import 'dart:convert';

import 'package:shared_preferences/shared_preferences.dart';

import '../models/address_entry.dart';
import '../models/address_record.dart';
import '../models/auth_session.dart';

abstract class AddressRepository {
  Future<void> saveAddress({
    required AuthSession session,
    required AddressEntry address,
  });

  Future<List<AddressRecord>> getMyAddresses({required AuthSession session});
}

class LocalAddressRepository implements AddressRepository {
  const LocalAddressRepository();
  static const String _localAddressPrefix = 'local_addresses_';

  @override
  Future<void> saveAddress({
    required AuthSession session,
    required AddressEntry address,
  }) async {
    await _persistLocalAddress(session: session, address: address);
  }

  @override
  Future<List<AddressRecord>> getMyAddresses({required AuthSession session}) async {
    return _loadLocalAddresses(session);
  }

  Future<void> _persistLocalAddress({required AuthSession session, required AddressEntry address}) async {
    final prefs = await SharedPreferences.getInstance();
    final key = '$_localAddressPrefix${session.email.toLowerCase()}';
    final existing = await _loadLocalAddresses(session);
    final records = <AddressRecord>[
      AddressRecord(
        id: DateTime.now().millisecondsSinceEpoch,
        houseNumber: address.houseNumber,
        colonia: address.colonia,
        street: address.street,
      ),
      ...existing,
    ];

    final encoded = jsonEncode(
      records
          .map(
            (record) => <String, dynamic>{
              'id': record.id,
              'houseNumber': record.houseNumber,
              'colonia': record.colonia,
              'street': record.street,
            },
          )
          .toList(growable: false),
    );
    await prefs.setString(key, encoded);
  }

  Future<List<AddressRecord>> _loadLocalAddresses(AuthSession session) async {
    final prefs = await SharedPreferences.getInstance();
    final key = '$_localAddressPrefix${session.email.toLowerCase()}';
    final raw = prefs.getString(key);
    if (raw == null || raw.trim().isEmpty) {
      return <AddressRecord>[];
    }

    final decoded = jsonDecode(raw);
    if (decoded is! List) {
      return <AddressRecord>[];
    }

    return decoded
        .whereType<Map<String, dynamic>>()
        .map(AddressRecord.fromJson)
        .toList(growable: false);
  }
}

class AddressException implements Exception {
  AddressException(this.message);
  final String message;

  @override
  String toString() => message;
}