second commit

lib/domain/entities/shift_report.dart

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+import 'package:equatable/equatable.dart';
+
+import '../../core/utils/extensions.dart';
+import 'transaction.dart';
+
+/// Everything the back office needs from a day at this terminal.
+///
+/// Computed from the locally stored transactions, so it can be produced with
+/// no connection and pushed whenever one is available.
+class ShiftReport extends Equatable {
+  const ShiftReport({
+    required this.businessDate,
+    required this.terminalId,
+    required this.cashierName,
+    required this.billCount,
+    required this.itemCount,
+    required this.grossSales,
+    required this.taxCollected,
+    required this.discountGiven,
+    required this.roundOff,
+    required this.paymentBreakdown,
+    required this.loyaltyPointsIssued,
+    required this.loyaltyPointsRedeemed,
+    this.firstBillAt,
+    this.lastBillAt,
+  });
+
+  final DateTime businessDate;
+  final String terminalId;
+  final String cashierName;
+
+  final int billCount;
+
+  /// Total units sold across every bill.
+  final double itemCount;
+
+  final double grossSales;
+  final double taxCollected;
+  final double discountGiven;
+  final double roundOff;
+
+  final Map<PaymentMethod, double> paymentBreakdown;
+
+  final int loyaltyPointsIssued;
+  final int loyaltyPointsRedeemed;
+
+  final DateTime? firstBillAt;
+  final DateTime? lastBillAt;
+
+  /// A zeroed report for a day with no trading. Not a const — [DateTime]
+  /// cannot appear in a constant expression.
+  factory ShiftReport.blank({
+    required DateTime businessDate,
+    required String terminalId,
+    required String cashierName,
+  }) =>
+      ShiftReport(
+        businessDate: businessDate,
+        terminalId: terminalId,
+        cashierName: cashierName,
+        billCount: 0,
+        itemCount: 0,
+        grossSales: 0,
+        taxCollected: 0,
+        discountGiven: 0,
+        roundOff: 0,
+        paymentBreakdown: const {},
+        loyaltyPointsIssued: 0,
+        loyaltyPointsRedeemed: 0,
+      );
+
+  bool get isEmpty => billCount == 0;
+
+  double get averageBasket =>
+      billCount == 0 ? 0 : (grossSales / billCount).asMoney;
+
+  double get netOfTax => (grossSales - taxCollected).asMoney;
+
+  /// Builds the report from the day's transactions.
+  factory ShiftReport.fromTransactions({
+    required List<SaleTransaction> transactions,
+    required DateTime businessDate,
+    required String terminalId,
+    required String cashierName,
+  }) {
+    final completed = transactions
+        .where((t) =>
+            t.status == TransactionStatus.completed &&
+            t.createdAt.year == businessDate.year &&
+            t.createdAt.month == businessDate.month &&
+            t.createdAt.day == businessDate.day)
+        .toList()
+      ..sort((a, b) => a.createdAt.compareTo(b.createdAt));
+
+    final byMethod = <PaymentMethod, double>{};
+    for (final t in completed) {
+      for (final p in t.payments) {
+        byMethod[p.method] = ((byMethod[p.method] ?? 0) + p.amount).asMoney;
+      }
+    }
+
+    return ShiftReport(
+      businessDate: businessDate,
+      terminalId: terminalId,
+      cashierName: cashierName,
+      billCount: completed.length,
+      itemCount:
+          completed.fold(0.0, (s, t) => s + t.cart.totalQuantity),
+      grossSales: completed.fold(0.0, (s, t) => s + t.total).asMoney,
+      taxCollected:
+          completed.fold(0.0, (s, t) => s + t.cart.taxAmount).asMoney,
+      discountGiven: completed
+          .fold(0.0,
+              (s, t) => s + t.cart.billDiscountTotal + t.cart.lineDiscountTotal)
+          .asMoney,
+      roundOff: completed.fold(0.0, (s, t) => s + t.cart.roundOff).asMoney,
+      paymentBreakdown: byMethod,
+      loyaltyPointsIssued:
+          completed.fold(0, (s, t) => s + t.pointsEarned),
+      loyaltyPointsRedeemed:
+          completed.fold(0, (s, t) => s + t.pointsRedeemed),
+      firstBillAt: completed.isEmpty ? null : completed.first.createdAt,
+      lastBillAt: completed.isEmpty ? null : completed.last.createdAt,
+    );
+  }
+
+  /// The JSON body that would be sent to the back office.
+  Map<String, Object?> toPayload() => {
+        'business_date': businessDate.toIso8601String().substring(0, 10),
+        'terminal_id': terminalId,
+        'cashier': cashierName,
+        'bill_count': billCount,
+        'item_count': itemCount,
+        'gross_sales': grossSales,
+        'net_of_tax': netOfTax,
+        'tax_collected': taxCollected,
+        'discount_given': discountGiven,
+        'round_off': roundOff,
+        'average_basket': averageBasket,
+        'loyalty_points_issued': loyaltyPointsIssued,
+        'loyalty_points_redeemed': loyaltyPointsRedeemed,
+        'first_bill_at': firstBillAt?.toIso8601String(),
+        'last_bill_at': lastBillAt?.toIso8601String(),
+        'payments': {
+          for (final e in paymentBreakdown.entries) e.key.name: e.value,
+        },
+      };
+
+  @override
+  List<Object?> get props =>
+      [businessDate, terminalId, billCount, grossSales];
+}