import 'package:flutter/material.dart';
import 'package:flutter_riverpod/flutter_riverpod.dart';

import '../../../core/theme/app_colors.dart';
import '../../../core/theme/app_dimens.dart';
import '../../../core/utils/formatters.dart';
import '../../../core/widgets/primary_button.dart';
import '../../../domain/entities/sync_event.dart';
import '../../../domain/entities/transaction.dart';
import '../../sync/providers/sync_controller.dart';
import '../widgets/module_widgets.dart';

/// The terminal's outbound half: what today produced, and what has been sent.
class EventsView extends ConsumerWidget {
  const EventsView({super.key});

  static Color statusColor(SyncStatus s) => switch (s) {
        SyncStatus.synced => AppColors.success,
        SyncStatus.failed => AppColors.danger,
        SyncStatus.syncing => AppColors.info,
        SyncStatus.pending => AppColors.warning,
      };

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final report = ref.watch(shiftReportProvider);
    final events = ref.watch(syncEventsProvider);
    final pushing = ref.watch(reportPushProvider);

    return ModulePage(
      children: [
        Wrap(
          spacing: AppSpacing.lg,
          runSpacing: AppSpacing.lg,
          children: [
            StatTile(
              label: 'Bills Today',
              value: '${report.billCount}',
              icon: Icons.receipt_long_rounded,
              caption: report.firstBillAt == null
                  ? 'no sales yet'
                  : '${Formatters.time(report.firstBillAt!)} – '
                      '${Formatters.time(report.lastBillAt!)}',
            ),
            StatTile(
              label: 'Items Sold',
              value: report.itemCount.toStringAsFixed(0),
              icon: Icons.shopping_basket_rounded,
              color: AppColors.info,
              caption: 'units across all bills',
            ),
            StatTile(
              label: "Today's Sales",
              value: Formatters.money(report.grossSales),
              icon: Icons.payments_rounded,
              color: AppColors.success,
              caption: 'gross takings',
            ),
            StatTile(
              label: 'Average Basket',
              value: Formatters.money(report.averageBasket),
              icon: Icons.trending_up_rounded,
              color: AppColors.tierGold,
              caption: 'per bill',
            ),
          ],
        ),
        const SizedBox(height: AppSpacing.lg),

        PanelCard(
          title: 'Shift report',
          subtitle: '${Formatters.date(report.businessDate)} · '
              '${report.cashierName} · ${report.terminalId}',
          action: TagChip(
            report.isEmpty ? 'Nothing to send' : 'Ready to push',
            color: report.isEmpty ? AppColors.textSecondary : AppColors.warning,
          ),
          child: Column(
            crossAxisAlignment: CrossAxisAlignment.stretch,
            mainAxisSize: MainAxisSize.min,
            children: [
              _row('Bills', '${report.billCount}'),
              _row('Items sold', report.itemCount.toStringAsFixed(0)),
              _row('Gross sales', Formatters.money(report.grossSales)),
              _row('Net of tax', Formatters.money(report.netOfTax)),
              _row('GST collected', Formatters.money(report.taxCollected)),
              _row('Discount given', Formatters.money(report.discountGiven)),
              _row('Round off', Formatters.money(report.roundOff)),
              _row('Points issued', '${report.loyaltyPointsIssued}'),
              _row('Points redeemed', '${report.loyaltyPointsRedeemed}'),

              if (report.paymentBreakdown.isNotEmpty) ...[
                const Divider(height: AppSpacing.xxl),
                const Align(
                  alignment: Alignment.centerLeft,
                  child: Text(
                    'By payment method',
                    style: TextStyle(
                      fontSize: 13,
                      fontWeight: FontWeight.w600,
                      color: AppColors.textSecondary,
                    ),
                  ),
                ),
                const SizedBox(height: AppSpacing.sm),
                for (final e in report.paymentBreakdown.entries)
                  ProgressRow(
                    label: '${e.key.emoji}  ${e.key.label}',
                    value: Formatters.money(e.value),
                    fraction: report.grossSales <= 0
                        ? 0
                        : e.value / report.grossSales,
                    color: _methodColor(e.key),
                  ),
              ],

