const SpeechRecognition = window.SpeechRecognition || window.webkitSpeechRecognition;
const SpeechGrammarList = window.SpeechGrammarList || window.webkitSpeechGrammarList;
const SpeechRecognitionEvent = window.SpeechRecognitionEvent || window.webkitSpeechRecognitionEvent;

if (!SpeechRecognition) {
  document.getElementById('not-supported').style.display = 'flex';
}

const recognition = new SpeechRecognition();

let total = 0;
const node = document.getElementById('target');
const button = document.getElementById('toggle');
const htmlNode = document.querySelector('.display');

recognition.continuous = true;
recognition.lang = 'en-US';
recognition.interimResults = false;
recognition.maxAlternatives = 1;

let listening = false;
recognition.onstart = () => { listening = true };
recognition.onend = () => { listening = false };

document.getElementById('toggle').onclick = function() {
  listening ? stop() : start();
}

function start() {
  recognition.start();
  button.textContent = "Stop Listening";
  htmlNode.classList.add('listening');
}

function stop() {
  recognition.abort();
  button.textContent = "Start Listening";
  htmlNode.classList.remove('listening');
}

function update(num) {
  node.textContent = num;
}


const synth = window.speechSynthesis;
function say(phrase) {
  const utterance = new SpeechSynthesisUtterance(phrase);
  stop();
  button.disabled = true;
  setTimeout(() => {
    start();
    button.disabled = true;
  }, 2500);
  console.log(`Saying: ${phrase}`);
  synth.speak(utterance);
}

recognition.onresult = function(event) {
  const last = event.results.length - 1;
  const phrase = event.results[last][0].transcript;
  
  requestData(phrase).then((response) => {
    console.log(response);
    
    const { intent, score } = response.data.intents[0] || { intent: "None" };
    
    if (score < .3) {
      recognition.abort();
      say("I'm not sure what you said.");
      return;
    }
  
    const { entities } = response.data;
    let entity;
    if (entities.length) {
      entity = entities[0];
    }
    
    switch (intent) {
      case "Calculator.Add":
        if (!entity) return;
        total += +entity.resolution.value;
        break;
      case "Calculator.Subtract":
        if (!entity) return;
        total -= +entity.resolution.value;
        break;
      case "Calculator.Multiply":
        if (!entity) return;
        total *= +entity.resolution.value;
        break;
      case "Calculator.Divide":
        if (!entity) return;
        total /= +entity.resolution.value;
        break;
      case "Calculator.Reset": 
        total = entity ? +entity.resolution.value : 0;
        break;
      case "App.Stop":
        stop();
        break;
      case "App.Repeat":
        say(`The current total is ${total}`);
        break;
      default:
        // should never reach here
    }
    update(total);
  }).catch(() => {
    stop();
    document.getElementById('not-available').style.display = 'flex';
  })
}

const requestData = (query) => {
  const uribase = `https://westus.api.cognitive.microsoft.com/luis/v2.0/apps/fedda2e4-21c0-42b6-a693-126f126b2388`;

  return axios({
    method: "get",
    url: uribase,
    params: {
      verbose: true,
      timezoneOffset: 0,
      q: query
    },
    headers: {
      "Content-Type": "application/json",
      "Ocp-Apim-Subscription-Key": "dac1f04f2a85466cb25bc4154692ab91"
    }
  });
}

update(total);