index.js

// This sample demonstrates handling intents from an Alexa skill using the Alexa Skills Kit SDK (v2).
// Please visit https://alexa.design/cookbook for additional examples on implementing slots, dialog management,
// session persistence, api calls, and more.
const Alexa = require('ask-sdk-core');
const persistenceAdapter = require('ask-sdk-s3-persistence-adapter');

const LaunchRequestHandler = {
    canHandle(handlerInput) {
        return handlerInput.requestEnvelope.request.type === 'LaunchRequest';
    },
    handle(handlerInput) {
        const speakOutput = 'Hello! Welcome to Cake walk. What is your birthday?';
        const repromptText = 'I was born Nov. 6th, 2014. When were you born?';    

        return handlerInput.responseBuilder
            .speak(speakOutput)
            .reprompt(repromptText)
            .getResponse();
    }
};
const HasBirthdayLaunchRequestHandler = {
    canHandle(handlerInput) {
        console.log(JSON.stringify(handlerInput.requestEnvelope.request));
        const attributesManager = handlerInput.attributesManager;
        const sessionAttributes = attributesManager.getSessionAttributes() || {};
        
        const year = sessionAttributes.hasOwnProperty('year') ? sessionAttributes.year : 0;
        const month = sessionAttributes.hasOwnProperty('month') ? sessionAttributes.month : 0;
        const day = sessionAttributes.hasOwnProperty('day') ? sessionAttributes.day : 0;
        
        return handlerInput.requestEnvelope.request.type === 'LaunchRequest' &&
            year &&
            month &&
            day;
    },
    async handle(handlerInput) {
        
        const serviceClientFactory = handlerInput.serviceClientFactory;
        const deviceId = handlerInput.requestEnvelope.context.System.device.deviceId;
        
        const attributesManager = handlerInput.attributesManager;
        const sessionAttributes = attributesManager.getSessionAttributes() || {};
        
        const year = sessionAttributes.hasOwnProperty('year') ? sessionAttributes.year : 0;
        const month = sessionAttributes.hasOwnProperty('month') ? sessionAttributes.month : 0;
        const day = sessionAttributes.hasOwnProperty('day') ? sessionAttributes.day : 0;
        
        let userTimeZone;
        try {
            const upsServiceClient = serviceClientFactory.getUpsServiceClient();
            userTimeZone = await upsServiceClient.getSystemTimeZone(deviceId);    
        } catch (error) {
            if (error.name !== 'ServiceError') {
                return handlerInput.responseBuilder.speak("There was a problem connecting to the service.").getResponse();
            }
            console.log('error', error.message);
        }
        console.log('userTimeZone', userTimeZone);
        
        const oneDay = 24*60*60*1000;
        
        // getting the current date with the time
        const currentDateTime = new Date(new Date().toLocaleString("en-US", {timeZone: userTimeZone}));
        // removing the time from the date because it affects our difference calculation
        const currentDate = new Date(currentDateTime.getFullYear(), currentDateTime.getMonth(), currentDateTime.getDate());
        let currentYear = currentDate.getFullYear();
        
        console.log('currentDateTime:', currentDateTime);
        console.log('currentDate:', currentDate);
        
        // getting the next birthday
        let nextBirthday = Date.parse(`${month} ${day}, ${currentYear}`);
        
        // adjust the nextBirthday by one year if the current date is after their birthday
        if (currentDate.getTime() > nextBirthday) {
            nextBirthday = Date.parse(`${month} ${day}, ${currentYear + 1}`);
            currentYear++;
        }
        
        // setting the default speakOutput to Happy xth Birthday!! 
        // Alexa will automatically correct the ordinal for you.
        // no need to worry about when to use st, th, rd
        let speakOutput = `Happy ${currentYear - year}th birthday!`;
        if (currentDate.getTime() !== nextBirthday) {
            const diffDays = Math.round(Math.abs((currentDate.getTime() - nextBirthday)/oneDay));
            speakOutput = `Welcome back. It looks like there are ${diffDays} days until your ${currentYear - year}th birthday.`
        }
        
        return handlerInput.responseBuilder
            .speak(speakOutput)
            .getResponse();
    }
};
const CaptureBirthdayIntentHandler = {
    canHandle(handlerInput) {
        return handlerInput.requestEnvelope.request.type === 'IntentRequest'
            && handlerInput.requestEnvelope.request.intent.name === 'CaptureBirthdayIntent';
    },
    async handle(handlerInput) {
        const year = handlerInput.requestEnvelope.request.intent.slots.year.value;
        const month = handlerInput.requestEnvelope.request.intent.slots.month.value;
        const day = handlerInput.requestEnvelope.request.intent.slots.day.value;
        
        const attributesManager = handlerInput.attributesManager;
        
        const birthdayAttributes = {
            "year": year,
            "month": month,
            "day": day
            
