/*
 * Copyright (c) 2014 The Polymer Project Authors. All rights reserved.
 * This code may only be used under the BSD style license found at http://polymer.github.io/LICENSE.txt
 * The complete set of authors may be found at http://polymer.github.io/AUTHORS.txt
 * The complete set of contributors may be found at http://polymer.github.io/CONTRIBUTORS.txt
 * Code distributed by Google as part of the polymer project is also
 * subject to an additional IP rights grant found at http://polymer.github.io/PATENTS.txt
 */
(function(scope) {

  // magic words

  var ATTRIBUTES_ATTRIBUTE = 'attributes';
  var ATTRIBUTES_REGEX = /\s|,/;

  // attributes api

  var attributes = {
    
    inheritAttributesObjects: function(prototype) {
      // chain our lower-cased publish map to the inherited version
      this.inheritObject(prototype, 'publishLC');
      // chain our instance attributes map to the inherited version
      this.inheritObject(prototype, '_instanceAttributes');
    },

    publishAttributes: function(prototype, base) {
      // merge names from 'attributes' attribute into the 'publish' object
      var attributes = this.getAttribute(ATTRIBUTES_ATTRIBUTE);
      if (attributes) {
        // create a `publish` object if needed.
        // the `publish` object is only relevant to this prototype, the 
        // publishing logic in `declaration/properties.js` is responsible for
        // managing property values on the prototype chain.
        // TODO(sjmiles): the `publish` object is later chained to it's 
        //                ancestor object, presumably this is only for 
        //                reflection or other non-library uses. 
        var publish = prototype.publish || (prototype.publish = {}); 
        // names='a b c' or names='a,b,c'
        var names = attributes.split(ATTRIBUTES_REGEX);
        // record each name for publishing
        for (var i=0, l=names.length, n; i<l; i++) {
          // remove excess ws
          n = names[i].trim();
          // looks weird, but causes n to exist on `publish` if it does not;
          // a more careful test would need expensive `in` operator
          if (n && publish[n] === undefined) {
            publish[n] = undefined;
          }
        }
      }
    },

    // record clonable attributes from <element>
    accumulateInstanceAttributes: function() {
      // inherit instance attributes
      var clonable = this.prototype._instanceAttributes;
      // merge attributes from element
      var a$ = this.attributes;
      for (var i=0, l=a$.length, a; (i<l) && (a=a$[i]); i++) {  
        if (this.isInstanceAttribute(a.name)) {
          clonable[a.name] = a.value;
        }
      }
    },

    isInstanceAttribute: function(name) {
      return !this.blackList[name] && name.slice(0,3) !== 'on-';
    },

    // do not clone these attributes onto instances
    blackList: {
      name: 1,
      'extends': 1,
      constructor: 1,
      noscript: 1,
      assetpath: 1,
      'cache-csstext': 1
    }
    
  };

  // add ATTRIBUTES_ATTRIBUTE to the blacklist
  attributes.blackList[ATTRIBUTES_ATTRIBUTE] = 1;

  // exports

  scope.api.declaration.attributes = attributes;

})(Polymer);