"use strict";

var forEach       = require("./for-each")
  , isPlainObject = require("./is-plain-object")
  , ensureValue   = require("./valid-value")
  , isArray       = Array.isArray
  , copy
  , copyItem;

copyItem = function (value) {
	var index;
	if (!isPlainObject(value) && !isArray(value)) return value;
	index = this[0].indexOf(value);
	if (index === -1) return copy.call(this, value);
	return this[1][index];
};

copy = function (source) {
	var target = isArray(source) ? [] : {};
	this[0].push(source);
	this[1].push(target);
	if (isArray(source)) {
		source.forEach(function (value, key) {
			target[key] = copyItem.call(this, value, key);
		}, this);
	} else {
		forEach(
			source,
			function (value, key) {
				target[key] = copyItem.call(this, value, key);
			},
			this
		);
	}
	return target;
};

module.exports = function (source) {
	var obj = Object(ensureValue(source));
	if (obj !== source) return obj;
	return copy.call([[], []], obj);
};