import 'package:intl/intl.dart';
import 'package:prosapp_web_app/models/profesional.dart';
import 'package:prosapp_web_app/models/schedules_entity.dart';
import 'package:prosapp_web_app/models/service.dart';
import 'package:prosapp_web_app/providers/auth_provider.dart';
import 'package:prosapp_web_app/providers/professional_form_provider.dart';
import 'package:prosapp_web_app/providers/professional_provider.dart';
import 'package:prosapp_web_app/models/service_status.dart';
import 'package:prosapp_web_app/providers/services_provider.dart';
import 'package:prosapp_web_app/utils/time_of_day_utils.dart';
import 'package:provider/provider.dart';
import 'package:table_calendar/table_calendar.dart';
import 'package:flutter/material.dart';

const _kPrimary   = Color(0xFF1565C0);
const _kAvailable = Color(0xFF16A34A);
const _kOccupied  = Color(0xFFDC2626);
const _kBlocked   = Color(0xFFF59E0B);

extension _Th on BuildContext {
  ThemeData get _t => Theme.of(this);
  Color get bg => _t.scaffoldBackgroundColor;
  Color get card => _t.cardColor;
  Color get onSurface => _t.colorScheme.onSurface;
  Color get muted => _t.colorScheme.onSurface.withOpacity(0.55);
  Color get subtle => _t.colorScheme.onSurface.withOpacity(0.35);
  bool get isDark => _t.brightness == Brightness.dark;
  Color get shadow => isDark ? Colors.transparent : Colors.black.withOpacity(0.07);
  Color get shadowSm => isDark ? Colors.transparent : Colors.black.withOpacity(0.04);
}

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

  @override
  State<ProfessionalCalendarView> createState() =>
      _ProfessionalCalendarViewState();
}

class _ProfessionalCalendarViewState extends State<ProfessionalCalendarView> {
  DateTime _selected = DateTime.now();
  List<Service>? _services;
  bool _loading = true;

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

  Future<void> _load() async {
    setState(() => _loading = true);
    final auth = Provider.of<AuthProvider>(context, listen: false);
    final fp = Provider.of<ProfessionalFormProvider>(context, listen: false);
    final sp = Provider.of<ServicesProvider>(context, listen: false);
    final pro = await Provider.of<ProfessionalProvider>(context, listen: false)
        .getProfessional(auth.user!.id);
    fp.setProfesional(pro);
    // getServicesForProfessional returns void; read from sp.services after it resolves
    await sp.getServicesForProfessional(pro.id);
    if (mounted) setState(() {
      _services = sp.services.map((s) => s.service).toList();
      _loading = false;
    });
  }

  void _onDaySelected(DateTime day, DateTime _) =>
      setState(() => _selected = day);

  @override
  Widget build(BuildContext context) {
    return Container(
      color: context.bg,
      child: Consumer<ProfessionalFormProvider>(
        builder: (context, fp, _) {
          if (fp.profesional == null || _loading) {
            return const Center(child: CircularProgressIndicator(color: _kPrimary));
          }
          final pro = fp.profesional!;
          final sp = Provider.of<ServicesProvider>(context, listen: false);
          final schedule = _scheduleFor(_selected.weekday, pro);
          final slots = _buildSlots(schedule, pro.slotDurationMinutes);
          final occupied = slots.where((t) => _isOccupied(t, _services, _selected)).length;
          final blocked  = slots.where((t) => _isSelfBooked(t, _services, _selected)).length;

          return ListView(
            physics: const ClampingScrollPhysics(),
            padding: const EdgeInsets.only(bottom: 32),
            children: [
              _calendarCard(context),
              _dayHeader(context, schedule, slots.length, occupied, blocked),
              if (slots.isEmpty)
                _emptyState(context)
              else
                ..._slotCards(context, slots, sp, pro.id),
            ],
          );
        },
      ),
    );
  }

