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

import '../../../application/voucher/voucher_redeem_form/voucher_redeem_form_bloc.dart';
import '../../../application/wallet/wallet_loader/wallet_loader_bloc.dart';
import '../../../common/extension/extension.dart';
import '../../../common/theme/theme.dart';
import '../../../domain/wallet/wallet.dart';
import '../../../injection.dart';
import '../../components/button/button.dart';
import '../../components/toast/flushbar.dart';
import '../pin/pin_guard.dart';
import '../pin/widgets/pin_sheet.dart';
import '../wallet/wallet_ui.dart';
import '../wallet/widgets/wallet_confirm_dialog.dart';
import 'reward_ui.dart';

/// Detail voucher di katalog dan tukar EnakPoint ke voucher (§9.2). Pop
/// dengan `true` bila voucher berhasil ditukar.
@RoutePage()
class RewardDetailPage extends StatefulWidget implements AutoRouteWrapper {
  const RewardDetailPage({super.key, required this.voucher});

  final Voucher voucher;

  @override
  State<RewardDetailPage> createState() => _RewardDetailPageState();

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

class _RewardDetailPageState extends State<RewardDetailPage> {
  /// Diisi bila server menjawab voucher habis / tidak tersedia; katalog
  /// dimuat ulang saat kembali ke halaman sebelumnya.
  String? _unavailableMessage;

  Voucher get _voucher => widget.voucher;

  Future<void> _redeem() async {
    final confirmed = await showWalletConfirmDialog(
      context,
      title: 'Tukar voucher?',
      message:
          'Tukar ${_voucher.pointCost.thousandFormat} EnakPoint dengan '
          '${_voucher.name}? Tidak bisa dibatalkan.',
      confirmLabel: 'Tukar',
    );
    if (!confirmed || !mounted) return;
    if (!await ensurePinReady(context) || !mounted) return;

    final success = await showPinSheet(
      context,
      title: 'Tukar voucher',
      onSubmit: (pin) async {
        final bloc = context.read<VoucherRedeemFormBloc>();
        bloc.add(
          VoucherRedeemFormEvent.submitted(voucherId: _voucher.id, pin: pin),
        );
        final result = await bloc.stream.firstWhere((s) => !s.isSubmitting);
        return result.failureOption.toNullable();
      },
      onFailure: _showFailure,
    );

    if (success && mounted) {
      context.read<WalletLoaderBloc>().add(const WalletLoaderEvent.fetched());
    }
  }

  void _showFailure(WalletFailure failure) {
    if (failure.isPinError) return;

    if (failure.isNetworkError) {
      AppFlushbar.showError(
        context,
        'Koneksi terputus, status penukaran belum diketahui. Tekan Tukar lagi '
        'untuk mengulang. EnakPoint tidak akan terpotong dua kali.',
      );
      return;
    }

    final description = describeVoucherRedeemFailure(failure);
    if (description.reloadCatalog) {
      setState(() => _unavailableMessage = description.message);
    }
    AppFlushbar.showError(context, description.message);
  }

  @override
  Widget build(BuildContext context) {
    return BlocBuilder<VoucherRedeemFormBloc, VoucherRedeemFormState>(
      builder: (context, state) {
        final result = state.result;
        return PopScope(
          canPop: result == null,
          onPopInvokedWithResult: (didPop, _) {
            if (!didPop && result != null) context.router.pop(true);
          },
          child: Scaffold(
            backgroundColor: AppColor.background,
            appBar: AppBar(title: const Text('Detail voucher')),
            body: AnimatedSwitcher(
              duration: const Duration(milliseconds: 300),
              child: result != null
                  ? KeyedSubtree(
                      key: const ValueKey('success'),
                      child: _buildSuccess(result),
                    )
                  : KeyedSubtree(
                      key: const ValueKey('detail'),
                      child: _buildDetail(state),
                    ),
            ),
          ),
        );
      },
    );
  }

