import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:em2rp/models/vehicle_model.dart';
import 'package:em2rp/services/vehicle_service.dart';
import 'package:em2rp/utils/colors.dart';

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

  @override
  State<VehiclesManagement> createState() => _VehiclesManagementState();
}

class _VehiclesManagementState extends State<VehiclesManagement> {
  final _service = VehicleService();
  bool _isLoading = false;

  static const _fuelTypes = ['Diesel', 'Essence', 'Electrique'];

  void _showVehicleDialog({VehicleModel? vehicle}) {
    final formKey = GlobalKey<FormState>();
    final nameCtrl =
        TextEditingController(text: vehicle?.name ?? '');
    final consoCtrl = TextEditingController(
        text: vehicle?.consumptionPer100km.toString() ?? '');
    final maintCtrl = TextEditingController(
        text: vehicle?.maintenanceCostPerKm.toString() ?? '');
    String fuelType = vehicle?.fuelType ?? 'Diesel';
    int tollCategory = vehicle?.tollCategoryId ?? 2;

    showDialog(
      context: context,
      builder: (ctx) => StatefulBuilder(builder: (ctx, setDlg) {
        return AlertDialog(
          title: Text(vehicle == null ? 'Ajouter un véhicule' : 'Modifier le véhicule'),
          content: SizedBox(
            width: 480,
            child: Form(
              key: formKey,
              child: Column(
                mainAxisSize: MainAxisSize.min,
                children: [
                  // Nom
                  TextFormField(
                    controller: nameCtrl,
                    decoration: const InputDecoration(
                      labelText: 'Nom du véhicule *',
                      border: OutlineInputBorder(),
                      prefixIcon: Icon(Icons.directions_car_outlined),
                      hintText: 'ex: Renault Master',
                    ),
                    validator: (v) =>
                        v == null || v.trim().isEmpty ? 'Requis' : null,
                  ),
                  const SizedBox(height: 14),
                  // Type de carburant
                  DropdownButtonFormField<String>(
                    value: fuelType,
                    decoration: const InputDecoration(
                      labelText: 'Type de carburant *',
                      border: OutlineInputBorder(),
                      prefixIcon: Icon(Icons.local_gas_station_outlined),
                    ),
                    items: _fuelTypes
                        .map((f) => DropdownMenuItem(value: f, child: Text(f)))
                        .toList(),
                    onChanged: (v) => setDlg(() => fuelType = v!),
                  ),
                  const SizedBox(height: 14),
                  // Consommation
                  TextFormField(
                    controller: consoCtrl,
                    decoration: InputDecoration(
                      labelText: fuelType == 'Electrique'
                          ? 'Consommation (kWh/100km) *'
                          : 'Consommation (L/100km) *',
                      border: const OutlineInputBorder(),
                      prefixIcon: const Icon(Icons.speed_outlined),
                    ),
                    keyboardType:
                        const TextInputType.numberWithOptions(decimal: true),
                    inputFormatters: [
                      FilteringTextInputFormatter.allow(
                          RegExp(r'^\d+\.?\d{0,2}'))
                    ],
                    validator: (v) {
                      if (v == null || v.isEmpty) return 'Requis';
                      if (double.tryParse(v) == null) return 'Nombre invalide';
                      return null;
                    },
                  ),
                  const SizedBox(height: 14),
                  // Coût maintenance
                  TextFormField(
                    controller: maintCtrl,
                    decoration: const InputDecoration(
                      labelText: 'Coût maintenance (€/km) *',
                      border: OutlineInputBorder(),
                      prefixIcon: Icon(Icons.build_outlined),
                      hintText: 'ex: 0.08',
                    ),
                    keyboardType:
                        const TextInputType.numberWithOptions(decimal: true),
                    inputFormatters: [
                      FilteringTextInputFormatter.allow(
                          RegExp(r'^\d+\.?\d{0,3}'))
                    ],
                    validator: (v) {
                      if (v == null || v.isEmpty) return 'Requis';
                      if (double.tryParse(v) == null) return 'Nombre invalide';
                      return null;
                    },
                  ),
                  const SizedBox(height: 14),
                  // Catégorie péage
                  Column(
                    crossAxisAlignment: CrossAxisAlignment.start,
                    children: [
                      Text(
                        'Catégorie de péage : $tollCategory',
