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/transaction.dart';
import '../../../domain/repositories/sync_repository.dart';
import '../../sync/providers/sync_controller.dart';
import '../widgets/module_widgets.dart';

/// End-of-day sync.
///
/// Shows what the terminal produced today and uploads every bill still at
/// `sync_status = 0`. Accepted bills flip to 1; anything that fails stays at 0
/// and is retried on the next tap.
class EventsView extends ConsumerWidget {
  const EventsView({super.key});

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final report = ref.watch(todayReportProvider);
    final pending = ref.watch(unsyncedCountProvider).value ?? 0;
    final rows = ref.watch(orderSyncRowsProvider).value ?? const [];
    final syncState = ref.watch(orderSyncProvider);
    final events = ref.watch(syncEventsProvider);

    final r = report.value;

    return ModulePage(
      children: [
        Wrap(
          spacing: AppSpacing.lg,
          runSpacing: AppSpacing.lg,
          children: [
            StatTile(
              label: 'Bills Today',
              value: '${r?.billCount ?? 0}',
              icon: Icons.receipt_long_rounded,
              caption: r?.firstBillAt == null
                  ? 'no sales yet'
                  : '${Formatters.time(r!.firstBillAt!)} – '
                      '${Formatters.time(r.lastBillAt!)}',
            ),
            StatTile(
              label: 'Items Sold',
              value: (r?.itemCount ?? 0).toStringAsFixed(0),
              icon: Icons.shopping_basket_rounded,
              color: AppColors.info,
              caption: 'units across all bills',
            ),
            StatTile(
              label: "Today's Sales",
              value: Formatters.money(r?.grossSales ?? 0),
              icon: Icons.payments_rounded,
              color: AppColors.success,
              caption: 'gross takings',
            ),
            StatTile(
              label: 'Awaiting Sync',
              value: '$pending',
              icon: Icons.cloud_off_rounded,
              color: pending > 0 ? AppColors.warning : AppColors.success,
              caption: pending > 0
                  ? 'held on this terminal'
                  : 'everything uploaded',
            ),
          ],
        ),
        const SizedBox(height: AppSpacing.lg),

        PanelCard(
          title: 'Upload bills to server',
          subtitle: r == null
              ? 'Reading today\u2019s trading from SQLite\u2026'
              : '${Formatters.date(r.businessDate)} \u00b7 ${r.cashierName} '
                  '\u00b7 ${r.terminalId}',
          action: TagChip(
            pending > 0 ? '$pending pending' : 'All synced',
            color: pending > 0 ? AppColors.warning : AppColors.success,
          ),
          child: Column(
            crossAxisAlignment: CrossAxisAlignment.stretch,
            mainAxisSize: MainAxisSize.min,
            children: [
              if (r != null && !r.isEmpty) ...[
                _row('Bills', '${r.billCount}'),
                _row('Items sold', r.itemCount.toStringAsFixed(0)),
                _row('Gross sales', Formatters.money(r.grossSales)),
                _row('GST collected', Formatters.money(r.taxCollected)),
                _row('Discount given', Formatters.money(r.discountGiven)),
                _row('Average basket', Formatters.money(r.averageBasket)),
                if (r.paymentBreakdown.isNotEmpty) ...[
                  const Divider(height: AppSpacing.xxl),
                  for (final e in r.paymentBreakdown.entries)
                    ProgressRow(
                      label: '${e.key.emoji}  ${e.key.label}',
                      value: Formatters.money(e.value),
                      fraction:
                          r.grossSales <= 0 ? 0 : e.value / r.grossSales,
                      color: _methodColor(e.key),
                    ),
                ],
                const SizedBox(height: AppSpacing.lg),
              ],

              if (syncState is SyncRunning) ...[
                Text(
                  syncState.stage,
                  style: const TextStyle(
                    fontSize: 13,
                    color: AppColors.textSecondary,
                  ),
                ),
                const SizedBox(height: AppSpacing.sm),
                ClipRRect(
                  borderRadius: AppRadius.brPill,
                  child: LinearProgressIndicator(
                    value: syncState.progress,
                    minHeight: 8,
                    backgroundColor: AppColors.divider,
                    valueColor:
                        const AlwaysStoppedAnimation<Color>(AppColors.primary),
                  ),
                ),
                const SizedBox(height: AppSpacing.lg),
              ],

              if (syncState is SyncFinished)
                _outcomeBanner(syncState.outcome),

