/*
 * 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) {

  // instance api for attributes

  var attributes = {
    // copy attributes defined in the element declaration to the instance
    // e.g. <polymer-element name="x-foo" tabIndex="0"> tabIndex is copied
    // to the element instance here.
    copyInstanceAttributes: function () {
      var a$ = this._instanceAttributes;
      for (var k in a$) {
        if (!this.hasAttribute(k)) {
          this.setAttribute(k, a$[k]);
        }
      }
    },
    // for each attribute on this, deserialize value to property as needed
    takeAttributes: function() {
      // if we have no publish lookup table, we have no attributes to take
      // TODO(sjmiles): ad hoc
      if (this._publishLC) {
        for (var i=0, a$=this.attributes, l=a$.length, a; (a=a$[i]) && i<l; i++) {
          this.attributeToProperty(a.name, a.value);
        }
      }
    },
    // if attribute 'name' is mapped to a property, deserialize
    // 'value' into that property
    attributeToProperty: function(name, value) {
      // try to match this attribute to a property (attributes are
      // all lower-case, so this is case-insensitive search)
      var name = this.propertyForAttribute(name);
      if (name) {
        // filter out 'mustached' values, these are to be
        // replaced with bound-data and are not yet values
        // themselves
        if (value && value.search(scope.bindPattern) >= 0) {
          return;
        }
        // get original value
        var currentValue = this[name];
        // deserialize Boolean or Number values from attribute
        var value = this.deserializeValue(value, currentValue);
        // only act if the value has changed
        if (value !== currentValue) {
          // install new value (has side-effects)
          this[name] = value;
        }
      }
    },
    // return the published property matching name, or undefined
    propertyForAttribute: function(name) {
      var match = this._publishLC && this._publishLC[name];
      return match;
    },
    // convert representation of `stringValue` based on type of `currentValue`
    deserializeValue: function(stringValue, currentValue) {
      return scope.deserializeValue(stringValue, currentValue);
    },
    // convert to a string value based on the type of `inferredType`
    serializeValue: function(value, inferredType) {
      if (inferredType === 'boolean') {
        return value ? '' : undefined;
      } else if (inferredType !== 'object' && inferredType !== 'function'
          && value !== undefined) {
        return value;
      }
    },
    // serializes `name` property value and updates the corresponding attribute
    // note that reflection is opt-in.
    reflectPropertyToAttribute: function(name) {
      var inferredType = typeof this[name];
      // try to intelligently serialize property value
      var serializedValue = this.serializeValue(this[name], inferredType);
      // boolean properties must reflect as boolean attributes
      if (serializedValue !== undefined) {
        this.setAttribute(name, serializedValue);
        // TODO(sorvell): we should remove attr for all properties
        // that have undefined serialization; however, we will need to
        // refine the attr reflection system to achieve this; pica, for example,
        // relies on having inferredType object properties not removed as
        // attrs.
      } else if (inferredType === 'boolean') {
        this.removeAttribute(name);
      }
    }
  };

  // exports

  scope.api.instance.attributes = attributes;

})(Polymer);