                        style: const TextStyle(fontWeight: FontWeight.w500),
                      ),
                      const SizedBox(height: 4),
                      Row(
                        children: List.generate(5, (i) {
                          final cat = i + 1;
                          return Expanded(
                            child: GestureDetector(
                              onTap: () => setDlg(() => tollCategory = cat),
                              child: Container(
                                margin: const EdgeInsets.symmetric(horizontal: 3),
                                padding: const EdgeInsets.symmetric(vertical: 8),
                                decoration: BoxDecoration(
                                  color: tollCategory == cat
                                      ? AppColors.rouge
                                      : Colors.grey[200],
                                  borderRadius: BorderRadius.circular(8),
                                ),
                                child: Center(
                                  child: Text(
                                    '$cat',
                                    style: TextStyle(
                                      color: tollCategory == cat
                                          ? Colors.white
                                          : Colors.black87,
                                      fontWeight: FontWeight.bold,
                                    ),
                                  ),
                                ),
                              ),
                            ),
                          );
                        }),
                      ),
                      const SizedBox(height: 4),
                      Text(
                        'Classe 1 – Véhicules légers\n'
                        'Classe 2 – Véhicules intermédiaires\n'
                        'Classe 3 – Poids lourds, autocars et autres véhicules à 2 essieux\n'
                        'Classe 4 - Poids lourds et autres véhicules à 3 essieux et plus\n'
                        'Classe 5 – Motos, side-cars et trikes',
                        style: TextStyle(fontSize: 11, color: Colors.grey[600]),
                      ),
                    ],
                  ),
                ],
              ),
            ),
          ),
          actions: [
            TextButton(
              onPressed: () => Navigator.pop(ctx),
              child: const Text('Annuler'),
            ),
            ElevatedButton(
              style: ElevatedButton.styleFrom(
                backgroundColor: AppColors.rouge,
                foregroundColor: Colors.white,
              ),
              onPressed: () async {
                if (!formKey.currentState!.validate()) return;
                Navigator.pop(ctx);
                setState(() => _isLoading = true);
                try {
                  final v = VehicleModel(
                    id: vehicle?.id ?? '',
                    name: nameCtrl.text.trim(),
                    fuelType: fuelType,
                    consumptionPer100km:
                        double.parse(consoCtrl.text.trim()),
                    maintenanceCostPerKm:
                        double.parse(maintCtrl.text.trim()),
                    tollCategoryId: tollCategory,
                  );
                  if (vehicle == null) {
                    await _service.addVehicle(v);
                  } else {
                    await _service.updateVehicle(v);
                  }
                } catch (e) {
                  if (mounted) {
                    ScaffoldMessenger.of(context).showSnackBar(
                      SnackBar(
                          content: Text('Erreur: $e'),
                          backgroundColor: Colors.red),
                    );
                  }
                } finally {
                  if (mounted) setState(() => _isLoading = false);
                }
              },
              child: Text(vehicle == null ? 'Ajouter' : 'Enregistrer'),
            ),
          ],
        );
      }),
    );
  }

  Future<void> _delete(VehicleModel v) async {
    final confirm = await showDialog<bool>(
      context: context,
      builder: (ctx) => AlertDialog(
        title: const Text('Supprimer le véhicule'),
        content: Text('Supprimer "${v.name}" ?'),
        actions: [
          TextButton(
              onPressed: () => Navigator.pop(ctx, false),
              child: const Text('Annuler')),
          ElevatedButton(
            style: ElevatedButton.styleFrom(
                backgroundColor: Colors.red, foregroundColor: Colors.white),
            onPressed: () => Navigator.pop(ctx, true),
            child: const Text('Supprimer'),
          ),
        ],
      ),
    );
    if (confirm == true) {
      setState(() => _isLoading = true);
      try {
        await _service.deleteVehicle(v.id);
      } finally {
        if (mounted) setState(() => _isLoading = false);
      }
    }
  }

