const text = document.querySelector('.trm-typed-text');

const words = [
  "UI/UX设计师",
  "Web开发人员",
  "摄影师",
  "梦想家 :)"
];

setTyper(text, words);

function setTyper(element, words) {

  const LETTER_TYPE_DELAY = 100;
  const WORD_STAY_DELAY = 3000;

  const DIRECTION_FORWARDS = 0;
  const DIRECTION_BACKWARDS = 1;

  var direction = DIRECTION_FORWARDS;
  var wordIndex = 0;
  var letterIndex = 0;

  var wordTypeInterval;

  startTyping();

  function startTyping() {
    wordTypeInterval = setInterval(typeLetter, LETTER_TYPE_DELAY);
  }

  function typeLetter() {
    const word = words[wordIndex];

    if (direction == DIRECTION_FORWARDS) {
      letterIndex++;

      if (letterIndex == word.length) {
        direction = DIRECTION_BACKWARDS;
        clearInterval(wordTypeInterval);
        setTimeout(startTyping, WORD_STAY_DELAY);
      }

    } else if (direction == DIRECTION_BACKWARDS) {
      letterIndex--;

      if (letterIndex == 0) {
        nextWord();
      }
    }

    const textToType = word.substring(0, letterIndex);

    element.textContent = textToType;
  }

  function nextWord() {

    letterIndex = 0;
    direction = DIRECTION_FORWARDS;
    wordIndex++;

    if (wordIndex == words.length) {
      wordIndex = 0;
    }

  }
}

/*----------------------------------------------------------
------------------------------------------------------------

REINIT

------------------------------------------------------------
----------------------------------------------------------*/
document.addEventListener("swup:contentReplaced", function() {
  const text = document.querySelector('.trm-typed-text');

  const words = [
    "UI/UX设计师",
    "Web开发人员",
    "摄影师",
    "梦想家 :)"
  ];

  setTyper(text, words);

  function setTyper(element, words) {

    const LETTER_TYPE_DELAY = 100;
    const WORD_STAY_DELAY = 3000;

    const DIRECTION_FORWARDS = 0;
    const DIRECTION_BACKWARDS = 1;

    var direction = DIRECTION_FORWARDS;
    var wordIndex = 0;
    var letterIndex = 0;

    var wordTypeInterval;

    startTyping();

    function startTyping() {
      wordTypeInterval = setInterval(typeLetter, LETTER_TYPE_DELAY);
    }

    function typeLetter() {
      const word = words[wordIndex];

      if (direction == DIRECTION_FORWARDS) {
        letterIndex++;

        if (letterIndex == word.length) {
          direction = DIRECTION_BACKWARDS;
          clearInterval(wordTypeInterval);
          setTimeout(startTyping, WORD_STAY_DELAY);
        }

      } else if (direction == DIRECTION_BACKWARDS) {
        letterIndex--;

        if (letterIndex == 0) {
          nextWord();
        }
      }

      const textToType = word.substring(0, letterIndex);

      element.textContent = textToType;
    }

    function nextWord() {

      letterIndex = 0;
      direction = DIRECTION_FORWARDS;
      wordIndex++;

      if (wordIndex == words.length) {
        wordIndex = 0;
      }

    }
  }
});