///
/// CCC isolate-backed crypto provider for message payloads.
///
import 'dart:convert';

import 'package:letusmsg/ccc/ccc_iso_manager.dart';
import 'package:letusmsg/ccc/crypto_abstract.dart';

/// Real crypto provider backed by `CryptoIsolateManager`.
///
/// Notes:
/// - Requires `context.channelUuid` for channel-scoped operation.
/// - Uses JSON map serialization for current message payload format.
class CryptoCcc implements CryptoAbstract<Map<String, dynamic>> {
  final CryptoIsolateManager _manager;
  bool _initialized = false;

  CryptoCcc(this._manager);

  @override
  String get providerName => 'CryptoCcc';

  @override
  bool get isPlaintextMode => false;

  Future<void> _ensureInitialized() async {
    if (_initialized) return;
    await _manager.initialize();
    _initialized = true;
  }

  String _requireChannelUuid(CryptoContext? context) {
    final channelUuid = context?.channelUuid;
    if (channelUuid == null || channelUuid.isEmpty) {
      throw ArgumentError('CryptoCcc requires a non-empty channelUuid in CryptoContext');
    }
    return channelUuid;
  }

  @override
  Future<List<int>> encrypt(Map<String, dynamic> input, {CryptoContext? context}) async {
    await _ensureInitialized();
    final channelUuid = _requireChannelUuid(context);

    final plainBytes = utf8.encode(jsonEncode(input));
    final result = await _manager.encrypt(
      plainBytes,
      channelUuid: channelUuid,
      messageSequence: context?.messageSequence,
      cipherSequence: context?.cipherSequence,
      params: context?.cipherParams,
      isUserMessage: context?.isUserMessage ?? false,
    );

    if (!result.success) {
      throw Exception('CryptoCcc encrypt failed: ${result.error ?? 'unknown error'}');
    }

    return result.data;
  }

  @override
  Future<Map<String, dynamic>> decrypt(List<int> data, {CryptoContext? context}) async {
    await _ensureInitialized();
    final channelUuid = _requireChannelUuid(context);

    final result = await _manager.decrypt(
      data,
      channelUuid: channelUuid,
      messageSequence: context?.messageSequence,
      cipherSequence: context?.cipherSequence,
      params: context?.cipherParams,
    );

    if (!result.success) {
      throw Exception('CryptoCcc decrypt failed: ${result.error ?? 'unknown error'}');
    }

    return jsonDecode(utf8.decode(result.data));
  }
}