# Copyright (c) 2015, Frappe Technologies Pvt. Ltd. and Contributors
# License: GNU General Public License v3. See license.txt

from __future__ import unicode_literals
import frappe, erpnext
from frappe.utils import flt, cstr, cint, comma_and, today, getdate, formatdate, now
from frappe import _
from erpnext.accounts.utils import get_stock_and_account_balance
from frappe.model.meta import get_field_precision
from erpnext.accounts.doctype.budget.budget import validate_expense_against_budget
from erpnext.accounts.doctype.accounting_dimension.accounting_dimension import get_accounting_dimensions


class ClosedAccountingPeriod(frappe.ValidationError): pass
class StockAccountInvalidTransaction(frappe.ValidationError): pass
class StockValueAndAccountBalanceOutOfSync(frappe.ValidationError): pass

def make_gl_entries(gl_map, cancel=False, adv_adj=False, merge_entries=True, update_outstanding='Yes'):
	if gl_map:
		if not cancel:
			validate_accounting_period(gl_map)
			gl_map = process_gl_map(gl_map, merge_entries)
			if gl_map and len(gl_map) > 1:
				save_entries(gl_map, adv_adj, update_outstanding)
			else:
				frappe.throw(_("Incorrect number of General Ledger Entries found. You might have selected a wrong Account in the transaction."))
		else:
			make_reverse_gl_entries(gl_map, adv_adj=adv_adj, update_outstanding=update_outstanding)

def validate_accounting_period(gl_map):
	accounting_periods = frappe.db.sql(""" SELECT
			ap.name as name
		FROM
			`tabAccounting Period` ap, `tabClosed Document` cd
		WHERE
			ap.name = cd.parent
			AND ap.company = %(company)s
			AND cd.closed = 1
			AND cd.document_type = %(voucher_type)s
			AND %(date)s between ap.start_date and ap.end_date
			""", {
				'date': gl_map[0].posting_date,
				'company': gl_map[0].company,
				'voucher_type': gl_map[0].voucher_type
			}, as_dict=1)

	if accounting_periods:
		frappe.throw(_("You cannot create or cancel any accounting entries with in the closed Accounting Period {0}")
			.format(frappe.bold(accounting_periods[0].name)), ClosedAccountingPeriod)

def process_gl_map(gl_map, merge_entries=True):
	if merge_entries:
		gl_map = merge_similar_entries(gl_map)
	for entry in gl_map:
		# toggle debit, credit if negative entry
		if flt(entry.debit) < 0:
			entry.credit = flt(entry.credit) - flt(entry.debit)
			entry.debit = 0.0

		if flt(entry.debit_in_account_currency) < 0:
			entry.credit_in_account_currency = \
				flt(entry.credit_in_account_currency) - flt(entry.debit_in_account_currency)
			entry.debit_in_account_currency = 0.0

		if flt(entry.credit) < 0:
			entry.debit = flt(entry.debit) - flt(entry.credit)
			entry.credit = 0.0

		if flt(entry.credit_in_account_currency) < 0:
			entry.debit_in_account_currency = \
				flt(entry.debit_in_account_currency) - flt(entry.credit_in_account_currency)
			entry.credit_in_account_currency = 0.0

	return gl_map

def merge_similar_entries(gl_map):
	merged_gl_map = []
	accounting_dimensions = get_accounting_dimensions()
	for entry in gl_map:
		# if there is already an entry in this account then just add it
		# to that entry
		same_head = check_if_in_list(entry, merged_gl_map, accounting_dimensions)
		if same_head:
			same_head.debit	= flt(same_head.debit) + flt(entry.debit)
			same_head.debit_in_account_currency	= \
				flt(same_head.debit_in_account_currency) + flt(entry.debit_in_account_currency)
			same_head.credit = flt(same_head.credit) + flt(entry.credit)
			same_head.credit_in_account_currency = \
				flt(same_head.credit_in_account_currency) + flt(entry.credit_in_account_currency)
		else:
			merged_gl_map.append(entry)

	company = gl_map[0].company if gl_map else erpnext.get_default_company()
	company_currency = erpnext.get_company_currency(company)
	precision = get_field_precision(frappe.get_meta("GL Entry").get_field("debit"), company_currency)

	# filter zero debit and credit entries
	merged_gl_map = filter(lambda x: flt(x.debit, precision)!=0 or flt(x.credit, precision)!=0, merged_gl_map)
	merged_gl_map = list(merged_gl_map)

	return merged_gl_map

def check_if_in_list(gle, gl_map, dimensions=None):
	account_head_fieldnames = ['party_type', 'party', 'against_voucher', 'against_voucher_type',
		'cost_center', 'project']

	if dimensions:
		account_head_fieldnames = account_head_fieldnames + dimensions

	for e in gl_map:
		same_head = True
		if e.account != gle.account:
			same_head = False

		for fieldname in account_head_fieldnames:
			if cstr(e.get(fieldname)) != cstr(gle.get(fieldname)):
				same_head = False

		if same_head:
			return e

def save_entries(gl_map, adv_adj, update_outstanding):
	validate_cwip_accounts(gl_map)

	round_off_debit_credit(gl_map)

	if gl_map:
		check_freezing_date(gl_map[0]["posting_date"], adv_adj)

	for entry in gl_map:
		make_entry(entry, adv_adj, update_outstanding)

