text: from __future__ import unicode_literals
  import frappe
  
  
  def execute():
  	frappe.reload_doc("selling", "doctype", "customer")
  	frappe.reload_doc("buying", "doctype", "supplier")
  	frappe.reload_doc("setup", "doctype", "supplier_type")
  	frappe.reload_doc("accounts", "doctype", "payment_term")
  	frappe.reload_doc("accounts", "doctype", "payment_terms_template_detail")
  	frappe.reload_doc("accounts", "doctype", "payment_terms_template")
  
  	payment_terms = []
  	records = []
  	for doctype in ("Customer", "Supplier", "Supplier Type"):
  		credit_days = frappe.db.sql("""
  			SELECT DISTINCT `credit_days`, `credit_days_based_on`, `name`
  			from `tab{0}`
  			where
  				((credit_days_based_on='Fixed Days' or credit_days_based_on is null)
  					and credit_days is not null)
  				or credit_days_based_on='Last Day of the Next Month'
  		""".format(doctype))
  
  		credit_records = ((record[0], record[1], record[2]) for record in credit_days)
  		for days, based_on, party_name in credit_records:
  			if based_on == "Fixed Days":
  				pyt_template_name = 'Default Payment Term - N{0}'.format(days)
  			else:
  				pyt_template_name = 'Default Payment Term - EO2M'
  
  			if not frappe.db.exists("Payment Terms Template", pyt_template_name):
  				payment_term = make_payment_term(days, based_on)
  				template = make_template(payment_term)
  			else:
  				template = frappe.get_doc("Payment Terms Template", pyt_template_name)
  
  			payment_terms.append('WHEN `name`={0} THEN {1}'.format(frappe.db.escape(party_name), template.template_name))
  			records.append(frappe.db.escape(party_name))
  
  		begin_query_str = "UPDATE `tab{0}` SET `payment_terms` = CASE ".format(doctype)
  		value_query_str = " ".join(payment_terms)
  		cond_query_str = " ELSE `payment_terms` END WHERE "
  
  		if records:
  			frappe.db.sql(
  				begin_query_str + value_query_str + cond_query_str + '`name` IN %s',
  				(records,)
  			)
  
  
  def make_template(payment_term):
  	doc = frappe.new_doc('Payment Terms Template Detail')
  	doc.payment_term = payment_term.payment_term_name
  	doc.due_date_based_on = payment_term.due_date_based_on
  	doc.invoice_portion = payment_term.invoice_portion
  	doc.description = payment_term.description
  	doc.credit_days = payment_term.credit_days
  	doc.credit_months = payment_term.credit_months
  
  	template = frappe.new_doc('Payment Terms Template')
  	template.template_name = 'Default Payment Term - {0}'.format(payment_term.payment_term_name)
  	template.append('terms', doc)
  	template.save()
  
  	return template
  
  
  def make_payment_term(days, based_on):
  	based_on_map = {
  		'Fixed Days': 'Day(s) after invoice date',
  		'Last Day of the Next Month': 'Month(s) after the end of the invoice month'
  	}
  
  	doc = frappe.new_doc('Payment Term')
  	doc.due_date_based_on = based_on_map.get(based_on)
  	doc.invoice_portion = 100
  
  	if based_on == 'Fixed Days':
  		doc.credit_days = days
  		doc.description = 'Net payable within {0} days'.format(days)
  		doc.payment_term_name = 'N{0}'.format(days)
  	else:
  		doc.credit_months = 1
  		doc.description = 'Net payable by the end of next month'
  		doc.payment_term_name = 'EO2M'
  
  	doc.save()
  	return doc
  