import 'package:auto_route/auto_route.dart';
import 'package:flutter/material.dart';

import '../../../common/theme/theme.dart';
import '../../../sample/community_sample_data.dart';
import '../../components/assets/assets.gen.dart';
import '../../components/toast/flushbar.dart';
import '../../router/app_router.gr.dart';
import 'community_ui.dart';
import 'widgets/community_compose_sheet.dart';
import 'widgets/community_event_card.dart';
import 'widgets/community_group_card.dart';
import 'widgets/community_post_card.dart';

enum _CommunityTab { forYou, groups, events }

@RoutePage()
class CommunityPage extends StatefulWidget {
  const CommunityPage({super.key});

  @override
  State<CommunityPage> createState() => _CommunityPageState();
}

class _CommunityPageState extends State<CommunityPage> {
  final List<CommunityPost> _posts = [...communityPosts];
  final Set<String> _goingEventIds = {};
  _CommunityTab _tab = _CommunityTab.forYou;

  void _openGroup(CommunityGroup group) =>
      context.router.push(CommunityDetailRoute(group: group));

  void _openPost(CommunityPost post) =>
      context.router.push(CommunityPostDetailRoute(post: post));

  Future<void> _compose() async {
    final joined = communityGroups
        .where((g) => joinedCommunityIds.value.contains(g.id))
        .toList();
    if (joined.isEmpty) {
      AppFlushbar.showError(context, 'Gabung komunitas dulu untuk posting');
      setState(() => _tab = _CommunityTab.groups);
      return;
    }

    final post = await CommunityComposeSheet.show(context, groups: joined);
    if (post == null || !mounted) return;

    setState(() {
      _posts.insert(0, post);
      _tab = _CommunityTab.forYou;
    });
    AppFlushbar.showSuccess(context, 'Postingan kamu sudah terbit');
  }

  void _toggleEvent(CommunityEvent event) {
    final going = !_goingEventIds.contains(event.id);
    setState(() {
      going ? _goingEventIds.add(event.id) : _goingEventIds.remove(event.id);
    });
    if (going) {
      AppFlushbar.showSuccess(context, 'Kamu terdaftar di ${event.title}');
    }
  }

  @override
  Widget build(BuildContext context) {
    return ValueListenableBuilder<Set<String>>(
      valueListenable: joinedCommunityIds,
      builder: (context, joinedIds, _) {
        return Scaffold(
          backgroundColor: CommunityColor.background,
          floatingActionButton: AnimatedScale(
            scale: _tab == _CommunityTab.events ? 0 : 1,
            duration: const Duration(milliseconds: 200),
            child: FloatingActionButton.extended(
              onPressed: _compose,
              elevation: 2,
              backgroundColor: AppColor.primary,
              foregroundColor: AppColor.white,
              shape: const StadiumBorder(),
              icon: const Icon(Icons.edit_rounded, size: 20),
              label: Text(
                'Tulis',
                style: AppStyle.md.copyWith(
                  color: AppColor.white,
                  fontWeight: FontWeight.w700,
                ),
              ),
            ),
          ),
          body: CustomScrollView(
            slivers: [
              SliverAppBar(
                pinned: true,
                automaticallyImplyLeading: false,
                backgroundColor: CommunityColor.background,
                title: const Text('EnakCommunity'),
                actions: [
                  IconButton(
                    onPressed: () =>
                        context.router.push(const NotificationRoute()),
                    icon: const Icon(
                      Icons.notifications_none_rounded,
                      color: AppColor.textPrimary,
                    ),
                  ),
                  const SizedBox(width: 4),
                ],
              ),
              SliverToBoxAdapter(child: _buildHero(joinedIds.length)),
              SliverPersistentHeader(
                pinned: true,
                delegate: _TabHeaderDelegate(
                  selected: _tab,
                  onChanged: (tab) => setState(() => _tab = tab),
                ),
              ),
              ...switch (_tab) {
                _CommunityTab.forYou => _buildForYou(joinedIds),
                _CommunityTab.groups => _buildGroups(joinedIds),
                _CommunityTab.events => _buildEvents(),
              },
              const SliverToBoxAdapter(child: SizedBox(height: 96)),
            ],
          ),
        );
      },
    );
  }

  Widget _buildHero(int joinedCount) {
    final myPostCount = _posts
        .where((p) => p.author.id == currentMember.id)
        .length;

