Add SaleCalculator

src/main/java/SaleCalculator.java

@@ -0,0 +1,37 @@
+import java.math.BigDecimal;
+import java.util.Formatter.BigDecimalLayoutForm;
+
+public class SaleCalculator {
+    private BigDecimal purchasePrice;
+    private BigDecimal salesPrice;
+    private BigDecimal quantity;
+
+    public SaleCalculator(Share share) {
+        this.purchasePrice = share.getPurchasePrice();
+        this.salesPrice = salesPrice; // Ask about this one...
+        this.quantity = share.getQuantity();
+    }
+
+    public BigDecimal calculateGross() {
+        return this.salesPrice.multiply(this.quantity);
+    }
+
+    public BigDecimal calculateCommission() {
+        BigDecimal rate = new BigDecimal("0.01");
+        return calculateGross().multiply(rate);
+    }
+
+    public BigDecimal calculateTax() {
+        BigDecimal sellingCost = this.purchasePrice.multiply(this.quantity);
+        BigDecimal profit = calculateGross().subtract(calculateCommission()).subtract(sellingCost);
+        BigDecimal rate = new BigDecimal("0.3");
+        return profit.multiply(rate);
+    }
+
+    public BigDecimal calculateTotal() {
+        return calculateGross().subtract(calculateCommission()).subtract(calculateTax());
+    }
+
+
+
+}