import 'package:em2rp/providers/local_user_provider.dart';
import 'package:em2rp/providers/event_provider.dart';
import 'package:flutter/material.dart';
import 'package:em2rp/views/widgets/custom_app_bar.dart';
import 'package:em2rp/views/widgets/nav/main_drawer.dart';
import 'package:provider/provider.dart';
import 'package:table_calendar/table_calendar.dart';
import 'package:em2rp/models/event_model.dart';
import 'package:em2rp/views/widgets/calendar_widgets/event_details.dart';
import 'package:intl/date_symbol_data_local.dart';
import 'package:em2rp/views/widgets/calendar_widgets/month_view.dart';
import 'package:em2rp/views/widgets/calendar_widgets/week_view.dart';
import 'package:em2rp/views/pages/event_add_page.dart';
import 'package:em2rp/views/widgets/calendar_widgets/mobile_calendar_view.dart';
import 'package:em2rp/utils/colors.dart';

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

  @override
  State<CalendarPage> createState() => _CalendarPageState();
}

class _CalendarPageState extends State<CalendarPage> {
  CalendarFormat _calendarFormat = CalendarFormat.month;
  DateTime _focusedDay = DateTime.now();
  DateTime? _selectedDay;
  EventModel? _selectedEvent;
  bool _calendarCollapsed = false;
  int _selectedEventIndex = 0;

  @override
  void initState() {
    super.initState();
    initializeDateFormatting('fr_FR', null);
    Future.microtask(() => _loadEvents());
    // Sélection automatique de l'événement le plus proche de maintenant
    WidgetsBinding.instance.addPostFrameCallback((_) {
      final eventProvider = Provider.of<EventProvider>(context, listen: false);
      final events = eventProvider.events;
      if (events.isNotEmpty) {
        final now = DateTime.now();
        events.sort((a, b) => a.startDateTime.compareTo(b.startDateTime));
        int closestIdx = 0;
        Duration minDiff = (events[0].startDateTime.difference(now)).abs();
        for (int i = 1; i < events.length; i++) {
          final diff = (events[i].startDateTime.difference(now)).abs();
          if (diff < minDiff) {
            minDiff = diff;
            closestIdx = i;
          }
        }
        final closestEvent = events[closestIdx];
        setState(() {
          _selectedDay = DateTime(closestEvent.startDateTime.year,
              closestEvent.startDateTime.month, closestEvent.startDateTime.day);
          _focusedDay = _selectedDay!;
          _selectedEventIndex = 0;
          _selectedEvent = closestEvent;
        });
      }
    });
  }

  Future<void> _loadEvents() async {
    final localAuthProvider =
        Provider.of<LocalUserProvider>(context, listen: false);
    final eventProvider = Provider.of<EventProvider>(context, listen: false);
    final userId = localAuthProvider.uid;
    print('Permissions utilisateur: ${localAuthProvider.permissions}');
    final canViewAllEvents = localAuthProvider.hasPermission('view_all_events');
    print('canViewAllEvents: $canViewAllEvents');

    if (userId != null) {
      await eventProvider.loadUserEvents(userId,
          canViewAllEvents: canViewAllEvents);
    }
  }

  void _changeWeek(int delta) {
    setState(() {
      _focusedDay = _focusedDay.add(Duration(days: 7 * delta));
    });
  }

  @override
  Widget build(BuildContext context) {
    final eventProvider = Provider.of<EventProvider>(context);
    final localUserProvider = Provider.of<LocalUserProvider>(context);
    final isAdmin = localUserProvider.hasPermission('view_all_users');
    final isMobile = MediaQuery.of(context).size.width < 600;

    if (eventProvider.isLoading) {
      return const Scaffold(
        body: Center(
          child: CircularProgressIndicator(),
        ),
      );
    }

    return Scaffold(
      appBar: CustomAppBar(
        title: _getMonthName(_focusedDay.month),
        actions: [
          IconButton(
            icon: Icon(
              _calendarCollapsed
                  ? Icons.keyboard_arrow_down
                  : Icons.keyboard_arrow_up,
              color: AppColors.blanc,
            ),
            onPressed: () {
              setState(() {
                _calendarCollapsed = !_calendarCollapsed;
              });
            },
          ),
        ],
      ),
      drawer: const MainDrawer(currentPage: '/calendar'),
      body: isMobile ? _buildMobileLayout() : _buildDesktopLayout(),
      floatingActionButton: isAdmin
          ? FloatingActionButton(
              backgroundColor: Colors.white,
              onPressed: () {
                Navigator.of(context).push(
                  MaterialPageRoute(
                    builder: (context) => const EventAddPage(),
                  ),
                );
              },
              child: const Icon(Icons.add, color: Colors.red),
              tooltip: 'Ajouter un événement',
            )
          : null,
    );
  }

