app.js

/*-----------------------------------------------------------------------------
A speech to text bot for the Microsoft Bot Framework. 
-----------------------------------------------------------------------------*/

// This loads the environment variables from the .env file
require('dotenv-extended').load();

const builder = require("botbuilder"),
    fs = require("fs"),
    needle = require("needle"),
    restify = require("restify"),
    request = require("request"),
    speechService = require("./speech-service.js"),
    url = require("url");

//=========================================================
// Bot Setup
//=========================================================

// Setup Restify Server
const server = restify.createServer();
server.listen(process.env.port || process.env.PORT || 3979, () => {
    console.log("%s listening to %s", server.name, server.url);
});

// Create chat bot
const connector = new builder.ChatConnector({
    appId: process.env.MICROSOFT_APP_ID,
    appPassword: process.env.MICROSOFT_APP_PASSWORD
});

const bot = new builder.UniversalBot(connector);
server.post("/api/messages", connector.listen());

//=========================================================
// Bots Dialogs
//=========================================================

bot.dialog("/", session => {
    if (hasAudioAttachment(session)) {
        var stream = getAudioStreamFromAttachment(session.message.attachments[0]);
        speechService.getTextFromAudioStream(stream)
            .then(text => {
                session.send(processText(session.message.text, text));
            })
            .catch(error => {
                session.send("Oops! Something went wrong. Try again later.");
                console.error(error);
            });
    }
    else {
        session.send("Did you upload an audio file? I'm more of an audible person. Try sending me a wav file");
    }
});

//=========================================================
// Utilities
//=========================================================
const hasAudioAttachment = session => {
    return ((session.message.attachments.length > 0) && ((session.message.attachments[0].contentType === "audio/wav") || (session.message.attachments[0].contentType === "application/octet-stream")));
}

const getAudioStreamFromAttachment = attachment => {
    var headers = {};
    if (isSkypeAttachment(attachment)) {
        // The Skype attachment URLs are secured by JwtToken,
        // you should set the JwtToken of your bot as the authorization header for the GET request your bot initiates to fetch the image.
        // https://github.com/Microsoft/BotBuilder/issues/662
        connector.getAccessToken((error, token) => {
            var tok = token;
            headers['Authorization'] = 'Bearer ' + token;
            headers['Content-Type'] = 'application/octet-stream';

            return needle.get(attachment.contentUrl, { headers: headers });
        });
    }

    headers['Content-Type'] = attachment.contentType;
    return needle.get(attachment.contentUrl, { headers: headers });
}

const isSkypeAttachment = attachment => {
    if (url.parse(attachment.contentUrl).hostname.substr(-"skype.com".length) == "skype.com") {
        return true;
    }

    return false;
}

const processText = (input, text) => {
    var result = "You said: " + text + ".";

    if (input.toUpperCase().trim() == "WORD") {
        const wordCount = text.split(" ").filter(x => x).length;
        result += " Word Count: " + wordCount;
    }
    else if (input.toUpperCase().trim() == "CHARACTER") {
        const characterCount = text.replace(/ /g, "").length;
        result += " Character Count: " + characterCount;
    }
    else if (input.toUpperCase().trim() == "SPACE") {
        const spaceCount = (text.split(" ").length - 1);
        result += " Space Count: " + spaceCount;
    }
    else if (input.toUpperCase().trim() == "VOWEL") {
        const m = text.match(/[aeiou]/gi);
        const vowelCount =  m === null ? 0 : m.length;
        result += " Vowel Count: " + vowelCount;
    }
    else if (input) {
        const keywordCount = text.toUpperCase().split(" ").filter(x => x == input.toUpperCase()).length;
        result += " Keyword " + input + " found " + keywordCount + " times.";
    }

    return result;
}

//=========================================================
// Bots Events
//=========================================================

// Sends greeting message when the bot is first added to a conversation
bot.on("conversationUpdate", message => {
    if (message.membersAdded) {
        message.membersAdded.forEach(identity => {
            if (identity.id === message.address.bot.id) {
                const reply = new builder.Message()
                    .address(message.address)
                    .text("Hi! I am SpeechToText Bot. I can understand the content of any audio and convert it to text. Try sending me a wav file.");
                bot.send(reply);
                return;
            }
        });
    }
});