Files
schuetz3-erpnext/erpnext/regional/india/e_invoice_utils.py
2020-12-30 11:56:07 +05:30

462 lines
16 KiB
Python

# -*- coding: utf-8 -*-
# Copyright (c) 2020, Frappe Technologies Pvt. Ltd. and contributors
# For license information, please see license.txt
from __future__ import unicode_literals
import os
import re
import jwt
import json
import base64
import frappe
from Crypto.PublicKey import RSA
from Crypto.Cipher import PKCS1_v1_5, AES
from Crypto.Util.Padding import pad, unpad
from frappe.model.document import Document
from frappe import _, get_module_path, scrub
from erpnext.regional.india.utils import get_gst_accounts
from frappe.utils.data import get_datetime, cstr, cint, format_date
from frappe.integrations.utils import make_post_request, make_get_request
def validate_einvoice_fields(doc):
if not doc.doctype in ['Sales Invoice', 'Purchase Invoice']: return
if doc.docstatus == 1 and doc._action == 'submit' and not doc.irn:
frappe.throw(_("You must generate IRN before submitting the document."), title=_("Missing IRN"))
elif doc.docstatus == 2 and doc._action == 'cancel' and not doc.irn_cancelled:
frappe.throw(_("You must cancel IRN before cancelling the document."), title=_("Not Allowed"))
def get_einv_credentials():
return frappe.get_doc("E Invoice Settings")
def rsa_encrypt(msg, key):
if not (isinstance(msg, bytes) or isinstance(msg, bytearray)):
msg = str.encode(msg)
rsa_pub_key = RSA.import_key(key)
cipher = PKCS1_v1_5.new(rsa_pub_key)
enc_msg = cipher.encrypt(msg)
b64_enc_msg = base64.b64encode(enc_msg)
return b64_enc_msg.decode()
def aes_decrypt(enc_msg, key):
encode_as_b64 = True
if not (isinstance(key, bytes) or isinstance(key, bytearray)):
key = base64.b64decode(key)
encode_as_b64 = False
cipher = AES.new(key, AES.MODE_ECB)
b64_enc_msg = base64.b64decode(enc_msg)
msg_bytes = cipher.decrypt(b64_enc_msg)
msg_bytes = unpad(msg_bytes, AES.block_size) # due to ECB/PKCS5Padding
if encode_as_b64:
msg_bytes = base64.b64encode(msg_bytes)
return msg_bytes.decode()
def aes_encrypt(msg, key):
if not (isinstance(key, bytes) or isinstance(key, bytearray)):
key = base64.b64decode(key)
cipher = AES.new(key, AES.MODE_ECB)
bytes_msg = str.encode(msg)
padded_bytes_msg = pad(bytes_msg, AES.block_size)
enc_msg = cipher.encrypt(padded_bytes_msg)
b64_enc_msg = base64.b64encode(enc_msg)
return b64_enc_msg.decode()
def jwt_decrypt(token):
return jwt.decode(token, verify=False)
def get_header(creds):
headers = { 'content-type': 'application/json' }
headers.update(dict(client_id=creds.client_id, client_secret=creds.client_secret, user_name=creds.username))
headers.update(dict(Gstin=creds.gstin, AuthToken=creds.auth_token))
return headers
@frappe.whitelist()
def fetch_token():
einv_creds = get_einv_credentials()
endpoint = 'https://einv-apisandbox.nic.in/eivital/v1.03/auth'
headers = { 'content-type': 'application/json' }
headers.update(dict(client_id=einv_creds.client_id, client_secret=einv_creds.client_secret))
payload = dict(UserName=einv_creds.username, ForceRefreshAccessToken=bool(einv_creds.auto_refresh_token))
appkey = bytearray(os.urandom(32))
enc_appkey = rsa_encrypt(appkey, einv_creds.public_key)
password = einv_creds.get_password(fieldname='password')
enc_password = rsa_encrypt(password, einv_creds.public_key)
payload.update(dict(Password=enc_password, AppKey=enc_appkey))
res = make_post_request(endpoint, headers=headers, data=json.dumps({ 'data': payload }))
handle_err_response(res)
auth_token, token_expiry, sek = extract_token_and_sek(res, appkey)
einv_creds.auth_token = auth_token
einv_creds.token_expiry = get_datetime(token_expiry)
einv_creds.sek = sek
einv_creds.save()
def extract_token_and_sek(response, appkey):
data = response.get('Data')
