var buildSpeechletResponse = (outputText, shouldEndSession) => {
    return {
        outputSpeech: {
            type: "PlainText",
            text: outputText
        },
        shouldEndSession: shouldEndSession
    }
}

var generateResponse = (speechletResponse, sessionAttributes) => {
    return {
        version: "1.0",
        sessionAttributes: sessionAttributes,
        response: speechletResponse
    }
}

function getRandomInt(max) { 'intialising random number generation'
    return Math.floor(Math.random() * Math.floor(max));
}

exports.handler = (event, context, callback) => {
    var attributes = event.session.attributes;
    if ( typeof attributes === 'undefined' ) {
        attributes = {};
    }
    switch (event.request.type) {
        case "LaunchRequest":
            attributes.c0 = (getRandomInt(52));
            attributes.c1 = (getRandomInt(52));
            context.succeed(generateResponse(buildSpeechletResponse(`Your first number is ${attributes.c0}. Higher or Lower?`, false), attributes))
            break;
        case "IntentRequest":
            var result;
            switch (event.request.intent.name) {
                case "higher":
                    if (attributes.c1 < attributes.c0) {
                        result = `Take a drink! It was ${attributes.c1}. `;
                    } else {
                        result = `Correct! It was ${attributes.c1}. `;
                    }
                    attributes.c0 = attributes.c1;
                    attributes.c1 = (getRandomInt(52));
                    context.succeed(generateResponse(buildSpeechletResponse(result+`Higher or Lower?`, false), attributes))
                    break;
                case "lower":
                    if (attributes.c1 > attributes.c0) {
                        result = `Take a drink! It was ${attributes.c1}. `
                    } else {
                        result = `Correct! It was ${attributes.c1}. `
                    }
                    attributes.c0 = attributes.c1;
                    attributes.c1 = (getRandomInt(52));
                    context.succeed(generateResponse(buildSpeechletResponse(result+`Higher or Lower?`, false), attributes))
                    break;
                case "lastnumber":
                    context.succeed(generateResponse(buildSpeechletResponse(`The number is ${attributes.c0}. Higher or Lower?`, false), attributes))
                    break;
            }
            break;
    }
}