fix rates

lib/domain/entities/carton.dart

@@ -62,7 +62,7 @@ class Carton {
   double get actualWeight =>
       cargoTypes == null ? 0 : cargoTypes.fold(0, (p, e) => e.weight + p);
 
-  double getShipmentWeight(double volumetricRatio) {
+  int getShipmentWeight(double volumetricRatio) {
     if (length == null ||
         length <= 0 ||
         width == null ||
@@ -71,8 +71,8 @@ class Carton {
         height <= 0 ||
         volumetricRatio == null ||
         volumetricRatio <= 0) return 0;
-
-    return (length * width * height) / volumetricRatio;
+  
+    return ((length * width * height) / volumetricRatio).round();
   }
 
   /// getCargoTypeForCalWeight returns carton with shipment weight
@@ -95,25 +95,26 @@ class Carton {
   /// 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;
+    int sw = getShipmentWeight(rate.volumetricRatio);
 
     // 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 wd = sw - aw;
+    wd = wd - rate.diffDiscountWeight;
+    double wdAmount = wd > 0 ? wd * rate.diffWeightRate : 0;
+
+    DiscountByWeight discountByWeight = rate.getDiscountByWeight(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;
+      double amount = e.weight * r;
       total += amount;
     });
-    return total;
+    return total + wdAmount;
   }
 
   List<ShipmentStatus> shipmentHistory;

lib/domain/entities/rate.dart

@@ -8,6 +8,9 @@ class Rate {
   double freeDeliveryWeight;
   double volumetricRatio;
 
+  double diffDiscountWeight;
+  double diffWeightRate;
+
   List<CargoType> cargoTypes;
   List<CustomDuty> customDuties;
   List<DiscountByWeight> discountByWeights;
@@ -22,17 +25,20 @@ class Rate {
       ? null
       : cargoTypes.firstWhere((e) => e.name == "General");
 
-  Rate({
-    this.deliveryFee,
-    this.freeDeliveryWeight,
-    this.volumetricRatio,
-  });
+  Rate(
+      {this.deliveryFee,
+      this.freeDeliveryWeight,
+      this.volumetricRatio,
+      this.diffDiscountWeight,
+      this.diffWeightRate});
 
   factory Rate.fromMap(Map<String, dynamic> map) {
     return Rate(
       deliveryFee: (map['delivery_fee'] ?? 0).toDouble(),
       freeDeliveryWeight: (map['free_delivery_weight'] ?? 0).toDouble(),
       volumetricRatio: (map['volumetric_ratio'] ?? 0).toDouble(),
+      diffDiscountWeight: (map['diff_discount_weight'] ?? 0).toDouble(),
+      diffWeightRate: (map['diff_weight_rate'] ?? 0).toDouble(),
     );
   }
 
@@ -41,17 +47,21 @@ class Rate {
       "delivery_fee": deliveryFee,
       'free_delivery_weight': freeDeliveryWeight,
       'volumetric_ratio': volumetricRatio,
+      'diff_discount_weight': diffDiscountWeight,
+      'diff_weight_rate': diffWeightRate,
     };
   }
 
   bool isChangedForEdit(Rate rate) {
     return rate.freeDeliveryWeight != this.freeDeliveryWeight ||
         rate.deliveryFee != this.deliveryFee ||
-        rate.volumetricRatio != this.volumetricRatio;
+        rate.volumetricRatio != this.volumetricRatio ||
+        rate.diffDiscountWeight != this.diffDiscountWeight ||
+        rate.diffWeightRate != this.diffWeightRate;
   }
 
   @override
   String toString() {
-    return 'Rate{deliveryFee:$deliveryFee,freeDeliveryWeight:$freeDeliveryWeight,volumetricRatio:$volumetricRatio}';
+    return 'Rate{deliveryFee:$deliveryFee,freeDeliveryWeight:$freeDeliveryWeight,volumetricRatio:$volumetricRatio,diffDiscountWeight:$diffDiscountWeight,diffWeightRate:$diffWeightRate}';
   }
 }