social-app/apps/lib/features/auth/ui/screens/register_verification_screen.dart

import 'dart:async';

import 'package:flutter/material.dart';
import 'package:flutter_bloc/flutter_bloc.dart';
import 'package:go_router/go_router.dart';
import 'package:formz/formz.dart';
import '../../../../core/theme/design_tokens.dart';
import '../../../../shared/widgets/app_button.dart';
import '../../../../shared/widgets/fixed_length_code_input.dart';
import '../../../../shared/widgets/link_button.dart';
import '../../../../shared/widgets/toast/toast.dart';
import '../../../../shared/widgets/toast/toast_type.dart';
import '../../presentation/cubits/register_cubit.dart';
import '../../presentation/bloc/auth_bloc.dart';
import '../../presentation/bloc/auth_event.dart';
import '../widgets/auth_page_scaffold.dart';

class RegisterVerificationScreen extends StatelessWidget {
  final RegisterCubit? cubit;

  const RegisterVerificationScreen({super.key, this.cubit});

  @override
  Widget build(BuildContext context) {
    final registerCubit =
        cubit ?? (GoRouterState.of(context).extra as RegisterCubit?);

    if (registerCubit == null) {
      return Scaffold(
        body: Center(child: Text('Error: RegisterCubit not found')),
      );
    }

    return BlocProvider.value(
      value: registerCubit,
      child: const RegisterVerificationView(),
    );
  }
}

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

  @override
  State<RegisterVerificationView> createState() =>
      _RegisterVerificationViewState();
}

class _RegisterVerificationViewState extends State<RegisterVerificationView> {
  final _codeController = TextEditingController();
  Timer? _countdownTimer;
  int _countdown = 0;
  bool _firstSendCompleted = false;

  @override
  void initState() {
    super.initState();
  }

  @override
  void dispose() {
    _countdownTimer?.cancel();
    _codeController.dispose();
    super.dispose();
  }

  void _startCountdown() {
    setState(() {
      _countdown = 60;
    });
    _countdownTimer?.cancel();
    _countdownTimer = Timer.periodic(const Duration(seconds: 1), (timer) {
      if (_countdown > 0) {
        setState(() {
          _countdown--;
        });
      } else {
        timer.cancel();
      }
    });
  }

  Future<void> _handleComplete() async {
    final cubit = context.read<RegisterCubit>();
    cubit.verificationCodeChanged(_codeController.text);

    if (!cubit.state.isStep2Valid) {
      String? errorMsg;
      if (_codeController.text.isEmpty) {
        errorMsg = '请输入验证码';
      } else {
        errorMsg = '验证码必须是 6 位数字';
      }
      if (mounted) {
        Toast.show(context, errorMsg, type: ToastType.warning);
      }
      return;
    }

    final response = await cubit.submitStep2();
    if (response != null && mounted) {
      context.read<AuthBloc>().add(AuthLoggedIn(user: response.user));
      context.go('/home');
    }
  }

  Future<void> _handleResendCode() async {
    final cubit = context.read<RegisterCubit>();
    final success = await cubit.resendCode();

    if (success && mounted) {
      _startCountdown();
      Toast.show(context, '验证码已发送', type: ToastType.success);
    }
  }

  @override
  Widget build(BuildContext context) {
    return AuthPageScaffold(
      mainContent: Column(
        mainAxisSize: MainAxisSize.min,
        crossAxisAlignment: CrossAxisAlignment.center,
        children: [
          _buildAppIcon(),
          const SizedBox(height: 24),
          _buildAppTitle(),
          const SizedBox(height: 24),
          _buildFormContainer(),
        ],
      ),
      footer: _buildFooter(),
    );
  }

  Widget _buildAppIcon() {
    return Container(
      width: 104,
      height: 104,
      decoration: BoxDecoration(
        color: AppColors.appIconRing,
        borderRadius: BorderRadius.circular(52),
        border: Border.all(color: AppColors.appIconBorder, width: 1),
      ),
      child: Center(
        child: ClipRRect(
          borderRadius: BorderRadius.circular(38),
          child: Image.asset(
            'assets/images/logo.png',
            width: 76,
            height: 76,
            fit: BoxFit.cover,
          ),
        ),
      ),
    );
  }

  Widget _buildAppTitle() {
    return const Text(
      'linksy',
      style: TextStyle(
        fontFamily: 'Playfair Display',
        fontSize: 34,
        fontWeight: FontWeight.w700,
        fontStyle: FontStyle.italic,
        color: AppColors.appTitle,
        letterSpacing: 0.5,
      ),
    );
  }