        };
        attributesManager.setPersistentAttributes(birthdayAttributes);
        await attributesManager.savePersistentAttributes();    
        
        const speakOutput = `Thanks, I'll remember that you were born ${month} ${day} ${year}.`;
        return handlerInput.responseBuilder
            .speak(speakOutput)
            //.reprompt('add a reprompt if you want to keep the session open for the user to respond')
            .getResponse();
    }
};

const HelpIntentHandler = {
    canHandle(handlerInput) {
        return handlerInput.requestEnvelope.request.type === 'IntentRequest'
            && handlerInput.requestEnvelope.request.intent.name === 'AMAZON.HelpIntent';
    },
    handle(handlerInput) {
        const speakOutput = 'You can say hello to me! How can I help?';

        return handlerInput.responseBuilder
            .speak(speakOutput)
            .reprompt(speakOutput)
            .getResponse();
    }
};
const CancelAndStopIntentHandler = {
    canHandle(handlerInput) {
        return handlerInput.requestEnvelope.request.type === 'IntentRequest'
            && (handlerInput.requestEnvelope.request.intent.name === 'AMAZON.CancelIntent'
                || handlerInput.requestEnvelope.request.intent.name === 'AMAZON.StopIntent');
    },
    handle(handlerInput) {
        const speakOutput = 'Goodbye!';
        return handlerInput.responseBuilder
            .speak(speakOutput)
            .getResponse();
    }
};
const SessionEndedRequestHandler = {
    canHandle(handlerInput) {
        return handlerInput.requestEnvelope.request.type === 'SessionEndedRequest';
    },
    handle(handlerInput) {
        // Any cleanup logic goes here.
        return handlerInput.responseBuilder.getResponse();
    }
};

// The intent reflector is used for interaction model testing and debugging.
// It will simply repeat the intent the user said. You can create custom handlers
// for your intents by defining them above, then also adding them to the request
// handler chain below.
const IntentReflectorHandler = {
    canHandle(handlerInput) {
        return handlerInput.requestEnvelope.request.type === 'IntentRequest';
    },
    handle(handlerInput) {
        const intentName = handlerInput.requestEnvelope.request.intent.name;
        const speakOutput = `You just triggered ${intentName}`;

        return handlerInput.responseBuilder
            .speak(speakOutput)
            //.reprompt('add a reprompt if you want to keep the session open for the user to respond')
            .getResponse();
    }
};

// Generic error handling to capture any syntax or routing errors. If you receive an error
// stating the request handler chain is not found, you have not implemented a handler for
// the intent being invoked or included it in the skill builder below.
const ErrorHandler = {
    canHandle() {
        return true;
    },
    handle(handlerInput, error) {
        console.log(`~~~~ Error handled: ${error.message}`);
        const speakOutput = `Sorry, I couldn't understand what you said. Please try again.`;

        return handlerInput.responseBuilder
            .speak(speakOutput)
            .reprompt(speakOutput)
            .getResponse();
    }
};

const LoadBirthdayInterceptor = {
    async process(handlerInput) {
        const attributesManager = handlerInput.attributesManager;
        const sessionAttributes = await attributesManager.getPersistentAttributes() || {};
        
        const year = sessionAttributes.hasOwnProperty('year') ? sessionAttributes.year : 0;
        const month = sessionAttributes.hasOwnProperty('month') ? sessionAttributes.month : 0;
        const day = sessionAttributes.hasOwnProperty('day') ? sessionAttributes.day : 0;
        
        if (year && month && day) {
            attributesManager.setSessionAttributes(sessionAttributes);
        }
    }
}

// The SkillBuilder acts as the entry point for your skill, routing all request and response
// payloads to the handlers above. Make sure any new handlers or interceptors you've
// defined are included below. The order matters - they're processed top to bottom.
exports.handler = Alexa.SkillBuilders.custom()
    .withPersistenceAdapter(
        new persistenceAdapter.S3PersistenceAdapter({bucketName:process.env.S3_PERSISTENCE_BUCKET})
    )
    .addRequestHandlers(
        HasBirthdayLaunchRequestHandler,
        LaunchRequestHandler,
        CaptureBirthdayIntentHandler,
        HelpIntentHandler,
        CancelAndStopIntentHandler,
        SessionEndedRequestHandler,
        IntentReflectorHandler) // make sure IntentReflectorHandler is last so it doesn't override your custom intent handlers
    .addErrorHandlers(
        ErrorHandler)
    .addRequestInterceptors(
        LoadBirthdayInterceptor
    )
    .withApiClient(new Alexa.DefaultApiClient())
    .lambda();