import 'package:flutter/material.dart';
import '../theme/app_theme.dart';
import '../widgets/widgets.dart' as w;

enum TruckStatus { disponible, enRuta, mantenimiento, detenido }

extension TruckStatusX on TruckStatus {
  String get label {
    switch (this) {
      case TruckStatus.disponible:
        return 'Disponible';
      case TruckStatus.enRuta:
        return 'En ruta';
      case TruckStatus.mantenimiento:
        return 'Mantenimiento';
      case TruckStatus.detenido:
        return 'Detenido';
    }
  }

  w.StatusBadge get badge {
    switch (this) {
      case TruckStatus.disponible:
        return w.StatusBadge.green(label);
      case TruckStatus.enRuta:
        return w.StatusBadge.amber(label);
      case TruckStatus.mantenimiento:
        return w.StatusBadge.gray(label);
      case TruckStatus.detenido:
        return w.StatusBadge.gray(label);
    }
  }
}

class AdminUser {
  final String id;
  final String nombre;
  final String apellido;
  final String email;
  final String telefono;

  const AdminUser({
    required this.id,
    required this.nombre,
    required this.apellido,
    required this.email,
    required this.telefono,
  });

  String get nombreCompleto => '$nombre $apellido';
  String get iniciales =>
      '${nombre.isNotEmpty ? nombre[0] : ''}${apellido.isNotEmpty ? apellido[0] : ''}'
          .toUpperCase();

  AdminUser copyWith({
    String? nombre,
    String? apellido,
    String? email,
    String? telefono,
  }) {
    return AdminUser(
      id: id,
      nombre: nombre ?? this.nombre,
      apellido: apellido ?? this.apellido,
      email: email ?? this.email,
      telefono: telefono ?? this.telefono,
    );
  }
}

class AdminRoute {
  final String id;
  final String nombre;
  final String zona;
  final bool activa;

  const AdminRoute({
    required this.id,
    required this.nombre,
    required this.zona,
    this.activa = true,
  });

  AdminRoute copyWith({
    String? nombre,
    String? zona,
    bool? activa,
  }) {
    return AdminRoute(
      id: id,
      nombre: nombre ?? this.nombre,
      zona: zona ?? this.zona,
      activa: activa ?? this.activa,
    );
  }
}

class AdminTruck {
  final String id;
  final String placas;
  final String modelo;
  final String conductor;
  final TruckStatus status;
  final String rutaId;

  const AdminTruck({
    required this.id,
    required this.placas,
    required this.modelo,
    required this.conductor,
    required this.status,
    required this.rutaId,
  });

  AdminTruck copyWith({
    String? placas,
    String? modelo,
    String? conductor,
    TruckStatus? status,
    String? rutaId,
  }) {
    return AdminTruck(
      id: id,
      placas: placas ?? this.placas,
      modelo: modelo ?? this.modelo,
      conductor: conductor ?? this.conductor,
      status: status ?? this.status,
      rutaId: rutaId ?? this.rutaId,
    );
  }
}

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

  @override
  State<AdminScreen> createState() => _AdminScreenState();
}

class _AdminScreenState extends State<AdminScreen>
    with SingleTickerProviderStateMixin {
  late final TabController _tabController;
  int _activeTab = 0;

  final List<AdminUser> _usuarios = [
    const AdminUser(
      id: 'user-01',
      nombre: 'Laura',
      apellido: 'Gómez',
      email: 'laura.gomez@rutaverde.com',
      telefono: '+52 461 987 1234',
    ),
    const AdminUser(
      id: 'user-02',
      nombre: 'Miguel',
      apellido: 'Sánchez',
      email: 'miguel.sanchez@rutaverde.com',
      telefono: '+52 461 123 7890',
    ),
  ];

  final List<AdminRoute> _rutas = [
    const AdminRoute(
      id: 'ruta-01',
      nombre: 'Ruta Norte',
      zona: 'Zona Norte',
    ),
    const AdminRoute(
      id: 'ruta-02',
      nombre: 'Ruta Sur',
      zona: 'Zona Sur',
      activa: false,
    ),
  ];

