Made of little things.

import { config } from '@napplet/sdk';
import { runtimeHasDomain } from './domain-availability.js';
import settingsSchema from '../config.schema.json';

export interface GameSettings {
  sound: boolean;
  touchControls: boolean;
  multiplayer: boolean;
}

export const defaultSettings: GameSettings = { sound: true, touchControls: true, multiplayer: true };

/**
 * Subscribe to host-managed settings. Config is optional: without it the
 * defaults apply. Calls back once with the initial values when available.
 */
export function watchSettings(onChange: (settings: GameSettings) => void): () => void {
  if (!runtimeHasDomain('config')) return () => undefined;
  let close: () => void = () => undefined;
  void (async () => {
    // Do not replace a schema that the host already supplied.
    if (!config.schema) {
      await config.registerSchema(settingsSchema as Parameters<typeof config.registerSchema>[0]);
    }
    const subscription = config.subscribe((values) => {
      onChange({
        sound: values.sound !== false,
        touchControls: values.touchControls !== false,
        multiplayer: values.multiplayer !== false,
      });
    });
    close = () => subscription.close();
  })().catch(() => {
    // Optional operations may be unavailable even when a host exposes the domain.
  });
  return () => close();
}