/**
 * Expose `parse`.
 */

module.exports = parse;

/**
 * Tests for browser support.
 */

var innerHTMLBug = false;
var bugTestDiv;
if (typeof document !== 'undefined') {
  bugTestDiv = document.createElement('div');
  // Setup
  bugTestDiv.innerHTML = '  <link/><table></table><a href="/a">a</a><input type="checkbox"/>';
  // Make sure that link elements get serialized correctly by innerHTML
  // This requires a wrapper element in IE
  innerHTMLBug = !bugTestDiv.getElementsByTagName('link').length;
  bugTestDiv = undefined;
}

/**
 * Wrap map from jquery.
 */

var map = {
  legend: [1, '<fieldset>', '</fieldset>'],
  tr: [2, '<table><tbody>', '</tbody></table>'],
  col: [2, '<table><tbody></tbody><colgroup>', '</colgroup></table>'],
  // for script/link/style tags to work in IE6-8, you have to wrap
  // in a div with a non-whitespace character in front, ha!
  _default: innerHTMLBug ? [1, 'X<div>', '</div>'] : [0, '', '']
};

map.td =
map.th = [3, '<table><tbody><tr>', '</tr></tbody></table>'];

map.option =
map.optgroup = [1, '<select multiple="multiple">', '</select>'];

map.thead =
map.tbody =
map.colgroup =
map.caption =
map.tfoot = [1, '<table>', '</table>'];

map.polyline =
map.ellipse =
map.polygon =
map.circle =
map.text =
map.line =
map.path =
map.rect =
map.g = [1, '<svg xmlns="http://www.w3.org/2000/svg" version="1.1">','</svg>'];

/**
 * Parse `html` and return a DOM Node instance, which could be a TextNode,
 * HTML DOM Node of some kind (<div> for example), or a DocumentFragment
 * instance, depending on the contents of the `html` string.
 *
 * @param {String} html - HTML string to "domify"
 * @param {Document} doc - The `document` instance to create the Node for
 * @return {DOMNode} the TextNode, DOM Node, or DocumentFragment instance
 * @api private
 */

function parse(html, doc) {
  if ('string' != typeof html) throw new TypeError('String expected');

  // default to the global `document` object
  if (!doc) doc = document;

  // tag name
  var m = /<([\w:]+)/.exec(html);
  if (!m) return doc.createTextNode(html);

  html = html.replace(/^\s+|\s+$/g, ''); // Remove leading/trailing whitespace

  var tag = m[1];

  // body support
  if (tag == 'body') {
    var el = doc.createElement('html');
    el.innerHTML = html;
    return el.removeChild(el.lastChild);
  }

  // wrap map
  var wrap = Object.prototype.hasOwnProperty.call(map, tag) ? map[tag] : map._default;
  var depth = wrap[0];
  var prefix = wrap[1];
  var suffix = wrap[2];
  var el = doc.createElement('div');
  el.innerHTML = prefix + html + suffix;
  while (depth--) el = el.lastChild;

  // one element
  if (el.firstChild == el.lastChild) {
    return el.removeChild(el.firstChild);
  }

  // several elements
  var fragment = doc.createDocumentFragment();
  while (el.firstChild) {
    fragment.appendChild(el.removeChild(el.firstChild));
  }

  return fragment;
}