams: {
        payload: jsonToProto.jsonToStructProto(payload)
      }
    };
  }

  constructRequestWithEvent(eventName, sessionPath) {
    return {
      session: sessionPath,
      queryInput: {
        event: {
          name: eventName,
          languageCode: 'en'
        },
      },
    };
  }

  //This function calls Dialogflow DetectIntent API to retrieve the response
  //https://cloud.google.com/dialogflow/docs/reference/rest/v2/projects.agent.sessions/detectIntent
  async detectIntentHelper(detectIntentRequest) {
    let [response] = await this.sessionClient.detectIntent(detectIntentRequest);
    return (response.queryResult);
  }

  async detectIntent(text, sessionId, payload) {
    const sessionPath = this.sessionClient.sessionPath(
        this.projectId, sessionId);
    const request = this.constructRequest(text, sessionPath, payload);
    return await this.detectIntentHelper(request);
  }

  async detectIntentWithEvent(eventName, sessionId) {
    const sessionPath = this.sessionClient.sessionPath(
        this.projectId, sessionId);
    const request = this.constructRequestWithEvent(
        eventName, sessionPath);
    return await this.detectIntentHelper(request);
  }
};