import 'dart:math';

import 'package:fl_clash/common/common.dart';
import 'package:fl_clash/enum/enum.dart';
import 'package:fl_clash/models/models.dart';
import 'package:fl_clash/state.dart';
import 'package:fl_clash/widgets/widgets.dart';
import 'package:flutter/material.dart';
import 'package:provider/provider.dart';

import 'card.dart';
import 'common.dart';

List<Proxy> currentProxies = [];
String? currentTestUrl;

typedef GroupNameKeyMap = Map<String, GlobalObjectKey<ProxyGroupViewState>>;

class ProxiesTabFragment extends StatefulWidget {
  const ProxiesTabFragment({super.key});

  @override
  State<ProxiesTabFragment> createState() => ProxiesTabFragmentState();
}

class ProxiesTabFragmentState extends State<ProxiesTabFragment>
    with TickerProviderStateMixin {
  TabController? _tabController;
  final _hasMoreButtonNotifier = ValueNotifier<bool>(false);
  GroupNameKeyMap _keyMap = {};

  @override
  void dispose() {
    _destroyTabController();
    super.dispose();
  }

  scrollToGroupSelected() {
    final currentGroupName = globalState.appController.config.currentGroupName;
    _keyMap[currentGroupName]?.currentState?.scrollToSelected();
  }

  _buildMoreButton() {
    return Selector<AppState, bool>(
      selector: (_, appState) => appState.viewMode == ViewMode.mobile,
      builder: (_, value, ___) {
        return IconButton(
          onPressed: _showMoreMenu,
          icon: value
              ? const Icon(
                  Icons.expand_more,
                )
              : const Icon(
                  Icons.chevron_right,
                ),
        );
      },
    );
  }

  _showMoreMenu() {
    showSheet(
      context: context,
      width: 380,
      isScrollControlled: false,
      body: SingleChildScrollView(
        padding: const EdgeInsets.all(16),
        child: Selector2<AppState, Config, ProxiesSelectorState>(
          selector: (_, appState, config) {
            final currentGroups = appState.currentGroups;
            final groupNames = currentGroups.map((e) => e.name).toList();
            return ProxiesSelectorState(
              groupNames: groupNames,
              currentGroupName: config.currentGroupName,
            );
          },
          builder: (_, state, __) {
            return SizedBox(
              width: double.infinity,
              child: Wrap(
                alignment: WrapAlignment.center,
                runSpacing: 8,
                spacing: 8,
                children: [
                  for (final groupName in state.groupNames)
                    SettingTextCard(
                      groupName,
                      onPressed: () {
                        final index = state.groupNames
                            .indexWhere((item) => item == groupName);
                        if (index == -1) return;
                        _tabController?.animateTo(index);
                        globalState.appController.config.updateCurrentGroupName(
                          groupName,
                        );
                        Navigator.of(context).pop();
                      },
                      isSelected: groupName == state.currentGroupName,
                    )
                ],
              ),
            );
          },
        ),
      ),
      title: appLocalizations.proxyGroup,
    );
  }

  _tabControllerListener([int? index]) {
    final appController = globalState.appController;
    final currentGroups = appController.appState.currentGroups;
    if (_tabController?.index == null) {
      return;
    }
    final currentGroup = currentGroups[index ?? _tabController!.index];
    currentProxies = currentGroup.all;
    currentTestUrl = currentGroup.testUrl;
    WidgetsBinding.instance.addPostFrameCallback((_) {
      appController.config.updateCurrentGroupName(
        currentGroup.name,
      );
    });
  }

  _destroyTabController() {
    _tabController?.removeListener(_tabControllerListener);
    _tabController?.dispose();
    _tabController = null;
  }

  _updateTabController(int length, int index) {
    if (length == 0) {
      _destroyTabController();
      return;
    }
    final realIndex = index == -1 ? 0 : index;
    _tabController ??= TabController(
      length: length,
      initialIndex: realIndex,
      vsync: this,
    );
    _tabControllerListener(realIndex);
    _tabController?.addListener(_tabControllerListener);
  }

