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

import '../../../application/wallet/transfer_form/transfer_form_bloc.dart';
import '../../../application/wallet/wallet_history_loader/wallet_history_loader_bloc.dart';
import '../../../application/wallet/wallet_loader/wallet_loader_bloc.dart';
import '../../../common/extension/extension.dart';
import '../../../common/function/app_function.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_ui.dart';
import 'widgets/wallet_history_section.dart';
import 'widgets/wallet_confirm_dialog.dart';
import 'widgets/wallet_result_view.dart';

/// Transfer EnakPoint / EnakCoin ke customer lain (§8.2).
@RoutePage()
class TransferPage extends StatefulWidget implements AutoRouteWrapper {
  const TransferPage({super.key});

  @override
  State<TransferPage> createState() => _TransferPageState();

  @override
  Widget wrappedRoute(BuildContext context) => MultiBlocProvider(
    providers: [
      BlocProvider(create: (_) => getIt<TransferFormBloc>()),
      BlocProvider(
        create: (_) => getIt<WalletHistoryLoaderBloc>()
          ..add(
            const WalletHistoryLoaderEvent.filterChanged(
              types: [
                WalletTransactionType.transferOut,
                WalletTransactionType.transferIn,
              ],
            ),
          ),
      ),
    ],
    child: this,
  );
}

class _TransferPageState extends State<TransferPage> {
  final TextEditingController _phoneController = TextEditingController();
  final TextEditingController _amountController = TextEditingController();
  final ScrollController _scrollController = ScrollController();

  @override
  void initState() {
    super.initState();
    // Halaman ini juga dibuka dari beranda, saldo belum tentu sudah dimuat.
    context.read<WalletLoaderBloc>().add(const WalletLoaderEvent.fetched());
    _scrollController.addListener(_onScroll);
  }

  @override
  void dispose() {
    _phoneController.dispose();
    _amountController.dispose();
    _scrollController.dispose();
    super.dispose();
  }

  void _onScroll() {
    final position = _scrollController.position;
    if (position.pixels >= position.maxScrollExtent - 200) {
      context.read<WalletHistoryLoaderBloc>().add(
        const WalletHistoryLoaderEvent.loadedMore(),
      );
    }
  }

  Future<void> _onRefresh() async {
    context.read<WalletLoaderBloc>().add(const WalletLoaderEvent.fetched());
    final history = context.read<WalletHistoryLoaderBloc>();
    history.add(const WalletHistoryLoaderEvent.refreshed());
    await history.stream.firstWhere((s) => !s.isFetching);
  }

  void _onCurrencyChanged(WalletCurrency currency) {
    if (context.read<TransferFormBloc>().state.currency == currency) return;
    HapticFeedback.selectionClick();
    context.read<TransferFormBloc>().add(
      TransferFormEvent.currencyChanged(currency),
    );
    context.read<WalletHistoryLoaderBloc>().add(
      WalletHistoryLoaderEvent.currencyChanged(currency),
    );
  }

  void _fillAmount(int amount) {
    final text = amount.thousandFormat;
    _amountController.value = TextEditingValue(
      text: text,
      selection: TextSelection.collapsed(offset: text.length),
    );
    context.read<TransferFormBloc>().add(
      TransferFormEvent.amountChanged(amount),
    );
  }

  Future<void> _onRecipientFound(TransferFormState state) async {
    final recipient = state.recipient!;
    final confirmed = await showWalletConfirmDialog(
      context,
      title: 'Kirim ke ${recipient.name} (${recipient.phoneNumber})?',
      message:
          'Kamu akan mengirim ${state.amount.thousandFormat} '
          '${state.currency.label}. Transfer bersifat final dan tidak bisa '
          'dibatalkan.',
      confirmLabel: 'Kirim',
    );
    if (!confirmed || !mounted) return;
    if (!await ensurePinReady(context) || !mounted) return;

    final success = await showPinSheet(
      context,
      title: 'Transfer ${state.currency.label}',
      onSubmit: (pin) async {
        final bloc = context.read<TransferFormBloc>();
        bloc.add(TransferFormEvent.submitted(pin));
        final result = await bloc.stream.firstWhere((s) => !s.isSubmitting);
        return result.failureOption.toNullable();
      },
    );

    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 transfer belum diketahui. Tekan Lanjut lagi '
        'untuk mengulang. Saldo tidak akan terpotong dua kali.',
      );
      return;
    }

    final reason = failure.maybeMap(
      rejected: (value) => _transferRejectReason(value.cause),
      orElse: () => null,
    );