  final List<AdminTruck> _camiones = [
    const AdminTruck(
      id: 'truck-01',
      placas: 'ABC-1234',
      modelo: 'Volvo FH',
      conductor: 'Javier Pérez',
      status: TruckStatus.enRuta,
      rutaId: 'ruta-01',
    ),
    const AdminTruck(
      id: 'truck-02',
      placas: 'DEF-5678',
      modelo: 'Mercedes 1830',
      conductor: 'Ana Díaz',
      status: TruckStatus.disponible,
      rutaId: 'ruta-02',
    ),
  ];

  @override
  void initState() {
    super.initState();
    _tabController = TabController(length: 3, vsync: this)
      ..addListener(() {
        if (_tabController.indexIsChanging) return;
        setState(() => _activeTab = _tabController.index);
      });
  }

  @override
  void dispose() {
    _tabController.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      backgroundColor: AppTheme.background,
      appBar: AppBar(
        title: const Text('Panel de administración'),
        bottom: TabBar(
          controller: _tabController,
          indicatorColor: AppTheme.primary,
          tabs: const [
            Tab(text: 'Usuarios'),
            Tab(text: 'Rutas'),
            Tab(text: 'Camiones'),
          ],
        ),
      ),
      body: TabBarView(
        controller: _tabController,
        children: [
          _buildUsersTab(),
          _buildRoutesTab(),
          _buildTrucksTab(),
        ],
      ),
      floatingActionButton: FloatingActionButton.extended(
        onPressed: () {
          if (_activeTab == 0) {
            _showUserForm();
          } else if (_activeTab == 1) {
            _showRouteForm();
          } else {
            _showTruckForm();
          }
        },
        label: Text(_activeTab == 0
            ? 'Nuevo usuario'
            : _activeTab == 1
                ? 'Nueva ruta'
                : 'Nuevo camión'),
        icon: const Icon(Icons.add),
      ),
    );
  }

  Widget _buildUsersTab() {
    if (_usuarios.isEmpty) {
      return _buildEmptyState('No hay usuarios registrados aún.');
    }

    return ListView.separated(
      padding: const EdgeInsets.all(16),
      itemCount: _usuarios.length,
      separatorBuilder: (_, __) => const SizedBox(height: 12),
      itemBuilder: (context, index) {
        final user = _usuarios[index];
        return w.AppCard(
          child: Row(
            children: [
              CircleAvatar(
                backgroundColor: AppTheme.primaryLight,
                foregroundColor: AppTheme.primary,
                child: Text(user.iniciales),
              ),
              const SizedBox(width: 14),
              Expanded(
                child: Column(
                  crossAxisAlignment: CrossAxisAlignment.start,
                  children: [
                    Text(user.nombreCompleto,
                        style: const TextStyle(
                            fontSize: 15, fontWeight: FontWeight.w600)),
                    const SizedBox(height: 4),
                    Text(user.email,
                        style: const TextStyle(
                            fontSize: 13, color: AppTheme.textSecondary)),
                    const SizedBox(height: 2),
                    Text(user.telefono, style: const TextStyle(fontSize: 13)),
                  ],
                ),
              ),
              IconButton(
                icon: const Icon(Icons.edit_outlined, color: AppTheme.primary),
                onPressed: () => _showUserForm(user: user),
              ),
              IconButton(
                icon: const Icon(Icons.delete_outline, color: AppTheme.danger),
                onPressed: () => _confirmDeleteUser(user),
              ),
            ],
          ),
        );
      },
    );
  }