    return Container(
      margin: const EdgeInsets.fromLTRB(16, 4, 16, 8),
      padding: const EdgeInsets.fromLTRB(20, 20, 16, 16),
      decoration: BoxDecoration(
        gradient: const LinearGradient(
          colors: [CommunityColor.blush, Color(0xFFFFF6EE)],
          begin: Alignment.topLeft,
          end: Alignment.bottomRight,
        ),
        borderRadius: BorderRadius.circular(28),
      ),
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          Row(
            crossAxisAlignment: CrossAxisAlignment.start,
            children: [
              Expanded(
                child: Column(
                  crossAxisAlignment: CrossAxisAlignment.start,
                  children: [
                    Text(
                      'Halo, Foodie! 👋',
                      style: AppStyle.xxl.copyWith(fontWeight: FontWeight.w700),
                    ),
                    const SizedBox(height: 6),
                    Text(
                      'Berbagi cerita kuliner, ikut event seru, dan temukan '
                      'teman makan baru.',
                      style: AppStyle.sm.copyWith(
                        height: 1.45,
                        color: AppColor.textSecondary,
                        fontWeight: FontWeight.w500,
                      ),
                    ),
                  ],
                ),
              ),
              const SizedBox(width: 8),
              Assets.icons.enakcommunityIcon.image(width: 72, height: 72),
            ],
          ),
          const SizedBox(height: 14),
          Row(
            children: [
              _HeroStat(value: '$joinedCount', label: 'Komunitas'),
              const SizedBox(width: 8),
              _HeroStat(value: '$myPostCount', label: 'Postingan'),
              const SizedBox(width: 8),
              _HeroStat(value: '${_goingEventIds.length}', label: 'Event'),
            ],
          ),
          const SizedBox(height: 14),
          Material(
            color: AppColor.white,
            borderRadius: BorderRadius.circular(999),
            child: InkWell(
              borderRadius: BorderRadius.circular(999),
              onTap: _compose,
              child: Padding(
                padding: const EdgeInsets.fromLTRB(6, 6, 16, 6),
                child: Row(
                  children: [
                    const CommunityAvatar(member: currentMember, size: 32),
                    const SizedBox(width: 10),
                    Expanded(
                      child: Text(
                        'Apa yang kamu makan hari ini?',
                        style: AppStyle.sm.copyWith(
                          color: CommunityColor.muted,
                          fontWeight: FontWeight.w600,
                        ),
                      ),
                    ),
                    const Icon(
                      Icons.edit_note_rounded,
                      color: AppColor.primary,
                    ),
                  ],
                ),
              ),
            ),
          ),
        ],
      ),
    );
  }

  List<Widget> _buildForYou(Set<String> joinedIds) {
    return [
      SliverToBoxAdapter(
        child: CommunitySectionTitle(
          title: 'Komunitas Populer',
          actionLabel: 'Lihat semua',
          onAction: () => setState(() => _tab = _CommunityTab.groups),
        ),
      ),
      SliverToBoxAdapter(
        child: SizedBox(
          height: 176,
          child: ListView.separated(
            scrollDirection: Axis.horizontal,
            padding: const EdgeInsets.symmetric(horizontal: 16),
            itemCount: communityGroups.length,
            separatorBuilder: (_, _) => const SizedBox(width: 12),
            itemBuilder: (context, index) {
              final group = communityGroups[index];
              return CommunityGroupCard(
                group: group,
                isJoined: joinedIds.contains(group.id),
                onTap: () => _openGroup(group),
                onJoin: () => toggleJoinCommunity(group.id),
              );
            },
          ),
        ),
      ),
      const SliverToBoxAdapter(
        child: CommunitySectionTitle(title: 'Obrolan Terbaru'),
      ),
      SliverList.builder(
        itemCount: _posts.length,
        itemBuilder: (context, index) {
          final post = _posts[index];
          return CommunityPostCard(
            key: ValueKey(post.id),
            post: post,
            onTap: () => _openPost(post),
            onGroupTap: () => _openGroup(post.group),
          );
        },
      ),
    ];
  }

  List<Widget> _buildGroups(Set<String> joinedIds) {
    final joined = communityGroups
        .where((g) => joinedIds.contains(g.id))
        .toList();
    final discover = communityGroups
        .where((g) => !joinedIds.contains(g.id))
        .toList();

    Widget tile(CommunityGroup group) => CommunityGroupTile(
      key: ValueKey(group.id),
      group: group,
      isJoined: joinedIds.contains(group.id),
      onTap: () => _openGroup(group),
      onJoin: () => toggleJoinCommunity(group.id),
    );

    return [
      const SliverToBoxAdapter(
        child: CommunitySectionTitle(title: 'Komunitas Saya'),
      ),
      if (joined.isEmpty)
        const SliverToBoxAdapter(
          child: _SoftEmpty(
            emoji: '🤝',
            title: 'Belum gabung komunitas',
            message: 'Pilih komunitas di bawah yang sesuai seleramu.',
          ),
        )
      else
        SliverList.list(children: joined.map(tile).toList()),
      if (discover.isNotEmpty) ...[
        const SliverToBoxAdapter(
          child: CommunitySectionTitle(title: 'Jelajahi Komunitas'),
        ),
        SliverList.list(children: discover.map(tile).toList()),
      ],
    ];
  }

