(function(Backbone, $) {
  function decorateModels(self, models) {
    var decoratee = models instanceof Backbone.Collection ? models.models : models,
        proto = _(self)
            .chain()
            .functions()
            .without('collection', 'constructor', 'initialize', 'model')
            .inject(function(result, method) { result[method] = self[method]; return result; }, {})
            .value();

    if (decoratee instanceof Array) {
      _(proto).each(function(fn, name) {
        self[name] = function() {
          var args = arguments;
          return _(decoratee).map(function(model) {
            return fn.apply(model, args);
          });
        };
      });
    } else {
      _(proto).each(function(fn, name) {
        self[name] = function() {
          return fn.apply(decoratee, arguments);
        };
      });
    }
  }

  function Decorator(models, options) {
    decorateModels(this, models);
    this.initialize.apply(this, arguments);
  }

  _(Decorator).extend({
    extend: function(protoProps, classProps) {
      var Klass = Backbone.Model.extend.apply(this, arguments);

      if (protoProps.model) {
        protoProps.model.prototype.decorator = function() {
          return new Klass(this);
        };
      }

      if (protoProps.collection) {
        protoProps.collection.prototype.decorator = function() {
          return new Klass(this);
        };
      }

      return Klass;
    }
  }, Backbone.include ? Backbone.include : {});

  _(Decorator.prototype).extend({
    initialize: $.noop
  });

  Backbone.Decorator = Decorator;
})(Backbone, jQuery);