  Widget _buildRoutesTab() {
    if (_rutas.isEmpty) {
      return _buildEmptyState('No hay rutas registradas aún.');
    }

    return ListView.separated(
      padding: const EdgeInsets.all(16),
      itemCount: _rutas.length,
      separatorBuilder: (_, __) => const SizedBox(height: 12),
      itemBuilder: (context, index) {
        final ruta = _rutas[index];
        return w.AppCard(
          child: Column(
            crossAxisAlignment: CrossAxisAlignment.start,
            children: [
              Row(
                children: [
                  Expanded(
                    child: Text(ruta.nombre,
                        style: const TextStyle(
                            fontSize: 15, fontWeight: FontWeight.w600)),
                  ),
                  Text(ruta.activa ? 'Activa' : 'Inactiva',
                      style: TextStyle(
                          fontSize: 13,
                          color: ruta.activa
                              ? AppTheme.primary
                              : AppTheme.textSecondary)),
                ],
              ),
              const SizedBox(height: 8),
              Text('Zona ${ruta.zona}',
                  style: const TextStyle(
                      fontSize: 13, color: AppTheme.textSecondary)),
              const SizedBox(height: 12),
              Row(
                mainAxisAlignment: MainAxisAlignment.end,
                children: [
                  TextButton.icon(
                    onPressed: () => _showRouteForm(route: ruta),
                    icon: const Icon(Icons.edit_outlined, size: 18),
                    label: const Text('Editar'),
                  ),
                  const SizedBox(width: 8),
                  TextButton.icon(
                    onPressed: () => _confirmDeleteRoute(ruta),
                    icon: const Icon(Icons.delete_outline, size: 18),
                    label: const Text('Eliminar'),
                  ),
                ],
              ),
            ],
          ),
        );
      },
    );
  }

  Widget _buildTrucksTab() {
    if (_camiones.isEmpty) {
      return _buildEmptyState('No hay camiones registrados aún.');
    }

    return ListView.separated(
      padding: const EdgeInsets.all(16),
      itemCount: _camiones.length,
      separatorBuilder: (_, __) => const SizedBox(height: 12),
      itemBuilder: (context, index) {
        final truck = _camiones[index];
        final route = _rutas.firstWhere(
          (route) => route.id == truck.rutaId,
          orElse: () =>
              const AdminRoute(id: 'none', nombre: 'Sin ruta', zona: ''),
        );

        return w.AppCard(
          child: Column(
            crossAxisAlignment: CrossAxisAlignment.start,
            children: [
              Row(
                children: [
                  Expanded(
                    child: Text(truck.placas,
                        style: const TextStyle(
                            fontSize: 15, fontWeight: FontWeight.w600)),
                  ),
                  truck.status.badge,
                ],
              ),
              const SizedBox(height: 8),
              Text('${truck.modelo} · ${truck.conductor}',
                  style: const TextStyle(fontSize: 13)),
              const SizedBox(height: 4),
              Text('Ruta: ${route.nombre}',
                  style: const TextStyle(
                      fontSize: 13, color: AppTheme.textSecondary)),
              const SizedBox(height: 12),
              Row(
                mainAxisAlignment: MainAxisAlignment.end,
                children: [
                  TextButton.icon(
                    onPressed: () => _showTruckForm(truck: truck),
                    icon: const Icon(Icons.edit_outlined, size: 18),
                    label: const Text('Editar'),
                  ),
                  const SizedBox(width: 8),
                  TextButton.icon(
                    onPressed: () => _confirmDeleteTruck(truck),
                    icon: const Icon(Icons.delete_outline, size: 18),
                    label: const Text('Eliminar'),
                  ),
                ],
              ),
            ],
          ),
        );
      },
    );
  }

