/**
 * Shell wrapper.
 *
 * Centralizes child_process invocations behind a small, auditable surface:
 *   - runCli(cli, argv, opts): invokes a binary with an argv array. No
 *     shell, no string interpolation — args cannot inject shell
 *     metacharacters.
 *   - whichBinary(name): cross-platform PATH lookup (`which` on POSIX,
 *     `where.exe` on Windows).
 *
 * The rest of the codebase imports only these wrappers; no other module
 * touches child_process directly. Concentrating shell-outs in one file
 * makes them easy to audit.
 */

import { execFile as _runFile, execFileSync as _runFileSync } from 'node:child_process';
import { promisify } from 'node:util';

const _runFileAsync = promisify(_runFile);

export interface RunOptions {
	timeout?: number;
	maxBuffer?: number;
}

/** Run a binary with arguments and return stdout. No shell, no injection. */
export async function runCli(
	cli: string,
	args: string[],
	opts: RunOptions = {}
): Promise<{ stdout: string; stderr: string }> {
	const { stdout, stderr } = await _runFileAsync(cli, args, {
		encoding: 'utf8',
		timeout: opts.timeout ?? 120_000,
		maxBuffer: opts.maxBuffer ?? 4 * 1024 * 1024,
	});
	return { stdout, stderr };
}

/** Cross-platform binary lookup using `which` / `where.exe`. */
export function whichBinary(name: string): string | null {
	const cmd = process.platform === 'win32' ? 'where.exe' : 'which';
	try {
		const result = _runFileSync(cmd, [name], { encoding: 'utf8' }).trim();
		const first = result.split('\n')[0]?.trim();
		return first || null;
	} catch {
		return null;
	}
}