import 'dart:async';
import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import '../providers/auth_provider.dart';
import '../providers/time_provider.dart';
import '../services/time_service.dart';

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

  @override
  ConsumerState<TimerWidget> createState() => _TimerWidgetState();
}

class _TimerWidgetState extends ConsumerState<TimerWidget> {
  Timer? _timer;
  Duration _elapsed = Duration.zero;
  String? _activeRegistrationId;

  @override
  void dispose() {
    _timer?.cancel();
    super.dispose();
  }

  void _startTimer(DateTime startTime, String registrationId) {
    _activeRegistrationId = registrationId;
    _timer = Timer.periodic(const Duration(seconds: 1), (timer) {
      if (mounted) {
        setState(() {
          _elapsed = DateTime.now().difference(startTime);
        });
      }
    });
  }

  void _stopTimer() {
    _timer?.cancel();
    _activeRegistrationId = null;
    setState(() {
      _elapsed = Duration.zero;
    });
  }

  Future<void> _handleStartStop() async {
    final user = ref.read(currentUserProvider);
    final userData = await ref.read(userDataProvider.future);
    if (user == null || userData == null) return;

    final timeService = ref.read(timeServiceProvider);
    final activeReg = await ref.read(activeRegistrationProvider.future);

    try {
      if (activeReg != null) {
        // Stopp timer
        await timeService.stopTimer(activeReg.id, user.uid);
        _stopTimer();
        ref.invalidate(activeRegistrationProvider);
        ref.invalidate(todayRegistrationsProvider);
        
        if (mounted) {
          ScaffoldMessenger.of(context).showSnackBar(
            const SnackBar(
              content: Text('Timer stoppet'),
              backgroundColor: Colors.green,
            ),
          );
        }
      } else {
        // Start timer
        final registrationId = await timeService.startTimer(
          userId: user.uid,
          organizationId: userData.organizationId,
        );
        _startTimer(DateTime.now(), registrationId);
        ref.invalidate(activeRegistrationProvider);
        ref.invalidate(todayRegistrationsProvider);
        
        if (mounted) {
          ScaffoldMessenger.of(context).showSnackBar(
            const SnackBar(
              content: Text('Timer startet'),
              backgroundColor: Colors.green,
            ),
          );
        }
      }
    } catch (e) {
      if (mounted) {
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(
            content: Text('Feil: $e'),
            backgroundColor: Colors.red,
          ),
        );
      }
    }
  }

  @override
  Widget build(BuildContext context) {
    final activeReg = ref.watch(activeRegistrationProvider);

    return activeReg.when(
      data: (registration) {
        if (registration != null && _activeRegistrationId == null) {
          // Start timer hvis det finnes en aktiv registrering
          WidgetsBinding.instance.addPostFrameCallback((_) {
            _startTimer(registration.startTime, registration.id);
          });
        }

        final isActive = registration != null;
        final hours = _elapsed.inHours;
        final minutes = _elapsed.inMinutes.remainder(60);
        final seconds = _elapsed.inSeconds.remainder(60);

        return Card(
          elevation: 4,
          child: Padding(
            padding: const EdgeInsets.all(24.0),
            child: Column(
              children: [
                Text(
                  isActive ? 'Timer kjører' : 'Klar til å starte',
                  style: Theme.of(context).textTheme.titleMedium,
                ),
                const SizedBox(height: 16),
                
                // Timer display
                Container(
                  padding: const EdgeInsets.symmetric(
                    horizontal: 32,
                    vertical: 16,
                  ),
                  decoration: BoxDecoration(
                    color: isActive
                        ? Theme.of(context).colorScheme.primaryContainer
                        : Theme.of(context).colorScheme.surfaceVariant,
                    borderRadius: BorderRadius.circular(12),
                  ),
                  child: Text(
                    '${hours.toString().padLeft(2, '0')}:${minutes.toString().padLeft(2, '0')}:${seconds.toString().padLeft(2, '0')}',
                    style: Theme.of(context).textTheme.displayMedium?.copyWith(
                          fontWeight: FontWeight.bold,
                          fontFeatures: [const FontFeature.tabularFigures()],
                        ),
                  ),
                ),
                const SizedBox(height: 24),
                
                // Start/Stop button
                SizedBox(
                  width: double.infinity,
                  child: FilledButton.icon(
                    onPressed: _handleStartStop,
                    icon: Icon(isActive ? Icons.stop : Icons.play_arrow),
                    label: Text(isActive ? 'Stopp' : 'Start'),
                    style: FilledButton.styleFrom(
                      padding: const EdgeInsets.symmetric(vertical: 16),
                      backgroundColor: isActive
                          ? Colors.red
                          : Theme.of(context).colorScheme.primary,
                    ),
                  ),
                ),
              ],
            ),
          ),
        );
      },
      loading: () => const Card(
        child: Padding(
          padding: EdgeInsets.all(24.0),
          child: Center(child: CircularProgressIndicator()),
        ),
      ),
      error: (error, _) => Card(
        child: Padding(
          padding: const EdgeInsets.all(24.0),
          child: Text('Feil: $error'),
        ),
      ),
    );
  }
}