// ignore_for_file: empty_catches

import 'dart:async';
import 'dart:io';

import 'package:flutter/material.dart';
import 'package:karing/app/local_services/vpn_service.dart';
import 'package:karing/app/modules/biz.dart';
import 'package:karing/app/modules/server_manager.dart';
import 'package:karing/app/modules/setting_manager.dart';
import 'package:karing/app/runtime/return_result.dart';
import 'package:karing/app/utils/network_utils.dart';
import 'package:karing/app/utils/parallel_task_queue.dart';
import 'package:karing/app/utils/singbox_config_builder.dart';
import 'package:karing/i18n/strings.g.dart';
import 'package:karing/screens/common_widget.dart';
import 'package:karing/screens/dialog_utils.dart';
import 'package:karing/screens/dns_settings_screen.dart';
import 'package:karing/screens/theme_config.dart';
import 'package:karing/screens/theme_define.dart';
import 'package:karing/screens/widgets/framework.dart';
import 'package:tuple/tuple.dart';

class DnsAutoSetupScreen extends LasyRenderingStatefulWidget {
  static RouteSettings routSettings() {
    return const RouteSettings(name: "DnsAutoSetupScreen");
  }

  const DnsAutoSetupScreen({super.key});

  @override
  State<DnsAutoSetupScreen> createState() => _DnsAutoSetupScreenState();
}

class _DnsAutoSetupScreenState extends LasyRenderingState<DnsAutoSetupScreen> {
  static ParallelTaskQueue? _taskQueue;
  static const int _kMaxTasks = 5;
  final List _searchedData = [];
  Timer? _timer;

  @override
  void initState() {
    _searchedData.addAll(SettingManager.getConfig().dns.list);
    _searchedData.addAll(SettingConfigItemDNS.kDNSList);
    const Duration duration = Duration(seconds: 1);
    _timer ??= Timer.periodic(duration, (timer) async {
      setState(() {});
    });

    super.initState();
  }

  @override
  void dispose() {
    _timer?.cancel();
    _timer = null;
    super.dispose();
    SettingManager.save();
  }

  @override
  Widget build(BuildContext context) {
    final tcontext = Translations.of(context);
    Size windowSize = MediaQuery.of(context).size;
    return Scaffold(
      appBar: PreferredSize(preferredSize: Size.zero, child: AppBar()),
      body: SafeArea(
        child: Padding(
          padding: const EdgeInsets.fromLTRB(0, 20, 0, 0),
          child: Column(
            children: [
              Padding(
                padding: const EdgeInsets.fromLTRB(0, 0, 0, 0),
                child: Row(
                  mainAxisAlignment: MainAxisAlignment.spaceBetween,
                  children: [
                    InkWell(
                      onTap: () => Navigator.pop(context),
                      child: const SizedBox(
                        width: 50,
                        height: 30,
                        child: Icon(Icons.arrow_back_ios_outlined, size: 26),
                      ),
                    ),
                    SizedBox(
                      width: windowSize.width - 50 * 2,
                      child: Text(
                        tcontext.SettingsScreen.dnsAutoSetServer,
                        textAlign: TextAlign.center,
                        overflow: TextOverflow.ellipsis,
                        style: const TextStyle(
                          fontWeight: ThemeConfig.kFontWeightTitle,
                          fontSize: ThemeConfig.kFontSizeTitle,
                        ),
                      ),
                    ),
                    Row(
                      children: [
                        _taskQueue != null
                            ? const Row(
                                children: [
                                  SizedBox(width: 12),
                                  SizedBox(
                                    width: 26,
                                    height: 26,
                                    child: RepaintBoundary(
                                      child: CircularProgressIndicator(),
                                    ),
                                  ),
                                  SizedBox(width: 12),
                                ],
                              )
                            : InkWell(
                                onTap: () async {
                                  checkLatency();
                                },
                                child: const SizedBox(
                                  width: 50,
                                  height: 30,
                                  child: Icon(Icons.bolt_outlined, size: 26),
                                ),
                              ),
                      ],
                    ),
                  ],
                ),
              ),
              const SizedBox(height: 10),
              Expanded(
                child: FutureBuilder(
                  future: VPNService.getTunMode(),
                  builder:
                      (BuildContext context, AsyncSnapshot<bool> snapshot) {
                        return _loadListView(
                          snapshot.hasData && snapshot.data!,
                        );
                      },
                ),
              ),
            ],
          ),
        ),
      ),
    );
  }