auth_token = data.get('AuthToken')
token_expiry = data.get('TokenExpiry')
enc_sek = data.get('Sek')
sek = aes_decrypt(enc_sek, appkey)
return auth_token, token_expiry, sek
def attach_signed_json(invoice, data):
f = frappe.get_doc({
"doctype": "File",
"file_name": invoice.name + "e_invoice.json",
"attached_to_doctype": invoice.doctype,
"attached_to_name": invoice.name,
"content": json.dumps(data),
"is_private": True
}).insert()
def get_gstin_details(gstin):
einv_creds = get_einv_credentials()
endpoint = 'https://einv-apisandbox.nic.in/eivital/v1.03/Master/gstin/{gstin}'.format(gstin=gstin)
headers = get_header(einv_creds)
res = make_get_request(endpoint, headers=headers)
handle_err_response(res)
enc_json = res.get('Data')
json_str = aes_decrypt(enc_json, einv_creds.sek)
data = json.loads(json_str)
return data
@frappe.whitelist()
def generate_irn(doctype, name):
endpoint = 'https://einv-apisandbox.nic.in/eicore/v1.03/Invoice'
einv_creds = get_einv_credentials()
headers = get_header(einv_creds)
invoice = frappe.get_doc(doctype, name)
e_invoice = make_e_invoice(invoice)
enc_e_invoice_json = aes_encrypt(e_invoice, einv_creds.sek)
payload = dict(Data=enc_e_invoice_json)
res = make_post_request(endpoint, headers=headers, data=json.dumps(payload))
res = handle_err_response(res)
enc_json = res.get('Data')
json_str = aes_decrypt(enc_json, einv_creds.sek)
data = json.loads(json_str)
handle_irn_response(data)
attach_signed_json(invoice, data['DecryptedSignedInvoice'])
return data
def get_irn_details(irn):
einv_creds = get_einv_credentials()
endpoint = 'https://einv-apisandbox.nic.in/eicore/v1.03/Invoice/irn/{irn}'.format(irn=irn)
headers = get_header(einv_creds)
res = make_get_request(endpoint, headers=headers)
handle_err_response(res)
# enc_json = res.get('Data')
# json_str = aes_decrypt(enc_json, einv_creds.sek)
# data = json.loads(json_str)
# handle_irn_response(data)
return res
@frappe.whitelist()
def cancel_irn(irn, reason, remark=''):
einv_creds = get_einv_credentials()
endpoint = 'https://einv-apisandbox.nic.in/eicore/v1.03/Invoice/Cancel'
headers = get_header(einv_creds)
cancel_e_inv = json.dumps(dict(Irn=irn, CnlRsn=reason, CnlRem=remark))
enc_json = aes_encrypt(cancel_e_inv, einv_creds.sek)
payload = dict(Data=enc_json)
res = make_post_request(endpoint, headers=headers, data=json.dumps(payload))
handle_err_response(res)
return res
def handle_irn_response(data):
enc_signed_invoice = data['SignedInvoice']
enc_signed_qr_code = data['SignedQRCode']
signed_invoice = jwt_decrypt(enc_signed_invoice)['data']
signed_qr_code = jwt_decrypt(enc_signed_qr_code)['data']
data['DecryptedSignedInvoice'] = json.loads(signed_invoice)
data['DecryptedSignedQRCode'] = json.loads(signed_qr_code)
def handle_err_response(response):
if response.get('Status') == 0:
err_details = response.get('ErrorDetails')
print(response)
err_msg = ""
for d in err_details:
err_code = d.get('ErrorCode')
if err_code == '2150':
irn = [d['Desc']['Irn'] for d in response.get('InfoDtls') if d['InfCd'] == 'DUPIRN']
response = get_irn_details(irn[0])
return response
err_msg += d.get('ErrorMessage')
err_msg += "<br>"
frappe.throw(_(err_msg), title=_('API Request Failed'))
return response
def read_json(name):
file_path = os.path.join(os.path.dirname(__file__), "{name}.json".format(name=name))
with open(file_path, 'r') as f:
return cstr(f.read())
def get_trans_details(invoice):
supply_type = ''
if invoice.gst_category == 'Registered Regular': supply_type = 'B2B'
elif invoice.gst_category == 'SEZ': supply_type = 'SEZWOP'
elif invoice.gst_category == 'Overseas': supply_type = 'EXPWOP'
elif invoice.gst_category == 'Deemed Export': supply_type = 'DEXP'
if not supply_type:
return _('Invalid invoice transaction category.')