		# check against budget
		validate_expense_against_budget(entry)

	validate_account_for_perpetual_inventory(gl_map)


def make_entry(args, adv_adj, update_outstanding):
	gle = frappe.new_doc("GL Entry")
	gle.update(args)
	gle.flags.ignore_permissions = 1
	gle.insert()
	gle.run_method("on_update_with_args", adv_adj, update_outstanding)
	gle.submit()

	# check against budget
	validate_expense_against_budget(args)

def validate_account_for_perpetual_inventory(gl_map):
	if cint(erpnext.is_perpetual_inventory_enabled(gl_map[0].company)):
		account_list = [gl_entries.account for gl_entries in gl_map]

		aii_accounts = [d.name for d in frappe.get_all("Account",
			filters={'account_type': 'Stock', 'is_group': 0, 'company': gl_map[0].company})]

		for account in account_list:
			if account not in aii_accounts:
				continue

			# Always use current date to get stock and account balance as there can future entries for
			# other items
			account_bal, stock_bal, warehouse_list = get_stock_and_account_balance(account,
				getdate(), gl_map[0].company)

			if gl_map[0].voucher_type=="Journal Entry":
				# In case of Journal Entry, there are no corresponding SL entries,
				# hence deducting currency amount
				account_bal -= flt(gl_map[0].debit) - flt(gl_map[0].credit)
				if account_bal == stock_bal:
					frappe.throw(_("Account: {0} can only be updated via Stock Transactions")
						.format(account), StockAccountInvalidTransaction)

			elif account_bal != stock_bal:
				precision = get_field_precision(frappe.get_meta("GL Entry").get_field("debit"),
					currency=frappe.get_cached_value('Company',  gl_map[0].company,  "default_currency"))

				diff = flt(stock_bal - account_bal, precision)
				error_reason = _("Stock Value ({0}) and Account Balance ({1}) are out of sync for account {2} and it's linked warehouses.").format(
					stock_bal, account_bal, frappe.bold(account))
				error_resolution = _("Please create adjustment Journal Entry for amount {0} ").format(frappe.bold(diff))
				stock_adjustment_account = frappe.db.get_value("Company",gl_map[0].company,"stock_adjustment_account")

				db_or_cr_warehouse_account =('credit_in_account_currency' if diff < 0 else 'debit_in_account_currency')
				db_or_cr_stock_adjustment_account = ('debit_in_account_currency' if diff < 0 else 'credit_in_account_currency')

				journal_entry_args = {
				'accounts':[
					{'account': account, db_or_cr_warehouse_account : abs(diff)},
					{'account': stock_adjustment_account, db_or_cr_stock_adjustment_account : abs(diff) }]
				}

				frappe.msgprint(msg="""{0}<br></br>{1}<br></br>""".format(error_reason, error_resolution),
					raise_exception=StockValueAndAccountBalanceOutOfSync,
					title=_('Values Out Of Sync'),
					primary_action={
						'label': _('Make Journal Entry'),
						'client_action': 'erpnext.route_to_adjustment_jv',
						'args': journal_entry_args
					})

def validate_cwip_accounts(gl_map):
	cwip_enabled = any([cint(ac.enable_cwip_accounting) for ac in frappe.db.get_all("Asset Category","enable_cwip_accounting")])

	if cwip_enabled and gl_map[0].voucher_type == "Journal Entry":
			cwip_accounts = [d[0] for d in frappe.db.sql("""select name from tabAccount
				where account_type = 'Capital Work in Progress' and is_group=0""")]

			for entry in gl_map:
				if entry.account in cwip_accounts:
					frappe.throw(
						_("Account: <b>{0}</b> is capital Work in progress and can not be updated by Journal Entry").format(entry.account))

def round_off_debit_credit(gl_map):
	precision = get_field_precision(frappe.get_meta("GL Entry").get_field("debit"),
		currency=frappe.get_cached_value('Company',  gl_map[0].company,  "default_currency"))

	debit_credit_diff = 0.0
	for entry in gl_map:
		entry.debit = flt(entry.debit, precision)
		entry.credit = flt(entry.credit, precision)
		debit_credit_diff += entry.debit - entry.credit

	debit_credit_diff = flt(debit_credit_diff, precision)

	if gl_map[0]["voucher_type"] in ("Journal Entry", "Payment Entry"):
		allowance = 5.0 / (10**precision)
	else:
		allowance = .5