  Widget _buildDetail(VoucherRedeemFormState state) {
    final faceValue = voucherFaceValueLabel(_voucher.type, _voucher.faceValue);

    return BlocBuilder<WalletLoaderBloc, WalletLoaderState>(
      builder: (context, walletState) {
        final pointBalance = walletState.summary.pointBalance;
        final canAfford =
            !walletState.hasLoaded || pointBalance >= _voucher.pointCost;

        final String? blockedLabel = _unavailableMessage != null
            ? 'Voucher tidak tersedia'
            : _voucher.isOutOfStock
            ? 'Habis'
            : !canAfford
            ? 'EnakPoint kurang'
            : null;

        return Column(
          children: [
            Expanded(
              child: ListView(
                padding: const EdgeInsets.all(16),
                children: [
                  Container(
                    padding: const EdgeInsets.all(20),
                    decoration: BoxDecoration(
                      color: AppColor.white,
                      borderRadius: BorderRadius.circular(
                        AppValue.borderRadius,
                      ),
                    ),
                    child: Column(
                      children: [
                        VoucherImage(
                          url: _voucher.imageUrl,
                          size: 120,
                          dimmed:
                              _voucher.isOutOfStock ||
                              _unavailableMessage != null,
                        ),
                        const SizedBox(height: 16),
                        Text(
                          voucherTypeLabel(
                            _voucher.type,
                            _voucher.faceValue,
                          ).toUpperCase(),
                          style: AppStyle.xs.copyWith(
                            color: AppColor.textSecondary,
                            fontWeight: FontWeight.w700,
                            letterSpacing: 0.6,
                          ),
                        ),
                        const SizedBox(height: 4),
                        Text(
                          _voucher.name,
                          textAlign: TextAlign.center,
                          style: AppStyle.xl.copyWith(
                            fontWeight: FontWeight.w700,
                          ),
                        ),
                        if (faceValue != null)
                          Text(
                            faceValue,
                            style: AppStyle.md.copyWith(
                              color: AppColor.textSecondary,
                            ),
                          ),
                        if (_voucher.description != null) ...[
                          const SizedBox(height: 12),
                          Text(
                            _voucher.description!,
                            textAlign: TextAlign.center,
                            style: AppStyle.sm.copyWith(
                              color: AppColor.textSecondary,
                              height: 1.5,
                            ),
                          ),
                        ],
                      ],
                    ),
                  ),
                  const SizedBox(height: 12),
                  Container(
                    padding: const EdgeInsets.symmetric(
                      horizontal: 16,
                      vertical: 8,
                    ),
                    decoration: BoxDecoration(
                      color: AppColor.white,
                      borderRadius: BorderRadius.circular(
                        AppValue.borderRadius,
                      ),
                    ),
                    child: Column(
                      children: [
                        _InfoRow(
                          label: 'Ditukar dengan',
                          value:
                              '${_voucher.pointCost.thousandFormat} EnakPoint',
                        ),
                        if (walletState.hasLoaded)
                          _InfoRow(
                            label: 'Saldo EnakPoint kamu',
                            value: pointBalance.thousandFormat,
                            valueColor: canAfford ? null : AppColor.error,
                          ),
                        if (_voucher.validUntil != null)
                          _InfoRow(
                            label: 'Bisa ditukar sampai',
                            value: formatWibDateTime(_voucher.validUntil!),
                          ),
                        if (_voucher.available != null)
                          _InfoRow(
                            label: 'Sisa stok',
                            value: _voucher.isOutOfStock
                                ? 'Habis'
                                : _voucher.available!.thousandFormat,
                          ),
                        if (_voucher.maxPerCustomer != null)
                          _InfoRow(
                            label: 'Batas tukar',
                            value:
                                '${_voucher.maxPerCustomer!.thousandFormat}× '
                                'per customer',
                          ),
                      ],
                    ),
                  ),
                ],
              ),
            ),
            Container(
              color: AppColor.white,
              padding: const EdgeInsets.fromLTRB(16, 12, 16, 12),
              child: SafeArea(
                top: false,
                child: AppElevatedButton(
                  title:
                      blockedLabel ??
                      'Tukar ${_voucher.pointCost.thousandFormat} EnakPoint',
                  height: 48,
                  isLoading: state.isSubmitting,
                  onPressed: blockedLabel == null && !state.isSubmitting
                      ? _redeem
                      : null,
                ),
              ),
            ),
          ],
        );
      },
    );
  }

