google-assistant-for-pebble-cloud-function

import * as functions from 'firebase-functions';
import { google } from 'googleapis';
const OAuth2 = google.auth.OAuth2; 
import GoogleAssistant = require("google-assistant");

//these are the app's credentials; the client_id and secret
const googleAssistantCredentials = require('../src/googleAssistantCredentials.json');

//parsing library
const html2text = require('html-to-text');

//cloud function export
export const googleAssistant = functions.https.onRequest(async(request, response)=>{

    //request has three fields... command:string, hyperMode:int, tokens:OAuthTokensObject

    //create OAuth client
    const oAuth2ClientForAssistant = new OAuth2(
        googleAssistantCredentials.web.client_id,
        googleAssistantCredentials.web.client_secret,
        googleAssistantCredentials.web.redirect_uris[0]
    );

    //set user's refresh token as provided in request
    oAuth2ClientForAssistant.setCredentials(request.body.tokens);
    await oAuth2ClientForAssistant.refreshAccessToken().then(onfulfilled=>{oAuth2ClientForAssistant.setCredentials(onfulfilled.credentials)}).catch(error => console.log(error))
    
    //make assistant object
    const assistant: GoogleAssistant = new GoogleAssistant({oauth2Client:oAuth2ClientForAssistant});

    const conversationConfig = {
        textQuery: request.body.command, // if this is set, audio input is ignored
        // isNew: true, // set this to true if you want to force a new conversation and ignore the old state
        screen: {
            isOn: false
        }
    }

    //if user has HYPER mode enabled on Pebble, set screen.isOn flag to true; this results in different repsonses from GA
    if(request.body.hyperMode == 1){
        conversationConfig.screen.isOn = true;
    }

    // configures the conversation with the assistant
    const startConversation = (conversation:any) => {

        //holder string to append different responses to
        var responseText:string = '';
        
        //behavior of the assistant
        conversation
            .on('response', (text:string) => {
                if (conversationConfig.screen.isOn === false) {
                    //append text to holder string
                    responseText += text;
                }
            })
            .on('screen-data', async (screen:{format:string, data:Buffer}) => {
                if (conversationConfig.screen.isOn === true) {
                    //decode html data buffer
                    var html = await screen.data.toString('UTF-8');
                    //strip all html from response
                    var cfg = {
                        wordwrap: false,
                        ignoreHref: true,
                        ignoreImage: true,
                        preserveNewlines: true
                    };
                    var text = await html2text.fromString(html, cfg);
                    //append text to holder string
                    responseText += text;
                }
            })
            .on('ended', (error:any, continueConversation:boolean) => {
                if (error){
                    console.log('Conversation Ended Error:', error);
                    responseText += response.status(200).send({responseText:'Error: ' + JSON.stringify(error)});
                } 

            
                // example responseText you might get = "Will there be any more Star Wars movies?Disney isn't planning to release another Star Wars movie until 2022. Executives have publicly recognized the audience fatigue the current annual release schedule brings. It's the first time in four years that there won't be an annual Star Wars movie, but the franchise isn't really going anywhere.Source: The Mandalorian shows what Star Wars' future looks like over ...https://www.theverge.com/2019/12/27/21035823/mandalorian-finale-star-wars-rise-of-skywalker-baby-yoda-disney-plus-marvel theverge.com Try saying…   Star Wars chronological order?2020 Movie Releases?What's after the rise of Skywalker?";
                //console.log(responseText);

                //first, look for and then separate out source:
                var sourceTextArray = responseText.split(/(Source:)/);
                if (sourceTextArray.length > 1) {
                    //strip URLs from source text and reattach
                    const regex = /(?:(?:https?|ftp|file):\/\/|www\.|ftp\.)(?:\([-A-Z0-9+&@#\/%=~_|$?!:,.]*\)|[-A-Z0-9+&@#\/%=~_|$?!:,.])*(?:\([-A-Z0-9+&@#\/%=~_|$?!:,.]*\)|[A-Z0-9+&@#\/%=~_|$])/igm;
                    responseText = sourceTextArray[0] + " \n Source: " + sourceTextArray[2].replace(regex, " ");
                };

                //instantiate actionArray 
                var actionArray = [''];

                // Look for the phrase "Try saying…" and split the responseText string
                var groupArray = responseText.split(/(Try saying…)/);

                // If "Try saying…" token was found, handle the text before the token as the response and the text after the token as action items that will be sent to the client to pre-popualte the "actions" section of the Pebble's Google Assistant app UI. These items will be sent as an array.
                if (groupArray.length > 1) {

                    // handle response text, splitting at camelCase instances including situations like.This but not situations LIKE THIS.
                    responseText = groupArray[0];
                    var textArray = groupArray[0].split(/(?<=[a-z])(?=[A-Z])|(?<=[A-Z])(?=[A-Z][a-z])|(?<=[^A-z\s\d][\\\^]?)(?=[A-Z])/);
                    if (textArray.length > 1) {
                        // If splitting occurred, insert newline characters which will be handily parsed by the Pebble's C compiler
                        responseText = textArray.join(" \n ");
                    }
                    
                    //split the text which comes after "Try saying…" with the same regex as before. This time look for numbers too. We will keep them in this array and send it back to the Pebble client
                    actionArray = groupArray[2].split(/(?<=[a-z])(?=[A-Z])|(?<=[A-Z])(?=[A-Z][a-z])|(?<=[^A-z\s\d][\\\^]?)(?=[A-Z0-9])/);
                    
                    //trim whitespace from any items in the action array
                    for (let i = 0; i < actionArray.length; i++){
                        actionArray[i].trim();
                    }
                    
                } else {
                    // Try saying… token was not found so just insert newlines where appropriate
                    var splitText = responseText.split(/(?<=[a-z])(?=[A-Z])|(?<=[A-Z])(?=[A-Z][a-z])|(?<=[^A-z\s\d][\\\^]?)(?=[A-Z0-9])/);
                    if (splitText.length > 1){
                        responseText = splitText.join(" \n ");
                    }
                }

                //build response object
                var responseObject:{
                    responseText: string,
                    actionArray?: Array<string>
                } = {
                    responseText:responseText,
                    actionArray: actionArray
                };

                response.status(200).send({responseText:responseText});
            })
            .on('error', (error:any) => {
                // if there is an assistant error... send it to Pebble
                // console.error(error);
                response.status(200).send({responseText: "Error: " + JSON.stringify(error)});
            });
    };

    //starts the Google Assistant
    assistant.start(conversationConfig, startConversation);

});