erpnext/accounts/deferred_revenue.py

from __future__ import unicode_literals

import frappe
from frappe import _
from frappe.utils import date_diff, add_months, today, getdate, add_days, flt, get_last_day, cint, get_link_to_form
from erpnext.accounts.utils import get_account_currency
from frappe.email import sendmail_to_system_managers
from frappe.utils.background_jobs import enqueue

def validate_service_stop_date(doc):
	''' Validates service_stop_date for Purchase Invoice and Sales Invoice '''

	enable_check = "enable_deferred_revenue" \
		if doc.doctype=="Sales Invoice" else "enable_deferred_expense"

	old_stop_dates = {}
	old_doc = frappe.db.get_all("{0} Item".format(doc.doctype),
		{"parent": doc.name}, ["name", "service_stop_date"])

	for d in old_doc:
		old_stop_dates[d.name] = d.service_stop_date or ""

	for item in doc.items:
		if not item.get(enable_check): continue

		if item.service_stop_date:
			if date_diff(item.service_stop_date, item.service_start_date) < 0:
				frappe.throw(_("Service Stop Date cannot be before Service Start Date"))

			if date_diff(item.service_stop_date, item.service_end_date) > 0:
				frappe.throw(_("Service Stop Date cannot be after Service End Date"))

		if old_stop_dates and old_stop_dates.get(item.name) and item.service_stop_date!=old_stop_dates.get(item.name):
			frappe.throw(_("Cannot change Service Stop Date for item in row {0}").format(item.idx))

def build_conditions(process_type, account, company):
	conditions=''
	deferred_account = "item.deferred_revenue_account" if process_type=="Income" else "item.deferred_expense_account"

	if account:
		conditions += "AND %s='%s'"%(deferred_account, account)
	elif company:
		conditions += "AND p.company='%s'"%(company)

	return conditions

def convert_deferred_expense_to_expense(deferred_process, start_date=None, end_date=None, conditions=''):
	# book the expense/income on the last day, but it will be trigger on the 1st of month at 12:00 AM

	if not start_date:
		start_date = add_months(today(), -1)
	if not end_date:
		end_date = add_days(today(), -1)

	# check for the purchase invoice for which GL entries has to be done
	invoices = frappe.db.sql_list('''
		select distinct item.parent
		from `tabPurchase Invoice Item` item, `tabPurchase Invoice` p
		where item.service_start_date<=%s and item.service_end_date>=%s
		and item.enable_deferred_expense = 1 and item.parent=p.name
		and item.docstatus = 1 and ifnull(item.amount, 0) > 0
		{0}
	'''.format(conditions), (end_date, start_date)) #nosec

	# For each invoice, book deferred expense
	for invoice in invoices:
		doc = frappe.get_doc("Purchase Invoice", invoice)
		book_deferred_income_or_expense(doc, deferred_process, end_date)

	if frappe.flags.deferred_accounting_error:
		send_mail(deferred_process)

def convert_deferred_revenue_to_income(deferred_process, start_date=None, end_date=None, conditions=''):
	# book the expense/income on the last day, but it will be trigger on the 1st of month at 12:00 AM

	if not start_date:
		start_date = add_months(today(), -1)
	if not end_date:
		end_date = add_days(today(), -1)

	# check for the sales invoice for which GL entries has to be done
	invoices = frappe.db.sql_list('''
		select distinct item.parent
		from `tabSales Invoice Item` item, `tabSales Invoice` p
		where item.service_start_date<=%s and item.service_end_date>=%s
		and item.enable_deferred_revenue = 1 and item.parent=p.name
		and item.docstatus = 1 and ifnull(item.amount, 0) > 0
		{0}
	'''.format(conditions), (end_date, start_date)) #nosec

	for invoice in invoices:
		doc = frappe.get_doc("Sales Invoice", invoice)
		book_deferred_income_or_expense(doc, deferred_process, end_date)

	if frappe.flags.deferred_accounting_error:
		send_mail(deferred_process)

def get_booking_dates(doc, item, posting_date=None):
	if not posting_date:
		posting_date = add_days(today(), -1)

	last_gl_entry = False

	deferred_account = "deferred_revenue_account" if doc.doctype=="Sales Invoice" else "deferred_expense_account"

	prev_gl_entry = frappe.db.sql('''
		select name, posting_date from `tabGL Entry` where company=%s and account=%s and
		voucher_type=%s and voucher_no=%s and voucher_detail_no=%s
		order by posting_date desc limit 1
	''', (doc.company, item.get(deferred_account), doc.doctype, doc.name, item.name), as_dict=True)

	if prev_gl_entry:
		start_date = getdate(add_days(prev_gl_entry[0].posting_date, 1))
	else:
		start_date = item.service_start_date

	end_date = get_last_day(start_date)
	if end_date >= item.service_end_date:
		end_date = item.service_end_date
		last_gl_entry = True
	elif item.service_stop_date and end_date >= item.service_stop_date:
		end_date = item.service_stop_date
		last_gl_entry = True

	if end_date > getdate(posting_date):
		end_date = posting_date

	if getdate(start_date) <= getdate(end_date):
		return start_date, end_date, last_gl_entry
	else:
		return None, None, None

def calculate_amount(doc, item, last_gl_entry, total_days, total_booking_days, account_currency):
	if doc.doctype == "Sales Invoice":
		total_credit_debit, total_credit_debit_currency = "debit", "debit_in_account_currency"
		deferred_account = "deferred_revenue_account"
	else:
		total_credit_debit, total_credit_debit_currency = "credit", "credit_in_account_currency"
		deferred_account = "deferred_expense_account"