return frappe._dict(dict(
tax_scheme='GST', supply_type=supply_type, reverse_charge=invoice.reverse_charge
))
def get_doc_details(invoice):
invoice_type = 'CRN' if invoice.is_return else 'INV'
invoice_name = invoice.name
invoice_date = format_date(invoice.posting_date, 'dd/mm/yyyy')
return frappe._dict(dict(
invoice_type=invoice_type, invoice_name=invoice_name, invoice_date=invoice_date
))
def get_party_gstin_details(party_address):
gstin, address_line1, address_line2, phone, email_id = frappe.db.get_value(
"Address", party_address, ["gstin", "address_line1", "address_line2", "phone", "email_id"]
)
gstin_details = get_gstin_details(gstin)
legal_name = gstin_details.get('LegalName')
trade_name = gstin_details.get('TradeName')
location = gstin_details.get('AddrLoc')
state_code = gstin_details.get('StateCode')
pincode = cint(gstin_details.get('AddrPncd'))
if state_code == 97:
pincode = 999999
return frappe._dict(dict(
gstin=gstin, legal_name=legal_name, trade_name=trade_name, location=location,
pincode=pincode, state_code=state_code, address_line1=address_line1,
address_line2=address_line2, email=email_id, phone=phone
))
def get_overseas_address_details(party_address):
address_title, address_line1, address_line2, city, phone, email_id = frappe.db.get_value(
"Address", party_address, ["address_title", "address_line1", "address_line2", "city", "phone", "email_id"]
)
return frappe._dict(dict(
gstin='URP', legal_name=address_title, address_line1=address_line1,
address_line2=address_line2, email=email_id, phone=phone,
pincode=999999, state_code=96, place_of_supply=96, location=city
))
def get_item_list(invoice):
item_list = []
gst_accounts = get_gst_accounts(invoice.company)
gst_accounts_list = [d for accounts in gst_accounts.values() for d in accounts if d]
for d in invoice.items:
item_schema = read_json("einv_item_template")
item = frappe._dict(dict())
item.update(d.as_dict())
item.sr_no = d.idx
item.description = d.item_name
item.is_service_item = "N" if frappe.db.get_value("Item", d.item_code, "is_stock_item") else "Y"
item.batch_expiry_date = frappe.db.get_value("Batch", d.batch_no, "expiry_date") if d.batch_no else None
item.batch_expiry_date = format_date(item.batch_expiry_date, 'dd/mm/yyyy') if item.batch_expiry_date else None
item.tax_rate = 0
item.igst_amount = 0
item.cgst_amount = 0
item.sgst_amount = 0
item.cess_rate = 0
item.cess_amount = 0
for t in invoice.taxes:
if t.account_head in gst_accounts_list:
item_tax_detail = json.loads(t.item_wise_tax_detail).get(item.item_code)
if t.account_head in gst_accounts.cess_account:
item.cess_rate += item_tax_detail[0]
item.cess_amount += item_tax_detail[1]
elif t.account_head in gst_accounts.igst_account:
item.tax_rate += item_tax_detail[0]
item.igst_amount += item_tax_detail[1]
elif t.account_head in gst_accounts.sgst_account:
item.tax_rate += item_tax_detail[0]
item.sgst_amount += item_tax_detail[1]
elif t.account_head in gst_accounts.cgst_account:
item.tax_rate += item_tax_detail[0]
item.cgst_amount += item_tax_detail[1]
item.total_value = item.base_amount + item.igst_amount + item.sgst_amount + item.cgst_amount + item.cess_amount
e_inv_item = item_schema.format(item=item)
item_list.append(e_inv_item)
return ", ".join(item_list)
def get_value_details(invoice):
gst_accounts = get_gst_accounts(invoice.company)
gst_accounts_list = [d for accounts in gst_accounts.values() for d in accounts if d]
value_details = frappe._dict(dict())
value_details.base_net_total = invoice.base_net_total
value_details.invoice_discount_amt = invoice.discount_amount
value_details.round_off = invoice.base_rounding_adjustment
value_details.base_grand_total = invoice.base_rounded_total
value_details.grand_total = invoice.rounded_total
value_details.total_cgst_amt = 0
value_details.total_sgst_amt = 0
value_details.total_igst_amt = 0
value_details.total_cess_amt = 0
for t in invoice.taxes:
if t.account_head in gst_accounts_list:
if t.account_head in gst_accounts.cess_account:
value_details.total_cess_amt += t.base_tax_amount
elif t.account_head in gst_accounts.igst_account:
value_details.total_igst_amt += t.base_tax_amount
elif t.account_head in gst_accounts.sgst_account:
