feat(regional): Auto state wise taxation for GST India (#19877)

* feat(regional): Auto state wise taxation for GST India

* fix: Update gst category on addition of GSTIN

* fix: Codacy and travis fixes

* fix: Travis

* fix(test): Update GST category only if GSTIN field available

* fix: Test Cases

* fix: Do not skip accounts if place of supply is not present

* fix: Auto GST taxation for SEZ Party types

* fix: Automatic taxation for multi state

* fix: Codacy and travis fixes

* fix: Auto GST template selection in Sales Order

* fix: Move inter state check and source state to tax category

* fix: Remove unique check from tax template

* fix: Remove unique check from tax template

* fix: Address fetching logic in Sales

* fix: fecth tax template on company address change

* fix: fetch company gstin on address change

* fix: company_gstin set value fix

* fix: Mutiple fixes and code refactor

* fix: Add missing semicolon

* fix: Company address fetching in sales invoice

* fix: Remove print statement

* fix: Import functools

* fix: Naming fixes and code cleanup

* fix: Update patches

* fix: Remove changes in patches.txt

* fix: Iteritems compatibility for python 3

erpnext/regional/india/utils.py

@@ -7,6 +7,8 @@ from erpnext.controllers.taxes_and_totals import get_itemised_tax, get_itemised_
 from erpnext.controllers.accounts_controller import get_taxes_and_charges
 from erpnext.hr.utils import get_salary_assignment
 from erpnext.hr.doctype.salary_structure.salary_structure import make_salary_slip
+from erpnext.regional.india import number_state_mapping
+from six import string_types
 
 def validate_gstin_for_india(doc, method):
 	if hasattr(doc, 'gst_state') and doc.gst_state:
@@ -46,6 +48,14 @@ def validate_gstin_for_india(doc, method):
 			frappe.throw(_("Invalid GSTIN! First 2 digits of GSTIN should match with State number {0}.")
 				.format(doc.gst_state_number))
 
+def update_gst_category(doc, method):
+	for link in doc.links:
+		if link.link_doctype in ['Customer', 'Supplier']:
+			if doc.get('gstin'):
+				frappe.db.sql("""
+					UPDATE `tab{0}` SET gst_category = %s WHERE name = %s AND gst_category = 'Unregistered'
+				""".format(link.link_doctype), ("Registered Regular", link.link_name)) #nosec
+
 def set_gst_state_and_state_number(doc):
 	if not doc.gst_state:
 		if not doc.state:
@@ -122,44 +132,106 @@ def test_method():
 	'''test function'''
 	return 'overridden'
 
-def get_place_of_supply(out, doctype):
+def get_place_of_supply(party_details, doctype):
 	if not frappe.get_meta('Address').has_field('gst_state'): return
 
-	if doctype in ("Sales Invoice", "Delivery Note"):
-		address_name = out.shipping_address_name or out.customer_address
-	elif doctype == "Purchase Invoice":
-		address_name = out.shipping_address or out.supplier_address
+	if doctype in ("Sales Invoice", "Delivery Note", "Sales Order"):
+		address_name = party_details.shipping_address_name or party_details.customer_address
+	elif doctype in ("Purchase Invoice", "Purchase Order", "Purchase Receipt"):
+		address_name = party_details.shipping_address or party_details.supplier_address
 
 	if address_name:
 		address = frappe.db.get_value("Address", address_name, ["gst_state", "gst_state_number"], as_dict=1)
 		if address and address.gst_state and address.gst_state_number:
 			return cstr(address.gst_state_number) + "-" + cstr(address.gst_state)
 
-def get_regional_address_details(out, doctype, company):
-	out.place_of_supply = get_place_of_supply(out, doctype)
+@frappe.whitelist()
+def get_regional_address_details(party_details, doctype, company, return_taxes=None):
 
-	if not out.place_of_supply: return
+	if isinstance(party_details, string_types):
+		party_details = json.loads(party_details)
+		party_details = frappe._dict(party_details)
 
-	if doctype in ("Sales Invoice", "Delivery Note"):
+	party_details.place_of_supply = get_place_of_supply(party_details, doctype)
+	if doctype in ("Sales Invoice", "Delivery Note", "Sales Order"):
 		master_doctype = "Sales Taxes and Charges Template"
-		if not out.company_gstin:
-			return
-	elif doctype == "Purchase Invoice":
-		master_doctype = "Purchase Taxes and Charges Template"
-		if not out.supplier_gstin:
+
+		get_tax_template_for_sez(party_details, master_doctype, company, 'Customer')
+		get_tax_template_based_on_category(master_doctype, company, party_details)
+
+		if party_details.get('taxes_and_charges') and return_taxes:
+			return party_details
+
+		if not party_details.company_gstin:
 			return
 
