import type { ChildProcess } from 'node:child_process';
import spawn from 'cross-spawn';
import { getEnvironment } from './get-environment';
import type { StdioConfig } from './mcp-stdio-transport';

export function createChildProcess(
  config: StdioConfig,
  signal: AbortSignal,
): ChildProcess {
  if (
    globalThis.process.platform === 'win32' &&
    [config.command, ...(config.args ?? [])].some(value => /[\r\n]/.test(value))
  ) {
    throw new TypeError(
      'Stdio MCP commands and arguments must not contain line breaks on Windows.',
    );
  }

  return spawn(config.command, config.args ?? [], {
    env: getEnvironment(config.env),
    stdio: ['pipe', 'pipe', config.stderr ?? 'inherit'],
    shell: false,
    signal,
    windowsHide: globalThis.process.platform === 'win32' && isElectron(),
    cwd: config.cwd,
  });
}

function isElectron() {
  return 'type' in globalThis.process;
}