/**
 * Internal function that actually applies the state to the Stateful's state and
 * emits the `statechange` event.
 *
 * @param stateful The Stateful instance
 * @param state The State to be set
 */
function setStatefulState(stateful: Stateful<State>, state: State): void {
	state = deepAssign(stateWeakMap.get(stateful), state);
	stateful.emit({
		type: 'statechange',
		state,
		target: stateful
	});
}

function setStatefulState(stateful: Stateful<State>, value: State) {
	const state = deepAssign(stateWeakMap.get(stateful), value);
	stateful.emit({
		type: 'statechange',
		state,
		target: stateful
	});
	return state;
}

function createAxesConfiguration(shared: AxisConfiguration<Datum<number>>, chartOptions: any): any {
	const config: any = {};
	for (const side of ['bottomAxis', 'leftAxis', 'rightAxis', 'topAxis']) {
		config[side] = deepAssign({}, shared);
		if (side === 'leftAxis' || side === 'rightAxis') {
			config[side].labels = assign({
				anchor: 'end'
			}, config[side].labels);
		}
		if (side === 'bottomAxis' || side === 'topAxis') {
			config[side].labels = assign({
				dominantBaseline: 'middle',
				rotation: 90
			}, config[side].labels);
		}
	}
	return assign(config, chartOptions);
}