import process from 'node:process';
import {Buffer} from 'node:buffer';
import {promisify} from 'node:util';
import childProcess from 'node:child_process';
import fs, {constants as fsConstants} from 'node:fs/promises';

const execFile = promisify(childProcess.execFile);

export const powerShellPath = () => `${process.env.SYSTEMROOT || process.env.windir || String.raw`C:\Windows`}\\System32\\WindowsPowerShell\\v1.0\\powershell.exe`;

// Cache for PowerShell accessibility check
let canAccessCache;

export const canAccessPowerShell = async () => {
	canAccessCache ??= (async () => {
		try {
			await fs.access(powerShellPath(), fsConstants.X_OK);
			return true;
		} catch {
			return false;
		}
	})();

	return canAccessCache;
};

const argumentsPrefix = [
	'-NoProfile',
	'-NonInteractive',
	'-ExecutionPolicy',
	'Bypass',
	'-EncodedCommand',
];

const encodeCommand = command => Buffer.from(command, 'utf16le').toString('base64');

/*
PowerShell's tokenizer treats the typographic single quotes U+2018, U+2019, U+201A, and U+201B as string delimiters, exactly like the ASCII one, and it does not require the closing quote to match the opening quote. Escaping only the ASCII quote would let any of the others terminate the string and inject a statement. Doubling works for all of them.
*/
const escapeArgument = value => `'${String(value).replaceAll(/['‘’‚‛]/g, match => match + match)}'`;

const createArguments = command => [...argumentsPrefix, encodeCommand(command)];

const createExecFileOptions = options => ({
	encoding: 'utf8',
	...options,
	shell: false,
});

export const executePowerShell = async (command, options = {}) => {
	const {
		powerShellPath: psPath,
		...execFileOptions
	} = options;

	return execFile(
		psPath ?? powerShellPath(),
		createArguments(command),
		createExecFileOptions(execFileOptions),
	);
};

executePowerShell.argumentsPrefix = argumentsPrefix;
executePowerShell.encodeCommand = encodeCommand;
executePowerShell.escapeArgument = escapeArgument;
executePowerShell.createArguments = createArguments;

export const executePowerShellSync = (command, options = {}) => {
	const {
		powerShellPath: psPath,
		...execFileOptions
	} = options;

	return childProcess.execFileSync(
		psPath ?? powerShellPath(),
		createArguments(command),
		createExecFileOptions(execFileOptions),
	);
};