    AppFlushbar.showError(
      context,
      walletFailureMessage(
        failure,
        rejectedMessage: reason == null
            ? 'Transfer tidak bisa diproses.'
            : 'Transfer tidak bisa diproses. $reason',
      ),
    );
  }

  /// Mengenali alasan penolakan `304` dari `cause` (bahasa Inggris) tanpa
  /// menampilkannya mentah.
  String? _transferRejectReason(String cause) {
    final text = cause.toLowerCase();
    if (text.contains('daily')) return 'Melewati batas transfer harian.';
    if (text.contains('not enough') || text.contains('insufficient')) {
      return 'Saldo tidak cukup.';
    }
    if (text.contains('minimum') || text.contains('below')) {
      return 'Jumlah di bawah minimal transfer.';
    }
    if (text.contains('maximum') ||
        text.contains('exceed') ||
        text.contains('above')) {
      return 'Jumlah melebihi maksimal per transaksi.';
    }
    if (text.contains('disabled') || text.contains('not enabled')) {
      return 'Fitur transfer sedang tidak tersedia.';
    }
    return null;
  }

  String? _recipientError(TransferFormState state) {
    final failure = state.recipientFailureOption.toNullable();
    if (failure == null) return null;
    return failure.maybeMap(
      notFound: (_) => 'Nomor ini tidak terdaftar',
      rejected: (_) => 'Tidak bisa mengirim ke nomor ini',
      orElse: () => walletFailureMessage(failure),
    );
  }

  @override
  Widget build(BuildContext context) {
    return MultiBlocListener(
      listeners: [
        BlocListener<TransferFormBloc, TransferFormState>(
          listenWhen: (p, c) => p.failureOption != c.failureOption,
          listener: (context, state) =>
              state.failureOption.fold(() {}, _showFailure),
        ),
        BlocListener<TransferFormBloc, TransferFormState>(
          listenWhen: (p, c) =>
              p.recipient != c.recipient && c.recipient != null,
          listener: (context, state) => _onRecipientFound(state),
        ),
      ],
      child: BlocBuilder<TransferFormBloc, TransferFormState>(
        builder: (context, state) {
          final result = state.result;
          return Scaffold(
            backgroundColor: AppColor.background,
            appBar: AppBar(title: const Text('Transfer')),
            body: AnimatedSwitcher(
              duration: const Duration(milliseconds: 300),
              child: result != null
                  ? KeyedSubtree(
                      key: const ValueKey('success'),
                      child: _buildSuccess(result),
                    )
                  : KeyedSubtree(
                      key: const ValueKey('form'),
                      child: _buildForm(state),
                    ),
            ),
          );
        },
      ),
    );
  }

  Widget _buildForm(TransferFormState state) {
    return RefreshIndicator(
      color: AppColor.primary,
      onRefresh: _onRefresh,
      child: CustomScrollView(
        controller: _scrollController,
        physics: const AlwaysScrollableScrollPhysics(),
        keyboardDismissBehavior: ScrollViewKeyboardDismissBehavior.onDrag,
        slivers: [
          SliverPadding(
            padding: const EdgeInsets.fromLTRB(16, 16, 16, 28),
            sliver: SliverToBoxAdapter(
              child: BlocBuilder<WalletLoaderBloc, WalletLoaderState>(
                buildWhen: (p, c) =>
                    p.summary != c.summary || p.hasLoaded != c.hasLoaded,
                builder: (context, walletState) =>
                    _buildFormContent(state, walletState),
              ),
            ),
          ),
          SliverPadding(
            padding: const EdgeInsets.fromLTRB(16, 0, 16, 32),
            sliver: WalletHistorySection(
              title: 'Riwayat transfer',
              emptyIcon: Icons.swap_horiz_rounded,
              emptyTitle: 'Belum ada transfer',
              emptySubtitle: (currency) =>
                  'Transfer ${currency.label} yang kamu kirim atau terima '
                  'akan muncul di sini.',
            ),
          ),
        ],
      ),
    );
  }

