import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:intl/intl.dart';
import '../../providers/auth_provider.dart';
import '../../providers/time_provider.dart';
import '../../services/time_service.dart';
import '../../models/time_registration.dart';
import '../history/history_screen.dart';
import '../reports/reports_screen.dart';
import '../profile/profile_screen.dart';
import '../../widgets/timer_widget.dart';

class HomeScreen extends ConsumerStatefulWidget {
  const HomeScreen({super.key});

  @override
  ConsumerState<HomeScreen> createState() => _HomeScreenState();
}

class _HomeScreenState extends ConsumerState<HomeScreen> {
  int _selectedIndex = 0;

  @override
  Widget build(BuildContext context) {
    final List<Widget> screens = [
      const HomeTab(),
      const HistoryScreen(),
      const ReportsScreen(),
      const ProfileScreen(),
    ];

    return Scaffold(
      body: screens[_selectedIndex],
      bottomNavigationBar: NavigationBar(
        selectedIndex: _selectedIndex,
        onDestinationSelected: (index) {
          setState(() {
            _selectedIndex = index;
          });
        },
        destinations: const [
          NavigationDestination(
            icon: Icon(Icons.home_outlined),
            selectedIcon: Icon(Icons.home),
            label: 'Hjem',
          ),
          NavigationDestination(
            icon: Icon(Icons.history_outlined),
            selectedIcon: Icon(Icons.history),
            label: 'Historikk',
          ),
          NavigationDestination(
            icon: Icon(Icons.bar_chart_outlined),
            selectedIcon: Icon(Icons.bar_chart),
            label: 'Rapporter',
          ),
          NavigationDestination(
            icon: Icon(Icons.person_outlined),
            selectedIcon: Icon(Icons.person),
            label: 'Profil',
          ),
        ],
      ),
    );
  }
}

class HomeTab extends ConsumerWidget {
  const HomeTab({super.key});

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final userData = ref.watch(userDataProvider);
    final todayRegistrations = ref.watch(todayRegistrationsProvider);

    return Scaffold(
      appBar: AppBar(
        title: const Text('TimeReg'),
        actions: [
          IconButton(
            icon: const Icon(Icons.notifications_outlined),
            onPressed: () {
              // TODO: Implementer varsler
            },
          ),
        ],
      ),
      body: SafeArea(
        child: SingleChildScrollView(
          padding: const EdgeInsets.all(16.0),
          child: Column(
            crossAxisAlignment: CrossAxisAlignment.stretch,
            children: [
              // Velkomst
              userData.when(
                data: (user) => user != null
                    ? Text(
                        'Hei, ${user.displayName}!',
                        style: Theme.of(context).textTheme.headlineSmall,
                      )
                    : const SizedBox.shrink(),
                loading: () => const SizedBox.shrink(),
                error: (_, __) => const SizedBox.shrink(),
              ),
              const SizedBox(height: 8),
              Text(
                DateFormat('EEEE d. MMMM yyyy', 'nb_NO').format(DateTime.now()),
                style: Theme.of(context).textTheme.bodyMedium?.copyWith(
                      color: Colors.grey,
                    ),
              ),
              const SizedBox(height: 24),
              
              // Timer widget
              const TimerWidget(),
              const SizedBox(height: 24),
              