  Widget _buildFormContainer() {
    return BlocConsumer<RegisterCubit, RegisterState>(
      listener: (context, state) {
        if (!mounted) return;

        if (state.status == FormzSubmissionStatus.failure &&
            state.errorMessage != null) {
          Toast.show(context, state.errorMessage!, type: ToastType.error);

          if (!_firstSendCompleted) {
            _firstSendCompleted = true;
            setState(() {
              _countdown = 0;
            });
          }
        }

        if (state.status == FormzSubmissionStatus.success &&
            !_firstSendCompleted) {
          _firstSendCompleted = true;
          _startCountdown();
          Toast.show(
            context,
            '验证码已发送，如未收到请检查垃圾邮件或确认邮箱已注册',
            type: ToastType.info,
            duration: const Duration(seconds: 5),
          );
        }
      },
      builder: (context, state) {
        return SizedBox(
          width: 327,
          child: Column(
            crossAxisAlignment: CrossAxisAlignment.stretch,
            children: [
              _buildCodeInput(state),
              const SizedBox(height: 12),
              _buildStepIndicator(),
              const SizedBox(height: 12),
              AppButton(
                text: '完成注册',
                onPressed: state.status == FormzSubmissionStatus.inProgress
                    ? null
                    : _handleComplete,
              ),
            ],
          ),
        );
      },
    );
  }

  Widget _buildCodeInput(RegisterState state) {
    final canResend =
        _countdown == 0 && state.status != FormzSubmissionStatus.inProgress;

    return Column(
      crossAxisAlignment: CrossAxisAlignment.start,
      children: [
        const Text(
          '邮箱验证码',
          style: TextStyle(
            fontSize: 13,
            fontWeight: FontWeight.w500,
            color: AppColors.slate600,
          ),
        ),
        const SizedBox(height: 6),
        Row(
          children: [
            Expanded(
              child: SizedBox(
                height: 40,
                child: FixedLengthCodeInput(
                  controller: _codeController,
                  length: 6,
                  semanticLabel: '邮箱验证码输入框',
                  keyboardType: TextInputType.number,
                  allowedCharacters: const {
                    '0',
                    '1',
                    '2',
                    '3',
                    '4',
                    '5',
                    '6',
                    '7',
                    '8',
                    '9',
                  },
                  onChanged: (value) {
                    context.read<RegisterCubit>().verificationCodeChanged(
                      value,
                    );
                  },
                ),
              ),
            ),
            const SizedBox(width: 8),
            _buildResendButton(canResend, state),
          ],
        ),
      ],
    );
  }

  Widget _buildResendButton(bool canResend, RegisterState state) {
    final canPress =
        canResend && state.status != FormzSubmissionStatus.inProgress;

    return SizedBox(
      width: 70,
      height: 44,
      child: TextButton(
        onPressed: canPress ? _handleResendCode : null,
        style: TextButton.styleFrom(
          backgroundColor: canResend ? AppColors.primary : AppColors.slate100,
          foregroundColor: canResend ? AppColors.white : AppColors.slate400,
          shape: RoundedRectangleBorder(
            borderRadius: BorderRadius.circular(AppRadius.sm),
          ),
          padding: EdgeInsets.zero,
        ),
        child: state.status == FormzSubmissionStatus.inProgress
            ? const SizedBox(
                width: 16,
                height: 16,
                child: CircularProgressIndicator(
                  strokeWidth: 2,
                  valueColor: AlwaysStoppedAnimation<Color>(AppColors.slate400),
                ),
              )
            : Text(
                canResend ? '重发' : '${_countdown}s',
                style: const TextStyle(
                  fontSize: 14,
                  fontWeight: FontWeight.w500,
                ),
              ),
      ),
    );
  }

  Widget _buildStepIndicator() {
    return Row(
      children: [
        Expanded(
          child: Container(
            height: 4,
            decoration: BoxDecoration(
              color: AppColors.primary,
              borderRadius: BorderRadius.circular(99),
            ),
          ),
        ),
        const SizedBox(width: 6),
        Expanded(
          child: Container(
            height: 4,
            decoration: BoxDecoration(
              color: AppColors.primary,
              borderRadius: BorderRadius.circular(99),
            ),
          ),
        ),
      ],
    );
  }

  Widget _buildFooter() {
    return LinkButton(text: '已有账号？去登录', onTap: () => context.go('/'));
  }
}