feat: add discount fields in sale and purchase forms

packages/webapp/src/containers/Sales/Invoices/InvoiceForm/InvoiceFormFooterRight.tsx

@@ -9,6 +9,9 @@ import {
   TotalLine,
   TotalLineBorderStyle,
   TotalLineTextStyle,
+  FFormGroup,
+  FInputGroup,
+  FSelect,
 } from '@/components';
 import { useInvoiceAggregatedTaxRates } from './utils';
 import { TaxType } from '@/interfaces/TaxRates';
@@ -18,6 +21,7 @@ import {
   InvoiceSubTotalFormatted,
   InvoiceTotalFormatted,
 } from './components';
+import { Button } from '@blueprintjs/core';
 
 export function InvoiceFormFooterRight() {
   const {
@@ -38,6 +42,31 @@ export function InvoiceFormFooterRight() {
         }
         value={<InvoiceSubTotalFormatted />}
       />
+      <FFormGroup name={'discount'} label={'Discount'} inline>
+        <FInputGroup
+          name={'discount'}
+          rightElement={
+            <FSelect
+              name={'discount_type'}
+              items={[
+                { text: 'USD', value: 'amount' },
+                { text: '%', value: 'percentage' },
+              ]}
+              input={({ text }) => (
+                <Button small minimal>
+                  {text}
+                </Button>
+              )}
+              filterable={false}
+            />
+          }
+        />
+      </FFormGroup>
+
+      <FFormGroup name={'adjustment'} label={'Adjustment'} inline>
+        <FInputGroup name={'adjustment'} />
+      </FFormGroup>
+
       {taxEntries.map((tax, index) => (
         <TotalLine
           key={index}

packages/webapp/src/containers/Sales/Invoices/InvoiceForm/utils.tsx

@@ -70,6 +70,9 @@ export const defaultInvoice = {
   entries: [...repeatValue(defaultInvoiceEntry, MIN_LINES_NUMBER)],
   attachments: [],
   payment_methods: {},
+  discount: '',
+  discount_type: 'amount',
+  adjustment: '',
 };
 
 // Invoice entry request schema.
@@ -301,6 +304,20 @@ export const useInvoiceSubtotal = () => {
   return React.useMemo(() => getEntriesTotal(entries), [entries]);
 };
 
+/**
+ * Retrieves the invoice discount amount.
+ * @returns {number}
+ */
+export const useInvoiceDiscountAmount = () => {
+  const { values } = useFormikContext();
+  const subtotal = useInvoiceSubtotal();
+  const discount = parseFloat(values.discount);
+
+  return values?.discount_type === 'percentage'
+    ? (subtotal * discount) / 100
+    : discount;
+};
+
 /**
  * Detarmines whether the invoice has foreign customer.
  * @returns {boolean}
@@ -382,10 +399,12 @@ export const useInvoiceTotal = () => {
   const subtotal = useInvoiceSubtotal();
   const totalTaxAmount = useInvoiceTotalTaxAmount();
   const isExclusiveTax = useIsInvoiceTaxExclusive();
+  const discountAmount = useInvoiceDiscountAmount();
 
-  return R.compose(R.when(R.always(isExclusiveTax), R.add(totalTaxAmount)))(
-    subtotal,
-  );
+  return R.compose(
+    R.when(R.always(isExclusiveTax), R.add(totalTaxAmount)),
+    R.subtract(R.__, discountAmount),
+  )(subtotal);
 };
 
 /**