/*! Copyright (c) 2017, Andrea Giammarchi, @WebReflection */
(function (F, O, R) {'use strict';

  if ('implements' in F) return;

  var
    dPs = O.defineProperties,
    gOPDs = O.getOwnPropertyDescriptors,
    ownKeys = R.ownKeys
  ;

  function Interface() {}
  Interface.prototype = O.create(null);

  function augmentFunction(target, implementable) {
    var descriptors = gOPDs(implementable);
    if (typeof implementable === 'function') {
      delete descriptors.prototype;
      dPs(target, descriptors);
      dPs(target.prototype, gOPDs(implementable.prototype));
    } else {
      augmentObject(target.prototype, implementable, descriptors);
    }
  }

  function augmentObject(target, implementable) {
    if (implementable instanceof Interface) {
      dPs(target, gOPDs(implementable));
    } else {
      for (var
        descriptors = gOPDs(implementable),
        keys = ownKeys(descriptors),
        i = 0, length = keys.length; i < length; i++
      ) {
        descriptors[keys[i]].enumerable = false;
      }
      dPs(target, descriptors);
    }
  }

  O.defineProperty(
    F, 'implements',
    {
      configurable: true,
        value: function () {
          for (var
            isObject = this === O,
            target = isObject ? {} : class extends this {},
            descriptors = isObject ? target : target.prototype,
            i = 0, l = arguments.length; i < l; i++
          ) {
            dPs(descriptors, gOPDs(arguments[i]));
          }
          return target;
      }
    }
  );

  O.defineProperty(
    F, 'interface',
    {
      configurable: true,
      value: function () {
        for (var
          isClass = typeof arguments[arguments.length - 1] === 'function',
          iFace = isClass ? class extends Interface {} : new Interface,
          augment = isClass ? augmentFunction : augmentObject,
          i = 0, length = arguments.length; i < length; i++
        ) {
          augment(iFace, arguments[i]);
        }
        return iFace;
      }
    }
  );

}(Function.prototype, Object, Reflect));