/**
 * Copyright 2013-2015, Facebook, Inc.
 * All rights reserved.
 *
 * This source code is licensed under the BSD-style license found in the
 * LICENSE file in the root directory of this source tree. An additional grant
 * of patent rights can be found in the PATENTS file in the same directory.
 *
 * @providesModule getMarkupWrap
 */

/*eslint-disable fb-www/unsafe-html */

var ExecutionEnvironment = require('ExecutionEnvironment');

var invariant = require('invariant');

/**
 * Dummy container used to detect which wraps are necessary.
 */
var dummyNode =
  ExecutionEnvironment.canUseDOM ? document.createElement('div') : null;

/**
 * Some browsers cannot use `innerHTML` to render certain elements standalone,
 * so we wrap them, render the wrapped nodes, then extract the desired node.
 *
 * In IE8, certain elements cannot render alone, so wrap all elements ('*').
 */

var shouldWrap = {};

var selectWrap = [1, '<select multiple="true">', '</select>'];
var tableWrap = [1, '<table>', '</table>'];
var trWrap = [3, '<table><tbody><tr>', '</tr></tbody></table>'];

var svgWrap = [1, '<svg xmlns="http://www.w3.org/2000/svg">', '</svg>'];

var markupWrap = {
  '*': [1, '?<div>', '</div>'],

  'area': [1, '<map>', '</map>'],
  'col': [2, '<table><tbody></tbody><colgroup>', '</colgroup></table>'],
  'legend': [1, '<fieldset>', '</fieldset>'],
  'param': [1, '<object>', '</object>'],
  'tr': [2, '<table><tbody>', '</tbody></table>'],

  'optgroup': selectWrap,
  'option': selectWrap,

  'caption': tableWrap,
  'colgroup': tableWrap,
  'tbody': tableWrap,
  'tfoot': tableWrap,
  'thead': tableWrap,

  'td': trWrap,
  'th': trWrap,
};

// Initialize the SVG elements since we know they'll always need to be wrapped
// consistently. If they are created inside a <div> they will be initialized in
// the wrong namespace (and will not display).
var svgElements = [
  'circle',
  'clipPath',
  'defs',
  'ellipse',
  'g',
  'image',
  'line',
  'linearGradient',
  'mask',
  'path',
  'pattern',
  'polygon',
  'polyline',
  'radialGradient',
  'rect',
  'stop',
  'text',
  'tspan',
];
svgElements.forEach((nodeName) => {
  markupWrap[nodeName] = svgWrap;
  shouldWrap[nodeName] = true;
});

/**
 * Gets the markup wrap configuration for the supplied `nodeName`.
 *
 * NOTE: This lazily detects which wraps are necessary for the current browser.
 *
 * @param {string} nodeName Lowercase `nodeName`.
 * @return {?array} Markup wrap configuration, if applicable.
 */
function getMarkupWrap(nodeName) {
  invariant(!!dummyNode, 'Markup wrapping node not initialized');
  if (!markupWrap.hasOwnProperty(nodeName)) {
    nodeName = '*';
  }
  if (!shouldWrap.hasOwnProperty(nodeName)) {
    if (nodeName === '*') {
      dummyNode.innerHTML = '<link />';
    } else {
      dummyNode.innerHTML = '<' + nodeName + '></' + nodeName + '>';
    }
    shouldWrap[nodeName] = !dummyNode.firstChild;
  }
  return shouldWrap[nodeName] ? markupWrap[nodeName] : null;
}


module.exports = getMarkupWrap;
