import 'package:dio/dio.dart';

import '../services/device_header_service.dart';
import '../storage/secure_identity_storage.dart';
import '../storage/preferences_storage.dart';
import '../storage/storage_service.dart';
import 'api_exception.dart';

final _defaultIdentityStorage = SecureIdentityStorage(
  PreferencesStorage(StorageService.to.preferences),
);

Future<void> saveJwt(String token) => _defaultIdentityStorage.saveJwt(token);
Future<void> clearJwt() => _defaultIdentityStorage.clearJwt();
Future<String?> loadJwt() => _defaultIdentityStorage.readJwt();

class AuthInterceptor extends Interceptor {
  AuthInterceptor(this._sessionStorage, {required Uri backendOrigin})
    : _backendOrigin = backendOrigin;

  final AuthSessionStorage _sessionStorage;
  final Uri _backendOrigin;

  @override
  Future<void> onRequest(
    RequestOptions options,
    RequestInterceptorHandler handler,
  ) async {
    if (!_sameOrigin(options.uri, _backendOrigin)) {
      _stripSensitiveHeaders(options.headers);
      handler.next(options);
      return;
    }
    await DeviceHeaderService.to.ensureInitialized();
    options.headers.addAll(DeviceHeaderService.to.commonHeaders());
    options.headers.addAll(DeviceHeaderService.to.platformIdentityHeaders());
    final jwt = _sessionStorage.accessToken ?? await _sessionStorage.restore();
    if (jwt != null && jwt.isNotEmpty) {
      options.headers['Authorization'] = 'Bearer $jwt';
    }
    options.extra[authSessionGenerationExtra] = _sessionStorage.generation;
    handler.next(options);
  }
}

bool _sameOrigin(Uri request, Uri backend) =>
    request.scheme.toLowerCase() == backend.scheme.toLowerCase() &&
    request.host.toLowerCase() == backend.host.toLowerCase() &&
    request.port == backend.port;

void _stripSensitiveHeaders(Map<String, dynamic> headers) {
  const sensitive = {
    'authorization',
    'x-device-id',
    'user-devicetoken',
    'user-android-id',
    'user-android-oaid',
    'user-android-imei',
    'user-android-mac',
    'user-ios-idfv',
    'user-ios-idfa',
    'user-ios-paid',
  };
  headers.removeWhere((key, _) => sensitive.contains(key.toLowerCase()));
}