// ==UserScript==
// @name         Incremental Reading
// @namespace    http://tampermonkey.net/
// @version      0.8.0
// @description  Read. Recite.
// @description:en  Read. Recite.
// @author       Feng Ya
// @match        https://www.instapaper.com/read/*
// @grant        GM_addStyle
// @downloadURL https://update.greasyfork.icu/scripts/37587/Incremental%20Reading.user.js
// @updateURL https://update.greasyfork.icu/scripts/37587/Incremental%20Reading.meta.js
// ==/UserScript==

(function() {
  'use strict';

  // Your code here...

  GM_addStyle(`
  .mask {
    color: rgba(255, 242, 51, 0.298) !important;
  }

  .wrong {
    color: red !important;
  }

  .correct {
    color: green !important;
  }

  .cloze {
    position: absolute;
    z-index: 9;
    background: transparent;
    border: none;
  }
  `);

  console.log('Incremental Reading for Language Learning.');

  const highlight = {
    add() {
      document.querySelectorAll('span.highlight').forEach(highlight => {
        const id = highlight.getAttribute('data-api-id');
        highlight.insertAdjacentHTML(
          'beforebegin',
          `<input class="cloze" data-api-id="${id}" type="text" style="width: ${
            highlight.offsetWidth
          }px" autocomplete="off" autocorrect="off" autocapitalize="off" spellcheck="false">`
        );
      });
    },
    toggle() {
      document.querySelectorAll('span.highlight').forEach(highlight => {
        highlight.classList.toggle('mask');
      });
    },
  };

  const cloze = {
    add() {
      document.querySelectorAll('.cloze').forEach(cloze => {
        const id = cloze.getAttribute('data-api-id');
        const answer = document.querySelector(
          `span.highlight[data-api-id="${id}"]`
        );
        cloze.addEventListener('keypress', event => {
          answer.classList.remove('wrong');
          answer.classList.remove('correct');

          // Enter or Tab
          if (event.keyCode === 13 || event.keyCode === 9) {
            if (cloze.value !== answer.textContent)
              answer.classList.add('wrong');
            else answer.classList.add('correct');
          }
        });
      });
    },
    clear() {
      document.querySelectorAll('.cloze').forEach(cloze => {
        cloze.parentNode.removeChild(cloze);
      });
    },
  };

  // remove old clozes (used only in development)
  cloze.clear();

  highlight.add();
  highlight.toggle();
  cloze.add();

  let clozeMode = true;

  document.body.addEventListener('click', event => {
    if (event.target.nodeName !== 'BODY') return;

    // Instapaper: Remove Note
    if (document.querySelectorAll('div.highlight_popover.reveal').length > 0)
      return;

    if (clozeMode) {
      cloze.clear();
    } else {
      highlight.add();
      cloze.add();
    }

    highlight.toggle();

    clozeMode = !clozeMode;
  });
})();