import 'dart:convert';
import 'dart:math';
import 'dart:typed_data';

import 'package:archive/archive.dart';
import 'package:crypto/crypto.dart';
import 'package:http/http.dart' as http;
import 'package:pointycastle/export.dart';

import '../config/title_server_config.dart';
import '../models/user_data.dart';
import 'api_log.dart';
import '../models/user_character.dart';
import '../models/user_kaleidx_scope.dart';
import '../models/user_preview.dart';
import '../models/user_rating.dart';

class TitleApiException implements Exception {
  final String message;
  const TitleApiException(this.message);
  @override
  String toString() => 'TitleApiException: $message';
}

class UserLoginResult {
  final String token;
  final int loginId;
  final String lastLoginDate;
  final int loginDateTime;

  const UserLoginResult({
    required this.token,
    required this.loginId,
    required this.lastLoginDate,
    required this.loginDateTime,
  });
}

class TitleApiService {
  static const String _obfuscateConstant = 'MaimaiChn';

  static String? lastRawResponse;

  final TitleServerConfig _config;
  String? _cookies;

  TitleApiService(this._config, {this._cookies});

  /// 从 [TitleServerConfigHolder] 构造；未配置时返回 `null`。
  ///
  /// 各页原本都写 `if (!holder.isConfigured) ...; TitleApiService(holder.config!, ...)`，
  /// 收口成一个工厂，避免 `config!` 与 `isConfigured` 散落在十几个地方。
  static TitleApiService? fromHolder({String? cookies}) {
    final holder = TitleServerConfigHolder();
    if (!holder.isConfigured) return null;
    return TitleApiService(holder.config!, cookies: cookies);
  }

  String? get cookies => _cookies;

  /// 组装 payload 时需要同一份配置（地点 / 区域 / clientId）。
  TitleServerConfig get config => _config;

  Uint8List _aesEncrypt(Uint8List plaintext) {
    final cipher = PaddedBlockCipherImpl(
      PKCS7Padding(),
      CBCBlockCipher(AESEngine()),
    )..init(
        true,
        PaddedBlockCipherParameters(
          ParametersWithIV(
            KeyParameter(Uint8List.fromList(_config.aesKeyBytes)),
            Uint8List.fromList(_config.aesIvBytes),
          ),
          null,
        ),
      );
    return cipher.process(plaintext);
  }

  Uint8List _aesDecrypt(Uint8List ciphertext) {
    final cipher = PaddedBlockCipherImpl(
      PKCS7Padding(),
      CBCBlockCipher(AESEngine()),
    )..init(
        false,
        PaddedBlockCipherParameters(
          ParametersWithIV(
            KeyParameter(Uint8List.fromList(_config.aesKeyBytes)),
            Uint8List.fromList(_config.aesIvBytes),
          ),
          null,
        ),
      );
    return cipher.process(ciphertext);
  }

  Uint8List _compress(List<int> data) {
    return Uint8List.fromList(ZLibEncoder().encode(data));
  }

  Uint8List _decompress(List<int> data) {
    return Uint8List.fromList(ZLibDecoder().decodeBytes(data));
  }

  Uint8List _buildRequestBody(Map<String, dynamic> packet) {
    final jsonStr = jsonEncode(packet);
    final jsonBytes = utf8.encode(jsonStr);
    final compressed = _compress(jsonBytes);
    return _aesEncrypt(compressed);
  }

  /// Port of empurple `HttpResult.cookieHeader()`: only the `JSESSIONID`
  /// from the Set-Cookie response headers is used for subsequent requests.
  void _captureCookiesFromResponse(http.Response response, String apiName) {
    final headerKeys = response.headers.keys.toList();
    for (final key in headerKeys) {
      if (!key.toLowerCase().contains('set-cookie')) continue;
      final value = response.headers[key]!;
      final match =
          RegExp(r'JSESSIONID=([^;,]+)', caseSensitive: false).firstMatch(value);
      if (match != null) {
        _cookies = 'JSESSIONID=${match.group(1)!.trim()}';
        ApiLog.log('[$apiName] >>> Captured session cookie: $_cookies');
        return;
      }
    }
  }

  Map<String, dynamic> _processResponseBody(Uint8List bodyBytes) {
    try {
      final decrypted = _aesDecrypt(bodyBytes);
      final decompressed = _decompress(decrypted);
      final jsonStr = utf8.decode(decompressed);
      return jsonDecode(jsonStr) as Map<String, dynamic>;
    } on FormatException catch (e) {
      throw TitleApiException('Response body is not valid JSON: $e');
    } on Exception catch (e) {
      throw TitleApiException('Failed to process response body: $e');
    }
  }

