eatvio_app/lib/features/registration/presentation/pages/verify_email_screen.dart

import 'dart:async';

import 'package:eatvio_app/core/locator_service.dart';
import 'package:eatvio_app/core/theme/custom_text_style.dart';
import 'package:eatvio_app/core/theme/theme_helper.dart';
import 'package:eatvio_app/core/utils/toasts.dart';
import 'package:eatvio_app/core/widgets/custom_outlined_button.dart';
import 'package:eatvio_app/features/registration/presentation/bloc/verify_email_cubit/verify_email_cubit.dart';
import 'package:eatvio_app/features/registration/presentation/bloc/verify_email_cubit/verify_email_state.dart';
import 'package:flutter/material.dart';
import 'package:flutter_bloc/flutter_bloc.dart';
import 'package:go_router/go_router.dart';

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

  @override
  State<VerifyEmailScreen> createState() => _VerifyEmailScreenState();
}

class _VerifyEmailScreenState extends State<VerifyEmailScreen> {
  final List<FocusNode> _focusNodes = List.generate(4, (_) => FocusNode());
  final List<TextEditingController> _controllers = List.generate(4, (_) => TextEditingController());
  String email = '';
  late final GoRouter goRouter;
  late Timer _timer;
  int _secondsRemaining = 60;
  bool _canSendAgain = false;
  @override
  void initState() {
    super.initState();
    goRouter = GoRouter.of(context);    
    _startTimer();
  }

  @override
  void dispose() {
    for (var controller in _controllers) {
      controller.dispose();
    }
    for (var node in _focusNodes) {
      node.dispose();
    }
    super.dispose();
  }

  void _startTimer() {
    setState(() {
      _canSendAgain = false;
      _secondsRemaining = 60;
    });
    _timer = Timer.periodic(const Duration(seconds: 1), (timer) {
      setState(() {
        if (_secondsRemaining > 0) {
          _secondsRemaining--;
        } else {
          _canSendAgain = true;
          _timer.cancel();
        }
      });
    });
  }

  void _checkAndSubmitCode(BuildContext context) {
    final code = _controllers.map((c) => c.text).join();
    if (code.length == 4) {
      context.read<VerifyEmailCubit>().tryVerify(code);
    }
  }

  @override
  Widget build(BuildContext context) {
    return BlocProvider<VerifyEmailCubit>(
      create: (_) => sl<VerifyEmailCubit>()..sendEmailCode(),
      child: BlocConsumer<VerifyEmailCubit, VerifyEmailState>(
        listener: (context, state) {
          if (state is VerifyEmailStateLoaded) {
            setState(() {
              email = state.email;
            });
          } else if (state is VerifyEmailStateVerifySuccess) {
            showSuccessToast('Почта успешно подтверждена');
            goRouter.pushNamed('feedScreen');
          } else if (state is VerifyEmailStateVerifyError) {
            showErrorToast("Неверный код. Попробуйте снова.");
            for (var controller in _controllers) {
              controller.clear();
            }
            FocusScope.of(context).requestFocus(_focusNodes[0]);
          }
        },
        builder: (context, state) {
          return Scaffold(
            appBar: AppBar(title: const Text("Подтвердите почту")),
            body: Padding(
              padding: const EdgeInsets.all(24.0),
              child: Column(
                mainAxisAlignment: MainAxisAlignment.center,
                children: [
                  Text("Код отправлен на почту\n$email", textAlign: TextAlign.center),
                  const SizedBox(height: 20),
                  Row(mainAxisAlignment: MainAxisAlignment.spaceEvenly, children: List.generate(4, (index) => _buildCodeField(context, index))),
                  const SizedBox(height: 40),
                  CustomOutlinedButton(
                    text: 'Запросить код повторно',
                    height: 52,
                    isDisabled: !_canSendAgain,
                    buttonTextStyle: TextStyles.textMSemibold.copyWith(color: appTheme.whiteA700),
                    buttonStyle: ButtonStyle(
                      side: const WidgetStatePropertyAll(BorderSide.none),
                      backgroundColor: WidgetStatePropertyAll(_canSendAgain ? appTheme.blueA400 : appTheme.gray),
                    ),
                    onPressed: () async {
                      await context.read<VerifyEmailCubit>().sendEmailCode();
                      _startTimer();
                    },
                  ),
                  const SizedBox(height: 8),
                  if (!_canSendAgain)
                    Text("Зпросить код повторно можно через $_secondsRemaining с.", style: TextStyles.textSMedium.copyWith(color: appTheme.gray)),
                ],
              ),
            ),
          );
        },
      ),
    );
  }

  Widget _buildCodeField(BuildContext context, int index) {
    return SizedBox(
      width: 50,
      child: TextField(
        controller: _controllers[index],
        focusNode: _focusNodes[index],
        keyboardType: TextInputType.number,
        textAlign: TextAlign.center,
        maxLength: 1,
        style: const TextStyle(fontSize: 24),
        decoration: InputDecoration(
          counterText: "",
          border: OutlineInputBorder(borderRadius: BorderRadius.circular(8.0)),
        ),
        onChanged: (value) {
          if (value.isNotEmpty && index < 3) {
            FocusScope.of(context).requestFocus(_focusNodes[index + 1]);
          }
          if (value.isEmpty && index > 0) {
            FocusScope.of(context).requestFocus(_focusNodes[index - 1]);
          }
          _checkAndSubmitCode(context);
        },
      ),
    );
  }
}