Feature: Tax report and consequently sale report should show tax broken up properly for taxes such as GST

barker/barker/routers/reports/tax_report.py

@@ -1,4 +1,7 @@
+import re
+
 from datetime import date, datetime, time, timedelta
+from decimal import Decimal
 from typing import List
 
 from fastapi import APIRouter, Depends, Security
@@ -62,4 +65,21 @@ def get_tax(s: date, f: date, db: Session) -> List[TaxReportItem]:
         .group_by(Tax.name, Inventory.tax_rate)
         .order_by(Tax.name, Inventory.tax_rate)
     ).all()
-    return [TaxReportItem(name=f"{i[0]} - {i[1]:.2%}", taxRate=i[1], saleAmount=i[2], amount=i[3]) for i in amounts]
+    return sum([get_tax_item(*i) for i in amounts], [])
+
+
+def get_tax_item(name: str, rate: Decimal, net: Decimal, amount: Decimal) -> List[TaxReportItem]:
+    items = name.split(";")
+    if len(items) == 1:
+        return [TaxReportItem(name=name, taxRate=rate, saleAmount=net, amount=amount)]
+    else:
+        r = []
+        for i, item in enumerate(it.strip() for it in items):
+            match = re.match(r"(^.*)\s+\((.*?)/(.*?)\)[^(]*$", item)
+            if not match or len(match.groups()) != 3:
+                raise Exception("Error in tax as it has multiple items, but the format is wrong.")
+            ratio = Decimal(match.group(2)) / Decimal(match.group(3))
+            sub_net = round(net * ratio, 2)
+            sub_amount = round(amount * ratio, 2)
+            r.append(TaxReportItem(name=f"{match.group(1)}", taxRate=rate, saleAmount=sub_net, amount=sub_amount))
+        return r