  Widget _calendarCard(BuildContext context) {
    return Center(
      child: ConstrainedBox(
        constraints: const BoxConstraints(maxWidth: 720),
        child: Container(
          margin: const EdgeInsets.fromLTRB(16, 20, 16, 0),
          decoration: BoxDecoration(
            color: context.card,
            borderRadius: BorderRadius.circular(16),
            boxShadow: [BoxShadow(color: context.shadow, blurRadius: 16, offset: const Offset(0, 4))],
          ),
          child: ClipRRect(
            borderRadius: BorderRadius.circular(16),
            child: TableCalendar(
              locale: 'es_CO',
              firstDay: DateTime.now().subtract(const Duration(days: 365)),
              lastDay: DateTime.utc(2030, 12, 31),
              focusedDay: _selected,
              availableGestures: AvailableGestures.all,
              onDaySelected: _onDaySelected,
              selectedDayPredicate: (d) => isSameDay(d, _selected),
              calendarStyle: CalendarStyle(
                todayDecoration: BoxDecoration(
                  border: Border.all(color: _kPrimary, width: 2), shape: BoxShape.circle),
                todayTextStyle: const TextStyle(color: _kPrimary, fontWeight: FontWeight.w700),
                selectedDecoration: const BoxDecoration(color: _kPrimary, shape: BoxShape.circle),
                selectedTextStyle: const TextStyle(color: Colors.white, fontWeight: FontWeight.w700),
                weekendTextStyle: TextStyle(color: Colors.red.shade400),
                defaultTextStyle: TextStyle(color: context.onSurface),
                outsideDaysVisible: false,
              ),
              headerStyle: HeaderStyle(
                formatButtonVisible: false,
                titleCentered: true,
                titleTextStyle: TextStyle(
                    fontSize: 15, fontWeight: FontWeight.w700, color: context.onSurface),
                leftChevronIcon: const Icon(Icons.chevron_left, color: _kPrimary),
                rightChevronIcon: const Icon(Icons.chevron_right, color: _kPrimary),
              ),
              daysOfWeekStyle: DaysOfWeekStyle(
                weekdayStyle: TextStyle(fontSize: 12, fontWeight: FontWeight.w600, color: context.muted),
                weekendStyle: const TextStyle(fontSize: 12, fontWeight: FontWeight.w600, color: Color(0xFFEF4444)),
              ),
            ),
          ),
        ),
      ),
    );
  }

  Widget _dayHeader(BuildContext context, ScheduleEntity? schedule, int total, int occupied, int blocked) {
    final dayName = DateFormat('EEEE', 'es').format(_selected);
    final dateStr = DateFormat('d MMMM yyyy', 'es').format(_selected);
    final available = total - occupied - blocked;
    final hasSchedule = schedule != null && schedule.enabled;

    return Center(
      child: ConstrainedBox(
        constraints: const BoxConstraints(maxWidth: 720),
        child: Container(
          margin: const EdgeInsets.fromLTRB(16, 12, 16, 0),
          padding: const EdgeInsets.fromLTRB(16, 14, 16, 14),
          decoration: BoxDecoration(
            color: context.card,
            borderRadius: BorderRadius.circular(16),
            boxShadow: [BoxShadow(color: context.shadowSm, blurRadius: 12, offset: const Offset(0, 2))],
          ),
          child: Row(children: [
            Container(
              width: 48, height: 52,
              decoration: BoxDecoration(color: _kPrimary, borderRadius: BorderRadius.circular(12)),
              child: Column(mainAxisAlignment: MainAxisAlignment.center, children: [
                Text(DateFormat('d').format(_selected),
                    style: const TextStyle(color: Colors.white, fontSize: 20, fontWeight: FontWeight.w800, height: 1)),
                Text(DateFormat('MMM', 'es').format(_selected).toUpperCase(),
                    style: const TextStyle(color: Colors.white70, fontSize: 10, fontWeight: FontWeight.w600)),
              ]),
            ),
            const SizedBox(width: 14),
            Expanded(child: Column(crossAxisAlignment: CrossAxisAlignment.start, children: [
              Text(_capitalize(dayName),
                  style: TextStyle(fontSize: 16, fontWeight: FontWeight.w700, color: context.onSurface)),
              Text(dateStr, style: TextStyle(fontSize: 12, color: context.subtle)),
            ])),
            if (hasSchedule && total > 0) ...[
              _StatPill(label: '$occupied', sublabel: 'ocupadas', color: _kOccupied),
              const SizedBox(width: 8),
              _StatPill(label: '$blocked', sublabel: 'bloqueadas', color: _kBlocked),
              const SizedBox(width: 8),
              _StatPill(label: '$available', sublabel: 'libres', color: _kAvailable),
            ],
          ]),
        ),
      ),
    );
  }