  Widget _buildDesktopLayout() {
    final eventProvider = Provider.of<EventProvider>(context);
    return Row(
      children: [
        // Calendrier (65% de la largeur)
        Expanded(
          flex: 65,
          child: _buildCalendar(),
        ),
        // Détails de l'événement (35% de la largeur)
        Expanded(
          flex: 35,
          child: _selectedEvent != null
              ? EventDetails(
                  event: _selectedEvent!,
                  selectedDate: _selectedDay,
                  events: eventProvider.events,
                  onSelectEvent: (event, date) {
                    setState(() {
                      _selectedEvent = event;
                      _selectedDay = date;
                    });
                  },
                )
              : Center(
                  child: _selectedDay != null
                      ? Text('Aucun événement ne démarre à cette date')
                      : const Text(
                          'Sélectionnez un événement pour voir les détails'),
                ),
        ),
      ],
    );
  }

  Widget _buildMobileLayout() {
    final eventProvider = Provider.of<EventProvider>(context);
    final eventsForSelectedDay = _selectedDay == null
        ? []
        : eventProvider.events
            .where((e) =>
                e.startDateTime.year == _selectedDay!.year &&
                e.startDateTime.month == _selectedDay!.month &&
                e.startDateTime.day == _selectedDay!.day)
            .toList()
      ..sort((a, b) => a.startDateTime.compareTo(b.startDateTime));
    final hasEvents = eventsForSelectedDay.isNotEmpty;
    final currentEvent =
        hasEvents && _selectedEventIndex < eventsForSelectedDay.length
            ? eventsForSelectedDay[_selectedEventIndex]
            : null;

    return Stack(
      children: [
        // Calendrier + détails en dessous
        AnimatedPositioned(
          duration: const Duration(milliseconds: 400),
          curve: Curves.easeInOut,
          top: _calendarCollapsed ? -600 : 0, // cache le calendrier en haut
          left: 0,
          right: 0,
          height: _calendarCollapsed ? 0 : null,
          child: Container(
            height: MediaQuery.of(context).size.height,
            child: Column(
              children: [
                _buildMonthHeader(context),
                if (!_calendarCollapsed)
                  MobileCalendarView(
                    focusedDay: _focusedDay,
                    selectedDay: _selectedDay,
                    events: eventProvider.events,
                    onDaySelected: (day) {
                      final eventsForDay = eventProvider.events
                          .where((e) =>
                              e.startDateTime.year == day.year &&
                              e.startDateTime.month == day.month &&
                              e.startDateTime.day == day.day)
                          .toList()
                        ..sort((a, b) =>
                            a.startDateTime.compareTo(b.startDateTime));
                      setState(() {
                        _selectedDay = day;
                        _calendarCollapsed = false;
                        _selectedEventIndex = 0;
                        _selectedEvent =
                            eventsForDay.isNotEmpty ? eventsForDay[0] : null;
                      });
                    },
                  ),
                Expanded(
                  child: hasEvents
                      ? EventDetails(
                          event: eventsForSelectedDay[_selectedEventIndex],
                          selectedDate: _selectedDay,
                          events: eventsForSelectedDay.cast<EventModel>(),
                          onSelectEvent: (event, date) {
                            final idx = eventsForSelectedDay
                                .indexWhere((e) => e.id == event.id);
                            setState(() {
                              _selectedEventIndex = idx >= 0 ? idx : 0;
                              _selectedEvent = event;
                            });
                          },
                        )
                      : Center(
                          child:
                              Text('Aucun événement ne démarre à cette date')),
                ),
              ],
            ),
          ),
        ),
        // Vue détail (prend tout l'espace quand calendrier caché)
        if (_calendarCollapsed && _selectedDay != null)
          AnimatedPositioned(
            duration: const Duration(milliseconds: 400),
            curve: Curves.easeInOut,
            top: _calendarCollapsed ? 0 : 600,
            left: 0,
            right: 0,
            bottom: 0,
            child: Container(
              height: MediaQuery.of(context).size.height,
              child: Column(
                children: [
                  _buildMonthHeader(context),
                  Expanded(
                    child: Stack(
                      children: [
                        if (currentEvent != null)
                          EventDetails(
                            event: currentEvent,
                            selectedDate: _selectedDay,
                            events: eventsForSelectedDay.cast<EventModel>(),
                            onSelectEvent: (event, date) {
                              final idx = eventsForSelectedDay
                                  .indexWhere((e) => e.id == event.id);
                              setState(() {
                                _selectedEventIndex = idx >= 0 ? idx : 0;
                                _selectedEvent = event;
                              });
                            },
                          ),
                        if (!hasEvents)
                          Center(
                            child:
                                Text('Aucun événement ne démarre à cette date'),
                          ),
                      ],
                    ),
                  ),
                ],
              ),
            ),
          ),
      ],
    );
  }

