var isLength = require('../internal/isLength'),
    isNative = require('../lang/isNative'),
    isObject = require('../lang/isObject'),
    shimKeys = require('../internal/shimKeys');

/* Native method references for those with the same name as other `lodash` methods. */
var nativeKeys = isNative(nativeKeys = Object.keys) && nativeKeys;

/**
 * Creates an array of the own enumerable property names of `object`.
 *
 * **Note:** Non-object values are coerced to objects. See the
 * [ES spec](https://people.mozilla.org/~jorendorff/es6-draft.html#sec-object.keys)
 * for more details.
 *
 * @static
 * @memberOf _
 * @category Object
 * @param {Object} object The object to query.
 * @returns {Array} Returns the array of property names.
 * @example
 *
 * function Foo() {
 *   this.a = 1;
 *   this.b = 2;
 * }
 *
 * Foo.prototype.c = 3;
 *
 * _.keys(new Foo);
 * // => ['a', 'b'] (iteration order is not guaranteed)
 *
 * _.keys('hi');
 * // => ['0', '1']
 */
var keys = !nativeKeys ? shimKeys : function(object) {
  if (object) {
    var Ctor = object.constructor,
        length = object.length;
  }
  if ((typeof Ctor == 'function' && Ctor.prototype === object) ||
      (typeof object != 'function' && isLength(length))) {
    return shimKeys(object);
  }
  return isObject(object) ? nativeKeys(object) : [];
};

module.exports = keys;
