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:eatvio_app/features/registration/presentation/widgets/change_email_dialog.dart';
import 'package:eatvio_app/features/registration/presentation/widgets/code_not_received_dialog.dart';
import 'package:eatvio_app/features/registration/services/registration_analytics_service.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();
    // Report email verification screen opened
    RegistrationAnalyticsService.reportRegistrationStep(16); // Email verification step
  }

  @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: Builder(
        builder: (context) {
          return BlocConsumer<VerifyEmailCubit, VerifyEmailState>(
            listener: (context, state) {
              if (state is VerifyEmailStateLoaded) {
                setState(() {
                  email = state.email;
                });
                _startTimer();
              } 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]);
              } else if (state is VerifyEmailStateChangeEmailSuccess) {
                showSuccessToast('Код подтверждения отправлен на новый email');
                // Диалог закроется автоматически в ChangeEmailDialog при успешной смене
              } else if (state is VerifyEmailStateChangeEmailError) {
                showErrorToast('Ошибка при смене email. Попробуйте снова.');
              }
            },
            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: 16),
                      GestureDetector(
                        onTap: () {
                          final verifyEmailCubit = context.read<VerifyEmailCubit>();
                          showDialog(context: context, builder: (context) => CodeNotReceivedDialog(
                            currentEmail: email,
                            verifyEmailCubit: verifyEmailCubit,
                          ));
                        },
                        child: Text(
                          'Не приходит код?',
                          style: TextStyles.textSMedium.copyWith(color: appTheme.blueA400, decoration: TextDecoration.underline),
                        ),
                      ),
                      const SizedBox(height: 24),
                      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)),
                      const SizedBox(height: 16),
                      CustomOutlinedButton(
                        text: 'Сменить email',
                        height: 52,
                        buttonTextStyle: TextStyles.textMSemibold.copyWith(color: appTheme.blueA400),
                        buttonStyle: ButtonStyle(
                          side: WidgetStatePropertyAll(BorderSide(color: appTheme.blueA400)),
                          backgroundColor: const WidgetStatePropertyAll(Colors.transparent),
                        ),
                        onPressed: () {
                          final verifyEmailCubit = context.read<VerifyEmailCubit>();
                          showDialog(
                            context: context,
                            builder: (context) => ChangeEmailDialog(currentEmail: email, verifyEmailCubit: verifyEmailCubit),
                          );
                        },
                      ),
                    ],
                  ),
                ),
              );
            },
          );
        },
      ),
    );
  }

  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);
        },
      ),
    );
  }
}