'use strict';

Object.defineProperty(exports, "__esModule", {
    value: true
});

var _extends = Object.assign || function (target) { for (var i = 1; i < arguments.length; i++) { var source = arguments[i]; for (var key in source) { if (Object.prototype.hasOwnProperty.call(source, key)) { target[key] = source[key]; } } } return target; };

function _toConsumableArray(arr) { if (Array.isArray(arr)) { for (var i = 0, arr2 = Array(arr.length); i < arr.length; i++) { arr2[i] = arr[i]; } return arr2; } else { return Array.from(arr); } }

function copyWith(obj, key, value) {
    var result = typeof key === 'number' ? [].concat(_toConsumableArray(obj)) : _extends({}, obj);
    result[key] = value;
    return result;
}

var cowValueModel = exports.cowValueModel = function cowValueModel() {
    for (var _len = arguments.length, keyDescriptions = Array(_len), _key = 0; _key < _len; _key++) {
        keyDescriptions[_key] = arguments[_key];
    }

    var keys = [];

    function fillKeys(keyDescriptions) {
        keyDescriptions.forEach(function (each) {
            if (typeof each === 'number') keys.push(each);else if (Array.isArray(each)) fillKeys(each);else keys.push.apply(keys, _toConsumableArray(each.toString().split('.')));
        });
    }

    fillKeys(keyDescriptions);

    function setField(x, index, val) {
        if (index >= keys.length) return val;
        var key = keys[index],
            value = x == null ? undefined : x[key],
            modified = setField(value, index + 1, val);
        return value === modified ? x : copyWith(x, key, modified);
    }

    var GET_SENTINEL = {};

    return function (obj) {
        var val = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : GET_SENTINEL;
        return val === GET_SENTINEL ? keys.reduce(function (x, key) {
            return x == null ? undefined : x[key];
        }, obj) : setField(obj, 0, val);
    };
};

var cowWorkshop = exports.cowWorkshop = function cowWorkshop(keys) {
    var fn = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : function (x) {
        return x;
    };
    return function (obj) {
        var _ref = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : {},
            _ref$result = _ref.result,
            result = _ref$result === undefined ? obj : _ref$result,
            _ref$resultKeys = _ref.resultKeys,
            resultKeys = _ref$resultKeys === undefined ? keys : _ref$resultKeys,
            diff = _ref.diff;

        keys.forEach(function (key, index) {
            var value = fn(cowValueModel(key)(obj));
            if (typeof value === "undefined") return;
            var modifier = cowValueModel(resultKeys[index]);
            var oldResult = result;
            result = modifier(oldResult, value);
            if (result !== oldResult) {
                diff = modifier(diff, value);
            }
        });
        return { result: result, diff: diff };
    };
};