  Icon _fuelIcon(String fuelType) {
    switch (fuelType) {
      case 'Electrique':
        return const Icon(Icons.electric_bolt, color: Colors.amber);
      case 'Essence':
        return const Icon(Icons.local_gas_station, color: Colors.green);
      default:
        return const Icon(Icons.local_gas_station, color: Colors.orange);
    }
  }

  @override
  Widget build(BuildContext context) {
    return Padding(
      padding: const EdgeInsets.all(24),
      child: Column(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          Row(
            children: [
              Icon(Icons.directions_car_outlined,
                  color: AppColors.rouge, size: 28),
              const SizedBox(width: 12),
              Text(
                'Véhicules',
                style: Theme.of(context)
                    .textTheme
                    .headlineSmall
                    ?.copyWith(fontWeight: FontWeight.bold),
              ),
              const Spacer(),
              ElevatedButton.icon(
                icon: const Icon(Icons.add),
                label: const Text('Ajouter un véhicule'),
                style: ElevatedButton.styleFrom(
                  backgroundColor: AppColors.rouge,
                  foregroundColor: Colors.white,
                ),
                onPressed: () => _showVehicleDialog(),
              ),
            ],
          ),
          const SizedBox(height: 8),
          Text(
            'Paramétrez la flotte de véhicules pour le calcul automatique des frais de déplacement.',
            style: Theme.of(context)
                .textTheme
                .bodyMedium
                ?.copyWith(color: Colors.grey[600]),
          ),
          const SizedBox(height: 24),
          if (_isLoading) const LinearProgressIndicator(),
          Expanded(
            child: StreamBuilder<List<VehicleModel>>(
              stream: _service.watchVehicles(),
              builder: (context, snap) {
                if (snap.connectionState == ConnectionState.waiting) {
                  return const Center(child: CircularProgressIndicator());
                }
                final vehicles = snap.data ?? [];
                if (vehicles.isEmpty) {
                  return Center(
                    child: Column(
                      mainAxisSize: MainAxisSize.min,
                      children: [
                        Icon(Icons.directions_car_outlined,
                            size: 64, color: Colors.grey[300]),
                        const SizedBox(height: 16),
                        Text(
                          'Aucun véhicule',
                          style: Theme.of(context)
                              .textTheme
                              .titleMedium
                              ?.copyWith(color: Colors.grey[500]),
                        ),
                        const SizedBox(height: 8),
                        const Text('Ajoutez des véhicules pour commencer.'),
                      ],
                    ),
                  );
                }
                return ListView.separated(
                  itemCount: vehicles.length,
                  separatorBuilder: (_, __) => const Divider(height: 1),
                  itemBuilder: (ctx, i) {
                    final v = vehicles[i];
                    return ListTile(
                      leading: CircleAvatar(
                        backgroundColor: Colors.grey[100],
                        child: _fuelIcon(v.fuelType),
                      ),
                      title: Text(v.name,
                          style:
                              const TextStyle(fontWeight: FontWeight.w600)),
                      subtitle: Text(
                        '${v.consumptionPer100km} ${v.consumptionUnit} • Maint. ${v.maintenanceCostPerKm} €/km • Classe péage ${v.tollCategoryId}',
                      ),
                      trailing: Row(
                        mainAxisSize: MainAxisSize.min,
                        children: [
                          Chip(
                            label: Text(v.fuelType),
                            backgroundColor: v.fuelType == 'Electrique'
                                ? Colors.amber[50]
                                : v.fuelType == 'Essence'
                                    ? Colors.green[50]
                                    : Colors.orange[50],
                            side: BorderSide.none,
                          ),
                          IconButton(
                            icon: const Icon(Icons.edit_outlined),
                            tooltip: 'Modifier',
                            onPressed: () => _showVehicleDialog(vehicle: v),
                          ),
                          IconButton(
                            icon: const Icon(Icons.delete_outline,
                                color: Colors.red),
                            tooltip: 'Supprimer',
                            onPressed: () => _delete(v),
                          ),
                        ],
                      ),
                    );
                  },
                );
              },
            ),
          ),
        ],
      ),
    );
  }
}