import 'package:sysfarma_mobile/src/app/widgets/app_panel.dart';
import 'package:sysfarma_mobile/src/core/network/api_client.dart';
import 'package:sysfarma_mobile/src/core/theme/app_tokens.dart';
import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:go_router/go_router.dart';

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

  @override
  ConsumerState<ChangePasswordScreen> createState() =>
      _ChangePasswordScreenState();
}

class _ChangePasswordScreenState extends ConsumerState<ChangePasswordScreen> {
  final _formKey = GlobalKey<FormState>();
  final _currentCtrl = TextEditingController();
  final _newCtrl = TextEditingController();
  final _confirmCtrl = TextEditingController();

  bool _obscureCurrent = true;
  bool _obscureNew = true;
  bool _obscureConfirm = true;
  bool _submitting = false;

  @override
  void dispose() {
    _currentCtrl.dispose();
    _newCtrl.dispose();
    _confirmCtrl.dispose();
    super.dispose();
  }

  Future<void> _submit() async {
    if (!_formKey.currentState!.validate()) return;
    setState(() => _submitting = true);
    try {
      final response = await ref.read(apiClientProvider).changePassword(
            currentPassword: _currentCtrl.text,
            newPassword: _newCtrl.text,
          );
      if (!mounted) return;
      if (response.success) {
        ScaffoldMessenger.of(context).showSnackBar(
          const SnackBar(
            content: Text('Contrasena actualizada'),
            backgroundColor: AppTokens.success,
          ),
        );
        context.pop();
      } else {
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(
            content: Text(response.message ?? 'No se pudo actualizar.'),
            backgroundColor: AppTokens.danger,
          ),
        );
      }
    } catch (e) {
      if (!mounted) return;
      ScaffoldMessenger.of(context).showSnackBar(
        SnackBar(
          content: Text('Error: $e'),
          backgroundColor: AppTokens.danger,
        ),
      );
    } finally {
      if (mounted) setState(() => _submitting = false);
    }
  }

  InputDecoration _dec(String label,
      {required VoidCallback onToggle, required bool obscure}) {
    return InputDecoration(
      labelText: label,
      border: OutlineInputBorder(
        borderRadius: BorderRadius.circular(AppTokens.radiusSmall),
      ),
      suffixIcon: IconButton(
        icon: Icon(
          obscure ? Icons.visibility_off_rounded : Icons.visibility_rounded,
          color: AppTokens.secondary,
        ),
        onPressed: onToggle,
      ),
    );
  }

  @override
  Widget build(BuildContext context) {
    return SafeArea(
      child: ListView(
        padding: AppTokens.pagePadding,
        children: [
          AppPanel(
            title: 'Cambiar contrasena',
            child: Form(
              key: _formKey,
              child: Column(
                crossAxisAlignment: CrossAxisAlignment.stretch,
                children: [
                  Text(
                    'Ingresa tu contrasena actual y define una nueva.',
                    style: Theme.of(context).textTheme.bodySmall?.copyWith(
                          color: AppTokens.secondary,
                        ),
                  ),
                  const SizedBox(height: 16),
                  TextFormField(
                    controller: _currentCtrl,
                    obscureText: _obscureCurrent,
                    decoration: _dec(
                      'Contrasena actual',
                      obscure: _obscureCurrent,
                      onToggle: () => setState(
                          () => _obscureCurrent = !_obscureCurrent),
                    ),
                    validator: (v) => (v == null || v.isEmpty)
                        ? 'Ingresa tu contrasena actual'
                        : null,
                  ),
                  const SizedBox(height: 14),
                  TextFormField(
                    controller: _newCtrl,
                    obscureText: _obscureNew,
                    decoration: _dec(
                      'Nueva contrasena',
                      obscure: _obscureNew,
                      onToggle: () =>
                          setState(() => _obscureNew = !_obscureNew),
                    ),
                    validator: (v) {
                      if (v == null || v.isEmpty) {
                        return 'Ingresa una nueva contrasena';
                      }
                      if (v.length < 6) {
                        return 'Debe tener al menos 6 caracteres';
                      }
                      return null;
                    },
                  ),
                  const SizedBox(height: 14),
                  TextFormField(
                    controller: _confirmCtrl,
                    obscureText: _obscureConfirm,
                    decoration: _dec(
                      'Confirmar nueva contrasena',
                      obscure: _obscureConfirm,
                      onToggle: () => setState(
                          () => _obscureConfirm = !_obscureConfirm),
                    ),
                    validator: (v) {
                      if (v == null || v.isEmpty) {
                        return 'Confirma tu nueva contrasena';
                      }
                      if (v != _newCtrl.text) {
                        return 'Las contrasenas no coinciden';
                      }
                      return null;
                    },
                  ),
                  const SizedBox(height: 20),
                  FilledButton.icon(
                    onPressed: _submitting ? null : _submit,
                    icon: _submitting
                        ? const SizedBox(
                            width: 18,
                            height: 18,
                            child: CircularProgressIndicator(
                              strokeWidth: 2,
                              color: Colors.white,
                            ),
                          )
                        : const Icon(Icons.lock_reset_rounded),
                    label: Text(_submitting
                        ? 'Actualizando...'
                        : 'Cambiar contrasena'),
                  ),
                ],
              ),
            ),
          ),
        ],
      ),
    );
  }
}