              const SizedBox(height: AppSpacing.xl),
              PrimaryButton(
                label: 'Push report to server',
                icon: Icons.cloud_upload_rounded,
                large: true,
                busy: pushing,
                onPressed: report.isEmpty
                    ? null
                    : () async {
                        final event = await ref
                            .read(reportPushProvider.notifier)
                            .pushToday();
                        if (!context.mounted) return;
                        final ok = event.status == SyncStatus.synced;
                        ScaffoldMessenger.of(context)
                          ..hideCurrentSnackBar()
                          ..showSnackBar(SnackBar(
                            backgroundColor:
                                ok ? AppColors.success : AppColors.danger,
                            content: Text(
                              ok
                                  ? 'Shift report sent.'
                                  : 'Push failed — the report is still saved '
                                      'on this terminal.',
                            ),
                          ));
                      },
              ),
              const SizedBox(height: AppSpacing.md),
              const Row(
                crossAxisAlignment: CrossAxisAlignment.start,
                children: [
                  Icon(Icons.shield_outlined,
                      size: 15, color: AppColors.textTertiary),
                  SizedBox(width: AppSpacing.sm),
                  Expanded(
                    child: Text(
                      'A failed push never discards data. The report stays '
                      'queued below and can be retried at any time.',
                      style: TextStyle(
                        fontSize: 12,
                        color: AppColors.textTertiary,
                        height: 1.5,
                      ),
                    ),
                  ),
                ],
              ),
            ],
          ),
        ),
        const SizedBox(height: AppSpacing.lg),

        PanelCard(
          title: 'Event log',
          subtitle: '${events.length} recorded · '
              '${events.where((e) => e.status != SyncStatus.synced).length} '
              'outstanding',
          child: events.isEmpty
              ? const Padding(
                  padding: EdgeInsets.symmetric(vertical: AppSpacing.lg),
                  child: Text(
                    'No sync activity yet. Importing the catalogue or pushing '
                    'a report will appear here.',
                    style: TextStyle(color: AppColors.textTertiary),
                  ),
                )
              : ResponsiveTable(
                  columns: const [
                    TableCol('Event', flex: 3),
                    TableCol('Detail', flex: 5, priority: 1),
                    TableCol('Time', flex: 2, numeric: true, priority: 1),
                    TableCol('Status', flex: 2, numeric: true),
                  ],
                  rows: events
                      .map((e) => [
                            Row(
                              mainAxisSize: MainAxisSize.min,
                              children: [
                                Icon(
                                  e.type.isInbound
                                      ? Icons.cloud_download_rounded
                                      : Icons.cloud_upload_rounded,
                                  size: 15,
                                  color: AppColors.textSecondary,
                                ),
                                const SizedBox(width: AppSpacing.sm),
                                Flexible(child: Cell(e.type.label, bold: true)),
                              ],
                            ),
                            Cell(
                              e.error ?? e.summary,
                              color: e.error != null
                                  ? AppColors.danger
                                  : AppColors.textSecondary,
                            ),
                            Cell(Formatters.time(e.createdAt),
                                color: AppColors.textTertiary),
                            e.status == SyncStatus.failed
                                ? _RetryButton(eventId: e.id)
                                : TagChip(
                                    e.status.label,
                                    color: statusColor(e.status),
                                  ),
                          ])
                      .toList(),
                ),
        ),
      ],
    );
  }

  static Color _methodColor(PaymentMethod m) => switch (m) {
        PaymentMethod.cash => AppColors.success,
        PaymentMethod.card => AppColors.info,
        PaymentMethod.upi => AppColors.primary,
        PaymentMethod.wallet => AppColors.warning,
        PaymentMethod.giftCard => AppColors.tierGold,
        PaymentMethod.loyalty => AppColors.tierSilver,
      };

  Widget _row(String label, String value) => Padding(
        padding: const EdgeInsets.symmetric(vertical: AppSpacing.xs + 2),
        child: Row(
          children: [
            Expanded(
              child: Text(
                label,
                style: const TextStyle(
                  fontSize: 13.5,
                  color: AppColors.textSecondary,
                ),
              ),
            ),
            const SizedBox(width: AppSpacing.md),
            Text(
              value,
              style: const TextStyle(
                fontSize: 13.5,
                fontWeight: FontWeight.w600,
                color: AppColors.textPrimary,
              ),
            ),
          ],
        ),
      );
}

class _RetryButton extends ConsumerWidget {
  const _RetryButton({required this.eventId});

  final String eventId;

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final busy = ref.watch(reportPushProvider);

    return TextButton.icon(
      onPressed: busy
          ? null
          : () => ref.read(reportPushProvider.notifier).retry(eventId),
      icon: const Icon(Icons.refresh_rounded, size: 15),
      label: const Text('Retry', style: TextStyle(fontSize: 12.5)),
      style: TextButton.styleFrom(
        foregroundColor: AppColors.danger,
        minimumSize: const Size(0, 30),
        padding: const EdgeInsets.symmetric(horizontal: AppSpacing.sm),
      ),
    );
  }
}