  Widget _buildEmptyState(String message) {
    return Center(
      child: Padding(
        padding: const EdgeInsets.all(24),
        child: Text(message,
            textAlign: TextAlign.center,
            style: const TextStyle(
              fontSize: 15,
              color: AppTheme.textSecondary,
            )),
      ),
    );
  }

  void _confirmDeleteUser(AdminUser user) {
    showDialog(
      context: context,
      builder: (ctx) => AlertDialog(
        backgroundColor: AppTheme.surface,
        shape: RoundedRectangleBorder(
            borderRadius: BorderRadius.circular(AppTheme.radiusLg)),
        title: const Text('Eliminar usuario'),
        content: const Text('¿Deseas eliminar este usuario?'),
        actions: [
          TextButton(
            onPressed: () => Navigator.pop(ctx),
            style:
                TextButton.styleFrom(foregroundColor: AppTheme.textSecondary),
            child: const Text('Cancelar'),
          ),
          TextButton(
            onPressed: () {
              setState(
                  () => _usuarios.removeWhere((item) => item.id == user.id));
              Navigator.pop(ctx);
            },
            style: TextButton.styleFrom(foregroundColor: AppTheme.danger),
            child: const Text('Eliminar'),
          ),
        ],
      ),
    );
  }

  void _confirmDeleteRoute(AdminRoute route) {
    showDialog(
      context: context,
      builder: (ctx) => AlertDialog(
        backgroundColor: AppTheme.surface,
        shape: RoundedRectangleBorder(
            borderRadius: BorderRadius.circular(AppTheme.radiusLg)),
        title: const Text('Eliminar ruta'),
        content: const Text('¿Deseas eliminar esta ruta?'),
        actions: [
          TextButton(
            onPressed: () => Navigator.pop(ctx),
            style:
                TextButton.styleFrom(foregroundColor: AppTheme.textSecondary),
            child: const Text('Cancelar'),
          ),
          TextButton(
            onPressed: () {
              setState(() => _rutas.removeWhere((item) => item.id == route.id));
              Navigator.pop(ctx);
            },
            style: TextButton.styleFrom(foregroundColor: AppTheme.danger),
            child: const Text('Eliminar'),
          ),
        ],
      ),
    );
  }

  void _confirmDeleteTruck(AdminTruck truck) {
    showDialog(
      context: context,
      builder: (ctx) => AlertDialog(
        backgroundColor: AppTheme.surface,
        shape: RoundedRectangleBorder(
            borderRadius: BorderRadius.circular(AppTheme.radiusLg)),
        title: const Text('Eliminar camión'),
        content: const Text('¿Deseas eliminar este camión?'),
        actions: [
          TextButton(
            onPressed: () => Navigator.pop(ctx),
            style:
                TextButton.styleFrom(foregroundColor: AppTheme.textSecondary),
            child: const Text('Cancelar'),
          ),
          TextButton(
            onPressed: () {
              setState(
                  () => _camiones.removeWhere((item) => item.id == truck.id));
              Navigator.pop(ctx);
            },
            style: TextButton.styleFrom(foregroundColor: AppTheme.danger),
            child: const Text('Eliminar'),
          ),
        ],
      ),
    );
  }

  void _showUserForm({AdminUser? user}) {
    final formKey = GlobalKey<FormState>();
    final nombreCtrl = TextEditingController(text: user?.nombre);
    final apellidoCtrl = TextEditingController(text: user?.apellido);
    final emailCtrl = TextEditingController(text: user?.email);
    final telefonoCtrl = TextEditingController(text: user?.telefono);