value_details.total_sgst_amt += t.base_tax_amount
elif t.account_head in gst_accounts.cgst_account:
value_details.total_cgst_amt += t.base_tax_amount
return value_details
def get_payment_details(invoice):
payee_name = invoice.company
mode_of_payment = ", ".join([d.mode_of_payment for d in invoice.payments])
paid_amount = invoice.base_paid_amount
outstanding_amount = invoice.outstanding_amount
return frappe._dict(dict(
payee_name=payee_name, mode_of_payment=mode_of_payment,
paid_amount=paid_amount, outstanding_amount=outstanding_amount
))
def get_return_doc_reference(invoice):
invoice_date = frappe.db.get_value("Sales Invoice", invoice.return_against, "posting_date")
return frappe._dict(dict(
invoice_name=invoice.return_against, invoice_date=invoice_date
))
def make_e_invoice(invoice):
schema = read_json("einv_template")
validations = read_json("einv_validation")
validations = json.loads(validations)
trans_details = get_trans_details(invoice)
doc_details = get_doc_details(invoice)
seller_details = get_party_gstin_details(invoice.company_address)
if invoice.gst_category == 'Overseas':
buyer_details = get_overseas_address_details(invoice.customer_address)
else:
buyer_details = get_party_gstin_details(invoice.customer_address)
place_of_supply = invoice.place_of_supply.split('-')[0]
buyer_details.update(dict(place_of_supply=place_of_supply))
item_list = get_item_list(invoice)
value_details = get_value_details(invoice)
dispatch_details = frappe._dict({})
period_details = frappe._dict({})
shipping_details = frappe._dict({})
export_details = frappe._dict({})
eway_bill_details = frappe._dict({})
if invoice.shipping_address_name and invoice.customer_address != invoice.shipping_address_name:
shipping_details = get_party_gstin_details(invoice.shipping_address_name)
payment_details = frappe._dict({})
if invoice.is_pos and invoice.base_paid_amount:
payment_details = get_payment_details(invoice)
prev_doc_details = frappe._dict({})
if invoice.is_return and invoice.return_against:
prev_doc_details = get_return_doc_reference(invoice)
e_invoice = schema.format(
trans_details=trans_details, doc_details=doc_details, dispatch_details=dispatch_details,
seller_details=seller_details, buyer_details=buyer_details, shipping_details=shipping_details,
item_list=item_list, value_details=value_details, payment_details=payment_details,
period_details=period_details, prev_doc_details=prev_doc_details,
export_details=export_details, eway_bill_details=eway_bill_details
)
e_invoice = json.loads(e_invoice)
run_e_invoice_validations(validations, e_invoice)
return json.dumps(e_invoice)
def run_e_invoice_validations(validations, e_invoice):
type_map = {
"string": cstr,
"number": cint,
"object": dict,
"array": list
}
# validate root mandatory keys
mandatory_fields = validations.get('required')
if mandatory_fields and not set(mandatory_fields).issubset(set(e_invoice.keys())):
print("Mandatory condition failed")
for field, value in validations.items():
if isinstance(value, list): value = value[0]
invoice_value = e_invoice.get(field)
if not invoice_value:
print(field, "value undefined")
continue
should_be_of_type = type_map[value.get('type').lower()]
if should_be_of_type == dict:
properties = value.get('properties')
if isinstance(invoice_value, list):
for d in invoice_value:
run_e_invoice_validations(properties, d)
else:
run_e_invoice_validations(properties, invoice_value)
if not invoice_value:
e_invoice.pop(field, None)
continue
if invoice_value == "None":
e_invoice.pop(field, None)
continue
e_invoice[field] = should_be_of_type(invoice_value) if e_invoice[field] else e_invoice[field]
should_be_of_len = value.get('maxLength')
should_be_greater_than = value.get('minimum')
should_be_less_than = value.get('maximum')
pattern_str = value.get('pattern')
pattern = re.compile(pattern_str or "")
if should_be_of_type == 'string' and not len(invoice_value) <= should_be_of_len:
print("Max Length Exceeded", field, invoice_value)
if should_be_of_type == 'number' and not (should_be_greater_than <= invoice_value <= should_be_of_len):
print("Value too large", field, invoice_value)
if pattern_str and not pattern.match(invoice_value):
print("Pattern Mismatch", field, invoice_value)