define([
  'summernote/base/core/dom',
  'summernote/base/core/range',
  'summernote/base/editing/Bullet'
], function (dom, range, Bullet) {

  /**
   * @class editing.Typing
   *
   * Typing
   *
   */
  var Typing = function () {

    // a Bullet instance to toggle lists off
    var bullet = new Bullet();

    /**
     * insert tab
     *
     * @param {WrappedRange} rng
     * @param {Number} tabsize
     */
    this.insertTab = function (rng, tabsize) {
      var tab = dom.createText(new Array(tabsize + 1).join(dom.NBSP_CHAR));
      rng = rng.deleteContents();
      rng.insertNode(tab, true);

      rng = range.create(tab, tabsize);
      rng.select();
    };

    /**
     * insert paragraph
     */
    this.insertParagraph = function (editable) {
      var rng = range.create(editable);

      // deleteContents on range.
      rng = rng.deleteContents();

      // Wrap range if it needs to be wrapped by paragraph
      rng = rng.wrapBodyInlineWithPara();

      // finding paragraph
      var splitRoot = dom.ancestor(rng.sc, dom.isPara);

      var nextPara;
      // on paragraph: split paragraph
      if (splitRoot) {
        // if it is an empty line with li
        if (dom.isEmpty(splitRoot) && dom.isLi(splitRoot)) {
          // toogle UL/OL and escape
          bullet.toggleList(splitRoot.parentNode.nodeName);
          return;
        // if it is an empty line with para on blockquote
        } else if (dom.isEmpty(splitRoot) && dom.isPara(splitRoot) && dom.isBlockquote(splitRoot.parentNode)) {
          // escape blockquote
          dom.insertAfter(splitRoot, splitRoot.parentNode);
          nextPara = splitRoot;
        // if new line has content (not a line break)
        } else {
          nextPara = dom.splitTree(splitRoot, rng.getStartPoint());

          var emptyAnchors = dom.listDescendant(splitRoot, dom.isEmptyAnchor);
          emptyAnchors = emptyAnchors.concat(dom.listDescendant(nextPara, dom.isEmptyAnchor));

          $.each(emptyAnchors, function (idx, anchor) {
            dom.remove(anchor);
          });

          // replace empty heading or pre with P tag
          if ((dom.isHeading(nextPara) || dom.isPre(nextPara)) && dom.isEmpty(nextPara)) {
            nextPara = dom.replace(nextPara, 'p');
          }
        }
      // no paragraph: insert empty paragraph
      } else {
        var next = rng.sc.childNodes[rng.so];
        nextPara = $(dom.emptyPara)[0];
        if (next) {
          rng.sc.insertBefore(nextPara, next);
        } else {
          rng.sc.appendChild(nextPara);
        }
      }

      range.create(nextPara, 0).normalize().select().scrollIntoView(editable);
    };
  };

  return Typing;
});
