import 'package:flutter/material.dart';
import '../models/sito.dart';
import '../services/api_service.dart';
import '../widgets/sito_card.dart';
import '../utils/constants.dart';

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

  @override
  State<SitiScreen> createState() => _SitiScreenState();
}

class _SitiScreenState extends State<SitiScreen> {
  final _apiService = ApiService();
  List<Sito> _siti = [];
  List<Sito> _sitiFiltered = [];
  bool _isLoading = true;
  String? _errorMessage;
  String? _selectedTipo;

  final Map<String, String> _tipiSito = {
    'ponte': 'Ponte',
    'galleria': 'Galleria',
    'diga': 'Diga',
    'frana': 'Frana',
    'versante': 'Versante',
    'edificio': 'Edificio',
  };

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

  Future<void> _loadSiti({bool refresh = false}) async {
    if (refresh) setState(() => _isLoading = true);

    try {
      final siti = await _apiService.getSiti();
      setState(() {
        _siti = siti;
        _applyFilter();
        _isLoading = false;
        _errorMessage = null;
      });
    } catch (e) {
      setState(() {
        _errorMessage = 'Errore caricamento siti: $e';
        _isLoading = false;
      });
    }
  }

  void _applyFilter() {
    if (_selectedTipo == null) {
      _sitiFiltered = _siti;
    } else {
      _sitiFiltered = _siti.where((s) => s.tipo == _selectedTipo).toList();
    }
  }

  void _showFilterDialog() {
    showDialog(
      context: context,
      builder: (context) => AlertDialog(
        title: const Text('Filtra per Tipo'),
        content: SingleChildScrollView(
          child: Column(
            mainAxisSize: MainAxisSize.min,
            children: [
              _buildFilterOption(null, 'Tutti i siti', Icons.all_inclusive),
              const Divider(),
              ..._tipiSito.entries.map((entry) {
                return _buildFilterOption(
                  entry.key,
                  entry.value,
                  _getIconForTipo(entry.key),
                );
              }),
            ],
          ),
        ),
      ),
    );
  }

  Widget _buildFilterOption(String? tipo, String label, IconData icon) {
    final isSelected = _selectedTipo == tipo;

    return ListTile(
      leading: Icon(
        icon,
        color: isSelected ? AppColors.primary : AppColors.textSecondary,
      ),
      title: Text(
        label,
        style: TextStyle(
          fontWeight: isSelected ? FontWeight.bold : FontWeight.normal,
          color: isSelected ? AppColors.primary : null,
        ),
      ),
      trailing: isSelected
          ? const Icon(Icons.check, color: AppColors.primary)
          : null,
      onTap: () {
        Navigator.pop(context);
        setState(() {
          _selectedTipo = tipo;
          _applyFilter();
        });
      },
    );
  }

  IconData _getIconForTipo(String tipo) {
    switch (tipo) {
      case 'ponte':
        return Icons.architecture;
      case 'galleria':
        return Icons.south_west;
      case 'diga':
        return Icons.water_damage;
      case 'frana':
        return Icons.landscape;
      case 'versante':
        return Icons.terrain;
      case 'edificio':
        return Icons.business;
      default:
        return Icons.location_on;
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Column(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            const Text('Siti Monitorati'),
            Text(
              _selectedTipo != null
                  ? _tipiSito[_selectedTipo]!
                  : '${_siti.length} siti totali',
              style: const TextStyle(fontSize: 12),
            ),
          ],
        ),
        actions: [
          IconButton(
            icon: const Icon(Icons.filter_list),
            onPressed: _showFilterDialog,
            tooltip: 'Filtra per tipo',
          ),
        ],
      ),
      body: _isLoading
          ? const Center(child: CircularProgressIndicator())
          : _errorMessage != null
              ? Center(
                  child: Column(
                    mainAxisAlignment: MainAxisAlignment.center,
                    children: [
                      const Icon(
                        Icons.error_outline,
                        size: 64,
                        color: AppColors.critical,
                      ),
                      const SizedBox(height: 16),
                      Text(_errorMessage!),
                      const SizedBox(height: 16),
                      ElevatedButton.icon(
                        onPressed: () => _loadSiti(refresh: true),
                        icon: const Icon(Icons.refresh),
                        label: const Text('Riprova'),
                      ),
                    ],
                  ),
                )
              : _sitiFiltered.isEmpty
                  ? Center(
                      child: Column(
                        mainAxisAlignment: MainAxisAlignment.center,
                        children: [
                          const Icon(
                            Icons.location_off,
                            size: 64,
                            color: AppColors.textSecondary,
                          ),
                          const SizedBox(height: 16),
                          Text(
                            _selectedTipo != null
                                ? 'Nessun sito di tipo ${_tipiSito[_selectedTipo]}'
                                : 'Nessun sito disponibile',
                            style: AppTextStyles.h3,
                          ),
                        ],
                      ),
                    )
                  : RefreshIndicator(
                      onRefresh: () => _loadSiti(refresh: true),
                      child: ListView.builder(
                        padding: const EdgeInsets.all(AppSizes.paddingM),
                        itemCount: _sitiFiltered.length,
                        itemBuilder: (context, index) {
                          return SitoCard(sito: _sitiFiltered[index]);
                        },
                      ),
                    ),
      floatingActionButton: _isLoading
          ? null
          : FloatingActionButton(
              onPressed: () => _loadSiti(refresh: true),
              child: const Icon(Icons.refresh),
            ),
    );
  }
}