Genarrative/src/persistence/gameSettingsStorage.ts

import {
  DEFAULT_MUSIC_VOLUME,
  DEFAULT_PLATFORM_THEME,
  type PlatformTheme,
  type RuntimeSettings,
} from '../../packages/shared/src/contracts/runtime';
import { isRecord, readStoredJson, writeStoredJson } from './storage';

const SETTINGS_STORAGE_KEY = 'tavernrealms.settings.v1';
const SETTINGS_STORAGE_VERSION = 1;

export type SavedGameSettings = RuntimeSettings;
export { DEFAULT_MUSIC_VOLUME };

type StoredGameSettings = SavedGameSettings & {
  version: number;
};

export function clampVolume(value: number) {
  if (!Number.isFinite(value)) {
    return DEFAULT_MUSIC_VOLUME;
  }

  return Math.max(0, Math.min(1, value));
}

export function normalizePlatformTheme(value: unknown): PlatformTheme {
  return value === 'dark' ? 'dark' : DEFAULT_PLATFORM_THEME;
}

function parseSavedSettings(value: unknown): SavedGameSettings | null {
  if (!isRecord(value)) {
    return null;
  }

  if (
    value.version === SETTINGS_STORAGE_VERSION &&
    typeof value.musicVolume === 'number'
  ) {
    return {
      musicVolume: clampVolume(value.musicVolume),
      platformTheme: normalizePlatformTheme(value.platformTheme),
    };
  }

  if (typeof value.musicVolume === 'number') {
    return {
      musicVolume: clampVolume(value.musicVolume),
      platformTheme: normalizePlatformTheme(value.platformTheme),
    };
  }

  return null;
}

export function readSavedSettings() {
  return (
    readStoredJson({
      key: SETTINGS_STORAGE_KEY,
      parse: parseSavedSettings,
    }) ?? {
      musicVolume: DEFAULT_MUSIC_VOLUME,
      platformTheme: DEFAULT_PLATFORM_THEME,
    }
  );
}

export function writeSavedSettings(settings: SavedGameSettings) {
  const payload: StoredGameSettings = {
    version: SETTINGS_STORAGE_VERSION,
    musicVolume: clampVolume(settings.musicVolume),
    platformTheme: normalizePlatformTheme(settings.platformTheme),
  };

  return writeStoredJson({
    key: SETTINGS_STORAGE_KEY,
    value: payload,
  });
}