updated vat allocation previous month work

taxes_az/taxes_az/doctype/vat_allocation/vat_allocation.json

@@ -163,7 +163,7 @@
  "index_web_pages_for_search": 1,
  "is_submittable": 1,
  "links": [],
- "modified": "2025-10-07 14:10:17.385408",
+ "modified": "2026-01-15 15:22:24.103624",
  "modified_by": "Administrator",
  "module": "Taxes Az",
  "name": "VAT allocation",
@@ -171,6 +171,7 @@
  "owner": "Administrator",
  "permissions": [
   {
+   "cancel": 1,
    "create": 1,
    "delete": 1,
    "email": 1,
@@ -180,10 +181,12 @@
    "report": 1,
    "role": "System Manager",
    "share": 1,
+   "submit": 1,
    "write": 1
   }
  ],
+ "row_format": "Dynamic",
  "sort_field": "creation",
  "sort_order": "DESC",
  "states": []
-}
+}

taxes_az/taxes_az/doctype/vat_allocation/vat_allocation.py

@@ -407,8 +407,13 @@ def get_sales_invoice_items_previous_months(year, month, customers=None, min_amo
         if customers and len(customers) > 0:
             customer_list = [c.get('customer') for c in customers if c.get('customer')]
     
-    # Find all previous VAT Allocation documents
-    # We need to find documents where (year < current_year) OR (year == current_year AND month < current_month)
+    # Chain Logic Implementation:
+    # Get ONLY the immediately previous VAT Allocation document (LIMIT 1).
+    # The query below (lines 434-445) fetches from BOTH child tables:
+    # - sales_invoice_table (last month's current items, if unpaid)
+    # - sales_invoice_previous_table (older months' items, if unpaid)
+    # This creates a "chain" where each month inherits the complete unpaid state
+    # from the previous month, preventing double-counting.
     vat_allocations = frappe.db.sql("""
         SELECT name, year, month
         FROM `tabVAT allocation`
@@ -418,6 +423,7 @@ def get_sales_invoice_items_previous_months(year, month, customers=None, min_amo
             OR (year = %(year)s AND month < %(month)s)
         )
         ORDER BY year DESC, month DESC
+        LIMIT 1
     """, {
         'year': year,
         'month': month_number