import 'package:auto_route/auto_route.dart';
import 'package:flutter/material.dart';
import 'package:flutter_bloc/flutter_bloc.dart';
import 'package:flutter_spinkit/flutter_spinkit.dart';

import '../../../application/auth/auth_bloc.dart';
import '../../../application/pin/pin_change_form/pin_change_form_bloc.dart';
import '../../../common/theme/theme.dart';
import '../../../domain/wallet/wallet.dart';
import '../../../injection.dart';
import '../../components/toast/flushbar.dart';
import '../../router/app_router.gr.dart';
import '../wallet/wallet_ui.dart';
import 'pin_rules.dart';
import 'widgets/pin_code_field.dart';

enum _Step { oldPin, newPin, confirm }

/// Ganti PIN (§6.3).
@RoutePage()
class PinChangePage extends StatefulWidget implements AutoRouteWrapper {
  const PinChangePage({super.key});

  @override
  State<PinChangePage> createState() => _PinChangePageState();

  @override
  Widget wrappedRoute(BuildContext context) =>
      BlocProvider(create: (_) => getIt<PinChangeFormBloc>(), child: this);
}

class _PinChangePageState extends State<PinChangePage> {
  final TextEditingController _controller = TextEditingController();

  _Step _step = _Step.oldPin;
  String _oldPin = '';
  String _newPin = '';
  String? _errorText;
  bool _isLocked = false;

  @override
  void dispose() {
    _controller.dispose();
    _oldPin = '';
    _newPin = '';
    super.dispose();
  }

  void _goTo(_Step step, {String? error}) {
    setState(() {
      _step = step;
      _errorText = error;
    });
    _controller.clear();
  }

  void _onCompleted(String value) {
    switch (_step) {
      case _Step.oldPin:
        _oldPin = value;
        _goTo(_Step.newPin);
      case _Step.newPin:
        final error = value == _oldPin
            ? 'PIN baru harus berbeda dari PIN lama.'
            : validateNewPin(
                value,
                birthDate: context.read<AuthBloc>().state.user.birthDate,
              );
        if (error != null) {
          _goTo(_Step.newPin, error: error);
          return;
        }
        _newPin = value;
        _goTo(_Step.confirm);
      case _Step.confirm:
        if (value != _newPin) {
          _newPin = '';
          _goTo(_Step.newPin, error: 'PIN tidak sama. Silakan ulangi.');
          return;
        }
        context.read<PinChangeFormBloc>().add(
          PinChangeFormEvent.submitted(
            oldPin: _oldPin,
            pin: _newPin,
            confirmPin: value,
          ),
        );
        _controller.clear();
    }
  }

  void _onFailure(WalletFailure failure) {
    _oldPin = '';
    _newPin = '';
    failure.maybeMap(
      pinInvalid: (_) =>
          _goTo(_Step.oldPin, error: walletFailureMessage(failure)),
      pinLocked: (_) {
        _goTo(_Step.oldPin, error: walletFailureMessage(failure));
        setState(() => _isLocked = true);
      },
      pinNotSet: (_) =>
          context.router.replace(PinSetupRoute(purpose: PinOtpPurpose.setup)),
      rejected: (_) => _goTo(
        _Step.newPin,
        error: 'PIN baru tidak memenuhi syarat. Coba PIN lain.',
      ),
      orElse: () {
        _goTo(_Step.oldPin);
        AppFlushbar.showError(context, walletFailureMessage(failure));
      },
    );
  }

  @override
  Widget build(BuildContext context) {
    return BlocConsumer<PinChangeFormBloc, PinChangeFormState>(
      listenWhen: (p, c) =>
          p.failureOrSuccessOption != c.failureOrSuccessOption,
      listener: (context, state) {
        state.failureOrSuccessOption.fold(
          () {},
          (either) => either.fold(_onFailure, (_) {
            _oldPin = '';
            _newPin = '';
            AppFlushbar.showSuccess(context, 'PIN berhasil diganti');
            context.router.maybePop();
          }),
        );
      },
      builder: (context, state) {
        final title = switch (_step) {
          _Step.oldPin => 'Masukkan PIN lama',
          _Step.newPin => 'Masukkan PIN baru',
          _Step.confirm => 'Konfirmasi PIN baru',
        };

        return Scaffold(
          appBar: AppBar(title: const Text('Ganti PIN')),
          body: Padding(
            padding: const EdgeInsets.all(20),
            child: Column(
              crossAxisAlignment: CrossAxisAlignment.start,
              children: [
                Text(
                  title,
                  style: AppStyle.xl.copyWith(fontWeight: FontWeight.w700),
                ),
                const SizedBox(height: 8),
                Text(
                  'PIN 6 digit, bukan angka berulang, berurutan, atau tanggal '
                  'lahir.',
                  style: AppStyle.md.copyWith(color: AppColor.textSecondary),
                ),
                const SizedBox(height: 28),
                PinCodeField(
                  key: ValueKey(_step),
                  controller: _controller,
                  enabled: !state.isSubmitting && !_isLocked,
                  hasError: _errorText != null,
                  onCompleted: _onCompleted,
                ),
                const SizedBox(height: 16),
                if (state.isSubmitting)
                  const Center(
                    child: SpinKitFadingCircle(
                      color: AppColor.primary,
                      size: 28,
                    ),
                  )
                else if (_errorText != null)
                  Text(
                    _errorText!,
                    style: AppStyle.md.copyWith(
                      color: AppColor.error,
                      fontWeight: FontWeight.w600,
                    ),
                  ),
                const SizedBox(height: 8),
                if (_step == _Step.oldPin)
                  Align(
                    alignment: Alignment.centerRight,
                    child: TextButton(
                      onPressed: () => context.router.replace(
                        PinSetupRoute(purpose: PinOtpPurpose.reset),
                      ),
                      child: Text(
                        'Lupa PIN',
                        style: AppStyle.md.copyWith(
                          color: AppColor.primary,
                          fontWeight: FontWeight.w700,
                        ),
                      ),
                    ),
                  ),
              ],
            ),
          ),
        );
      },
    );
  }
}