import 'dart:ui';

import 'locale_storage.dart';

const supportedLocaleCodes = ['en', 'ko'];
const defaultLocaleCode = 'en';

String normalizeLocaleCode(String? code) {
  if (code == null || code.isEmpty) {
    return defaultLocaleCode;
  }
  final normalized = code.toLowerCase();
  if (normalized == 'ko' || normalized.startsWith('ko-')) {
    return 'ko';
  }
  if (normalized == 'en' || normalized.startsWith('en-')) {
    return 'en';
  }
  return defaultLocaleCode;
}

String resolvePreferredLocaleCode() {
  final stored = LocaleStorage.read();
  if (stored != null && supportedLocaleCodes.contains(stored)) {
    return stored;
  }
  final deviceLocale = PlatformDispatcher.instance.locale;
  return normalizeLocaleCode(deviceLocale.languageCode);
}

String? extractLocaleFromPath(Uri uri) {
  if (uri.pathSegments.isEmpty) {
    return null;
  }
  final code = uri.pathSegments.first.toLowerCase();
  if (supportedLocaleCodes.contains(code)) {
    return code;
  }
  return null;
}

String stripLocalePath(Uri uri) {
  final segments = uri.pathSegments;
  if (segments.isNotEmpty && supportedLocaleCodes.contains(segments.first)) {
    final rest = segments.skip(1).join('/');
    if (rest.isEmpty) {
      return '/';
    }
    return '/$rest';
  }
  return uri.path;
}

String buildLocalizedPath(String localeCode, Uri uri) {
  final segments = uri.pathSegments;
  Iterable<String> restSegments = segments;
  if (segments.isNotEmpty) {
    final head = segments.first.toLowerCase();
    if (supportedLocaleCodes.contains(head) || head.length == 2) {
      restSegments = segments.skip(1);
    }
  }
  final newSegments = [localeCode, ...restSegments];
  final path = '/${newSegments.join('/')}';
  if (uri.queryParameters.isEmpty) {
    return path;
  }
  return Uri(path: path, queryParameters: uri.queryParameters).toString();
}