feat(report): add Purchase VAT offset report (Cədvəl 22)

Lists submitted Purchase Invoices flagged for VAT offset that have a VAT
offset line code: line code, VOEN/Name, e-taxes invoice series/number,
total, VAT (only the 521.3 ƏDV tax account), paid total (Grand Total -
Outstanding, Purchase Register logic) and proportional paid VAT.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

taxes_az/taxes_az/report/purchase_vat_offset_report/purchase_vat_offset_report.js

@@ -0,0 +1,26 @@
+// Copyright (c) 2026, Company and contributors
+// For license information, please see license.txt
+
+frappe.query_reports["Purchase VAT offset report"] = {
+	"filters": [
+		{
+			"fieldname": "company",
+			"label": __("Company"),
+			"fieldtype": "Link",
+			"options": "Company",
+			"default": frappe.defaults.get_user_default("Company")
+		},
+		{
+			"fieldname": "from_date",
+			"label": __("From Date"),
+			"fieldtype": "Date",
+			"default": frappe.datetime.month_start()
+		},
+		{
+			"fieldname": "to_date",
+			"label": __("To Date"),
+			"fieldtype": "Date",
+			"default": frappe.datetime.month_end()
+		}
+	]
+};

taxes_az/taxes_az/report/purchase_vat_offset_report/purchase_vat_offset_report.json

@@ -0,0 +1,23 @@
+{
+ "add_total_row": 0,
+ "columns": [],
+ "creation": "2026-06-29 12:00:00",
+ "disabled": 0,
+ "docstatus": 0,
+ "doctype": "Report",
+ "filters": [],
+ "idx": 0,
+ "is_standard": "Yes",
+ "letterhead": null,
+ "modified": "2026-06-29 12:00:00",
+ "modified_by": "Administrator",
+ "module": "Taxes Az",
+ "name": "Purchase VAT offset report",
+ "owner": "Administrator",
+ "prepared_report": 0,
+ "ref_doctype": "Purchase Invoice",
+ "report_name": "Purchase VAT offset report",
+ "report_type": "Script Report",
+ "roles": [],
+ "timeout": 0
+}

taxes_az/taxes_az/report/purchase_vat_offset_report/purchase_vat_offset_report.py

@@ -0,0 +1,158 @@
+# Copyright (c) 2026, Company and contributors
+# For license information, please see license.txt
+
+import frappe
+from frappe import _
+from frappe.utils import flt
+
+
+def execute(filters=None):
+	"""Main function for report execution"""
+	columns = get_columns(filters)
+	data = get_data(filters)
+
+	return columns, data
+
+
+def get_columns(filters=None):
+	"""Get report columns definition (Cədvəl 22 — ƏDV - Əvəzləşdirmə hesabatı)."""
+	return [
+		{
+			"label": _("Purchase Invoice"),
+			"fieldname": "purchase_invoice",
+			"fieldtype": "Link",
+			"options": "Purchase Invoice",
+			"width": 160
+		},
+		{
+			# Sətir kodu
+			"label": _("Line Code"),
+			"fieldname": "line_code",
+			"fieldtype": "Data",
+			"width": 100
+		},
+		{
+			# VÖEN / Adı
+			"label": _("VOEN / Name"),
+			"fieldname": "voen_name",
+			"fieldtype": "Data",
+			"width": 240
+		},
+		{
+			# Qaimənin seriyası
+			"label": _("Invoice Series"),
+			"fieldname": "invoice_series",
+			"fieldtype": "Data",
+			"width": 120
+		},
+		{
+			# Qaimənin nömrəsi
+			"label": _("Invoice Number"),
+			"fieldname": "invoice_number",
+			"fieldtype": "Data",
+			"width": 120
+		},
+		{
+			# Ümumi məbləğ, manatla
+			"label": _("Total Amount"),
+			"fieldname": "total_amount",
+			"fieldtype": "Currency",
+			"width": 140
+		},
+		{
+			# ƏDV məbləği, manatla
+			"label": _("VAT Amount"),
+			"fieldname": "vat_amount",
+			"fieldtype": "Currency",
+			"width": 130
+		},
+		{
+			# Ödənilmiş ümumi məbləğ, manatla
+			"label": _("Paid Total"),
+			"fieldname": "paid_total",
+			"fieldtype": "Currency",
+			"width": 150
+		},
+		{
+			# Ödənilmiş ƏDV məbləği, manatla
+			"label": _("Paid VAT"),
+			"fieldname": "paid_vat",
+			"fieldtype": "Currency",
+			"width": 140
+		}
+	]
+
+
+def get_data(filters=None):
+	"""Submitted Purchase Invoices flagged for VAT offset with a line code.
+
+	Paid amounts follow the Purchase Register logic: Grand Total minus the
+	Outstanding amount. Paid VAT is taken proportionally to the paid share.
+	"""
+	filters = filters or {}
+
+	conditions = (
+		"pi.docstatus = 1 AND pi.vat_offset = 1 "
+		"AND pi.vat_offset_line_code IS NOT NULL AND pi.vat_offset_line_code != ''"
+	)
+	params = {}
+
+	if filters.get("company"):
+		conditions += " AND pi.company = %(company)s"
+		params["company"] = filters["company"]
+	if filters.get("from_date"):
+		conditions += " AND pi.posting_date >= %(from_date)s"
+		params["from_date"] = filters["from_date"]
+	if filters.get("to_date"):
+		conditions += " AND pi.posting_date <= %(to_date)s"
+		params["to_date"] = filters["to_date"]
+
+	rows = frappe.db.sql(f"""
+		SELECT
+			pi.name AS purchase_invoice,
+			pi.vat_offset_line_code AS line_code,
+			pi.supplier_name,
+			sup.tax_id,
+			pi.etaxes_invoice_series,
+			pi.etaxes_invoice_number,
+			pi.grand_total,
+			pi.outstanding_amount,
+			COALESCE(SUM(CASE
+				WHEN ptc.account_head = '521.3 - ƏDV' OR acc.account_number = '521.3'
+				THEN ptc.tax_amount ELSE 0
+			END), 0) AS vat_amount
+		FROM
+			`tabPurchase Invoice` pi
+		LEFT JOIN `tabSupplier` sup ON sup.name = pi.supplier
+		LEFT JOIN `tabPurchase Taxes and Charges` ptc ON ptc.parent = pi.name
+		LEFT JOIN `tabAccount` acc ON acc.name = ptc.account_head
+		WHERE
+			{conditions}
+		GROUP BY
+			pi.name, pi.vat_offset_line_code, pi.supplier_name, sup.tax_id,
+			pi.etaxes_invoice_series, pi.etaxes_invoice_number,
+			pi.grand_total, pi.outstanding_amount, pi.posting_date
+		ORDER BY
+			pi.posting_date, pi.name
+	""", params, as_dict=1)
+
+	data = []
+	for r in rows:
+		grand_total = flt(r.grand_total)
+		vat_amount = flt(r.vat_amount)
+		paid_total = grand_total - flt(r.outstanding_amount)
+		paid_vat = vat_amount * (paid_total / grand_total) if grand_total else 0.0
+
+		data.append({
+			"purchase_invoice": r.purchase_invoice,
+			"line_code": r.line_code,
+			"voen_name": f"{(r.tax_id or '').strip()} / {(r.supplier_name or '').strip()}",
+			"invoice_series": r.etaxes_invoice_series,
+			"invoice_number": r.etaxes_invoice_number,
+			"total_amount": grand_total,
+			"vat_amount": vat_amount,
+			"paid_total": paid_total,
+			"paid_vat": paid_vat,
+		})
+
+	return data