  String _buildHash(String apiName) {
    final raw = apiName + _obfuscateConstant + _config.obfuscateParam;
    return md5.convert(utf8.encode(raw)).toString();
  }

  Future<Map<String, dynamic>> _callApi(
    String apiName,
    Map<String, dynamic> packet,
    int userId, {
    bool captureRaw = false,
  }) async {
    final hash = _buildHash(apiName);
    final body = _buildRequestBody(packet);
    final baseUrl = _normalizeUrl(_config.titleServerUrl);
    final url = Uri.parse('$baseUrl/$hash');

    ApiLog.log('══════════════════════════════════════');
    ApiLog.log('[$apiName] >>> REQUEST >>>');
    ApiLog.log('[$apiName] URL: $url');
    ApiLog.log('[$apiName] userId: $userId');
    ApiLog.log('[$apiName] hash: $hash');
    ApiLog.log('[$apiName] body (encrypted): ${body.length} bytes');
    final packetStr = const JsonEncoder.withIndent('  ').convert(packet);
    ApiLog.log('[$apiName] packet (plain):');
    ApiLog.log(packetStr);

    final uaSuffix = userId != 0 ? '$userId' : _config.clientId;
    final headers = <String, String>{
      'User-Agent': '$hash#$uaSuffix',
      'Content-Type': 'application/json',
      'Mai-Encoding': _config.apiVersion,
      'Accept-Encoding': '',
      'Charset': 'UTF-8',
      'Content-Encoding': 'deflate',
      'number': '0',
    };
    final cookies = _cookies;
    if (cookies != null) {
      headers['Cookie'] = cookies;
      ApiLog.log('[$apiName] Cookie: $cookies');
    }

    final response = await http
        .post(
          url,
          headers: headers,
          body: body,
        )
        .timeout(const Duration(seconds: 15));

    _captureCookiesFromResponse(response, apiName);

    ApiLog.log('[$apiName] HTTP status: ${response.statusCode}');
    ApiLog.log('[$apiName] response bytes: ${response.bodyBytes.length}');

    if (response.statusCode != 200) {
      throw TitleApiException('$apiName returned ${response.statusCode}');
    }

    if (response.bodyBytes.isEmpty) {
      throw TitleApiException('$apiName returned empty body');
    }

    final json = _processResponseBody(response.bodyBytes);
    final raw = const JsonEncoder.withIndent('  ').convert(json);
    if (captureRaw) lastRawResponse = raw;
    ApiLog.log('[$apiName] <<< RESPONSE <<<');
    ApiLog.log(raw);
    ApiLog.log('══════════════════════════════════════');

    return json;
  }

  static int calcRandom() {
    final rand = _RandomHelper();
    final max = 1037933;
    final num2 = (rand.nextInt(max - 1) + 1) * 2069 + 1024;
    var num3 = 0;
    var n = num2;
    for (var i = 0; i < 32; i++) {
      num3 <<= 1;
      num3 += n % 2;
      n >>= 1;
    }
    // 原版 num5 是 C# 的 int，`<<=` 溢出按二进制补码环绕，所以结果恒为合法的
    // signed int32（高位被置起时是负数）。Dart 的 int 是 64 位且 n 恒为正，
    // 不重解释就会产出 >2^31 的正数，超出 UserGamePlaylog.playSpecial 的 int
    // 声明，服务器反序列化失败直接返回 HTTP 500。
    return num3.toSigned(32);
  }

  String _normalizeUrl(String url) {
    var normalized = url.trim();
    if (normalized.endsWith('/')) {
      normalized = normalized.substring(0, normalized.length - 1);
    }
    return normalized;
  }

  Future<UserPreviewDataBean> getUserPreview({
    required int userId,
    required String token,
  }) async {
    // 走通用传输层，保留 `lastRawResponse`（主页调试卡要用 GetUserPreviewApi
    // 的原文，而不是随后 UserLoginApi / GetUserDataApi 的）。
    final json = await _callApi(
      'GetUserPreviewApi',
      {
        'userId': userId,
        'segaIdAuthKey': '',
        'token': token,
        'clientId': _config.clientId,
      },
      userId,
      captureRaw: true,
    );
    return UserPreviewDataBean.fromJson(json);
  }

  // ---- Generic data APIs ----

  Future<Map<String, dynamic>> getUserData(int userId) async {
    return _callApi('GetUserDataApi', {'userId': userId}, userId);
  }

