import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';
import 'package:go_router/go_router.dart';

import '../../core/auth_repository.dart';
import '../../core/session_controller.dart';
import '../../theme/toss_theme.dart';

/// New accounts only. Pre-seeded demo users (`alice@demo.msn`) are for sign-in, not registration.
class RegisterPage extends ConsumerStatefulWidget {
  const RegisterPage({super.key});

  @override
  ConsumerState<RegisterPage> createState() => _RegisterPageState();
}

class _RegisterPageState extends ConsumerState<RegisterPage> {
  final _email = TextEditingController();
  final _password = TextEditingController();
  final _name = TextEditingController();
  String? _error;
  bool _busy = false;

  @override
  void dispose() {
    _email.dispose();
    _password.dispose();
    _name.dispose();
    super.dispose();
  }

  Future<void> _submit() async {
    setState(() {
      _busy = true;
      _error = null;
    });
    try {
      final r = await ref.read(authRepositoryProvider).register(
            email: _email.text.trim(),
            password: _password.text,
            displayName: _name.text.trim().isEmpty ? null : _name.text.trim(),
          );
      await ref.read(sessionProvider.notifier).applyLogin(
            userId: r.userId,
            email: _email.text.trim(),
            defaultContextId: r.defaultContextId,
          );
      if (!mounted) return;
      context.go('/');
    } catch (e) {
      setState(() => _error = e.toString());
    } finally {
      if (mounted) setState(() => _busy = false);
    }
  }

  @override
  Widget build(BuildContext context) {
    final tt = Theme.of(context).textTheme;

    return Scaffold(
      backgroundColor: TossColors.bg,
      appBar: AppBar(title: const Text('회원가입')),
      body: SafeArea(
        child: SingleChildScrollView(
          padding: const EdgeInsets.all(24),
          child: Column(
            crossAxisAlignment: CrossAxisAlignment.stretch,
            children: [
              Text('새 계정 만들기', style: tt.headlineMedium),
              const SizedBox(height: 8),
              Text(
                '데모 계정은 로그인 화면에서 이용해 주세요.',
                style: tt.bodySmall,
              ),
              const SizedBox(height: 28),
              TextField(
                controller: _email,
                decoration: const InputDecoration(
                  labelText: '이메일',
                  prefixIcon: Icon(Icons.mail_outline_rounded, color: TossColors.textSecondary),
                ),
                keyboardType: TextInputType.emailAddress,
              ),
              const SizedBox(height: 12),
              TextField(
                controller: _password,
                decoration: const InputDecoration(
                  labelText: '비밀번호',
                  prefixIcon: Icon(Icons.lock_outline_rounded, color: TossColors.textSecondary),
                ),
                obscureText: true,
              ),
              const SizedBox(height: 12),
              TextField(
                controller: _name,
                decoration: const InputDecoration(
                  labelText: '표시 이름 (선택)',
                  prefixIcon: Icon(Icons.badge_outlined, color: TossColors.textSecondary),
                ),
              ),
              if (_error != null) ...[
                const SizedBox(height: 12),
                Text(
                  _error!,
                  style: TextStyle(color: Theme.of(context).colorScheme.error, fontSize: 13),
                ),
              ],
              const SizedBox(height: 28),
              SizedBox(
                height: 52,
                child: FilledButton(
                  onPressed: _busy ? null : _submit,
                  child: _busy
                      ? const SizedBox(
                          height: 22,
                          width: 22,
                          child: CircularProgressIndicator(strokeWidth: 2, color: Colors.white),
                        )
                      : const Text('가입하기'),
                ),
              ),
              TextButton(
                onPressed: _busy ? null : () => context.go('/login'),
                child: const Text('로그인으로 돌아가기'),
              ),
            ],
          ),
        ),
      ),
    );
  }
}