    showDialog(
      context: context,
      builder: (ctx) => AlertDialog(
        backgroundColor: AppTheme.surface,
        shape: RoundedRectangleBorder(
          borderRadius: BorderRadius.circular(AppTheme.radiusLg),
        ),
        title: Text(user == null ? 'Nuevo usuario' : 'Editar usuario'),
        content: Form(
          key: formKey,
          child: SingleChildScrollView(
            child: Column(
              mainAxisSize: MainAxisSize.min,
              children: [
                TextFormField(
                  controller: nombreCtrl,
                  decoration: const InputDecoration(labelText: 'Nombre'),
                  validator: (value) =>
                      value?.trim().isEmpty == true ? 'Requerido' : null,
                ),
                TextFormField(
                  controller: apellidoCtrl,
                  decoration: const InputDecoration(labelText: 'Apellido'),
                  validator: (value) =>
                      value?.trim().isEmpty == true ? 'Requerido' : null,
                ),
                TextFormField(
                  controller: emailCtrl,
                  decoration: const InputDecoration(labelText: 'Correo'),
                  keyboardType: TextInputType.emailAddress,
                  validator: (value) =>
                      value?.trim().isEmpty == true ? 'Requerido' : null,
                ),
                TextFormField(
                  controller: telefonoCtrl,
                  decoration: const InputDecoration(labelText: 'Teléfono'),
                  keyboardType: TextInputType.phone,
                ),
              ],
            ),
          ),
        ),
        actions: [
          TextButton(
            onPressed: () => Navigator.pop(ctx),
            style:
                TextButton.styleFrom(foregroundColor: AppTheme.textSecondary),
            child: const Text('Cancelar'),
          ),
          TextButton(
            onPressed: () {
              if (!formKey.currentState!.validate()) return;
              final nuevo = AdminUser(
                id: user?.id ?? 'user-${DateTime.now().millisecondsSinceEpoch}',
                nombre: nombreCtrl.text.trim(),
                apellido: apellidoCtrl.text.trim(),
                email: emailCtrl.text.trim(),
                telefono: telefonoCtrl.text.trim(),
              );
              setState(() {
                if (user == null) {
                  _usuarios.add(nuevo);
                } else {
                  final index =
                      _usuarios.indexWhere((item) => item.id == user.id);
                  if (index >= 0) _usuarios[index] = nuevo;
                }
              });
              Navigator.pop(ctx);
            },
            child: Text(user == null ? 'Crear' : 'Guardar'),
          ),
        ],
      ),
    );
  }

  void _showRouteForm({AdminRoute? route}) {
    final formKey = GlobalKey<FormState>();
    final nombreCtrl = TextEditingController(text: route?.nombre);
    final zonaCtrl = TextEditingController(text: route?.zona);
    bool activa = route?.activa ?? true;

    showDialog(
      context: context,
      builder: (ctx) => AlertDialog(
        backgroundColor: AppTheme.surface,
        shape: RoundedRectangleBorder(
          borderRadius: BorderRadius.circular(AppTheme.radiusLg),
        ),
        title: Text(route == null ? 'Nueva ruta' : 'Editar ruta'),
        content: Form(
          key: formKey,
          child: SingleChildScrollView(
            child: Column(
              mainAxisSize: MainAxisSize.min,
              children: [
                TextFormField(
                  controller: nombreCtrl,
                  decoration:
                      const InputDecoration(labelText: 'Nombre de ruta'),
                  validator: (value) =>
                      value?.trim().isEmpty == true ? 'Requerido' : null,
                ),
                TextFormField(
                  controller: zonaCtrl,
                  decoration: const InputDecoration(labelText: 'Zona'),
                  validator: (value) =>
                      value?.trim().isEmpty == true ? 'Requerido' : null,
                ),
                const SizedBox(height: 12),
                Row(
                  children: [
                    const Expanded(child: Text('Ruta activa')),
                    Switch.adaptive(
                      value: activa,
                      onChanged: (value) => setState(() {
                        activa = value;
                      }),
                    ),
                  ],
                ),
              ],
            ),
          ),
        ),
        actions: [
          TextButton(
            onPressed: () => Navigator.pop(ctx),
            style:
                TextButton.styleFrom(foregroundColor: AppTheme.textSecondary),
            child: const Text('Cancelar'),
          ),
          TextButton(
            onPressed: () {
              if (!formKey.currentState!.validate()) return;
              final nueva = AdminRoute(
                id: route?.id ??
                    'ruta-${DateTime.now().millisecondsSinceEpoch}',
                nombre: nombreCtrl.text.trim(),
                zona: zonaCtrl.text.trim(),
                activa: activa,
              );
              setState(() {
                if (route == null) {
                  _rutas.add(nueva);
                } else {
                  final index =
                      _rutas.indexWhere((item) => item.id == route.id);
                  if (index >= 0) _rutas[index] = nueva;
                }
              });
              Navigator.pop(ctx);
            },
            child: Text(route == null ? 'Crear' : 'Guardar'),
          ),
        ],
      ),
    );
  }