  Widget _buildFormContent(
    TransferFormState state,
    WalletLoaderState walletState,
  ) {
    final summary = walletState.summary;
    final balance = _balanceOf(summary, state.currency);
    final exceedsBalance = walletState.hasLoaded && state.amount > balance;
    final isBusy = state.isCheckingRecipient || state.isSubmitting;

    return Column(
      crossAxisAlignment: CrossAxisAlignment.stretch,
      children: [
        _buildSectionLabel('Kirim dari'),
        Row(
          children: [
            for (final currency in WalletCurrency.values) ...[
              if (currency != WalletCurrency.values.first)
                const SizedBox(width: 12),
              Expanded(
                child: _CurrencyOption(
                  currency: currency,
                  balance: _balanceOf(summary, currency),
                  isLoaded: walletState.hasLoaded,
                  selected: state.currency == currency,
                  onTap: isBusy ? null : () => _onCurrencyChanged(currency),
                ),
              ),
            ],
          ],
        ),
        const SizedBox(height: 20),
        Container(
          padding: const EdgeInsets.fromLTRB(16, 16, 16, 12),
          decoration: BoxDecoration(
            color: AppColor.white,
            borderRadius: BorderRadius.circular(AppValue.borderRadius),
          ),
          child: Column(
            crossAxisAlignment: CrossAxisAlignment.start,
            children: [
              _buildSectionLabel('Nomor HP penerima', inCard: true),
              TextField(
                controller: _phoneController,
                keyboardType: TextInputType.phone,
                textInputAction: TextInputAction.next,
                enabled: !isBusy,
                cursorColor: AppColor.primary,
                inputFormatters: [
                  FilteringTextInputFormatter.digitsOnly,
                  LengthLimitingTextInputFormatter(15),
                ],
                style: AppStyle.lg.copyWith(
                  fontWeight: FontWeight.w600,
                  letterSpacing: 0.5,
                ),
                onChanged: (value) => context.read<TransferFormBloc>().add(
                  TransferFormEvent.phoneChanged(value),
                ),
                decoration: InputDecoration(
                  hintText: '08xxxxxxxxxx',
                  errorText: _recipientError(state),
                  prefixIcon: const Padding(
                    padding: EdgeInsets.only(right: 10),
                    child: Icon(
                      Icons.person_outline_rounded,
                      color: AppColor.textSecondary,
                      size: 22,
                    ),
                  ),
                  prefixIconConstraints: const BoxConstraints(),
                ),
              ),
              const SizedBox(height: 24),
              _buildSectionLabel('Jumlah', inCard: true),
              TextField(
                controller: _amountController,
                keyboardType: TextInputType.number,
                textInputAction: TextInputAction.done,
                enabled: !isBusy,
                cursorColor: AppColor.primary,
                inputFormatters: [ThousandsInputFormatter()],
                style: AppStyle.h4.copyWith(fontWeight: FontWeight.w700),
                onChanged: (value) => context.read<TransferFormBloc>().add(
                  TransferFormEvent.amountChanged(
                    int.tryParse(digitsOnly(value)) ?? 0,
                  ),
                ),
                decoration: InputDecoration(
                  hintText: '0',
                  hintStyle: AppStyle.h4.copyWith(
                    color: AppColor.textLight,
                    fontWeight: FontWeight.w700,
                  ),
                  errorText: exceedsBalance ? 'Melebihi saldo kamu' : null,
                  suffixText: state.currency.label,
                  suffixStyle: AppStyle.md.copyWith(
                    color: AppColor.textSecondary,
                    fontWeight: FontWeight.w600,
                  ),
                ),
              ),
              const SizedBox(height: 4),
              Row(
                children: [
                  Expanded(
                    child: Text(
                      walletState.hasLoaded
                          ? 'Saldo tersedia ${balance.thousandFormat}'
                          : 'Memuat saldo…',
                      style: AppStyle.sm.copyWith(
                        color: AppColor.textSecondary,
                      ),
                    ),
                  ),
                  TextButton(
                    onPressed: walletState.hasLoaded && balance > 0 && !isBusy
                        ? () => _fillAmount(balance)
                        : null,
                    style: TextButton.styleFrom(
                      foregroundColor: AppColor.primary,
                      padding: const EdgeInsets.symmetric(horizontal: 8),
                      minimumSize: const Size(0, 32),
                      tapTargetSize: MaterialTapTargetSize.shrinkWrap,
                    ),
                    child: Text(
                      'Kirim semua',
                      style: AppStyle.sm.copyWith(fontWeight: FontWeight.w700),
                    ),
                  ),
                ],
              ),
            ],
          ),
        ),
        const SizedBox(height: 12),
        Row(
          crossAxisAlignment: CrossAxisAlignment.start,
          children: [
            const Icon(
              Icons.info_outline_rounded,
              size: 16,
              color: AppColor.textSecondary,
            ),
            const SizedBox(width: 6),
            Expanded(
              child: Text(
                'Transfer bersifat final dan tidak bisa dibatalkan. Pastikan '
                'nomor penerima sudah benar.',
                style: AppStyle.xs.copyWith(color: AppColor.textSecondary),
              ),
            ),
          ],
        ),
        const SizedBox(height: 20),
        AppElevatedButton(
          title: 'Lanjut',
          height: 48,
          isLoading: isBusy,
          onPressed: state.isFilled && !exceedsBalance && !isBusy
              ? () {
                  dismissKeyboard(context);
                  context.read<TransferFormBloc>().add(
                    const TransferFormEvent.recipientChecked(),
                  );
                }
              : null,
        ),
      ],
    );
  }