  @override
  Widget build(BuildContext context) {
    return Selector2<AppState, Config, ProxiesSelectorState>(
      selector: (_, appState, config) {
        final currentGroups = appState.currentGroups;
        final groupNames = currentGroups.map((e) => e.name).toList();
        return ProxiesSelectorState(
          groupNames: groupNames,
          currentGroupName: config.currentGroupName,
        );
      },
      shouldRebuild: (prev, next) {
        if (!stringListEquality.equals(prev.groupNames, next.groupNames)) {
          _destroyTabController();
          return true;
        }
        return false;
      },
      builder: (_, state, __) {
        if (state.groupNames.isEmpty) {
          return NullStatus(
            label: appLocalizations.nullProxies,
          );
        }
        final index = state.groupNames.indexWhere(
          (item) => item == state.currentGroupName,
        );
        _updateTabController(state.groupNames.length, index);
        if (state.groupNames.isEmpty) {
          return Container();
        }
        final GroupNameKeyMap keyMap = {};
        final children = state.groupNames.map((groupName) {
          keyMap[groupName] = GlobalObjectKey(groupName);
          return KeepScope(
            child: ProxyGroupView(
              key: keyMap[groupName],
              groupName: groupName,
            ),
          );
        }).toList();
        _keyMap = keyMap;
        return Column(
          mainAxisAlignment: MainAxisAlignment.start,
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            NotificationListener<ScrollMetricsNotification>(
              onNotification: (scrollNotification) {
                _hasMoreButtonNotifier.value =
                    scrollNotification.metrics.maxScrollExtent > 0;
                return true;
              },
              child: ValueListenableBuilder(
                valueListenable: _hasMoreButtonNotifier,
                builder: (_, value, child) {
                  return Stack(
                    alignment: AlignmentDirectional.centerStart,
                    children: [
                      TabBar(
                        controller: _tabController,
                        padding: EdgeInsets.only(
                          left: 16,
                          right: 16 + (value ? 16 : 0),
                        ),
                        dividerColor: Colors.transparent,
                        isScrollable: true,
                        tabAlignment: TabAlignment.start,
                        overlayColor:
                            const WidgetStatePropertyAll(Colors.transparent),
                        tabs: [
                          for (final groupName in state.groupNames)
                            Tab(
                              text: groupName,
                            ),
                        ],
                      ),
                      if (value)
                        Positioned(
                          right: 0,
                          child: child!,
                        ),
                    ],
                  );
                },
                child: Container(
                  decoration: BoxDecoration(
                    gradient: LinearGradient(
                        begin: Alignment.centerLeft,
                        end: Alignment.centerRight,
                        colors: [
                          context.colorScheme.surface.withOpacity(0.1),
                          context.colorScheme.surface,
                        ],
                        stops: const [
                          0.0,
                          0.1
                        ]),
                  ),
                  child: _buildMoreButton(),
                ),
              ),
            ),
            Expanded(
              child: TabBarView(
                controller: _tabController,
                children: children,
              ),
            )
          ],
        );
      },
    );
  }
}

class ProxyGroupView extends StatefulWidget {
  final String groupName;

  const ProxyGroupView({
    super.key,
    required this.groupName,
  });

  @override
  State<ProxyGroupView> createState() => ProxyGroupViewState();
}

class ProxyGroupViewState extends State<ProxyGroupView> {
  var isLock = false;
  final _controller = ScrollController();

  String get groupName => widget.groupName;

  _delayTest() async {
    if (isLock) return;
    isLock = true;
    await delayTest(
      currentProxies,
      currentTestUrl,
    );
    isLock = false;
  }