              // Dagens registreringer
              Card(
                child: Padding(
                  padding: const EdgeInsets.all(16.0),
                  child: Column(
                    crossAxisAlignment: CrossAxisAlignment.start,
                    children: [
                      Row(
                        mainAxisAlignment: MainAxisAlignment.spaceBetween,
                        children: [
                          Text(
                            'I dag',
                            style: Theme.of(context).textTheme.titleMedium?.copyWith(
                                  fontWeight: FontWeight.bold,
                                ),
                          ),
                          todayRegistrations.when(
                            data: (registrations) {
                              final totalMinutes = registrations
                                  .where((r) => r.endTime != null)
                                  .fold<int>(0, (sum, r) => sum + r.netWorkMinutes);
                              final hours = totalMinutes ~/ 60;
                              final minutes = totalMinutes % 60;
                              return Text(
                                '${hours}t ${minutes}m',
                                style: Theme.of(context).textTheme.titleLarge?.copyWith(
                                      fontWeight: FontWeight.bold,
                                      color: Theme.of(context).colorScheme.primary,
                                    ),
                              );
                            },
                            loading: () => const SizedBox(
                              width: 20,
                              height: 20,
                              child: CircularProgressIndicator(strokeWidth: 2),
                            ),
                            error: (_, __) => const Text('--'),
                          ),
                        ],
                      ),
                      const SizedBox(height: 16),
                      todayRegistrations.when(
                        data: (registrations) {
                          if (registrations.isEmpty) {
                            return const Text('Ingen registreringer i dag');
                          }
                          return Column(
                            children: registrations.map((reg) {
                              return ListTile(
                                contentPadding: EdgeInsets.zero,
                                leading: Icon(
                                  _getIconForType(reg.type),
                                  color: Theme.of(context).colorScheme.primary,
                                ),
                                title: Text(
                                  '${DateFormat('HH:mm').format(reg.startTime)} - ${reg.endTime != null ? DateFormat('HH:mm').format(reg.endTime!) : 'Pågår'}',
                                ),
                                subtitle: reg.comment != null
                                    ? Text(reg.comment!)
                                    : null,
                                trailing: reg.endTime != null
                                    ? Text(
                                        '${reg.netWorkMinutes ~/ 60}t ${reg.netWorkMinutes % 60}m',
                                        style: const TextStyle(
                                          fontWeight: FontWeight.bold,
                                        ),
                                      )
                                    : const Icon(Icons.play_arrow, color: Colors.green),
                              );
                            }).toList(),
                          );
                        },
                        loading: () => const Center(
                          child: CircularProgressIndicator(),
                        ),
                        error: (error, _) => Text('Feil: $error'),
                      ),
                    ],
                  ),
                ),
              ),
              const SizedBox(height: 16),
              
              // Ukens oversikt
              Card(
                child: Padding(
                  padding: const EdgeInsets.all(16.0),
                  child: Column(
                    crossAxisAlignment: CrossAxisAlignment.start,
                    children: [
                      Text(
                        'Denne uken',
                        style: Theme.of(context).textTheme.titleMedium?.copyWith(
                              fontWeight: FontWeight.bold,
                            ),
                      ),
                      const SizedBox(height: 16),
                      _WeekSummary(),
                    ],
                  ),
                ),
              ),
            ],
          ),
        ),
      ),
      floatingActionButton: FloatingActionButton.extended(
        onPressed: () {
          // TODO: Implementer manuell registrering
        },
        icon: const Icon(Icons.add),
        label: const Text('Manuell registrering'),
      ),
    );
  }

  IconData _getIconForType(RegistrationType type) {
    switch (type) {
      case RegistrationType.ordinary:
        return Icons.work_outline;
      case RegistrationType.overtime:
        return Icons.access_time_filled;
      case RegistrationType.oncall:
        return Icons.phone_in_talk;
      case RegistrationType.travel:
        return Icons.directions_car;
    }
  }
}

class _WeekSummary extends ConsumerWidget {
  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final now = DateTime.now();
    final startOfWeek = now.subtract(Duration(days: now.weekday - 1));
    final endOfWeek = startOfWeek.add(const Duration(days: 6, hours: 23, minutes: 59));
    
    final dateRange = DateRange(start: startOfWeek, end: endOfWeek);
    final totalHours = ref.watch(totalHoursProvider(dateRange));

    return totalHours.when(
      data: (hours) {
        final totalMinutes = hours['total'] ?? 0;
        final ordinaryMinutes = hours['ordinary'] ?? 0;
        final overtimeMinutes = hours['overtime'] ?? 0;
        
        return Column(
          children: [
            _SummaryRow(
              label: 'Total arbeidstid',
              value: '${totalMinutes ~/ 60}t ${totalMinutes % 60}m',
            ),
            const SizedBox(height: 8),
            _SummaryRow(
              label: 'Ordinær tid',
              value: '${ordinaryMinutes ~/ 60}t ${ordinaryMinutes % 60}m',
            ),
            const SizedBox(height: 8),
            _SummaryRow(
              label: 'Overtid',
              value: '${overtimeMinutes ~/ 60}t ${overtimeMinutes % 60}m',
            ),
          ],
        );
      },
      loading: () => const Center(child: CircularProgressIndicator()),
      error: (error, _) => Text('Feil: $error'),
    );
  }
}

class _SummaryRow extends StatelessWidget {
  final String label;
  final String value;

  const _SummaryRow({
    required this.label,
    required this.value,
  });

  @override
  Widget build(BuildContext context) {
    return Row(
      mainAxisAlignment: MainAxisAlignment.spaceBetween,
      children: [
        Text(label),
        Text(
          value,
          style: const TextStyle(fontWeight: FontWeight.bold),
        ),
      ],
    );
  }
}