export async function main()

in packages/cli/src/gemini.tsx [84:210]
115 lines of code
24 McCabe index (conditional complexity)

export async function main() {
  const workspaceRoot = process.cwd();
  const settings = loadSettings(workspaceRoot);

  await cleanupCheckpoints();
  if (settings.errors.length > 0) {
    for (const error of settings.errors) {
      let errorMessage = `Error in ${error.path}: ${error.message}`;
      if (!process.env.NO_COLOR) {
        errorMessage = `\x1b[31m${errorMessage}\x1b[0m`;
      }
      console.error(errorMessage);
      console.error(`Please fix ${error.path} and try again.`);
    }
    process.exit(1);
  }

  const extensions = loadExtensions(workspaceRoot);
  const config = await loadCliConfig(settings.merged, extensions, sessionId);

  // set default fallback to gemini api key
  // this has to go after load cli because thats where the env is set
  if (!settings.merged.selectedAuthType && process.env.GEMINI_API_KEY) {
    settings.setValue(
      SettingScope.User,
      'selectedAuthType',
      AuthType.USE_GEMINI,
    );
  }

  setMaxSizedBoxDebugging(config.getDebugMode());

  // Initialize centralized FileDiscoveryService
  config.getFileService();
  if (config.getCheckpointingEnabled()) {
    try {
      await config.getGitService();
    } catch {
      // For now swallow the error, later log it.
    }
  }

  if (settings.merged.theme) {
    if (!themeManager.setActiveTheme(settings.merged.theme)) {
      // If the theme is not found during initial load, log a warning and continue.
      // The useThemeCommand hook in App.tsx will handle opening the dialog.
      console.warn(`Warning: Theme "${settings.merged.theme}" not found.`);
    }
  }

  const memoryArgs = settings.merged.autoConfigureMaxOldSpaceSize
    ? getNodeMemoryArgs(config)
    : [];

  // hop into sandbox if we are outside and sandboxing is enabled
  if (!process.env.SANDBOX) {
    const sandboxConfig = config.getSandbox();
    if (sandboxConfig) {
      if (settings.merged.selectedAuthType) {
        // Validate authentication here because the sandbox will interfere with the Oauth2 web redirect.
        try {
          const err = validateAuthMethod(settings.merged.selectedAuthType);
          if (err) {
            throw new Error(err);
          }
          await config.refreshAuth(settings.merged.selectedAuthType);
        } catch (err) {
          console.error('Error authenticating:', err);
          process.exit(1);
        }
      }
      await start_sandbox(sandboxConfig, memoryArgs);
      process.exit(0);
    } else {
      // Not in a sandbox and not entering one, so relaunch with additional
      // arguments to control memory usage if needed.
      if (memoryArgs.length > 0) {
        await relaunchWithAdditionalArgs(memoryArgs);
        process.exit(0);
      }
    }
  }
  let input = config.getQuestion();
  const startupWarnings = await getStartupWarnings();

  // Render UI, passing necessary config values. Check that there is no command line question.
  if (process.stdin.isTTY && input?.length === 0) {
    setWindowTitle(basename(workspaceRoot), settings);
    render(
      <React.StrictMode>
        <AppWrapper
          config={config}
          settings={settings}
          startupWarnings={startupWarnings}
        />
      </React.StrictMode>,
      { exitOnCtrlC: false },
    );
    return;
  }
  // If not a TTY, read from stdin
  // This is for cases where the user pipes input directly into the command
  if (!process.stdin.isTTY) {
    input += await readStdin();
  }
  if (!input) {
    console.error('No input provided via stdin.');
    process.exit(1);
  }

  logUserPrompt(config, {
    'event.name': 'user_prompt',
    'event.timestamp': new Date().toISOString(),
    prompt: input,
    prompt_length: input.length,
  });

  // Non-interactive mode handled by runNonInteractive
  const nonInteractiveConfig = await loadNonInteractiveConfig(
    config,
    extensions,
    settings,
  );

  await runNonInteractive(nonInteractiveConfig, input);
  process.exit(0);
}