import {setupIfUndef} from './setup';

function _parseArgs(others: any[]) {
	const value = others[others.length - 1];
	const rest = Array.prototype.concat.apply([], others.slice(0, -1));  // exclude `value`
	const hierarchies = rest.slice(0, -1);
	const prop = rest[rest.length - 1];
	return {hierarchies, prop, value};
}

function set(optionalTarget: any, ...others: any[]) {
	const {hierarchies, prop, value} = _parseArgs(others);

	const target = optionalTarget || {};
	const current = setupIfUndef(target, hierarchies);
	current[prop] = value;
	return target;
}

function assign(target: any, ...others: any[]) {
	const {hierarchies, prop, value} = _parseArgs(others);

	const current = setupIfUndef(target, hierarchies);
	current[prop] = value;
	return current;
}

function put(target: any, ...others: any[]) {
	const {hierarchies, prop, value} = _parseArgs(others);

	const current = setupIfUndef(target, hierarchies);
	current[prop] = value;
	return value;
}

function setIfUndef(optionalTarget: any, ...others: any[]) {
	const {hierarchies, prop, value} = _parseArgs(others);

	const target = optionalTarget || {};
	const current = setupIfUndef(target, hierarchies);
	if (current[prop] === undefined) {
		current[prop] = value;
	}
	return target;
}

function assignIfUndef(target: any, ...others: any[]) {
	const {hierarchies, prop, value} = _parseArgs(others);

	const current = setupIfUndef(target, hierarchies);
	if (current[prop] === undefined) {
		current[prop] = value;
	}
	return current;
}

function putIfUndef(target: any, ...others: any[]) {
	const {hierarchies, prop, value} = _parseArgs(others);

	const current = setupIfUndef(target, hierarchies);
	if (current[prop] === undefined) {
		current[prop] = value;
	}
	return current[prop];
}

export {
	set,
	assign,
	put,
	setIfUndef,
	assignIfUndef,
	putIfUndef
};