  Future<UserDataBean> getUserDataTyped(int userId) async {
    final json = await getUserData(userId);
    return UserDataBean.fromJson(json);
  }

  Future<Map<String, dynamic>> getUserExtend(int userId) async {
    return _callApi('GetUserExtendApi', {'userId': userId}, userId);
  }

  Future<Map<String, dynamic>> getUserOption(int userId) async {
    return _callApi('GetUserOptionApi', {'userId': userId}, userId);
  }

  Future<Map<String, dynamic>> getUserRating(int userId) async {
    return _callApi('GetUserRatingApi', {'userId': userId}, userId);
  }

  Future<UserRatingBean> getUserRatingTyped(int userId) async {
    final json = await getUserRating(userId);
    return UserRatingBean.fromJson(json);
  }

  Future<Map<String, dynamic>> getUserCharge(int userId) async {
    return _callApi('GetUserChargeApi', {'userId': userId}, userId);
  }

  Future<Map<String, dynamic>> getUserActivity(int userId) async {
    return _callApi('GetUserActivityApi', {'userId': userId}, userId);
  }

  Future<Map<String, dynamic>> getUserMissionData(int userId) async {
    return _callApi('GetUserMissionDataApi', {'userId': userId}, userId);
  }

  // ---- UserLogin (returns full result) ----

  Future<UserLoginResult> userLoginFull({
    required int userId,
    required String token,
  }) async {
    const apiName = 'UserLoginApi';
    final now = DateTime.now().millisecondsSinceEpoch ~/ 1000;

    final packet = {
      'userId': userId,
      'accessCode': '',
      'regionId': _config.regionId,
      'placeId': _config.placeId,
      'clientId': _config.clientId,
      'dateTime': now - 600,
      'loginDateTime': now,
      'isContinue': false,
      'genericFlag': 0,
      'token': token,
    };

    final json = await _callApi(apiName, packet, userId);

    final returnCode = json['returnCode'] as int? ?? -1;
    if (returnCode != 1) {
      throw TitleApiException('UserLoginApi returnCode=$returnCode');
    }

    final loginId = (json['loginId'] as num?)?.toInt() ?? 0;
    final lastLoginDate = json['lastLoginDate'] as String? ?? '';
    final newToken = json['token'] as String? ?? '';

    return UserLoginResult(
      token: newToken,
      loginId: loginId,
      lastLoginDate: lastLoginDate,
      loginDateTime: now,
    );
  }

  // ---- UserLogout ----

  /// Port of empurple/eaquira behavior: the server may omit `returnCode`
  /// for fire-and-forget APIs. Only a present-but-not-1 code is an error.
  void _checkReturnCode(Map<String, dynamic> json, String apiName) {
    final returnCode = json['returnCode'];
    if (returnCode == null) return;
    final code = (returnCode as num).toInt();
    if (code != 1) {
      throw TitleApiException('$apiName returnCode=$code');
    }
  }

  Future<void> userLogout({
    required int userId,
    required int loginDateTime,
  }) async {
    const apiName = 'UserLogoutApi';

    final packet = {
      'userId': userId,
      'accessCode': '',
      'regionId': _config.regionId,
      'placeId': _config.placeId,
      'clientId': _config.clientId,
      'loginDateTime': loginDateTime,
      'type': 1, // LogoutType.Logout
    };

    final json = await _callApi(apiName, packet, userId);
    _checkReturnCode(json, apiName);
  }

  // ---- UpsertUserChargeLog (使用功能票) ----

  Future<void> upsertUserChargeLog({
    required int userId,
    required int ticketId,
    required int loginDateTime,
    required int playerRating,
    int playCount = 0,
  }) async {
    const apiName = 'UpsertUserChargelogApi';
    final now = DateTime.now();
    final validDate = DateTime(now.year, now.month, now.day, 4, 0, 0)
        .add(const Duration(days: 90));
    final purchaseDateStr = _formatDateTime(now);
    final validDateStr =
        '${validDate.year}-${validDate.month.toString().padLeft(2, '0')}-${validDate.day.toString().padLeft(2, '0')} '
        '${validDate.hour.toString().padLeft(2, '0')}:${validDate.minute.toString().padLeft(2, '0')}:${validDate.second.toString().padLeft(2, '0')}';

    final packet = {
      'userId': userId,
      'userChargelog': {
        'chargeId': ticketId,
        'price': 0,
        'purchaseDate': purchaseDateStr,
        'playCount': playCount,
        'playerRating': playerRating,
        'placeId': _config.placeId,
        'regionId': _config.regionId,
        'clientId': _config.clientId,
      },
      'userCharge': {
        'chargeId': ticketId,
        'stock': 1,
        'purchaseDate': purchaseDateStr,
        'validDate': validDateStr,
      },
      'loginDateTime': loginDateTime,
    };

    final json = await _callApi(apiName, packet, userId);
    _checkReturnCode(json, apiName);
  }