              PrimaryButton(
                label: pending > 0
                    ? 'Sync $pending bill${pending == 1 ? '' : 's'}'
                    : 'Nothing to sync',
                icon: Icons.cloud_upload_rounded,
                large: true,
                busy: syncState is SyncRunning,
                onPressed: pending == 0
                    ? null
                    : () => ref.read(orderSyncProvider.notifier).run(),
              ),
              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(
                      'Bills are written to SQLite the moment a sale '
                      'completes. A failed upload changes nothing on disk — '
                      'every bill stays until the server confirms it.',
                      style: TextStyle(
                        fontSize: 12,
                        color: AppColors.textTertiary,
                        height: 1.5,
                      ),
                    ),
                  ),
                ],
              ),
            ],
          ),
        ),
        const SizedBox(height: AppSpacing.lg),

        PanelCard(
          title: 'Orders',
          subtitle: '${rows.length} stored \u00b7 $pending awaiting upload',
          child: ResponsiveTable(
            columns: const [
              TableCol('Invoice', flex: 3),
              TableCol('Time', flex: 2, priority: 1),
              TableCol('Total', flex: 2, numeric: true),
              TableCol('Sync', flex: 2, numeric: true),
            ],
            rows: rows
                .map((o) => [
                      Cell(o.invoiceNumber, bold: true, mono: true),
                      Cell(Formatters.time(o.createdAt),
                          color: AppColors.textTertiary,),
                      Cell(Formatters.money(o.total), mono: true, bold: true),
                      TagChip(
                        o.isSynced ? 'Synced' : 'Pending',
                        color:
                            o.isSynced ? AppColors.success : AppColors.warning,
                      ),
                    ],)
                .toList(),
          ),
        ),

        if (events.isNotEmpty) ...[
          const SizedBox(height: AppSpacing.lg),
          PanelCard(
            title: 'Sync history',
            subtitle: 'This session',
            child: ResponsiveTable(
              columns: const [
                TableCol('Event', flex: 3),
                TableCol('Detail', flex: 5, priority: 1),
                TableCol('Time', 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,),
                      ],)
                  .toList(),
            ),
          ),
        ],
      ],
    );
  }

  Widget _outcomeBanner(SyncOutcome outcome) {
    final ok = outcome.isSuccess;
    final uploaded = outcome.uploaded;
    final attempted = outcome.attempted;

    return Container(
      margin: const EdgeInsets.only(bottom: AppSpacing.lg),
      padding: const EdgeInsets.all(AppSpacing.md),
      decoration: BoxDecoration(
        color: ok ? AppColors.successSurface : AppColors.dangerSurface,
        borderRadius: AppRadius.brSm,
      ),
      child: Row(
        crossAxisAlignment: CrossAxisAlignment.start,
        children: [
          Icon(
            ok ? Icons.check_circle_outline_rounded : Icons.wifi_off_rounded,
            size: 18,
            color: ok ? AppColors.success : AppColors.danger,
          ),
          const SizedBox(width: AppSpacing.sm),
          Expanded(
            child: Text(
              ok
                  ? '$uploaded of $attempted bills uploaded and marked synced.'
                  : '${outcome.error}',
              style: TextStyle(
                fontSize: 13,
                height: 1.45,
                color: ok ? AppColors.success : AppColors.danger,
              ),
            ),
          ),
        ],
      ),
    );
  }

  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,
                overflow: TextOverflow.ellipsis,
                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,
              ),
            ),
          ],
        ),
      );
}