function parseBindings(string) {
  var results = [];
  var lastIndex = 0;
  var index;
  while((index = string.indexOf('{{', lastIndex)) > -1) {
    if (lastIndex < index)
      results.push(string.substr(lastIndex, index - lastIndex));
    lastIndex = index;

    index = string.indexOf('}}', index);
    index = index < 0 ? string.length : index + 2;

    results.push(string.substr(lastIndex, index - lastIndex));
    lastIndex = index;
  }
  if (lastIndex != string.length)
    results.push(string.substr(lastIndex, string.length - lastIndex));
  return results.length === 0 ? [ string ] : results;
}

function binding(string) {
  var binding = string.replace(/\n/gm, ' ').match(/^\{\{(.*)\}\}$/);
  return binding ? binding[1] : _null;
}

function hasBindings(bindings) {
  return bindings.length > 1 || binding(bindings[0]) !== _null;
}

angularTextMarkup('{{}}', function(text, textNode, parentElement) {
  var bindings = parseBindings(text),
      self = this;
  if (hasBindings(bindings)) {
    if (isLeafNode(parentElement[0])) {
      parentElement.attr('ng:bind-template', text);
    } else {
      var cursor = textNode, newElement;
      foreach(parseBindings(text), function(text){
        var exp = binding(text);
        if (exp) {
          newElement = self.element('span');
          newElement.attr('ng:bind', exp);
        } else {
          newElement = self.text(text);
        }
        if (msie && text.charAt(0) == ' ') {
          newElement = jqLite('<span>&nbsp;</span>');
          var nbsp = newElement.html();
          newElement.text(text.substr(1));
          newElement.html(nbsp + newElement.html());
        }
        cursor.after(newElement);
        cursor = newElement;
      });
      textNode.remove();
    }
  }
});

// TODO: this should be widget not a markup
angularTextMarkup('OPTION', function(text, textNode, parentElement){
  if (nodeName(parentElement) == "OPTION") {
    var select = document.createElement('select');
    select.insertBefore(parentElement[0].cloneNode(true), _null);
    if (!select.innerHTML.match(/<option(\s.*\s|\s)value\s*=\s*.*>.*<\/\s*option\s*>/gi)) {
      parentElement.attr('value', text);
    }
  }
});

/**
 * @workInProgress
 * @ngdoc directive
 * @name angular.directive.ng:href
 *
 * @description
 * Using <angular/> markup like {{hash}} in an href attribute makes 
 * the page open to a wrong URL, ff the user clicks that link before 
 * angular has a chance to replace the {{hash}} with actual URL, the 
 * link will be broken and will most likely return a 404 error. 
 * The `ng:href` solves this problem by placing the `href` in the 
 * `ng:` namespace.
 *
 * The buggy way to write it:
 * <pre>
 * <a href="http://www.gravatar.com/avatar/{{hash}}"/>
 * </pre>
 * 
 * The correct way to write it:
 * <pre>
 * <a ng:href="http://www.gravatar.com/avatar/{{hash}}"/>
 * </pre>
 *
 * @element ANY
 * @param {template} template any string which can contain `{{}}` markup.
 */

/**
 * @workInProgress
 * @ngdoc directive
 * @name angular.directive.ng:src
 *
 * @description
 * Using <angular/> markup like `{{hash}}` in a `src` attribute doesn't 
 * work right: The browser will fetch from the URL with the literal 
 * text `{{hash}}` until <angular/> replaces the expression inside
 * `{{hash}}`. The `ng:src` attribute solves this problem by placing
 *  the `src` attribute in the `ng:` namespace.
 *
 * The buggy way to write it:
 * <pre>
 * <img src="http://www.gravatar.com/avatar/{{hash}}"/>
 * </pre>
 * 
 * The correct way to write it:
 * <pre>
 * <img ng:src="http://www.gravatar.com/avatar/{{hash}}"/>
 * </pre>
 *
 * @element ANY
 * @param {template} template any string which can contain `{{}}` markup.
 */

var NG_BIND_ATTR = 'ng:bind-attr';
var SPECIAL_ATTRS = {'ng:src': 'src', 'ng:href': 'href'};
angularAttrMarkup('{{}}', function(value, name, element){
  // don't process existing attribute markup
  if (angularDirective(name) || angularDirective("@" + name)) return;
  if (msie && name == 'src')
    value = decodeURI(value);
  var bindings = parseBindings(value),
      bindAttr;
  if (hasBindings(bindings)) {
    element.removeAttr(name);
    bindAttr = fromJson(element.attr(NG_BIND_ATTR) || "{}");
    bindAttr[SPECIAL_ATTRS[name] || name] = value;
    element.attr(NG_BIND_ATTR, toJson(bindAttr));
  }
});