rivy / js.os-paths

import { Platform } from '../platform-adapters/_base';

export type OSPaths = {

	new (): OSPaths;

	(): OSPaths;

	readonly home: () => string | undefined;

	readonly temp: () => string;

};

function isEmpty(s: string | null | undefined): boolean {

	return !s; // reminder: JS "falsey" == [undefined, null, NaN, 0, '', false]

}

const AdaptingIsWinOS = (adapter_: Platform.Adapter) => /^win/i.test(adapter_.process.platform);

const AdaptingNormalizePath = (adapter_: Platform.Adapter) => {

	return (path_: string | undefined): string | undefined => {

		return path_ ? adapter_.path.normalize(adapter_.path.join(path_, '.')) : void 0;

	};

};

const AdaptingHome = (adapter_: Platform.Adapter) => {

	const { env, os, path } = adapter_;

	const isWinOS = AdaptingIsWinOS(adapter_);

	const normalizePath = AdaptingNormalizePath(adapter_);

	const posix = () =>

		normalizePath((typeof os.homedir === 'function' ? os.homedir() : void 0) || env.get('HOME'));

	const windows = () => {

		const priorityList = [

			typeof os.homedir === 'function' ? os.homedir() : void 0,

			env.get('USERPROFILE'),

			env.get('HOME'),

			env.get('HOMEDRIVE') || env.get('HOMEPATH')

				? path.join(env.get('HOMEDRIVE') || '', env.get('HOMEPATH') || '')

				: void 0,

		];

		return normalizePath(priorityList.find((v) => !isEmpty(v)));

	};

	return isWinOS ? windows : posix;

};

const AdaptingTemp = (adapter_: Platform.Adapter) => {

	const { env, os, path } = adapter_;

	const isWinOS = AdaptingIsWinOS(adapter_);

	const normalizePath = AdaptingNormalizePath(adapter_);

	const posix = () => {

		const fallback = '/tmp';

		const priorityList = [

			typeof os.tmpdir === 'function' ? os.tmpdir() : void 0,

			env.get('TMPDIR'),

			env.get('TEMP'),

			env.get('TMP'),

		];

		return normalizePath(priorityList.find((v) => !isEmpty(v))) || fallback;

	};

	const windows = () => {

		const fallback = 'C:\\Temp';

		const priorityListLazy = [

			os.tmpdir,

			() => env.get('TEMP'),

			() => env.get('TMP'),

			() => joinPathToBase(env.get('LOCALAPPDATA'), ['Temp']),

			() => joinPathToBase(AdaptingHome(adapter_)(), ['AppData', 'Local', 'Temp']),

			() => joinPathToBase(env.get('ALLUSERSPROFILE'), ['Temp']),

			() => joinPathToBase(env.get('SystemRoot'), ['Temp']),

			() => joinPathToBase(env.get('windir'), ['Temp']),

			() => joinPathToBase(env.get('SystemDrive'), ['\\', 'Temp']),

		];

		const v = priorityListLazy.find((v) => v && !isEmpty(v()));

		return (v && normalizePath(v())) || fallback;

	};

	return isWinOS ? windows : posix;

};

export function OSPathsAdaptionBuilder_(adapter_: Platform.Adapter): OSPaths {

	// eslint-disable-next-line functional/no-class

	class OSPaths_ {

		constructor() {

			const OSPaths = function () {

				return new OSPaths_() as OSPaths;

			};

			OSPaths.home = AdaptingHome(adapter_);

			OSPaths.temp = AdaptingTemp(adapter_);

			return OSPaths;

		}

	}

	return new OSPaths_() as OSPaths;

}