  Future<bool> startVPN() async {
    return await Biz.startOrRestartIfDirtyVPN(context, "DnsAutoSetupScreen");
  }

  void checkLatency() async {
    bool ok = await startVPN();
    if (!ok) {
      return;
    }
    if (!mounted) {
      return;
    }

    if (_taskQueue != null) {
      return;
    }
    DnsSettingsScreen.getDirect().clear();
    DnsSettingsScreen.getCurrent().clear();
    setState(() {});
    _testConnectLatency(
      _searchedData,
      DnsSettingsScreen.getDirect(),
      DnsSettingsScreen.getCurrent(),
      kOutboundTagDirect,
      VPNService.getCurrent().tag,
      (
        Map<String, String> contectDirectLatency,
        Map<String, String> contectCurrentLatency,
      ) async {
        List<Tuple2<String, String>> bydDirect = contectDirectLatency.entries
            .map((entry) => Tuple2(entry.key, entry.value))
            .toList();
        List<Tuple2<String, String>> byCurrent = contectCurrentLatency.entries
            .map((entry) => Tuple2(entry.key, entry.value))
            .toList();
        bydDirect.removeWhere((ele) {
          return null == int.tryParse(ele.item2);
        });
        byCurrent.removeWhere((ele) {
          return null == int.tryParse(ele.item2);
        });
        bydDirect.sort(sort);
        byCurrent.sort(sort);
        if (bydDirect.isNotEmpty || byCurrent.isNotEmpty) {
          bool tun = await VPNService.getTunMode();
          var settingConfig = SettingManager.getConfig();

          settingConfig.dns.setOutboundDns(
            getNonResolverDNS(bydDirect, true, tun),
          );
          settingConfig.dns.setDirectDns(
            getNonResolverDNS(bydDirect, true, tun),
          );
          settingConfig.dns.setResolverDns(getResolverDNS(bydDirect, tun));
          bool enableProxyResolveByProxy =
              settingConfig.dns.proxyResolveMode ==
              SettingConfigItemDNSProxyResolveMode.proxy;
          if (!settingConfig.novice && enableProxyResolveByProxy) {
            settingConfig.dns.setProxyDns(
              getNonResolverDNS(byCurrent, false, tun),
            );
          } else {
            settingConfig.dns.setProxyDns(
              getNonResolverDNS(bydDirect, false, tun),
            );
          }

          SettingManager.setDirty(true);
          if (!mounted) {
            return;
          }
          final tcontext = Translations.of(context);
          DialogUtils.showAlertDialog(context, tcontext.meta.done);
        }
      },
    );

    if (!mounted) {
      return;
    }
    setState(() {});
  }

  static int sort(Tuple2<String, String> a, Tuple2<String, String> b) {
    int ua = int.parse(a.item2);
    int ub = int.parse(b.item2);
    return ua - ub;
  }

  Widget _loadListView(bool tun) {
    Size windowSize = MediaQuery.of(context).size;

    return Scrollbar(
      thumbVisibility: true,
      child: ListView.separated(
        itemCount: _searchedData.length,
        itemBuilder: (BuildContext context, int index) {
          var current = _searchedData[index];
          return createWidget(current, windowSize);
        },
        separatorBuilder: (BuildContext context, int index) {
          return const Divider(height: 1, thickness: 0.3);
        },
      ),
    );
  }

  static void _testConnectLatency(
    List items,
    Map<String, String> contectDirectLatency,
    Map<String, String> contectCurrentLatency,
    String detourDirect,
    String detourCurrent,
    Function(
      Map<String, String> contectDirectLatency,
      Map<String, String> contectCurrentLatency,
    )
    onfinish,
  ) {
    List<String> urls = [];

    for (var item in items) {
      String url = item["url"];
      if (_taskQueue == null || !_taskQueue!.hasTask(url)) {
        urls.add(url);
      }
    }
    _testConnectLatencyParallel(
      contectDirectLatency,
      contectCurrentLatency,
      detourDirect,
      detourCurrent,
      urls,
      onfinish,
    );
  }

  static void _testConnectLatencyParallel(
    Map<String, String> contectDirectLatency,
    Map<String, String> contectCurrentLatency,
    String detourDirect,
    String detourCurrent,
    List<String> urls,
    Function(
      Map<String, String> contectDirectLatency,
      Map<String, String> contectCurrentLatency,
    )
    onfinish,
  ) {
    if (urls.isEmpty) {
      return;
    }
    _taskQueue ??= ParallelTaskQueue(
      (url) async {
        bool started = await VPNService.getStarted();
        if (started) {
          if (url == SettingConfigItemDNS.kDNSLocal ||
              url == SettingConfigItemDNS.kDNSDHCP) {
            ReturnResult<int> resultDirect =
                await ServerManager.testDNSConnectLatency(
                  [url],
                  detourDirect,
                  null,
                );
            if (resultDirect.error != null) {
              contectDirectLatency[url] = resultDirect.error!.message;
            } else {
              contectDirectLatency[url] = resultDirect.data.toString();
            }

            contectCurrentLatency[url] = "not support";
          } else {
            var value = await Future.wait([
              ServerManager.testDNSConnectLatency([url], detourDirect, null),
              ServerManager.testDNSConnectLatency([url], detourCurrent, null),
            ]);

