/** =========================================================================
 * Processor
 * Modify the prepared source ready to be written to an iframe
 * ========================================================================== */

var processor = (function () {

  var processor = {};

  processor.blockingMethods = {
    kill: '<script>try{window.open=function(){};window.print=function(){};window.alert=function(){};window.prompt=function(){};window.confirm=function(){};}catch(e){}</script>',
    // RS: the empty comment in the end of the harness, ensures any
    // open comments are closed, and will ensure the harness is hidden
    // from the user.
    restore: '<!--jsbin live harness--><script>try{delete window.print;delete window.alert;delete window.prompt;delete window.confirm;delete window.open;}catch(e){}</script>'
  };

  /**
   * Grab the doctype from a string.
   *
   * Returns an object with doctype and tail keys.
   */
  processor.getDoctype = (function () {
    // Cached regex
    // [\s\S] matches multiline doctypes
    var regex = /<!doctype [\s\S]*?>/i;
    return function (str) {
      var doctype = (str.match(regex) || [''])[0],
          tail = str.substr(doctype.length);
      return {
        doctype: doctype,
        tail: tail
      };
    };
  }());

  /**
   * Replace HTML characters with encoded equivatents for debug mode.
   */
  processor.debug = function (source) {
    return '<pre>' + source.replace(/[<>&]/g, function (m) {
      if (m == '<') return '&lt;';
      if (m == '>') return '&gt;';
      if (m == '&') return '&amp;';
    }) + '</pre>';
  };

  /**
   * Render – build the final source code to be written to the iframe. Takes
   * the original source and an options object.
   */
  processor.render = function (source, options) {

    options = options || [];
    source = source || '';

    var combinedSource = [],
        realtime = (options.requested !== true),
        noRealtimeJs = (options.includeJsInRealtime === false);

    // If the render was realtime and we don't want javascript in realtime
    // renders – Auto-run JS is unchecked – then strip out the Javascript
    if (realtime && noRealtimeJs) {
      source = source.replace(/<script\b[^<]*(?:(?!<\/script>)<[^<]*)*<\/script>/gi, '');
    }

    // Strip autofocus from the markup, preventing the focus switching out of
    // the editable area.
    source = source.replace(/(<.*?\s)(autofocus)/g, '$1');

    // Make sure the doctype is the first thing in the source
    var doctypeObj = processor.getDoctype(source),
        doctype = doctypeObj.doctype;
    source = doctypeObj.tail;
    combinedSource.push(doctype);

    // Kill the blocking functions
    // IE requires that this is done in the script, rather than off the window
    // object outside of the doc.write.
    if (realtime && options.includeJsInRealtime) {
      combinedSource.push(processor.blockingMethods.kill);
    }

    // Push the source, split from the doctype above.
    combinedSource.push(source);

    // Restore the blocking functions
    if (realtime && options.includeJsInRealtime) {
      combinedSource.push(processor.blockingMethods.restore);
    }

    // In debug mode return an escaped version
    if (options.debug) {
      return processor.debug(combinedSource.join('\n'));
    }

    return combinedSource.join('\n');

  };

  return processor;

}());

if (typeof exports !== 'undefined') {
  module.exports = processor;
}