import 'dart:convert';
import '../core/failure.dart';
import '../models/server_profile.dart';

class ProfileTransfer {
  static const maxBytes = 5 * 1024 * 1024;
  static List<ServerProfile> decode(List<int> bytes) {
    if (bytes.length > maxBytes) throw const Failure('invalidImport');
    try {
      final text = utf8.decode(bytes).replaceFirst(RegExp(r'^\uFEFF'), '');
      final data = jsonDecode(text);
      if (data is! Map ||
          data['format'] != 'chj-server-profiles' ||
          data['version'] != 1 ||
          data['servers'] is! List ||
          data['servers'].isEmpty ||
          data['servers'].length > 10000) {
        throw const Failure('invalidImport');
      }
      return (data['servers'] as List)
          .map(
            (e) => ServerProfile.fromJson(
              Map<String, dynamic>.from(e),
              portable: true,
            ),
          )
          .toList();
    } catch (_) {
      throw const Failure('invalidImport');
    }
  }

  static List<int> encode(List<ServerProfile> profiles) => utf8.encode(
    const JsonEncoder.withIndent('  ').convert({
      'format': 'chj-server-profiles',
      'version': 1,
      'servers': profiles.map((p) => p.portable()).toList(),
    }),
  );
}