  List<Widget> _slotCards(BuildContext context, List<TimeOfDay> slots, ServicesProvider sp, String professionalId) {
    return slots.map((time) {
      final selfBooked = _isSelfBooked(time, _services, _selected);
      final occ        = !selfBooked && _isOccupied(time, _services, _selected);
      final matchService = (occ || selfBooked) ? _serviceFor(time, _services, _selected) : null;

      final Color color;
      final String label;
      final IconData icon;
      if (selfBooked) {
        color = _kBlocked;
        label = 'Bloqueado';
        icon  = Icons.lock_outline;
      } else if (occ) {
        color = _kOccupied;
        label = 'Ocupado';
        icon  = Icons.event_busy_outlined;
      } else {
        color = _kAvailable;
        label = 'Disponible';
        icon  = Icons.event_available_outlined;
      }

      return Center(
        child: ConstrainedBox(
          constraints: const BoxConstraints(maxWidth: 720),
          child: Container(
            margin: const EdgeInsets.fromLTRB(16, 8, 16, 0),
            decoration: BoxDecoration(
              color: context.card,
              borderRadius: BorderRadius.circular(14),
              boxShadow: [BoxShadow(color: context.shadowSm, blurRadius: 8, offset: const Offset(0, 2))],
            ),
            child: ClipRRect(
              borderRadius: BorderRadius.circular(14),
              child: IntrinsicHeight(
                child: Row(children: [
                  Container(width: 4, color: color),
                  Expanded(
                    child: Padding(
                      padding: const EdgeInsets.symmetric(horizontal: 14, vertical: 12),
                      child: Row(children: [
                        Container(
                          padding: const EdgeInsets.symmetric(horizontal: 12, vertical: 6),
                          decoration: BoxDecoration(
                            color: color.withOpacity(0.08), borderRadius: BorderRadius.circular(8)),
                          child: Text(ScheduleEntity.getFormatTime(time) ?? '',
                              style: TextStyle(fontSize: 15, fontWeight: FontWeight.w800, color: color)),
                        ),
                        const SizedBox(width: 14),
                        Expanded(child: Column(
                          crossAxisAlignment: CrossAxisAlignment.start,
                          mainAxisAlignment: MainAxisAlignment.center,
                          children: [
                            Text(label, style: TextStyle(fontSize: 14, fontWeight: FontWeight.w700, color: color)),
                            if (matchService != null && matchService.description.isNotEmpty)
                              Text(matchService.description,
                                  style: TextStyle(fontSize: 12, color: context.muted),
                                  maxLines: 1, overflow: TextOverflow.ellipsis)
                            else if (!occ && !selfBooked)
                              Text('Horario libre para nuevas citas',
                                  style: TextStyle(fontSize: 11, color: context.subtle)),
                          ],
                        )),
                        // Action button
                        if (selfBooked)
                          _ActionButton(
                            icon: Icons.lock_open_outlined,
                            color: _kBlocked,
                            tooltip: 'Desbloquear',
                            onTap: () => _confirmUnblock(context, sp, matchService!.id!, time),
                          )
                        else if (!occ)
                          _ActionButton(
                            icon: Icons.lock_outline,
                            color: context.subtle,
                            tooltip: 'Bloquear horario',
                            onTap: () => _confirmBlock(context, sp, time),
                          )
                        else
                          Container(
                            width: 32, height: 32,
                            decoration: BoxDecoration(color: color.withOpacity(0.1), shape: BoxShape.circle),
                            child: Icon(icon, size: 17, color: color),
                          ),
                      ]),
                    ),
                  ),
                ]),
              ),
            ),
          ),
        ),
      );
    }).toList();
  }