	amount, base_amount = 0, 0
	if not last_gl_entry:
		base_amount = flt(item.base_net_amount*total_booking_days/flt(total_days), item.precision("base_net_amount"))
		if account_currency==doc.company_currency:
			amount = base_amount
		else:
			amount = flt(item.net_amount*total_booking_days/flt(total_days), item.precision("net_amount"))
	else:
		gl_entries_details = frappe.db.sql('''
			select sum({0}) as total_credit, sum({1}) as total_credit_in_account_currency, voucher_detail_no
			from `tabGL Entry` where company=%s and account=%s and voucher_type=%s and voucher_no=%s and voucher_detail_no=%s
			group by voucher_detail_no
		'''.format(total_credit_debit, total_credit_debit_currency),
			(doc.company, item.get(deferred_account), doc.doctype, doc.name, item.name), as_dict=True)
		already_booked_amount = gl_entries_details[0].total_credit if gl_entries_details else 0
		base_amount = flt(item.base_net_amount - already_booked_amount, item.precision("base_net_amount"))
		if account_currency==doc.company_currency:
			amount = base_amount
		else:
			already_booked_amount_in_account_currency = gl_entries_details[0].total_credit_in_account_currency if gl_entries_details else 0
			amount = flt(item.net_amount - already_booked_amount_in_account_currency, item.precision("net_amount"))

	return amount, base_amount

def book_deferred_income_or_expense(doc, deferred_process, posting_date=None):
	enable_check = "enable_deferred_revenue" \
		if doc.doctype=="Sales Invoice" else "enable_deferred_expense"

	def _book_deferred_revenue_or_expense(item):
		start_date, end_date, last_gl_entry = get_booking_dates(doc, item, posting_date=posting_date)
		if not (start_date and end_date): return

		account_currency = get_account_currency(item.expense_account)
		if doc.doctype == "Sales Invoice":
			against, project = doc.customer, doc.project
			credit_account, debit_account = item.income_account, item.deferred_revenue_account
		else:
			against, project = doc.supplier, item.project
			credit_account, debit_account = item.deferred_expense_account, item.expense_account

		total_days = date_diff(item.service_end_date, item.service_start_date) + 1
		total_booking_days = date_diff(end_date, start_date) + 1

		amount, base_amount = calculate_amount(doc, item, last_gl_entry,
			total_days, total_booking_days, account_currency)

		make_gl_entries(doc, credit_account, debit_account, against,
			amount, base_amount, end_date, project, account_currency, item.cost_center, item, deferred_process)

		# Returned in case of any errors because it tries to submit the same record again and again in case of errors
		if frappe.flags.deferred_accounting_error:
			return

		if getdate(end_date) < getdate(posting_date) and not last_gl_entry:
			_book_deferred_revenue_or_expense(item)


	for item in doc.get('items'):
		if item.get(enable_check):
			_book_deferred_revenue_or_expense(item)

def process_deferred_accounting(posting_date=None):
	''' Converts deferred income/expense into income/expense
		Executed via background jobs on every month end '''

	if not posting_date:
		posting_date = today()

	if not cint(frappe.db.get_singles_value('Accounts Settings', 'automatically_process_deferred_accounting_entry')):
		return

	start_date = add_months(today(), -1)
	end_date = add_days(today(), -1)

	for record_type in ('Income', 'Expense'):
		doc = frappe.get_doc(dict(
			doctype='Process Deferred Accounting',
			posting_date=posting_date,
			start_date=start_date,
			end_date=end_date,
			type=record_type
		))

		doc.insert()
		doc.submit()

def make_gl_entries(doc, credit_account, debit_account, against,
	amount, base_amount, posting_date, project, account_currency, cost_center, item, deferred_process=None):
	# GL Entry for crediting the amount in the deferred expense
	from erpnext.accounts.general_ledger import make_gl_entries

	if amount == 0: return

	gl_entries = []
	gl_entries.append(
		doc.get_gl_dict({
			"account": credit_account,
			"against": against,
			"credit": base_amount,
			"credit_in_account_currency": amount,
			"cost_center": cost_center,
			"voucher_detail_no": item.name,
			'posting_date': posting_date,
			'project': project,
			'against_voucher_type': 'Process Deferred Accounting',
			'against_voucher': deferred_process
		}, account_currency, item=item)
	)
	# GL Entry to debit the amount from the expense
	gl_entries.append(
		doc.get_gl_dict({
			"account": debit_account,
			"against": against,
			"debit": base_amount,
			"debit_in_account_currency": amount,
			"cost_center": cost_center,
			"voucher_detail_no": item.name,
			'posting_date': posting_date,
			'project': project,
			'against_voucher_type': 'Process Deferred Accounting',
			'against_voucher': deferred_process
		}, account_currency, item=item)
	)

	if gl_entries:
		try:
			make_gl_entries(gl_entries, cancel=(doc.docstatus == 2), merge_entries=True)
			frappe.db.commit()
		except:
			frappe.db.rollback()
			traceback = frappe.get_traceback()
			frappe.log_error(message=traceback)

			frappe.flags.deferred_accounting_error = True

def send_mail(deferred_process):
	title = _("Error while processing deferred accounting for {0}".format(deferred_process))
	content = _("""
		Deferred accounting failed for some invoices:
		Please check Process Deferred Accounting {0}
		and submit manually after resolving errors
	""").format(get_link_to_form('Process Deferred Accounting', deferred_process))
	sendmail_to_system_managers(title, content)