add paginator

lib/domain/entities/box.dart

@@ -1,3 +1,5 @@
+import 'package:fcs/domain/entities/discount_by_weight.dart';
+import 'package:fcs/domain/entities/rate.dart';
 import 'package:fcs/domain/vo/shipment_status.dart';
 import 'package:fcs/domain/vo/delivery_address.dart';
 
@@ -17,9 +19,9 @@ class Box {
   String status;
   String cargoDesc;
   String desc;
-  int width;
-  int height;
-  int length;
+  double width;
+  double height;
+  double length;
   int shipmentWeight;
   bool isChecked;
   String cartonType;
@@ -38,7 +40,7 @@ class Box {
 
   List<CargoType> cargoTypes;
 
-  DeliveryAddress shippingAddress;
+  DeliveryAddress deliveryAddress;
 
   int get amount => rate != null && weight != null ? rate * weight : 0;
 
@@ -46,6 +48,9 @@ class Box {
       shipmentNumber + "-" + receiverNumber + " #" + boxNumber;
   double get price => rate.toDouble() * weight;
 
+  double get actualWeight =>
+      cargoTypes == null ? 0 : cargoTypes.fold(0, (p, e) => e.weight + p);
+
   double getShipmentWeight(double volumetricRatio) {
     if (length == null ||
         length <= 0 ||
@@ -59,6 +64,30 @@ class Box {
     return (length * width * height) / volumetricRatio;
   }
 
+  /// calAmount returns total amount
+  double calAmount(Rate rate) {
+    // get shipment weight
+    double volume = (length ?? 0) * (width ?? 0) * (height ?? 0);
+    double sw = volume / rate.volumetricRatio ?? 0;
+
+    // get actual weight
+    double aw = cargoTypes.fold(0.0, (p, c) => p + c.weight);
+    if (aw == 0 || sw == 0) return 0;
+
+    DiscountByWeight discountByWeight =
+        rate.getDiscountByWeight(sw > aw ? sw : aw);
+
+    double total = 0;
+    cargoTypes.forEach((e) {
+      double cargoWeight = aw > sw ? e.weight : e.weight / aw * sw;
+      double r =
+          e.rate - (discountByWeight != null ? discountByWeight.discount : 0);
+      double amount = cargoWeight * r;
+      total += amount;
+    });
+    return total;
+  }
+
   List<ShipmentStatus> shipmentHistory;
 
   Box(
@@ -91,5 +120,17 @@ class Box {
       this.shipmentHistory,
       this.packages,
       this.cargoTypes,
-      this.shippingAddress});
+      this.deliveryAddress});
+
+  Map<String, dynamic> toMap() {
+    List _cargoTypes = cargoTypes.map((c) => c.toMap()).toList();
+    return {
+      "id": id,
+      'cargo_types': _cargoTypes,
+      'length': length,
+      'width': width,
+      'height': height,
+      'delivery_address': deliveryAddress.toMap(),
+    };
+  }
 }