import 'package:flutter/material.dart';
import 'package:flutter_bloc/flutter_bloc.dart';
import 'package:go_router/go_router.dart';
import 'dart:developer' as dev;

import '../../core/app_colors.dart';
import '../../di/service_locator.dart';
import '../../domain/entities/client_notification.dart';
import '../components/custom_app_bar.dart';
import '../event/notifications_event.dart';
import '../state/notifications_state.dart';
import '../viewmodel/notifications_bloc.dart';

enum NotificationFilter {
  all,
  auth,
  payment,
  order,
}

class NotificationsScreen extends StatelessWidget {
  const NotificationsScreen({super.key});

  @override
  Widget build(BuildContext context) {
    return BlocProvider(
      create: (context) => getIt<NotificationsBloc>()..add(NotificationsFetchRequested(page: 1)),
      child: _NotificationsScreenContent(),
    );
  }
}

class _NotificationsScreenContent extends StatefulWidget {
  const _NotificationsScreenContent();

  @override
  State<_NotificationsScreenContent> createState() => _NotificationsScreenContentState();
}

class _NotificationsScreenContentState extends State<_NotificationsScreenContent> {
  NotificationFilter _filter = NotificationFilter.all;
  final ScrollController _scrollController = ScrollController();

  @override
  void initState() {
    super.initState();
  }

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

  void _setFilter(NotificationFilter filter) {
    setState(() => _filter = filter);
    _scrollController.jumpTo(0);
    context.read<NotificationsBloc>().add(NotificationsFetchRequested(page: 1));
  }

  @override
  Widget build(BuildContext context) {
    return NotificationsView(
      filter: _filter,
      onFilterChanged: _setFilter,
      scrollController: _scrollController,
    );
  }
}

class NotificationsView extends StatelessWidget {
  final NotificationFilter filter;
  final ValueChanged<NotificationFilter> onFilterChanged;
  final ScrollController? scrollController;

  const NotificationsView({
    super.key,
    this.filter = NotificationFilter.all,
    required this.onFilterChanged,
    this.scrollController,
  });

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Container(
        decoration: const BoxDecoration(gradient: AppColors.phoneScreenBg),
        child: SafeArea(
          child: Column(
            children: [
              const SizedBox(height: 16),
              const Padding(
                padding: EdgeInsets.symmetric(horizontal: 20),
                child: CustomAppBar(title: 'Уведомления'),
              ),
              const SizedBox(height: 16),

              _buildFilterBar(),

              const SizedBox(height: 16),

              Expanded(
                child: BlocBuilder<NotificationsBloc, NotificationsState>(
                  builder: (context, state) {
                    if (state.status == NotificationsStatus.loading) {
                      return const Center(child: CircularProgressIndicator(color: Colors.white));
                    }

                    if (state.status == NotificationsStatus.failure) {
                      return Center(
                        child: Column(
                          mainAxisAlignment: MainAxisAlignment.center,
                          children: [
                            const Text(
                              'Ошибка загрузки уведомлений',
                              style: TextStyle(
                                color: Colors.white,
                                fontSize: 16,
                                fontWeight: FontWeight.w600,
                              ),
                            ),
                            const SizedBox(height: 16),
                            Padding(
                              padding: const EdgeInsets.symmetric(horizontal: 40),
                              child: Text(
                                state.errorMessage ?? '',
                                style: TextStyle(
                                  color: Colors.white.withOpacity(0.6),
                                  fontSize: 14,
                                ),
                                textAlign: TextAlign.center,
                              ),
                            ),
                            const SizedBox(height: 24),
                            ElevatedButton(
                              onPressed: () {
                                context.read<NotificationsBloc>().add(NotificationsFetchRequested(page: 1));
                              },
                              child: const Text('Повторить'),
                            ),
                          ],
                        ),
                      );
                    }

                    final filtered = state.notifications.where((n) {
                      switch (filter) {
                        case NotificationFilter.all:
                          return true;
                        case NotificationFilter.auth:
                          return n.category == NotificationCategory.auth;
                        case NotificationFilter.payment:
                          return n.category == NotificationCategory.payment;
                        case NotificationFilter.order:
                          return n.category == NotificationCategory.scooter;
                        default:
                          return true;
                      }
                    }).toList();

                    if (filtered.isEmpty) {
                      return const _EmptyState();
                    }

                    return RefreshIndicator(
                      onRefresh: () async {
                        context.read<NotificationsBloc>().add(NotificationsFetchRequested(page: 1));
                      },
                      child: NotificationListener<ScrollNotification>(
                        onNotification: (scrollInfo) {
                          if (scrollInfo.metrics.pixels >= scrollInfo.metrics.maxScrollExtent - 50 &&
                              scrollInfo.metrics.maxScrollExtent > 0 &&
                              state.hasMore &&
                              !state.isLoadingMore &&
                              state.status == NotificationsStatus.success) {
                            context.read<NotificationsBloc>().add(NotificationsLoadMoreRequested());
                          }
                          return false;
                        },
                        child: ListView.builder(
                          controller: scrollController,
                          padding: const EdgeInsets.symmetric(horizontal: 20),
                          itemCount: filtered.length + (state.hasMore && filtered.length >= 10 ? 1 : 0),
                          itemBuilder: (context, index) {
                            if (index == filtered.length && state.hasMore && filtered.length >= 10) {
                              return const Padding(
                                padding: EdgeInsets.symmetric(vertical: 16),
                                child: Center(
                                  child: SizedBox(
                                    width: 24,
                                    height: 24,
                                    child: CircularProgressIndicator(color: Colors.white, strokeWidth: 2),
                                  ),
                                ),
                              );
                            }
                            return _NotificationCard(notification: filtered[index]);
                          },
                        ),
                      ),
                    );
                  },
                ),
              ),
            ],
          ),
        ),
      ),
    );
  }

