import 'dart:convert';
import 'dart:typed_data';
import '../models/message.dart';
import '../helpers/smaz.dart';
import '../utils/app_logger.dart';
import 'prefs_manager.dart';

class MessageStore {
  static const String _keyPrefix = 'messages_';

  String publicKeyHex = '';
  set setPublicKeyHex(String value) =>
      publicKeyHex = value.length > 10 ? value.substring(0, 10) : '';

  String get keyFor => '$_keyPrefix$publicKeyHex';

  Future<void> saveMessages(
    String contactKeyHex,
    List<Message> messages,
  ) async {
    if (publicKeyHex.isEmpty) {
      appLogger.warn('Public key hex is not set. Cannot save messages.');
      return;
    }
    final prefs = PrefsManager.instance;
    final key = '$keyFor$contactKeyHex';
    final jsonList = messages.map(_messageToJson).toList();
    await prefs.setString(key, jsonEncode(jsonList));
  }

  Future<List<Message>> loadMessages(String contactKeyHex) async {
    if (publicKeyHex.isEmpty) {
      appLogger.warn('Public key hex is not set. Cannot load messages.');
      return [];
    }
    final prefs = PrefsManager.instance;
    final key = '$keyFor$contactKeyHex';
    final oldKey = '$_keyPrefix$contactKeyHex';
    String? jsonString = prefs.getString(key);
    if (jsonString == null || jsonString.isEmpty) {
      // Attempt migration from legacy unscoped key on first load
      final legacyJsonString = prefs.getString(oldKey);
      prefs.remove(oldKey);
      if (legacyJsonString != null && legacyJsonString.isNotEmpty) {
        appLogger.info(
          'Migrating messages from legacy key $oldKey to scoped key $key',
        );
        await prefs.setString(key, legacyJsonString);
        jsonString = legacyJsonString;
      }
    }
    if (jsonString == null || jsonString.isEmpty) {
      jsonString = prefs.getString(keyFor);
    }
    if (jsonString == null || jsonString.isEmpty) {
      return [];
    }

    try {
      final jsonList = jsonDecode(jsonString) as List<dynamic>;
      return jsonList.map((json) => _messageFromJson(json)).toList();
    } catch (e) {
      return [];
    }
  }

  Future<void> clearMessages(String contactKeyHex) async {
    if (publicKeyHex.isEmpty) {
      appLogger.warn('Public key hex is not set. Cannot clear messages.');
      return;
    }
    final prefs = PrefsManager.instance;
    final key = '$keyFor$contactKeyHex';
    await prefs.remove(key);
  }

  Map<String, dynamic> _messageToJson(Message msg) {
    return {
      'senderKey': base64Encode(msg.senderKey),
      'text': msg.text,
      'timestamp': msg.timestamp.millisecondsSinceEpoch,
      'isOutgoing': msg.isOutgoing,
      'isCli': msg.isCli,
      'status': msg.status.index,
      'messageId': msg.messageId,
      'retryCount': msg.retryCount,
      'estimatedTimeoutMs': msg.estimatedTimeoutMs,
      'expectedAckHash': msg.expectedAckHash,
      'sentAt': msg.sentAt?.millisecondsSinceEpoch,
      'deliveredAt': msg.deliveredAt?.millisecondsSinceEpoch,
      'tripTimeMs': msg.tripTimeMs,
      'pathLength': msg.pathLength,
      'pathBytes': msg.pathBytes.isNotEmpty
          ? base64Encode(msg.pathBytes)
          : null,
      'reactions': msg.reactions,
      'reactionStatuses': msg.reactionStatuses.map(
        (key, value) => MapEntry(key, value.index),
      ),
      'fourByteRoomContactKey': base64Encode(msg.fourByteRoomContactKey),
    };
  }

  Message _messageFromJson(Map<String, dynamic> json) {
    final rawText = json['text'] as String;
    final isCli = json['isCli'] as bool? ?? false;
    final decodedText = isCli
        ? rawText
        : (Smaz.tryDecodePrefixed(rawText) ?? rawText);
    return Message(
      senderKey: Uint8List.fromList(base64Decode(json['senderKey'] as String)),
      text: decodedText,
      timestamp: DateTime.fromMillisecondsSinceEpoch(json['timestamp'] as int),
      isOutgoing: json['isOutgoing'] as bool,
      isCli: isCli,
      status: MessageStatus.values[json['status'] as int],
      messageId: json['messageId'] as String?,
      retryCount: json['retryCount'] as int? ?? 0,
      estimatedTimeoutMs: json['estimatedTimeoutMs'] as int?,
      expectedAckHash: json['expectedAckHash'] as int? ?? 0,
      sentAt: json['sentAt'] != null
          ? DateTime.fromMillisecondsSinceEpoch(json['sentAt'] as int)
          : null,
      deliveredAt: json['deliveredAt'] != null
          ? DateTime.fromMillisecondsSinceEpoch(json['deliveredAt'] as int)
          : null,
      tripTimeMs: json['tripTimeMs'] as int?,
      pathLength: json['pathLength'] as int?,
      pathBytes: json['pathBytes'] != null
          ? Uint8List.fromList(base64Decode(json['pathBytes'] as String))
          : Uint8List(0),
      reactions:
          (json['reactions'] as Map<String, dynamic>?)?.map(
            (key, value) => MapEntry(key, value as int),
          ) ??
          {},
      reactionStatuses:
          (json['reactionStatuses'] as Map<String, dynamic>?)?.map(
            (key, value) => MapEntry(key, MessageStatus.values[value as int]),
          ) ??
          {},
      fourByteRoomContactKey: json['fourByteRoomContactKey'] != null
          ? Uint8List.fromList(
              base64Decode(json['fourByteRoomContactKey'] as String),
            )
          : null,
    );
  }
}