  Widget _buildSuccess(VoucherRedeemResult result) {
    final redemption = result.redemption;
    final isPending = redemption.status == VoucherRedemptionStatus.pending;
    final isFailed = redemption.status == VoucherRedemptionStatus.failed;

    final (IconData icon, Color color, String title) = isPending
        ? (
            Icons.hourglass_top_rounded,
            AppColor.warning,
            'Voucher sedang diproses',
          )
        : isFailed
        ? (Icons.undo_rounded, AppColor.error, 'Penukaran gagal')
        : (Icons.check_circle, AppColor.success, 'Voucher berhasil ditukar');

    return SafeArea(
      child: Column(
        children: [
          Expanded(
            child: ListView(
              padding: const EdgeInsets.all(20),
              children: [
                const SizedBox(height: 24),
                Icon(icon, color: color, size: 72),
                const SizedBox(height: 16),
                Text(
                  title,
                  textAlign: TextAlign.center,
                  style: AppStyle.xl.copyWith(fontWeight: FontWeight.w700),
                ),
                const SizedBox(height: 4),
                Text(
                  redemption.voucherName,
                  textAlign: TextAlign.center,
                  style: AppStyle.md.copyWith(color: AppColor.textSecondary),
                ),
                const SizedBox(height: 24),
                if (isPending)
                  _Note(
                    'EnakPoint sudah terpotong. Cek lagi di Voucher saya. Bila '
                    'gagal, EnakPoint dikembalikan otomatis.',
                  )
                else if (isFailed)
                  _Note('EnakPoint sudah dikembalikan.')
                else if (redemption.code != null)
                  VoucherCodeBox(code: redemption.code!)
                else
                  const VoucherNoCodeNote(),
                const SizedBox(height: 16),
                if (!isPending && !isFailed && redemption.codeExpiresAt != null)
                  Text(
                    'Berlaku sampai '
                    '${formatWibDateTime(redemption.codeExpiresAt!)}',
                    textAlign: TextAlign.center,
                    style: AppStyle.sm.copyWith(color: AppColor.textSecondary),
                  ),
                const SizedBox(height: 6),
                Text(
                  'Saldo EnakPoint sekarang: '
                  '${result.pointBalance.thousandFormat}',
                  textAlign: TextAlign.center,
                  style: AppStyle.sm.copyWith(color: AppColor.textSecondary),
                ),
              ],
            ),
          ),
          Padding(
            padding: const EdgeInsets.all(20),
            child: AppElevatedButton(
              title: 'Lihat voucher saya',
              onPressed: () => context.router.pop(true),
            ),
          ),
        ],
      ),
    );
  }
}

class _Note extends StatelessWidget {
  const _Note(this.message);

  final String message;

  @override
  Widget build(BuildContext context) {
    return Container(
      padding: const EdgeInsets.all(14),
      decoration: BoxDecoration(
        color: AppColor.white,
        borderRadius: BorderRadius.circular(AppValue.borderRadius),
      ),
      child: Text(
        message,
        textAlign: TextAlign.center,
        style: AppStyle.sm.copyWith(color: AppColor.textSecondary),
      ),
    );
  }
}

class _InfoRow extends StatelessWidget {
  const _InfoRow({required this.label, required this.value, this.valueColor});

  final String label;
  final String value;
  final Color? valueColor;

  @override
  Widget build(BuildContext context) {
    return Padding(
      padding: const EdgeInsets.symmetric(vertical: 8),
      child: Row(
        children: [
          Text(
            label,
            style: AppStyle.sm.copyWith(color: AppColor.textSecondary),
          ),
          const SizedBox(width: 12),
          Expanded(
            child: Text(
              value,
              textAlign: TextAlign.end,
              style: AppStyle.sm.copyWith(
                color: valueColor ?? AppColor.textPrimary,
                fontWeight: FontWeight.w600,
              ),
            ),
          ),
        ],
      ),
    );
  }
}