  String _formatDateTime(DateTime dt) {
    return '${dt.year}-${dt.month.toString().padLeft(2, '0')}-${dt.day.toString().padLeft(2, '0')} '
        '${dt.hour.toString().padLeft(2, '0')}:${dt.minute.toString().padLeft(2, '0')}:${dt.second.toString().padLeft(2, '0')}.0';
  }

  // ---- UpsertUserAll (发包) ----

  /// Upload a single playlog record (fake game log).
  Future<void> uploadUserPlaylog(
    Map<String, dynamic> userPlaylog,
    int userId,
  ) async {
    const apiName = 'UploadUserPlaylogApi';
    final json = await _callApi(apiName, {
      'userId': userId,
      'userPlaylog': userPlaylog,
    }, userId);
    _checkReturnCode(json, apiName);
  }

  /// Fetch all user data needed to build an UpsertUserAll payload.
  /// Returns a map keyed by the raw API names (e.g. 'GetUserDataApi').
  Future<Map<String, Map<String, dynamic>>> fetchUserAllData(int userId) async {
    final results = await Future.wait([
      getUserData(userId),
      getUserExtend(userId),
      getUserOption(userId),
      getUserRating(userId),
      getUserCharge(userId),
      getUserActivity(userId),
      getUserMissionData(userId),
    ]);

    return {
      'GetUserDataApi': results[0],
      'GetUserExtendApi': results[1],
      'GetUserOptionApi': results[2],
      'GetUserRatingApi': results[3],
      'GetUserChargeApi': results[4],
      'GetUserActivityApi': results[5],
      'GetUserMissionDataApi': results[6],
    };
  }

  /// Send an UpsertUserAll payload to the server.
  Future<void> upsertUserAll(
    Map<String, dynamic> packet,
    int userId,
  ) async {
    const apiName = 'UpsertUserAllApi';
    final json = await _callApi(apiName, packet, userId);
    _checkReturnCode(json, apiName);
  }

  /// Fetch user character list.
  Future<List<Map<String, dynamic>>> getUserCharacter(int userId) async {
    final json = await _callApi(
      'GetUserCharacterApi',
      {'userId': userId},
      userId,
    );
    final list = json['userCharacterList'] as List<dynamic>? ?? [];
    return list.map((e) => e as Map<String, dynamic>).toList();
  }

  /// 旅行伙伴（角色）列表，对应 UserCharacterResponseVO。
  Future<List<UserCharacterBean>> getUserCharacters(int userId) async {
    final json = await _callApi(
      'GetUserCharacterApi',
      {'userId': userId},
      userId,
    );
    return UserCharacterBean.listFromResponse(json);
  }

  /// 区域进度列表，对应 UserMapResponseVO。
  ///
  /// 客户端 `PacketGetUserMap.cs:51-57` 是分页拉的：`nextIndex != 0` 就用它续拉，
  /// 把所有页的 `userMapList` 拼起来。这里照做，否则只能看到第一页的区域。
  Future<List<Map<String, dynamic>>> getUserMaps(int userId) async {
    const apiName = 'GetUserMapApi';
    final all = <Map<String, dynamic>>[];
    var nextIndex = 0;
    var pages = 0;

    do {
      final json = await _callApi(apiName, {
        'userId': userId,
        'nextIndex': nextIndex,
      }, userId);

      final list = json['userMapList'];
      if (list is List) {
        all.addAll(list.whereType<Map<String, dynamic>>());
      }
      nextIndex = (json['nextIndex'] as num?)?.toInt() ?? 0;
      pages++;
    } while (nextIndex != 0 && pages < 20);

    return all;
  }

  /// 万花宿命之门进度，对应 UserKaleidxScopeResponseVO。
  ///
  /// 与 `GetUserMapApi` 不同，这个接口不分页（`UserKaleidxScopeRequestVO`
  /// 只有 `userId` 一个字段），一次拿全。
  Future<List<UserKaleidxScopeBean>> getUserKaleidxScopes(int userId) async {
    final json = await _callApi(
      'GetUserKaleidxScopeApi',
      {'userId': userId},
      userId,
    );
    return UserKaleidxScopeBean.listFromResponse(json);
  }
}

class _RandomHelper {
  final _random = Random();

  int nextInt(int max) => _random.nextInt(max);
}