  List<Widget> _buildEvents() {
    return [
      SliverToBoxAdapter(
        child: Container(
          margin: const EdgeInsets.fromLTRB(16, 16, 16, 16),
          padding: const EdgeInsets.all(14),
          decoration: BoxDecoration(
            color: const Color(0xFFFFF8E1),
            borderRadius: BorderRadius.circular(18),
          ),
          child: Row(
            children: [
              const Text('🎁', style: TextStyle(fontSize: 24)),
              const SizedBox(width: 12),
              Expanded(
                child: Text(
                  'Hadiri event komunitas dan kumpulkan EnakPoint & EnakCoin '
                  'tambahan!',
                  style: AppStyle.sm.copyWith(
                    height: 1.4,
                    fontWeight: FontWeight.w600,
                  ),
                ),
              ),
            ],
          ),
        ),
      ),
      SliverList.builder(
        itemCount: communityEvents.length,
        itemBuilder: (context, index) {
          final event = communityEvents[index];
          return CommunityEventCard(
            event: event,
            isGoing: _goingEventIds.contains(event.id),
            onToggle: () => _toggleEvent(event),
          );
        },
      ),
    ];
  }
}

class _HeroStat extends StatelessWidget {
  const _HeroStat({required this.value, required this.label});

  final String value;
  final String label;

  @override
  Widget build(BuildContext context) {
    return Container(
      padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 6),
      decoration: BoxDecoration(
        color: AppColor.white.withOpacity(0.7),
        borderRadius: BorderRadius.circular(999),
      ),
      child: Text.rich(
        TextSpan(
          children: [
            TextSpan(
              text: '$value ',
              style: const TextStyle(
                color: AppColor.primary,
                fontWeight: FontWeight.w700,
              ),
            ),
            TextSpan(text: label),
          ],
        ),
        style: AppStyle.xs.copyWith(fontWeight: FontWeight.w600),
      ),
    );
  }
}

class _SoftEmpty extends StatelessWidget {
  const _SoftEmpty({
    required this.emoji,
    required this.title,
    required this.message,
  });

  final String emoji;
  final String title;
  final String message;

  @override
  Widget build(BuildContext context) {
    return Container(
      margin: const EdgeInsets.symmetric(horizontal: 16),
      padding: const EdgeInsets.symmetric(horizontal: 24, vertical: 24),
      decoration: communityCardDecoration(),
      child: Column(
        children: [
          Text(emoji, style: const TextStyle(fontSize: 32)),
          const SizedBox(height: 8),
          Text(title, style: AppStyle.md.copyWith(fontWeight: FontWeight.w700)),
          const SizedBox(height: 4),
          Text(
            message,
            textAlign: TextAlign.center,
            style: AppStyle.sm.copyWith(color: CommunityColor.muted),
          ),
        ],
      ),
    );
  }
}

/// Tab bergaya pil lembut yang menempel saat di-scroll.
class _TabHeaderDelegate extends SliverPersistentHeaderDelegate {
  _TabHeaderDelegate({required this.selected, required this.onChanged});

  final _CommunityTab selected;
  final ValueChanged<_CommunityTab> onChanged;

  static const double _height = 64;
  static const _labels = {
    _CommunityTab.forYou: 'Untukmu',
    _CommunityTab.groups: 'Komunitas',
    _CommunityTab.events: 'Event',
  };

  @override
  double get minExtent => _height;

  @override
  double get maxExtent => _height;

  @override
  Widget build(
    BuildContext context,
    double shrinkOffset,
    bool overlapsContent,
  ) {
    const tabs = _CommunityTab.values;
    final index = tabs.indexOf(selected);

    return Container(
      color: CommunityColor.background,
      padding: const EdgeInsets.fromLTRB(16, 8, 16, 8),
      child: Container(
        padding: const EdgeInsets.all(4),
        decoration: BoxDecoration(
          color: AppColor.white,
          borderRadius: BorderRadius.circular(999),
          boxShadow: communitySoftShadow,
        ),
        child: Stack(
          children: [
            AnimatedAlign(
              duration: const Duration(milliseconds: 250),
              curve: Curves.easeOutCubic,
              alignment: Alignment(-1 + 2 * index / (tabs.length - 1), 0),
              child: FractionallySizedBox(
                widthFactor: 1 / tabs.length,
                heightFactor: 1,
                child: Container(
                  decoration: BoxDecoration(
                    color: CommunityColor.blush,
                    borderRadius: BorderRadius.circular(999),
                  ),
                ),
              ),
            ),
            Row(
              children: tabs.map((tab) {
                final isSelected = tab == selected;
                return Expanded(
                  child: GestureDetector(
                    behavior: HitTestBehavior.opaque,
                    onTap: () => onChanged(tab),
                    child: Center(
                      child: Text(
                        _labels[tab]!,
                        style: AppStyle.sm.copyWith(
                          color: isSelected
                              ? AppColor.primary
                              : CommunityColor.muted,
                          fontWeight: isSelected
                              ? FontWeight.w700
                              : FontWeight.w600,
                        ),
                      ),
                    ),
                  ),
                );
              }).toList(),
            ),
          ],
        ),
      ),
    );
  }

  @override
  bool shouldRebuild(_TabHeaderDelegate oldDelegate) =>
      oldDelegate.selected != selected;
}