/**
 * External dependencies.
 */
import type { Experiment, Maybe } from '@nab/types';

/**
 * Internal dependencies.
 */
import type { State } from '../types';

type ExtensionName = keyof Extensions;
type Extensions = Required< Required< Experiment >[ 'extensions' ] >;

type GetExtension = typeof _getExtension & {
	CurriedSignature: typeof __getExtension;
};
export const getExtension = _getExtension as GetExtension;
function _getExtension< TName extends ExtensionName >(
	state: State,
	name: TName
): Maybe< Extensions[ TName ] > {
	return state.experiment.extensions[ name ];
}

/* eslint-disable @typescript-eslint/no-unused-vars */
function __getExtension< TName extends ExtensionName >(
	name: TName
): Maybe< Extensions[ TName ] > {
	return name ? undefined : undefined;
}
/* eslint-enable @typescript-eslint/no-unused-vars */

export function getExtensions( state: State ): Partial< Extensions > {
	return state.experiment.extensions;
}