  void _showTruckForm({AdminTruck? truck}) {
    final formKey = GlobalKey<FormState>();
    final placasCtrl = TextEditingController(text: truck?.placas);
    final modeloCtrl = TextEditingController(text: truck?.modelo);
    final conductorCtrl = TextEditingController(text: truck?.conductor);
    TruckStatus status = truck?.status ?? TruckStatus.disponible;
    String selectedRuta =
        truck?.rutaId ?? (_rutas.isNotEmpty ? _rutas.first.id : '');

    showDialog(
      context: context,
      builder: (ctx) => AlertDialog(
        backgroundColor: AppTheme.surface,
        shape: RoundedRectangleBorder(
          borderRadius: BorderRadius.circular(AppTheme.radiusLg),
        ),
        title: Text(truck == null ? 'Nuevo camión' : 'Editar camión'),
        content: Form(
          key: formKey,
          child: SingleChildScrollView(
            child: Column(
              mainAxisSize: MainAxisSize.min,
              children: [
                TextFormField(
                  controller: placasCtrl,
                  decoration: const InputDecoration(labelText: 'Placas'),
                  validator: (value) =>
                      value?.trim().isEmpty == true ? 'Requerido' : null,
                ),
                TextFormField(
                  controller: modeloCtrl,
                  decoration: const InputDecoration(labelText: 'Modelo'),
                  validator: (value) =>
                      value?.trim().isEmpty == true ? 'Requerido' : null,
                ),
                TextFormField(
                  controller: conductorCtrl,
                  decoration: const InputDecoration(labelText: 'Conductor'),
                  validator: (value) =>
                      value?.trim().isEmpty == true ? 'Requerido' : null,
                ),
                const SizedBox(height: 12),
                DropdownButtonFormField<String>(
                  value: selectedRuta.isEmpty ? null : selectedRuta,
                  decoration: const InputDecoration(labelText: 'Ruta'),
                  items: _rutas
                      .map((ruta) => DropdownMenuItem(
                            value: ruta.id,
                            child: Text(ruta.nombre),
                          ))
                      .toList(),
                  onChanged: (value) {
                    if (value != null) {
                      selectedRuta = value;
                    }
                  },
                  validator: (value) =>
                      value == null || value.isEmpty ? 'Requerido' : null,
                ),
                const SizedBox(height: 12),
                DropdownButtonFormField<TruckStatus>(
                  value: status,
                  decoration: const InputDecoration(labelText: 'Estatus'),
                  items: TruckStatus.values
                      .map((item) => DropdownMenuItem(
                            value: item,
                            child: Text(item.label),
                          ))
                      .toList(),
                  onChanged: (value) {
                    if (value != null) {
                      status = value;
                    }
                  },
                ),
              ],
            ),
          ),
        ),
        actions: [
          TextButton(
            onPressed: () => Navigator.pop(ctx),
            style:
                TextButton.styleFrom(foregroundColor: AppTheme.textSecondary),
            child: const Text('Cancelar'),
          ),
          TextButton(
            onPressed: () {
              if (!formKey.currentState!.validate()) return;
              final nuevo = AdminTruck(
                id: truck?.id ??
                    'truck-${DateTime.now().millisecondsSinceEpoch}',
                placas: placasCtrl.text.trim(),
                modelo: modeloCtrl.text.trim(),
                conductor: conductorCtrl.text.trim(),
                status: status,
                rutaId: selectedRuta,
              );
              setState(() {
                if (truck == null) {
                  _camiones.add(nuevo);
                } else {
                  final index =
                      _camiones.indexWhere((item) => item.id == truck.id);
                  if (index >= 0) _camiones[index] = nuevo;
                }
              });
              Navigator.pop(ctx);
            },
            child: Text(truck == null ? 'Crear' : 'Guardar'),
          ),
        ],
      ),
    );
  }
}