import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:go_router/go_router.dart';
import '../../config/app_config.dart';
import '../../core/network/api_exception.dart';
import 'auth_provider.dart';

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

  @override
  ConsumerState<LoginScreen> createState() => _LoginScreenState();
}

class _LoginScreenState extends ConsumerState<LoginScreen> {
  final _idController = TextEditingController();
  final _passwordController = TextEditingController();
  final _formKey = GlobalKey<FormState>();
  bool _isLoading = false;

  void _handleLogin() async {
    if (!_formKey.currentState!.validate()) return;

    final id = _idController.text.trim();
    final pwd = _passwordController.text.trim();

    setState(() => _isLoading = true);

    try {
      await ref.read(authProvider.notifier).login(id, pwd);
      if (mounted) {
        context.go('/camera');
      }
    } catch (e) {
      if (mounted) {
        ScaffoldMessenger.of(context).showSnackBar(
          SnackBar(
            content: Text(
              ApiException.from(e).displayMessage,
              style: const TextStyle(color: Colors.white),
            ),
            backgroundColor: AppConfig.errorColor,
          ),
        );
      }
    } finally {
      if (mounted) {
        setState(() => _isLoading = false);
      }
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: SafeArea(
        child: Center(
          child: SingleChildScrollView(
            padding: const EdgeInsets.symmetric(
              horizontal: AppConfig.spaceXXL,
              vertical: AppConfig.spaceXL,
            ),
            child: Form(
              key: _formKey,
              child: Column(
                mainAxisAlignment: MainAxisAlignment.center,
                crossAxisAlignment: CrossAxisAlignment.stretch,
                children: [
                  Image.asset(
                    'assets/logo.png',
                    width: 120,
                    height: 120,
                    errorBuilder: (context, error, stackTrace) => const Icon(
                      Icons.storefront, 
                      size: 80, 
                      color: AppConfig.primaryColor
                    ),
                  ),
                  const SizedBox(height: AppConfig.spaceXL),
                  Text(
                    'Selamat Datang Kembali',
                    style: AppConfig.h1,
                    textAlign: TextAlign.center,
                  ),
                  const SizedBox(height: AppConfig.spaceSmall),
                  Text(
                    'Masuk untuk menyinkronkan dokumen Anda ke server pusat',
                    style: AppConfig.bodyMedium,
                    textAlign: TextAlign.center,
                  ),
                  const SizedBox(height: AppConfig.spaceXXL * 1.5),
                  TextFormField(
                    controller: _idController,
                    decoration: const InputDecoration(
                      labelText: 'ID dari Admin',
                      prefixIcon: Icon(Icons.person_outline),
                    ),
                    validator: (value) {
                      if (value == null || value.trim().isEmpty) {
                        return 'Username/ID tidak boleh kosong';
                      }
                      return null;
                    },
                  ),
                  const SizedBox(height: AppConfig.spaceLarge),
                  TextFormField(
                    controller: _passwordController,
                    obscureText: true,
                    decoration: const InputDecoration(
                      labelText: 'Kata Sandi',
                      prefixIcon: Icon(Icons.lock_outline),
                    ),
                    validator: (value) {
                      if (value == null || value.trim().isEmpty) {
                        return 'Kata sandi tidak boleh kosong';
                      }
                      if (value.trim().length < 6) {
                        return 'Kata sandi minimal 6 karakter';
                      }
                      return null;
                    },
                  ),
                  const SizedBox(height: AppConfig.spaceXXL),
                  SizedBox(
                    height: 56,
                    child: ElevatedButton(
                      onPressed: _isLoading ? null : _handleLogin,
                      child: _isLoading
                          ? const SizedBox(
                              width: 24,
                              height: 24,
                              child: CircularProgressIndicator(color: Colors.white, strokeWidth: 3)
                            )
                          : const Text('Masuk'),
                    ),
                  ),
                const SizedBox(height: AppConfig.spaceXL),
                Text(
                  'Hubungi admin pusat untuk mendapatkan kredensial akun.',
                  style: AppConfig.bodySmall,
                  textAlign: TextAlign.center,
                ),
              ],
            ),
          ),
        ),
        ),
      ),
    );
  }
}