import 'package:dio/dio.dart';

import '../../hj_utils/text_util.dart';

/// 取消token管理
class CancelTokenManager {
  static CancelTokenManager? _instance;
  //取消token单例
  factory CancelTokenManager() {
    _instance ??= CancelTokenManager._();
    return _instance!;
  }
  CancelTokenManager._();

  /// 取消token列表
  final List<CancelTokenWarp> _cancelTokens = [];

  /// 创建cancleToken如果需要
  /// [url]
  CancelToken createToken(String url, [String uniquekey='']) {
    var ctw = CancelTokenWarp(url, CancelToken())..uniqueKey = uniquekey;
    _cancelTokens.add(ctw);
    return ctw.token;
  }

  /// 获取cancleToken如果需要
  /// [url]
  CancelToken? getToken(String url, [String uniquekey = '']) {
    // indexWhere 找不到返回 -1，避免 firstWhere 无 orElse 时抛 StateError
    final idx = _cancelTokens.indexWhere((it) =>
        TextUtil.isEmpty(uniquekey) ? it.url == url : (it.url == url && it.uniqueKey == uniquekey));
    return idx < 0 ? null : _cancelTokens[idx].token;
  }

  List<CancelTokenWarp> get peekList => _cancelTokens;

  /// 删除
  /// [url]
  CancelToken? remove(String url, [String uniquekey = '']) {
    // indexWhere 找不到返回 -1，避免 firstWhere 无 orElse 时抛 StateError
    final idx = _cancelTokens.indexWhere((it) =>
        TextUtil.isEmpty(uniquekey) ? it.url == url : (it.url == url && it.uniqueKey == uniquekey));
    if (idx < 0) return null;
    return _cancelTokens.removeAt(idx).token;
  }

  /// 正在请求的长度
  int get length => _cancelTokens.length;
}

class CancelTokenWarp {
  String url;
  CancelToken token;
  String? uniqueKey;
  CancelTokenWarp(this.url, this.token);
}