'use strict';
const Alexa = require("alexa-sdk");
const appId = 'amzn1.ask.skill.78e25d07-06c9-488b-afc1-9dabeae510bc'; //'amzn1.echo-sdk-ams.app.your-skill-id';

exports.handler = function(event, context, callback) {
    const alexa = Alexa.handler(event, context);
    alexa.appId = appId;
    alexa.registerHandlers(newSessionHandler, startGameHandlers, guessGameHandlers, guessAttemptHandlers);
    alexa.execute();
};

const states = {
    "STARTMODE": "_STARTMODE",
    "GUESSMODE": "_GUESSMODE"
}

const newSessionHandler = {
  'NewSession': function() {
      const welcomeMessage = 'Welcome to high low. Would you like to play ?';
      this.response.speak(welcomeMessage).listen('You can say Yes or No');
      this.handler.state = states.STARTMODE;
      this.emit(':responseReady');
  },
  'AMAZON.StopIntent': function(){
      this.response.speak('Goodbye!');
      this.emit(':responseReady');
  },
  'AMAZON.CancelIntent': function(){
      this.response.speak('Goodbye!');
      this.emit(':responseReady');
  }
};

const startGameHandlers = Alexa.CreateStateHandler(states.STARTMODE, {

   'AMAZON.StopIntent': function(){
      this.response.speak('Goodbye from startmode!');
      this.emit(':responseReady');
  },
  'AMAZON.YesIntent': function() {
       this.attributes["guessNumber"] = Math.floor(Math.random() * 100);
       this.handler.state = states.GUESSMODE;
       this.response.speak('Great. Start by guessing a number').listen("guess a number");
       this.emit(':responseReady');
  },
  'AMAZON.NoIntent': function(){
       this.response.speak('Goodbye!');
      this.emit(':responseReady');
  }


});

const guessGameHandlers = Alexa.CreateStateHandler(states.GUESSMODE, {
    'NumberGuessIntent': function(){
        const guessNum = parseInt(this.event.request.intent.slots.number.value);
        const targetNum = this.attributes["guessNumber"];
        console.log('user guessed: ' + guessNum);

        if(guessNum > targetNum){
            this.emit('TooHigh', guessNum);
        } else if( guessNum < targetNum){
            this.emit('TooLow', guessNum);
        } else if (guessNum === targetNum){
            // With a callback, use the arrow function to preserve the correct 'this' context
            this.emit('JustRight', () => {
                this.response.speak(guessNum.toString() + 'is correct! Would you like to play a new game?')
                .listen('Say yes to start a new game, or no to end the game.');
                this.emit(':responseReady');
        })
        } else {
            this.emit('NotANum');
        }
    },

    'AMAZON.StopIntent': function(){
      this.response.speak('Goodbye from GuessMode!');
      this.emit(':responseReady');
  },
  'AMAZON.CancelIntent': function(){
      this.response.speak('Goodbye from GuessMode!');
      this.emit(':responseReady');
  }
});

// These handlers are not bound to a state
const guessAttemptHandlers = {
    'TooHigh': function(val) {
        this.response.speak(val.toString() + ' is too high.')
        .listen('Try saying a smaller number.');
        this.emit(':responseReady');
    },
    'TooLow': function(val) {
        this.response.speak(val.toString() + ' is too low.')
        .listen('Try saying a larger number.');
        this.emit(':responseReady');
    },
    'JustRight': function(callback) {
        this.handler.state = states.STARTMODE;
        callback();
    },
    'NotANum': function() {
        this.response.speak('Sorry, I didn\'t get that. Try saying a number.')
        .listen('Try saying a number.');
        this.emit(':responseReady');
    }
};