import 'package:flutter/material.dart';

import '../theme.dart';

/// 처음 시작: 이름과 번호만 받는다. 키는 이 기기 안에서 조용히 만들고, 복구 코드는 없다.
///
/// [onStart] 가 문제를 돌려주면(번호·이름이 잘못됨) 아래에 보여 준다.
class OnboardingScreen extends StatefulWidget {
  const OnboardingScreen({super.key, required this.onStart});

  final Future<String?> Function(String phone, String name) onStart;

  @override
  State<OnboardingScreen> createState() => _OnboardingScreenState();
}

class _OnboardingScreenState extends State<OnboardingScreen> {
  final _phone = TextEditingController();
  final _name = TextEditingController();
  String? _error;
  bool _busy = false;

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

  bool get _ready => _phone.text.trim().length >= 9 && _name.text.trim().isNotEmpty;

  Future<void> _start() async {
    FocusScope.of(context).unfocus();
    setState(() {
      _busy = true;
      _error = null;
    });
    final err = await widget.onStart(_phone.text, _name.text);
    if (mounted && err != null) {
      setState(() {
        _busy = false;
        _error = err;
      });
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: SafeArea(
        child: LayoutBuilder(
          builder: (context, box) => SingleChildScrollView(
            padding: const EdgeInsets.fromLTRB(24, 0, 24, 24),
            child: ConstrainedBox(
              constraints: BoxConstraints(minHeight: box.maxHeight - 24),
              child: Column(crossAxisAlignment: CrossAxisAlignment.stretch, children: [
                const SizedBox(height: 72),
                Align(
                  alignment: Alignment.centerLeft,
                  child: Container(
                    width: 64,
                    height: 64,
                    decoration: BoxDecoration(color: Pal.accent, borderRadius: BorderRadius.circular(18)),
                    child: const Icon(Icons.hub, color: Colors.black, size: 36),
                  ),
                ),
                const SizedBox(height: 24),
                const Text('Friendly Map', style: TextStyle(fontSize: 28, fontWeight: FontWeight.w800)),
                const SizedBox(height: 8),
                const Text('대화하다 알게 된 관계를\n가족 · 학교 · 회사로 이어 두세요.', style: TextStyle(fontSize: 16, height: 1.5, color: Pal.muted)),
                const SizedBox(height: 40),
                TextField(
                  controller: _name,
                  textInputAction: TextInputAction.next,
                  onChanged: (_) => setState(() {}),
                  decoration: const InputDecoration(labelText: '이름'),
                ),
                const SizedBox(height: 12),
                TextField(
                  controller: _phone,
                  keyboardType: TextInputType.phone,
                  textInputAction: TextInputAction.done,
                  onChanged: (_) => setState(() {}),
                  onSubmitted: (_) => _ready && !_busy ? _start() : null,
                  decoration: const InputDecoration(labelText: '내 휴대폰 번호', hintText: '010-1234-5678'),
                ),
                if (_error != null)
                  Padding(
                    padding: const EdgeInsets.only(top: 10),
                    child: Text(_error!, style: const TextStyle(color: Pal.danger, fontSize: 13)),
                  ),
                const SizedBox(height: 32),
                const Text('모든 정보는 이 폰 안에 암호화되어 저장되고, 내가 보낸 것만 상대에게 가요.',
                    style: TextStyle(fontSize: 12, height: 1.5, color: Pal.muted)),
                const SizedBox(height: 12),
                SizedBox(
                  height: 52,
                  child: FilledButton(
                    onPressed: _ready && !_busy ? _start : null,
                    child: _busy
                        ? const SizedBox(width: 20, height: 20, child: CircularProgressIndicator(strokeWidth: 2, color: Colors.black))
                        : const Text('시작하기', style: TextStyle(fontSize: 16, fontWeight: FontWeight.w700)),
                  ),
                ),
              ]),
            ),
          ),
        ),
      ),
    );
  }
}