            if (value[0].error != null) {
              contectDirectLatency[url] = value[0].error!.message;
            } else {
              contectDirectLatency[url] = value[0].data.toString();
            }

            if (value[1].error != null) {
              contectCurrentLatency[url] = value[1].error!.message;
            } else {
              contectCurrentLatency[url] = value[1].data.toString();
            }
          }
        } else {
          _taskQueue?.cancel();
          _taskQueue = null;
        }
        return url;
      },
      (url, int left, int total, bool start, bool finish) {
        if (finish) {
          _taskQueue = null;
          onfinish(contectDirectLatency, contectCurrentLatency);
        }
      },
      _kMaxTasks,
      [],
    );
    _taskQueue!.addTasks(urls);
    _taskQueue!.run();
  }

  static List<String> getNonResolverDNS(
    List<Tuple2<String, String>> list,
    bool includeNotSecurity,
    bool tun,
  ) {
    List<String> result = [];
    for (var tuple in list) {
      if (tuple.item1 == SettingConfigItemDNS.kDNSLocal) {
        if (includeNotSecurity) {
          if (Platform.isWindows) {
            if (!tun) {
              result.add(tuple.item1);
            }
          } else {
            result.add(tuple.item1);
          }
        }
      } else if (tuple.item1 == SettingConfigItemDNS.kDNSDHCP) {
        if (includeNotSecurity) {
          if (!Platform.isAndroid) {
            result.add(tuple.item1);
          }
        }
      } else {
        Uri? uri = Uri.tryParse(tuple.item1);
        if (uri != null) {
          if (includeNotSecurity) {
            result.add(tuple.item1);
          } else {
            if (uri.scheme != "tcp" && uri.scheme != "udp") {
              result.add(tuple.item1);
            }
          }
        }
        if (result.length >= SettingConfigItemDNS.kDNSServerMax) {
          break;
        }
      }
    }

    return result;
  }

  static List<String> getResolverDNS(
    List<Tuple2<String, String>> list,
    bool tun,
  ) {
    List<String> result = [];
    for (var tuple in list) {
      if (tuple.item1 == SettingConfigItemDNS.kDNSLocal) {
        if (Platform.isWindows) {
          if (!tun) {
            result.add(tuple.item1);
          }
        } else {
          result.add(tuple.item1);
        }
      } else if (tuple.item1 == SettingConfigItemDNS.kDNSDHCP) {
        if (!Platform.isAndroid) {
          result.add(tuple.item1);
        }
      } else {
        Uri? uri = Uri.tryParse(tuple.item1);
        if (uri != null) {
          if (NetworkUtils.isIpv4(uri.host) || NetworkUtils.isIpv6(uri.host)) {
            result.add(tuple.item1);
          }
        }
      }
      if (result.length >= SettingConfigItemDNS.kDNSServerMax) {
        break;
      }
    }

    return result;
  }

  Widget createWidget(dynamic current, Size windowSize) {
    const double latencyWidth = 60.0;

    double centerWidth = windowSize.width - latencyWidth * 2 - 30;

    var addr = current[SettingConfigItemDNS.kDNSUrl];
    var isp = current[SettingConfigItemDNS.kDNSIsp];
    String? directLatenty = DnsSettingsScreen.getDirect()[addr];
    String? currentLatenty = DnsSettingsScreen.getCurrent()[addr];

    return Material(
      borderRadius: ThemeDefine.kBorderRadius,
      child: Container(
        padding: const EdgeInsets.symmetric(horizontal: 10),
        width: double.infinity,
        height: ThemeConfig.kListItemHeight + 5,
        child: Row(
          children: [
            Row(
              children: [
                Column(
                  mainAxisAlignment: MainAxisAlignment.center,
                  crossAxisAlignment: CrossAxisAlignment.start,
                  children: [
                    Row(
                      children: [
                        Text(
                          isp,
                          style: TextStyle(
                            fontSize: ThemeConfig.kFontSizeGroupItem,
                          ),
                        ),
                      ],
                    ),
                    Row(
                      children: [
                        SizedBox(
                          width: centerWidth,
                          child: Text(
                            addr,
                            style: TextStyle(
                              fontSize: ThemeConfig.kFontSizeGroupItem,
                            ),
                          ),
                        ),
                      ],
                    ),
                  ],
                ),
                CommonWidget.createLatencyWidget(
                  context,
                  ThemeConfig.kListItemHeight,
                  _taskQueue != null && directLatenty == null,
                  _taskQueue != null && _taskQueue!.running(addr),
                  directLatenty ?? "",
                ),
                CommonWidget.createLatencyWidget(
                  context,
                  ThemeConfig.kListItemHeight,
                  _taskQueue != null && currentLatenty == null,
                  _taskQueue != null && _taskQueue!.running(addr),
                  currentLatenty ?? "",
                ),
              ],
            ),
          ],
        ),
      ),
    );
  }
}
