import { Platform } from 'react-native';

import {
  deleteSecureItem,
  getSecureItem,
  setSecureItem,
} from '@/core/storage/secure';

import { supportedLanguages, type AppLanguage } from '@/i18n/resources';

import { THEME_NAMES, type ThemeName } from '@/constants/theme-bridge';

const KEY_LANGUAGE = 'app_settings_language';
const KEY_LARGE_TEXT = 'app_settings_large_text';
const KEY_DARK_MODE = 'app_settings_dark_mode';
const KEY_THEME_NAME = 'app_settings_theme_name';

const webFallback: Record<string, string> = {};

async function getStored(key: string): Promise<string | null> {
  if (Platform.OS === 'web') return webFallback[key] ?? null;
  return getSecureItem(key);
}

async function setStored(key: string, value: string): Promise<void> {
  if (Platform.OS === 'web') {
    webFallback[key] = value;
    return;
  }
  await setSecureItem(key, value);
}

async function deleteStored(key: string): Promise<void> {
  if (Platform.OS === 'web') {
    delete webFallback[key];
    return;
  }
  await deleteSecureItem(key);
}

export async function getAppLanguage(): Promise<AppLanguage | null> {
  const v = await getStored(KEY_LANGUAGE);
  if (!v) return null;
  return supportedLanguages.includes(v as AppLanguage)
    ? (v as AppLanguage)
    : null;
}

export async function setAppLanguage(lang: AppLanguage): Promise<void> {
  await setStored(KEY_LANGUAGE, lang);
}

export async function clearAppLanguage(): Promise<void> {
  await deleteStored(KEY_LANGUAGE);
}

export async function getLargeText(): Promise<boolean> {
  const v = await getStored(KEY_LARGE_TEXT);
  if (v == null || v === '') return true;
  return v === 'true';
}

export async function setLargeText(value: boolean): Promise<void> {
  await setStored(KEY_LARGE_TEXT, value ? 'true' : 'false');
}

export async function getDarkMode(): Promise<boolean> {
  const v = await getStored(KEY_DARK_MODE);
  return v === 'true';
}

export async function setDarkMode(value: boolean): Promise<void> {
  await setStored(KEY_DARK_MODE, value ? 'true' : 'false');
}

export async function getThemeName(): Promise<ThemeName> {
  const v = await getStored(KEY_THEME_NAME);
  if (!v || !THEME_NAMES.includes(v as ThemeName)) return 'default';
  return v as ThemeName;
}

export async function setThemeName(value: ThemeName): Promise<void> {
  await setStored(KEY_THEME_NAME, value);
}

export { supportedLanguages, THEME_NAMES };
export type { AppLanguage, ThemeName };