  Widget _buildSectionLabel(String text, {bool inCard = false}) {
    return Padding(
      padding: EdgeInsets.only(left: inCard ? 0 : 4, bottom: inCard ? 4 : 10),
      child: Text(
        text,
        style: AppStyle.sm.copyWith(
          color: AppColor.textSecondary,
          fontWeight: FontWeight.w600,
        ),
      ),
    );
  }

  int _balanceOf(WalletSummary summary, WalletCurrency currency) =>
      currency == WalletCurrency.point
      ? summary.pointBalance
      : summary.coinBalance;

  Widget _buildSuccess(TransferResult result) {
    return WalletResultView(
      title: 'Transfer berhasil',
      amountText:
          '${result.amount.thousandFormat} ${result.currency.label} terkirim',
      lines: [
        'Ke ${result.recipient.name} (${result.recipient.phoneNumber})',
        'Saldo tersisa: ${result.balance.thousandFormat} '
            '${result.currency.label}',
        ...result.lots
            .where((lot) => lot.expiresAt != null)
            .map(
              (lot) =>
                  '${lot.amount.thousandFormat} ${result.currency.label} yang '
                  'dikirim berlaku sampai ${formatWibDate(lot.expiresAt!)}',
            ),
      ],
      onDone: () => context.router.maybePop(),
    );
  }
}

/// Kartu pilihan mata uang beserta saldonya.
class _CurrencyOption extends StatelessWidget {
  const _CurrencyOption({
    required this.currency,
    required this.balance,
    required this.isLoaded,
    required this.selected,
    required this.onTap,
  });

  final WalletCurrency currency;
  final int balance;
  final bool isLoaded;
  final bool selected;
  final VoidCallback? onTap;

  @override
  Widget build(BuildContext context) {
    final radius = BorderRadius.circular(AppValue.borderRadius);

    return Material(
      color: Colors.transparent,
      child: InkWell(
        onTap: onTap,
        borderRadius: radius,
        child: AnimatedContainer(
          duration: const Duration(milliseconds: 220),
          curve: Curves.easeOut,
          padding: const EdgeInsets.all(14),
          decoration: BoxDecoration(
            color: selected
                ? AppColor.primaryWithOpacity(0.06)
                : AppColor.white,
            borderRadius: radius,
            border: Border.all(
              color: selected ? AppColor.primary : AppColor.white,
              width: 1.5,
            ),
          ),
          child: Column(
            crossAxisAlignment: CrossAxisAlignment.start,
            children: [
              Row(
                children: [
                  AnimatedScale(
                    scale: selected ? 1 : 0.85,
                    duration: const Duration(milliseconds: 220),
                    curve: Curves.easeOut,
                    alignment: Alignment.centerLeft,
                    child: WalletCurrencyIcon(currency: currency, size: 36),
                  ),
                  const Spacer(),
                  AnimatedScale(
                    scale: selected ? 1 : 0,
                    duration: const Duration(milliseconds: 220),
                    curve: Curves.easeOutBack,
                    child: const Icon(
                      Icons.check_circle_rounded,
                      size: 20,
                      color: AppColor.primary,
                    ),
                  ),
                ],
              ),
              const SizedBox(height: 12),
              Text(
                currency.label,
                style: AppStyle.sm.copyWith(color: AppColor.textSecondary),
              ),
              const SizedBox(height: 2),
              Text(
                isLoaded ? balance.thousandFormat : '–',
                maxLines: 1,
                overflow: TextOverflow.ellipsis,
                style: AppStyle.xl.copyWith(fontWeight: FontWeight.w700),
              ),
            ],
          ),
        ),
      ),
    );
  }
}