/**
 * @license
 * Copyright 2025 Vybestack LLC
 * SPDX-License-Identifier: Apache-2.0
 */

/**
 * Relaunch utilities for the CLI.
 * Handles spawning child processes with modified arguments/environment.
 */

import { spawn } from 'node:child_process';

/**
 * Relaunch the current application in a child process with additional Node.js arguments.
 * This is used to restart with higher memory limits or enter sandboxed environments.
 *
 * The child process inherits stdio for seamless I/O, and receives an environment
 * variable to prevent infinite relaunch loops.
 *
 * @param additionalArgs - Additional Node.js arguments (e.g., --max-old-space-size=4096)
 * @param argvTail - The argv tail to launch with (defaults to `process.argv.slice(1)`
 *   for compatibility). Callers that need to augment argv (e.g. transporting a
 *   bootstrap path across a memory relaunch) pass a custom tail.
 * @returns Promise that resolves to the child process exit code
 */
export async function relaunchAppInChildProcess(
  additionalArgs: string[],
  argvTail: string[] = process.argv.slice(1),
): Promise<number> {
  const nodeArgs = [...additionalArgs, ...argvTail];
  const newEnv = { ...process.env, LLXPRT_CODE_NO_RELAUNCH: 'true' };

  const child = spawn(process.execPath, nodeArgs, {
    stdio: 'inherit',
    env: newEnv,
  });

  return new Promise((resolve) => {
    child.on('close', (code) => {
      resolve(code ?? 0);
    });
  });
}