  Future<void> _confirmBlock(BuildContext context, ServicesProvider sp, TimeOfDay time) async {
    final timeStr = ScheduleEntity.getFormatTime(time) ?? '';
    final confirmed = await showDialog<bool>(
      context: context,
      builder: (_) => AlertDialog(
        title: const Text('Bloquear horario'),
        content: Text('¿Bloquear el horario de $timeStr? Los usuarios no podrán agendarse en este slot.'),
        actions: [
          TextButton(onPressed: () => Navigator.pop(context, false), child: const Text('Cancelar')),
          ElevatedButton(
            onPressed: () => Navigator.pop(context, true),
            style: ElevatedButton.styleFrom(backgroundColor: _kBlocked),
            child: const Text('Bloquear', style: TextStyle(color: Colors.white)),
          ),
        ],
      ),
    );
    if (confirmed != true) return;
    try {
      final dayStr = _selected.toIso8601String().split('T').first;
      await sp.blockSlot(dayStr, time);
      await _load();
    } catch (e) {
      if (mounted) ScaffoldMessenger.of(context).showSnackBar(SnackBar(content: Text('Error: $e')));
    }
  }

  Future<void> _confirmUnblock(BuildContext context, ServicesProvider sp, String serviceId, TimeOfDay time) async {
    final timeStr = ScheduleEntity.getFormatTime(time) ?? '';
    final confirmed = await showDialog<bool>(
      context: context,
      builder: (_) => AlertDialog(
        title: const Text('Desbloquear horario'),
        content: Text('¿Desbloquear el horario de $timeStr? Estará disponible para nuevas citas.'),
        actions: [
          TextButton(onPressed: () => Navigator.pop(context, false), child: const Text('Cancelar')),
          ElevatedButton(
            onPressed: () => Navigator.pop(context, true),
            style: ElevatedButton.styleFrom(backgroundColor: _kAvailable),
            child: const Text('Desbloquear', style: TextStyle(color: Colors.white)),
          ),
        ],
      ),
    );
    if (confirmed != true) return;
    try {
      await sp.unblockSlot(serviceId);
      await _load();
    } catch (e) {
      if (mounted) ScaffoldMessenger.of(context).showSnackBar(SnackBar(content: Text('Error: $e')));
    }
  }

  Widget _emptyState(BuildContext context) {
    return Center(
      child: ConstrainedBox(
        constraints: const BoxConstraints(maxWidth: 720),
        child: Container(
          margin: const EdgeInsets.fromLTRB(16, 12, 16, 0),
          padding: const EdgeInsets.symmetric(vertical: 40, horizontal: 24),
          decoration: BoxDecoration(
            color: context.card,
            borderRadius: BorderRadius.circular(16),
            boxShadow: [BoxShadow(color: context.shadowSm, blurRadius: 12, offset: const Offset(0, 2))],
          ),
          child: Column(children: [
            Container(
              width: 64, height: 64,
              decoration: BoxDecoration(
                color: context.subtle.withOpacity(0.1), shape: BoxShape.circle),
              child: Icon(Icons.event_busy_outlined, size: 32, color: context.subtle),
            ),
            const SizedBox(height: 16),
            Text('Sin horario este día',
                style: TextStyle(fontSize: 15, fontWeight: FontWeight.w700, color: context.muted)),
            const SizedBox(height: 6),
            Text('No tienes horario de atención configurado\npara este día de la semana.',
                textAlign: TextAlign.center,
                style: TextStyle(fontSize: 13, color: context.subtle, height: 1.5)),
          ]),
        ),
      ),
    );
  }

