import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:intl/intl.dart';
import '../../providers/admin_provider.dart';
import '../../providers/auth_provider.dart';
import '../../providers/time_provider.dart';
import '../../models/deviation.dart';

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

  @override
  ConsumerState<DeviationListScreen> createState() => _DeviationListScreenState();
}

class _DeviationListScreenState extends ConsumerState<DeviationListScreen> {
  bool _onlyUnacknowledged = true;

  @override
  Widget build(BuildContext context) {
    final deviationsAsync = ref.watch(organizationDeviationsProvider(_onlyUnacknowledged));

    return Scaffold(
      appBar: AppBar(
        title: const Text('Avvikshåndtering'),
        actions: [
          IconButton(
            icon: Icon(_onlyUnacknowledged ? Icons.filter_alt : Icons.filter_alt_off),
            onPressed: () {
              setState(() {
                _onlyUnacknowledged = !_onlyUnacknowledged;
              });
            },
            tooltip: _onlyUnacknowledged ? 'Vis alle' : 'Vis kun åpne',
          ),
        ],
      ),
      body: deviationsAsync.when(
        data: (deviations) {
          if (deviations.isEmpty) {
            return Center(
              child: Column(
                mainAxisAlignment: MainAxisAlignment.center,
                children: [
                  const Icon(Icons.check_circle_outline, size: 64, color: Colors.green),
                  const SizedBox(height: 16),
                  Text(
                    _onlyUnacknowledged ? 'Ingen åpne avvik!' : 'Ingen avvik funnet',
                    style: Theme.of(context).textTheme.titleMedium,
                  ),
                ],
              ),
            );
          }
          return ListView.builder(
            itemCount: deviations.length,
            itemBuilder: (context, index) {
              final deviation = deviations[index];
              return Card(
                margin: const EdgeInsets.symmetric(horizontal: 16, vertical: 8),
                child: ExpansionTile(
                  leading: Icon(
                    Icons.warning,
                    color: _getSeverityColor(deviation.severity),
                  ),
                  title: Text(
                    deviation.description,
                    style: const TextStyle(fontWeight: FontWeight.bold),
                  ),
                  subtitle: Text(
                    DateFormat('dd.MM.yyyy HH:mm').format(deviation.detectedAt),
                  ),
                  trailing: deviation.acknowledgedAt != null
                      ? const Icon(Icons.check_circle, color: Colors.green)
                      : null,
                  children: [
                    Padding(
                      padding: const EdgeInsets.all(16.0),
                      child: Column(
                        crossAxisAlignment: CrossAxisAlignment.stretch,
                        children: [
                          _DetailRow(label: 'Type', value: _getTypeDisplayName(deviation.type)),
                          if (deviation.metadata.actualValue != null)
                            _DetailRow(
                              label: 'Faktisk verdi',
                              value: '${deviation.metadata.actualValue}',
                            ),
                          if (deviation.metadata.limitValue != null)
                            _DetailRow(
                              label: 'Grenseverdi',
                              value: '${deviation.metadata.limitValue}',
                            ),
                          const SizedBox(height: 16),
                          if (deviation.acknowledgedAt == null)
                            FilledButton(
                              onPressed: () => _showAcknowledgeDialog(context, deviation),
                              child: const Text('Kvitter ut avvik'),
                            )
                          else
                            Text(
                              'Kvittert ut av ${deviation.acknowledgedBy ?? "ukjent"} den ${DateFormat('dd.MM.yyyy HH:mm').format(deviation.acknowledgedAt!)}',
                              style: const TextStyle(fontStyle: FontStyle.italic, color: Colors.grey),
                            ),
                        ],
                      ),
                    ),
                  ],
                ),
              );
            },
          );
        },
        loading: () => const Center(child: CircularProgressIndicator()),
        error: (error, _) => Center(child: Text('Feil: $error')),
      ),
    );
  }

  Future<void> _showAcknowledgeDialog(BuildContext context, Deviation deviation) async {
    final commentController = TextEditingController();
    
    final confirmed = await showDialog<bool>(
      context: context,
      builder: (context) => AlertDialog(
        title: const Text('Kvitter ut avvik'),
        content: Column(
          mainAxisSize: MainAxisSize.min,
          children: [
            const Text('Er du sikker på at du vil kvittere ut dette avviket?'),
            const SizedBox(height: 16),
            TextField(
              controller: commentController,
              decoration: const InputDecoration(
                labelText: 'Kommentar (valgfritt)',
                border: OutlineInputBorder(),
              ),
              maxLines: 3,
            ),
          ],
        ),
        actions: [
          TextButton(
            onPressed: () => Navigator.pop(context, false),
            child: const Text('Avbryt'),
          ),
          FilledButton(
            onPressed: () => Navigator.pop(context, true),
            child: const Text('Kvitter ut'),
          ),
        ],
      ),
    );

    if (confirmed == true) {
      try {
        final user = ref.read(currentUserProvider);
        if (user == null) return;

        final timeService = ref.read(timeServiceProvider);
        await timeService.acknowledgeDeviation(
          deviationId: deviation.id,
          userId: user.uid,
          comment: commentController.text.isNotEmpty ? commentController.text : null,
        );

        if (mounted) {
          ScaffoldMessenger.of(context).showSnackBar(
            const SnackBar(content: Text('Avvik kvittert ut')),
          );
          // Refresh list
          ref.invalidate(organizationDeviationsProvider);
        }
      } catch (e) {
        if (mounted) {
          ScaffoldMessenger.of(context).showSnackBar(
            SnackBar(content: Text('Feil: $e')),
          );
        }
      }
    }
  }

  Color _getSeverityColor(DeviationSeverity severity) {
    switch (severity) {
      case DeviationSeverity.warning:
        return Colors.orange;
      case DeviationSeverity.violation:
        return Colors.red;
    }
  }

  String _getTypeDisplayName(DeviationType type) {
    switch (type) {
      case DeviationType.dailyMax:
        return 'Daglig maksgrense';
      case DeviationType.weeklyMax:
        return 'Ukentlig maksgrense';
      case DeviationType.dailyRest:
        return 'Daglig hviletid';
      case DeviationType.weeklyRest:
        return 'Ukentlig hviletid';
      case DeviationType.averageExceeded:
        return 'Gjennomsnittsberegning overskredet';
      case DeviationType.nightWork:
        return 'Nattarbeid';
    }
  }
}

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

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

  @override
  Widget build(BuildContext context) {
    return Padding(
      padding: const EdgeInsets.symmetric(vertical: 4.0),
      child: Row(
        mainAxisAlignment: MainAxisAlignment.spaceBetween,
        children: [
          Text(label, style: const TextStyle(color: Colors.grey)),
          Text(value, style: const TextStyle(fontWeight: FontWeight.bold)),
        ],
      ),
    );
  }
}