skill.js

/**
 * This sample demonstrates a simple skill built with the Amazon Alexa Skills Kit.
 * The Intent Schema, Custom Slots, and Sample Utterances for this skill, as well as
 * testing instructions are located at http://amzn.to/1LzFrj6
 *
 * For additional samples, visit the Alexa Skills Kit Getting Started guide at
 * http://amzn.to/1LGWsLG
 */
 
 var https = require('https');

// Route the incoming request based on type (LaunchRequest, IntentRequest,
// etc.) The JSON body of the request is provided in the event parameter.
exports.handler = function (event, context) {
    try {
        console.log("event.session.application.applicationId=" + event.session.application.applicationId);

        if (event.session.new) {
            onSessionStarted({requestId: event.request.requestId}, event.session);
        }

        if (event.request.type === "LaunchRequest") {
            onLaunch(event.request,
                event.session,
                function callback(sessionAttributes, speechletResponse) {
                    context.succeed(buildResponse(sessionAttributes, speechletResponse));
                });
        } else if (event.request.type === "IntentRequest") {
            onIntent(event.request,
                event.session,
                function callback(sessionAttributes, speechletResponse) {
                    context.succeed(buildResponse(sessionAttributes, speechletResponse));
                });
        } else if (event.request.type === "SessionEndedRequest") {
            onSessionEnded(event.request, event.session);
            context.succeed();
        }
    } catch (e) {
        context.fail("Exception: " + e);
    }
};

/**
 * Called when the session starts.
 */
function onSessionStarted(sessionStartedRequest, session) {
    console.log("onSessionStarted requestId=" + sessionStartedRequest.requestId +
        ", sessionId=" + session.sessionId);
}

/**
 * Called when the user launches the skill without specifying what they want.
 */
function onLaunch(launchRequest, session, callback) {
    console.log("onLaunch requestId=" + launchRequest.requestId +
        ", sessionId=" + session.sessionId);

    // Dispatch to your skill's launch.
    getWelcomeResponse(callback);
}

/**
 * Called when the user specifies an intent for this skill.
 */
function onIntent(intentRequest, session, callback) {
    console.log("onIntent requestId=" + intentRequest.requestId +
        ", sessionId=" + session.sessionId);

    var intent = intentRequest.intent,
        intentName = intentRequest.intent.name;

    // Dispatch to your skill's intent handlers
    if ("LakeLevelsIntent" === intentName) {
        getLakeLevels(callback);
    } else if ("AMAZON.HelpIntent" === intentName) {
        getHelpResponse(callback);
    } else if ("AMAZON.StopIntent" === intentName || "AMAZON.CancelIntent" === intentName) {
        callback({}, buildExitResponse());
    } else {
        throw "Invalid intent";
    }
}

/**
 * Called when the user ends the session.
 * Is not called when the skill returns shouldEndSession=true.
 */
function onSessionEnded(sessionEndedRequest, session) {
    console.log("onSessionEnded requestId=" + sessionEndedRequest.requestId +
        ", sessionId=" + session.sessionId);
    // Add cleanup logic here
}

// --------------- Functions that control the skill's behavior -----------------------

function getWelcomeResponse(callback) {
    // If we wanted to initialize the session to have some attributes we could add those here.
    var sessionAttributes = {};
    var cardTitle = "Welcome";
    var speechOutput = "Please ask me if lake travis is full yet.";
    // If the user either does not reply to the welcome message or says something that is not
    // understood, they will be prompted again with this text.
    var repromptText = "Please ask me if the lake is full by saying, " +
        "is the lake full yet";
    var shouldEndSession = false;

    callback(sessionAttributes,
        buildSpeechletResponse(cardTitle, speechOutput, repromptText, shouldEndSession));
}

function getHelpResponse(callback) {
    // If we wanted to initialize the session to have some attributes we could add those here.
    var sessionAttributes = {};
    var cardTitle = "Help";
    var speechOutput = "This app monitors the water levels of Lake Travis. Try saying: is the lake full yet?";
    // If the user either does not reply to the welcome message or says something that is not
    // understood, they will be prompted again with this text.
    var repromptText = "Please ask me if the lake is full by saying, " +
        "is the lake is full yet?";
    var shouldEndSession = false;

    callback(sessionAttributes,
        buildSpeechletResponse(cardTitle, speechOutput, repromptText, shouldEndSession));
}

function getLakeData(callback) {
    https.get('https://lake-travis-water-levels.herokuapp.com/lakedata', function (res) {
      res.on('data', function (d) {
        callback(d);
      });
    
    }).on('error', function (e) {
      callback(null);
      console.error(e);
    });
}

function getLakeLevels(callback) {
    getLakeData(function (d) {
        if (d) {
            d = JSON.parse(d.toString());
            var pct = Math.floor((d.currentVolume / d.fullVolume) * 1000) / 10;
            var response;
            if (pct < 100) {
                response = "No, the lake is only " + pct + "% full.";
            } else {
                response = "Yes, the lake is " + pct + "% full.";
            }
            callback({}, buildSpeechletResponse('Water Levels', response, 'I didn\'t understand that', true));
        } else {
            callback({}, buildSpeechletResponse('Water Levels', 'Sorry, I was unable to find any data', 'I didn\'t understand that', true));
        }
    })
    
}


// --------------- Helpers that build all of the responses -----------------------

function buildSpeechletResponse(title, output, repromptText, shouldEndSession) {
    return {
        outputSpeech: {
            type: "PlainText",
            text: output
        },
        card: {
            type: "Simple",
            title: "Lake Travis - " + title,
            content: "Current Status: " + output
        },
        reprompt: {
            outputSpeech: {
                type: "PlainText",
                text: repromptText
            }
        },
        shouldEndSession: shouldEndSession
    };
}

function buildExitResponse() {
    return {
        outputSpeech: {
            type: "PlainText",
            text: "Goodbye"
        },
        shouldEndSession: true
    };
}

function buildResponse(sessionAttributes, speechletResponse) {
    return {
        version: "1.0",
        sessionAttributes: sessionAttributes,
        response: speechletResponse
    };
}