  ScheduleEntity? _scheduleFor(int weekday, Profesional pro) => switch (weekday) {
    1 => pro.schedules.monday, 2 => pro.schedules.tuesday,
    3 => pro.schedules.wednesday, 4 => pro.schedules.thursday,
    5 => pro.schedules.friday, 6 => pro.schedules.saturday,
    _ => pro.schedules.sunday,
  };

  List<TimeOfDay> _buildSlots(ScheduleEntity? s, int stepMinutes) {
    if (s == null || !s.enabled || s.range1Hour1 == null || s.range2Hour2 == null) return [];
    if (s.continuousDay) {
      return TimeOfDayUtils.genRanges(s.range1Hour1!, s.range2Hour2!, stepMinutes: stepMinutes);
    }
    if (s.range1Hour2 == null || s.range2Hour1 == null) return [];
    return [
      ...TimeOfDayUtils.genRanges(s.range1Hour1!, s.range1Hour2!, stepMinutes: stepMinutes),
      ...TimeOfDayUtils.genRanges(s.range2Hour1!, s.range2Hour2!, stepMinutes: stepMinutes),
    ];
  }

  bool _isOccupied(TimeOfDay time, List<Service>? services, DateTime day) {
    if (services == null) return false;
    final dayStr = day.toIso8601String().split('T').first;
    return services.any((s) =>
        s.day == dayStr &&
        s.range1Hour1 == time &&
        s.status != ServiceStatus.selfBooked &&
        s.status != ServiceStatus.cancelled &&
        s.status != ServiceStatus.denied);
  }

  bool _isSelfBooked(TimeOfDay time, List<Service>? services, DateTime day) {
    if (services == null) return false;
    final dayStr = day.toIso8601String().split('T').first;
    return services.any((s) =>
        s.day == dayStr &&
        s.range1Hour1 == time &&
        s.status == ServiceStatus.selfBooked);
  }

  Service? _serviceFor(TimeOfDay time, List<Service>? services, DateTime day) {
    if (services == null) return null;
    final dayStr = day.toIso8601String().split('T').first;
    try {
      return services.firstWhere((s) => s.day == dayStr && s.range1Hour1 == time);
    } catch (_) { return null; }
  }

  String _capitalize(String s) => s.isEmpty ? s : s[0].toUpperCase() + s.substring(1);
}

class _ActionButton extends StatelessWidget {
  final IconData icon;
  final Color color;
  final String tooltip;
  final VoidCallback onTap;
  const _ActionButton({required this.icon, required this.color, required this.tooltip, required this.onTap});

  @override
  Widget build(BuildContext context) {
    return Tooltip(
      message: tooltip,
      child: GestureDetector(
        onTap: onTap,
        child: Container(
          width: 32, height: 32,
          decoration: BoxDecoration(color: color.withOpacity(0.1), shape: BoxShape.circle),
          child: Icon(icon, size: 17, color: color),
        ),
      ),
    );
  }
}

class _StatPill extends StatelessWidget {
  final String label;
  final String sublabel;
  final Color color;
  const _StatPill({required this.label, required this.sublabel, required this.color});

  @override
  Widget build(BuildContext context) {
    return Container(
      padding: const EdgeInsets.symmetric(horizontal: 10, vertical: 6),
      decoration: BoxDecoration(
        color: color.withOpacity(0.08),
        borderRadius: BorderRadius.circular(8),
        border: Border.all(color: color.withOpacity(0.25)),
      ),
      child: Column(mainAxisSize: MainAxisSize.min, children: [
        Text(label,
            style: TextStyle(fontSize: 16, fontWeight: FontWeight.w800, color: color, height: 1)),
        Text(sublabel,
            style: TextStyle(fontSize: 9, color: color.withOpacity(0.8), fontWeight: FontWeight.w600)),
      ]),
    );
  }
}