  @override
  void dispose() {
    _controller.dispose();
    super.dispose();
  }

  scrollToSelected() {
    if (_controller.position.maxScrollExtent == 0) {
      return;
    }
    final sortedProxies = globalState.appController.getSortProxies(
      currentProxies,
      currentTestUrl,
    );
    _controller.animateTo(
      min(
        16 +
            getScrollToSelectedOffset(
              groupName: groupName,
              proxies: sortedProxies,
            ),
        _controller.position.maxScrollExtent,
      ),
      duration: const Duration(milliseconds: 300),
      curve: Curves.easeIn,
    );
  }

  initFab(bool isCurrent) {
    if (!isCurrent) {
      return;
    }
    WidgetsBinding.instance.addPostFrameCallback((_) {
      final commonScaffoldState =
          context.findAncestorStateOfType<CommonScaffoldState>();
      commonScaffoldState?.floatingActionButton = DelayTestButton(
        onClick: () async {
          await _delayTest();
        },
      );
    });
  }

  @override
  Widget build(BuildContext context) {
    return Selector2<AppState, Config, ProxyGroupSelectorState>(
      selector: (_, appState, config) {
        final group = appState.getGroupWithName(groupName)!;
        return ProxyGroupSelectorState(
          proxyCardType: config.proxiesStyle.cardType,
          proxiesSortType: config.proxiesStyle.sortType,
          columns: other.getProxiesColumns(
            appState.viewWidth,
            config.proxiesStyle.layout,
          ),
          sortNum: appState.sortNum,
          proxies: group.all,
          groupType: group.type,
          testUrl: group.testUrl,
        );
      },
      builder: (_, state, __) {
        final proxies = state.proxies;
        final columns = state.columns;
        final proxyCardType = state.proxyCardType;
        final sortedProxies = globalState.appController.getSortProxies(
          proxies,
          state.testUrl,
        );
        return ActiveBuilder(
          label: "proxies",
          builder: (isCurrent, child) {
            initFab(isCurrent);
            return child!;
          },
          child: Align(
            alignment: Alignment.topCenter,
            child: GridView.builder(
              controller: _controller,
              padding: const EdgeInsets.only(
                top: 16,
                left: 16,
                right: 16,
                bottom: 96,
              ),
              gridDelegate: SliverGridDelegateWithFixedCrossAxisCount(
                crossAxisCount: columns,
                mainAxisSpacing: 8,
                crossAxisSpacing: 8,
                mainAxisExtent: getItemHeight(proxyCardType),
              ),
              itemCount: sortedProxies.length,
              itemBuilder: (_, index) {
                final proxy = sortedProxies[index];
                return ProxyCard(
                  testUrl: state.testUrl,
                  groupType: state.groupType,
                  type: proxyCardType,
                  key: ValueKey('$groupName.${proxy.name}'),
                  proxy: proxy,
                  groupName: groupName,
                );
              },
            ),
          ),
        );
      },
    );
  }
}

class DelayTestButton extends StatefulWidget {
  final Future Function() onClick;

  const DelayTestButton({
    super.key,
    required this.onClick,
  });

  @override
  State<DelayTestButton> createState() => _DelayTestButtonState();
}

class _DelayTestButtonState extends State<DelayTestButton>
    with SingleTickerProviderStateMixin {
  late AnimationController _controller;
  late Animation<double> _scale;

  _healthcheck() async {
    _controller.forward();
    await widget.onClick();
    if (mounted) {
      _controller.reverse();
    }
  }

  @override
  void initState() {
    super.initState();
    _controller = AnimationController(
      vsync: this,
      duration: const Duration(
        milliseconds: 200,
      ),
    );
    _scale = Tween<double>(
      begin: 1.0,
      end: 0.0,
    ).animate(
      CurvedAnimation(
        parent: _controller,
        curve: const Interval(
          0,
          1,
        ),
      ),
    );
  }

  @override
  void dispose() {
    _controller.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return AnimatedBuilder(
      animation: _controller.view,
      builder: (_, child) {
        return SizedBox(
          width: 56,
          height: 56,
          child: Transform.scale(
            scale: _scale.value,
            child: child,
          ),
        );
      },
      child: FloatingActionButton(
        heroTag: null,
        onPressed: _healthcheck,
        child: const Icon(Icons.network_ping),
      ),
    );
  }
}