From 3b1e84b6d8180990455dee6da0d555aa9c3ce564 Mon Sep 17 00:00:00 2001
From: Methapon Metanipat <methapon@frappet.com>
Date: Fri, 4 Oct 2024 13:01:30 +0700
Subject: [PATCH] refactor: calculate utility

---
 src/controllers/05-quotation-controller.ts | 15 ++++++++-------
 src/utils/arithmetic.ts                    |  4 ++++
 2 files changed, 12 insertions(+), 7 deletions(-)
 create mode 100644 src/utils/arithmetic.ts

diff --git a/src/controllers/05-quotation-controller.ts b/src/controllers/05-quotation-controller.ts
index 213cb81..a5ced86 100644
--- a/src/controllers/05-quotation-controller.ts
+++ b/src/controllers/05-quotation-controller.ts
@@ -22,6 +22,7 @@ import {
 } from "../services/permission";
 import { isSystem } from "../utils/keycloak";
 import { isUsedError, notFoundError, relationError } from "../utils/error";
+import { precisionRound } from "../utils/arithmetic";
 
 type QuotationCreate = {
   status?: Status;
@@ -332,14 +333,14 @@ export class QuotationController extends Controller {
 
       const price = list.reduce(
         (a, c) => {
-          const price = c.pricePerUnit * c.amount;
-          const discount = Math.round(price * (c.discount || 0) * 100) / 100;
-          const vat = Math.round((price - discount) * c.vat * 100) / 100;
+          const price = precisionRound(c.pricePerUnit * c.amount);
+          const discount = precisionRound(price - (c.discount || 0));
+          const vat = precisionRound((price - discount) * c.vat);
 
-          a.totalPrice += price;
-          a.totalDiscount += discount;
-          a.vat += vat;
-          a.finalPrice += price - discount + vat;
+          a.totalPrice = precisionRound(a.totalPrice + price);
+          a.totalDiscount = precisionRound(a.totalDiscount + discount);
+          a.vat = precisionRound(a.vat + vat);
+          a.finalPrice = precisionRound(a.totalPrice - a.totalDiscount + a.vat);
 
           return a;
         },
diff --git a/src/utils/arithmetic.ts b/src/utils/arithmetic.ts
new file mode 100644
index 0000000..4f48f2d
--- /dev/null
+++ b/src/utils/arithmetic.ts
@@ -0,0 +1,4 @@
+export function precisionRound(number: number, precision = 2) {
+  var factor = Math.pow(10, precision);
+  return Math.round(number * factor) / factor;
+}