import 'package:flutter/material.dart';

import '../services/auth_service.dart';
import 'forgot_password_screen.dart';
import 'register_screen.dart';

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

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

class _LoginScreenState extends State<LoginScreen> {
  final _formKey = GlobalKey<FormState>();
  final _emailController = TextEditingController();
  final _passwordController = TextEditingController();
  bool _loading = false;

  @override
  void dispose() {
    _emailController.dispose();
    _passwordController.dispose();
    super.dispose();
  }

  Future<void> _run(Future<void> Function() action) async {
    setState(() => _loading = true);
    try {
      await action();
    } catch (e) {
      if (!mounted) return;
      ScaffoldMessenger.of(context).showSnackBar(
        SnackBar(content: Text(e.toString())),
      );
    } finally {
      if (mounted) setState(() => _loading = false);
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Center(
        child: ConstrainedBox(
          constraints: const BoxConstraints(maxWidth: 420),
          child: Card(
            margin: const EdgeInsets.all(20),
            child: Padding(
              padding: const EdgeInsets.all(20),
              child: Form(
                key: _formKey,
                child: Column(
                  mainAxisSize: MainAxisSize.min,
                  children: [
                    const Text(
                      'Welcome Back',
                      style: TextStyle(
                        fontSize: 28,
                        fontWeight: FontWeight.bold,
                      ),
                    ),
                    const SizedBox(height: 16),
                    TextFormField(
                      controller: _emailController,
                      decoration: const InputDecoration(labelText: 'Email'),
                      validator: (value) =>
                          (value == null || value.trim().isEmpty)
                              ? 'Email is required'
                              : null,
                    ),
                    const SizedBox(height: 12),
                    TextFormField(
                      controller: _passwordController,
                      obscureText: true,
                      decoration: const InputDecoration(labelText: 'Password'),
                      validator: (value) =>
                          (value == null || value.isEmpty)
                              ? 'Password is required'
                              : null,
                    ),
                    const SizedBox(height: 16),
                    SizedBox(
                      width: double.infinity,
                      child: FilledButton(
                        onPressed: _loading
                            ? null
                            : () {
                                if (!_formKey.currentState!.validate()) return;
                                _run(() async {
                                  await AuthService.instance
                                      .signInWithEmailPassword(
                                    email: _emailController.text.trim(),
                                    password: _passwordController.text,
                                  );
                                });
                              },
                        child: _loading
                            ? const SizedBox(
                                width: 18,
                                height: 18,
                                child:
                                    CircularProgressIndicator(strokeWidth: 2),
                              )
                            : const Text('Sign In'),
                      ),
                    ),
                    TextButton(
                      onPressed: _loading
                          ? null
                          : () {
                              Navigator.of(context).push(
                                MaterialPageRoute(
                                  builder: (_) => const ForgotPasswordScreen(),
                                ),
                              );
                            },
                      child: const Text('Forgot Password?'),
                    ),
                    const Divider(height: 24),
                    SizedBox(
                      width: double.infinity,
                      child: OutlinedButton.icon(
                        onPressed: _loading
                            ? null
                            : () => _run(() async {
                                  await AuthService.instance.signInWithGoogle();
                                }),
                        icon: const Icon(Icons.login),
                        label: const Text('Continue with Google'),
                      ),
                    ),
                    const SizedBox(height: 8),
                    SizedBox(
                      width: double.infinity,
                      child: OutlinedButton.icon(
                        onPressed: _loading
                            ? null
                            : () => _run(() async {
                                  await AuthService.instance.signInWithGithub();
                                }),
                        icon: const Icon(Icons.code),
                        label: const Text('Continue with GitHub'),
                      ),
                    ),
                    const SizedBox(height: 8),
                    TextButton(
                      onPressed: _loading
                          ? null
                          : () {
                              Navigator.of(context).push(
                                MaterialPageRoute(
                                  builder: (_) => const RegisterScreen(),
                                ),
                              );
                            },
                      child: const Text('Create an account'),
                    ),
                  ],
                ),
              ),
            ),
          ),
        ),
      ),
    );
  }
}