  Widget _buildFilterBar() {
    final items = [
      {'label': 'Все', 'value': NotificationFilter.all},
      {'label': 'Авторизация', 'value': NotificationFilter.auth},
      {'label': 'Оплата', 'value': NotificationFilter.payment},
      {'label': 'Поездка', 'value': NotificationFilter.order},
    ];

    return Container(
      height: 40,
      padding: const EdgeInsets.symmetric(horizontal: 20),
      child: SingleChildScrollView(
        scrollDirection: Axis.horizontal,
        child: Row(
          children: items.map((item) {
            final isActive = item['value'] == filter;
            return Padding(
              padding: const EdgeInsets.only(right: 12),
              child: GestureDetector(
                onTap: () => onFilterChanged(item['value'] as NotificationFilter),
                child: Container(
                  height: 32,
                  padding: const EdgeInsets.symmetric(horizontal: 16),
                  alignment: Alignment.center,
                  decoration: BoxDecoration(
                    gradient: isActive ? AppColors.activeButtonGradient : null,
                    color: isActive ? null : Colors.transparent,
                    borderRadius: BorderRadius.circular(20),
                    border: Border.all(
                      color: isActive
                          ? Colors.transparent
                          : Colors.white.withOpacity(0.4),
                      width: 1,
                    ),
                  ),
                  child: Text(
                    item['label'] as String,
                    textAlign: TextAlign.center,
                    style: TextStyle(
                      color: isActive
                          ? AppColors.activeButtonText
                          : Colors.white,
                      fontSize: 14,
                      fontWeight: isActive ? FontWeight.bold : FontWeight.normal,
                    ),
                  ),
                ),
              ),
            );
          }).toList(),
        ),
      ),
    );
  }
}

class _EmptyState extends StatelessWidget {
  const _EmptyState();

  @override
  Widget build(BuildContext context) {
    return Column(
      mainAxisAlignment: MainAxisAlignment.center,
      crossAxisAlignment: CrossAxisAlignment.center,
      children: [
        Image.asset(
          'assets/notification_empty.png',
          width: 280,
          height: 280,
          fit: BoxFit.contain,
          errorBuilder: (context, error, stackTrace) {
            return const Icon(
              Icons.notifications_none_outlined,
              size: 120,
              color: Colors.white38,
            );
          },
        ),
        const SizedBox(height: 32),
        const Padding(
          padding: EdgeInsets.symmetric(horizontal: 40),
          child: Text(
            'У вас пока нет уведомлений.',
            textAlign: TextAlign.center,
            style: TextStyle(
              color: Colors.white70,
              fontSize: 16,
              height: 1.5,
            ),
          ),
        ),
      ],
    );
  }
}

class _NotificationCard extends StatelessWidget {
  final ClientNotification notification;

  const _NotificationCard({required this.notification});

  @override
  Widget build(BuildContext context) {
    final date = _formatDate(notification.createdAt);

    return Container(
      margin: const EdgeInsets.only(bottom: 12),
      padding: const EdgeInsets.all(16),
      decoration: BoxDecoration(
        color: const Color(0xFF141530).withOpacity(0.7),
        borderRadius: BorderRadius.circular(16),
      ),
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          Text(
            date,
            style: TextStyle(
              color: Colors.white.withOpacity(0.6),
              fontSize: 12,
            ),
          ),
          const SizedBox(height: 8),
          Text(
            notification.content,
            style: const TextStyle(
              color: Colors.white,
              fontSize: 14,
            ),
          ),
        ],
      ),
    );
  }

  String _formatDate(DateTime date) {
    final localDate = date.toLocal();
    final now = DateTime.now();

    if (localDate.year == now.year &&
        localDate.month == now.month &&
        localDate.day == now.day) {
      return 'Сегодня, ${localDate.hour.toString().padLeft(2, '0')}:${localDate.minute.toString().padLeft(2, '0')}';
    }

    final yesterday = now.subtract(const Duration(days: 1));
    if (localDate.year == yesterday.year &&
        localDate.month == yesterday.month &&
        localDate.day == yesterday.day) {
      return 'Вчера, ${localDate.hour.toString().padLeft(2, '0')}:${localDate.minute.toString().padLeft(2, '0')}';
    }

    return '${localDate.day.toString().padLeft(2, '0')}.${localDate.month.toString().padLeft(2, '0')}.${localDate.year}';
  }

  String _getTypeLabel(NotificationType type) {
    switch (type) {
      case NotificationType.info:
        return 'Информация';
      case NotificationType.attention:
        return 'Внимание';
      case NotificationType.warning:
        return 'Предупреждение';
    }
  }

  String _getCategoryLabel(NotificationCategory category) {
    switch (category) {
      case NotificationCategory.auth:
        return 'Авторизация';
      case NotificationCategory.zone:
        return 'Зоны';
      case NotificationCategory.payment:
        return 'Оплата';
      case NotificationCategory.companyInfo:
        return 'Акции';
      case NotificationCategory.adminInfo:
        return 'Админ';
      case NotificationCategory.scooter:
        return 'Самокат';
    }
  }
}