	if abs(debit_credit_diff) >= allowance:
		frappe.throw(_("Debit and Credit not equal for {0} #{1}. Difference is {2}.")
			.format(gl_map[0].voucher_type, gl_map[0].voucher_no, debit_credit_diff))

	elif abs(debit_credit_diff) >= (1.0 / (10**precision)):
		make_round_off_gle(gl_map, debit_credit_diff, precision)

def make_round_off_gle(gl_map, debit_credit_diff, precision):
	round_off_account, round_off_cost_center = get_round_off_account_and_cost_center(gl_map[0].company)
	round_off_account_exists = False
	round_off_gle = frappe._dict()
	for d in gl_map:
		if d.account == round_off_account:
			round_off_gle = d
			if d.debit_in_account_currency:
				debit_credit_diff -= flt(d.debit_in_account_currency)
			else:
				debit_credit_diff += flt(d.credit_in_account_currency)
			round_off_account_exists = True

	if round_off_account_exists and abs(debit_credit_diff) <= (1.0 / (10**precision)):
		gl_map.remove(round_off_gle)
		return

	if not round_off_gle:
		for k in ["voucher_type", "voucher_no", "company",
			"posting_date", "remarks", "is_opening"]:
				round_off_gle[k] = gl_map[0][k]

	round_off_gle.update({
		"account": round_off_account,
		"debit_in_account_currency": abs(debit_credit_diff) if debit_credit_diff < 0 else 0,
		"credit_in_account_currency": debit_credit_diff if debit_credit_diff > 0 else 0,
		"debit": abs(debit_credit_diff) if debit_credit_diff < 0 else 0,
		"credit": debit_credit_diff if debit_credit_diff > 0 else 0,
		"cost_center": round_off_cost_center,
		"party_type": None,
		"party": None,
		"against_voucher_type": None,
		"against_voucher": None
	})

	if not round_off_account_exists:
		gl_map.append(round_off_gle)

def get_round_off_account_and_cost_center(company):
	round_off_account, round_off_cost_center = frappe.get_cached_value('Company',  company,
		["round_off_account", "round_off_cost_center"]) or [None, None]
	if not round_off_account:
		frappe.throw(_("Please mention Round Off Account in Company"))

	if not round_off_cost_center:
		frappe.throw(_("Please mention Round Off Cost Center in Company"))

	return round_off_account, round_off_cost_center

def make_reverse_gl_entries(gl_entries=None, voucher_type=None, voucher_no=None,
	adv_adj=False, update_outstanding="Yes"):
	"""
		Get original gl entries of the voucher
		and make reverse gl entries by swapping debit and credit
	"""

	if not gl_entries:
		gl_entries = frappe.get_all("GL Entry",
			fields = ["*"],
			filters = {
				"voucher_type": voucher_type,
				"voucher_no": voucher_no,
				"is_cancelled": 0
			})

	if gl_entries:
		validate_accounting_period(gl_entries)
		check_freezing_date(gl_entries[0]["posting_date"], adv_adj)
		set_as_cancel(gl_entries[0]['voucher_type'], gl_entries[0]['voucher_no'])

		for entry in gl_entries:
			entry['name'] = None
			debit = entry.get('debit', 0)
			credit = entry.get('credit', 0)

			debit_in_account_currency = entry.get('debit_in_account_currency', 0)
			credit_in_account_currency = entry.get('credit_in_account_currency', 0)

			entry['debit'] = credit
			entry['credit'] = debit
			entry['debit_in_account_currency'] = credit_in_account_currency
			entry['credit_in_account_currency'] = debit_in_account_currency

			entry['remarks'] = "On cancellation of " + entry['voucher_no']
			entry['is_cancelled'] = 1
			entry['posting_date'] = today()

			if entry['debit'] or entry['credit']:
				make_entry(entry, adv_adj, "Yes")


def check_freezing_date(posting_date, adv_adj=False):
	"""
		Nobody can do GL Entries where posting date is before freezing date
		except authorized person
	"""
	if not adv_adj:
		acc_frozen_upto = frappe.db.get_value('Accounts Settings', None, 'acc_frozen_upto')
		if acc_frozen_upto:
			frozen_accounts_modifier = frappe.db.get_value( 'Accounts Settings', None,'frozen_accounts_modifier')
			if getdate(posting_date) <= getdate(acc_frozen_upto) \
					and not frozen_accounts_modifier in frappe.get_roles():
				frappe.throw(_("You are not authorized to add or update entries before {0}").format(formatdate(acc_frozen_upto)))

def set_as_cancel(voucher_type, voucher_no):
	"""
		Set is_cancelled=1 in all original gl entries for the voucher
	"""
	frappe.db.sql("""UPDATE `tabGL Entry` SET is_cancelled = 1,
		modified=%s, modified_by=%s
		where voucher_type=%s and voucher_no=%s and is_cancelled = 0""",
		(now(), frappe.session.user, voucher_type, voucher_no))