  Widget _buildMonthHeader(BuildContext context) {
    return Padding(
      padding: const EdgeInsets.only(top: 8, bottom: 8),
      child: Row(
        children: [
          IconButton(
            icon: const Icon(Icons.chevron_left,
                color: AppColors.rouge, size: 28),
            onPressed: () {
              setState(() {
                _focusedDay =
                    DateTime(_focusedDay.year, _focusedDay.month - 1, 1);
              });
            },
          ),
          Expanded(
            child: GestureDetector(
              onTap: () {
                setState(() {
                  _calendarCollapsed = !_calendarCollapsed;
                });
              },
              child: Row(
                mainAxisAlignment: MainAxisAlignment.center,
                mainAxisSize: MainAxisSize.min,
                children: [
                  Text(
                    _getMonthName(_focusedDay.month),
                    style: const TextStyle(
                      color: AppColors.rouge,
                      fontWeight: FontWeight.bold,
                      fontSize: 20,
                    ),
                  ),
                  const SizedBox(width: 6),
                  Icon(
                    _calendarCollapsed
                        ? Icons.keyboard_arrow_down
                        : Icons.keyboard_arrow_up,
                    color: AppColors.rouge,
                    size: 26,
                  ),
                ],
              ),
            ),
          ),
          IconButton(
            icon: const Icon(Icons.chevron_right,
                color: AppColors.rouge, size: 28),
            onPressed: () {
              setState(() {
                _focusedDay =
                    DateTime(_focusedDay.year, _focusedDay.month + 1, 1);
              });
            },
          ),
        ],
      ),
    );
  }

  String _getMonthName(int month) {
    switch (month) {
      case 1:
        return 'Janvier';
      case 2:
        return 'Février';
      case 3:
        return 'Mars';
      case 4:
        return 'Avril';
      case 5:
        return 'Mai';
      case 6:
        return 'Juin';
      case 7:
        return 'Juillet';
      case 8:
        return 'Août';
      case 9:
        return 'Septembre';
      case 10:
        return 'Octobre';
      case 11:
        return 'Novembre';
      case 12:
        return 'Décembre';
      default:
        return '';
    }
  }

  Widget _buildCalendar() {
    final eventProvider = Provider.of<EventProvider>(context);

    if (_calendarFormat == CalendarFormat.week) {
      return WeekView(
        focusedDay: _focusedDay,
        events: eventProvider.events,
        onWeekChange: _changeWeek,
        onEventSelected: (event) {
          setState(() {
            _selectedEvent = event;
            _selectedDay = event.startDateTime;
          });
        },
        onSwitchToMonth: () {
          setState(() {
            _calendarFormat = CalendarFormat.month;
          });
        },
        onDaySelected: (selectedDay) {
          final eventsForDay = eventProvider.events
              .where((e) =>
                  e.startDateTime.year == selectedDay.year &&
                  e.startDateTime.month == selectedDay.month &&
                  e.startDateTime.day == selectedDay.day)
              .toList();
          eventsForDay
              .sort((a, b) => a.startDateTime.compareTo(b.startDateTime));
          setState(() {
            _selectedDay = selectedDay;
            if (eventsForDay.isNotEmpty) {
              _selectedEvent = eventsForDay.first;
            } else {
              _selectedEvent = null;
            }
          });
          if (eventsForDay.isEmpty) {
            ScaffoldMessenger.of(context).showSnackBar(
              const SnackBar(
                content: Text("Aucun événement ne démarre à cette date."),
                duration: Duration(seconds: 2),
              ),
            );
          }
        },
        selectedEvent: _selectedEvent,
      );
    } else {
      return MonthView(
        focusedDay: _focusedDay,
        selectedDay: _selectedDay,
        calendarFormat: _calendarFormat,
        events: eventProvider.events,
        onDaySelected: (selectedDay, focusedDay) {
          final eventsForDay = eventProvider.events
              .where((event) =>
                  event.startDateTime.year == selectedDay.year &&
                  event.startDateTime.month == selectedDay.month &&
                  event.startDateTime.day == selectedDay.day)
              .toList()
            ..sort((a, b) => a.startDateTime.compareTo(b.startDateTime));
          setState(() {
            _selectedDay = selectedDay;
            _focusedDay = focusedDay;
            if (eventsForDay.isNotEmpty) {
              _selectedEvent = eventsForDay.first;
            } else {
              _selectedEvent = null;
            }
          });
        },
        onFormatChanged: (format) {
          setState(() {
            _calendarFormat = format;
          });
        },
        onPageChanged: (focusedDay) {
          setState(() {
            _focusedDay = focusedDay;
          });
        },
        onEventSelected: (event) {
          setState(() {
            _selectedEvent = event;
          });
        },
      );
    }
  }
}