-	if ((doctype in ("Sales Invoice", "Delivery Note") and out.company_gstin
-		and out.company_gstin[:2] != out.place_of_supply[:2]) or (doctype == "Purchase Invoice"
-		and out.supplier_gstin and out.supplier_gstin[:2] != out.place_of_supply[:2])):
-		default_tax = frappe.db.get_value(master_doctype, {"company": company, "is_inter_state":1, "disabled":0})
+	elif doctype in ("Purchase Invoice", "Purchase Order", "Purchase Receipt"):
+		master_doctype = "Purchase Taxes and Charges Template"
+
+		get_tax_template_for_sez(party_details, master_doctype, company, 'Supplier')
+		get_tax_template_based_on_category(master_doctype, company, party_details)
+
+		if party_details.get('taxes_and_charges') and return_taxes:
+			return party_details
+
+		if not party_details.supplier_gstin:
+			return
+
+	if not party_details.place_of_supply: return
+
+	if ((doctype in ("Sales Invoice", "Delivery Note", "Sales Order") and party_details.company_gstin
+		and party_details.company_gstin[:2] != party_details.place_of_supply[:2]) or (doctype in ("Purchase Invoice",
+		"Purchase Order", "Purchase Receipt") and party_details.supplier_gstin and party_details.supplier_gstin[:2] != party_details.place_of_supply[:2])):
+		default_tax = get_tax_template(master_doctype, company, 1, party_details.company_gstin[:2])
 	else:
-		default_tax = frappe.db.get_value(master_doctype, {"company": company, "disabled":0, "is_default": 1})
+		default_tax = get_tax_template(master_doctype, company, 0, party_details.company_gstin[:2])
 
 	if not default_tax:
 		return
-	out["taxes_and_charges"] = default_tax
-	out.taxes = get_taxes_and_charges(master_doctype, default_tax)
+	party_details["taxes_and_charges"] = default_tax
+	party_details.taxes = get_taxes_and_charges(master_doctype, default_tax)
+
+	if return_taxes:
+		return party_details
+
+def get_tax_template_based_on_category(master_doctype, company, party_details):
+	if not party_details.get('tax_category'):
+		return
+
+	default_tax = frappe.db.get_value(master_doctype, {'company': company, 'tax_category': party_details.get('tax_category')},
+		'name')
+
+	if default_tax:
+		party_details["taxes_and_charges"] = default_tax
+		party_details.taxes = get_taxes_and_charges(master_doctype, default_tax)
+
+def get_tax_template(master_doctype, company, is_inter_state, state_code):
+	tax_categories = frappe.get_all('Tax Category', fields = ['name', 'is_inter_state', 'gst_state'],
+		filters = {'is_inter_state': is_inter_state})
+
+	default_tax = ''
+
+	for tax_category in tax_categories:
+		if tax_category.gst_state == number_state_mapping[state_code] or \
+	 		(not default_tax and not tax_category.gst_state):
+			default_tax = frappe.db.get_value(master_doctype,
+				{'disabled': 0, 'tax_category': tax_category.name}, 'name')
+
+	return default_tax
+
+def get_tax_template_for_sez(party_details, master_doctype, company, party_type):
+
+	gst_details = frappe.db.get_value(party_type, {'name': party_details.get(frappe.scrub(party_type))},
+			['gst_category', 'export_type'], as_dict=1)
+
+	if gst_details:
+		if gst_details.gst_category == 'SEZ' and gst_details.export_type == 'With Payment of Tax':
+			default_tax = frappe.db.get_value(master_doctype, {"company": company, "is_inter_state":1, "disabled":0,
+				"gst_state": number_state_mapping[party_details.company_gstin[:2]]})
+
+			party_details["taxes_and_charges"] = default_tax
+			party_details.taxes = get_taxes_and_charges(master_doctype, default_tax)
+
 
 def calculate_annual_eligible_hra_exemption(doc):
 	basic_component = frappe.get_cached_value('Company',  doc.company,  "basic_component")
@@ -555,7 +627,7 @@ def get_gst_accounts(company, account_wise=False):
 		filters={"parent": "GST Settings", "company": company},
 		fields=["cgst_account", "sgst_account", "igst_account", "cess_account"])
 
-	if not gst_settings_accounts:
+	if not gst_settings_accounts and not frappe.flags.in_test:
 		frappe.throw(_("Please set GST Accounts in GST Settings"))
 
 	for d in gst_settings_accounts: