# Copyright (c) 2013, Web Notes Technologies Pvt. Ltd. and Contributors
# License: GNU General Public License v3. See license.txt

from __future__ import unicode_literals
import frappe
from frappe.utils import cint, flt, cstr
from frappe import msgprint, _
import frappe.defaults

from erpnext.controllers.accounts_controller import AccountsController
from erpnext.accounts.general_ledger import make_gl_entries, delete_gl_entries, process_gl_map

class StockController(AccountsController):
	def make_gl_entries(self, repost_future_gle=True, allow_negative_stock=False):
		if self.docstatus == 2:
			delete_gl_entries(voucher_type=self.doctype, voucher_no=self.name)

		if cint(frappe.defaults.get_global_default("auto_accounting_for_stock")):
			warehouse_account = get_warehouse_account()

			if self.docstatus==1:
				gl_entries = self.get_gl_entries(warehouse_account, allow_negative_stock=allow_negative_stock)
				make_gl_entries(gl_entries)

			if repost_future_gle:
				items, warehouses = self.get_items_and_warehouses()
				update_gl_entries_after(self.posting_date, self.posting_time, warehouses, items,
					warehouse_account, allow_negative_stock)

	def get_gl_entries(self, warehouse_account=None, default_expense_account=None,
			default_cost_center=None, allow_negative_stock=False):

		# block_negative_stock(allow_negative_stock)

		if not warehouse_account:
			warehouse_account = get_warehouse_account()

		sle_map = self.get_stock_ledger_details()
		voucher_details = self.get_voucher_details(default_expense_account, default_cost_center, sle_map)

		gl_list = []
		warehouse_with_no_account = []
		for detail in voucher_details:
			sle_list = sle_map.get(detail.name)
			if sle_list:
				for sle in sle_list:
					if warehouse_account.get(sle.warehouse):
						# from warehouse account

						self.check_expense_account(detail)

						stock_value_difference = flt(sle.stock_value_difference, 2)
						if not stock_value_difference:
							valuation_rate = get_valuation_rate(sle.item_code, sle.warehouse, sle.posting_date)
							stock_value_difference = flt(sle.actual_qty)*flt(valuation_rate)

						gl_list.append(self.get_gl_dict({
							"account": warehouse_account[sle.warehouse],
							"against": detail.expense_account,
							"cost_center": detail.cost_center,
							"remarks": self.get("remarks") or "Accounting Entry for Stock",
							"debit": stock_value_difference
						}))

						# to target warehouse / expense account
						gl_list.append(self.get_gl_dict({
							"account": detail.expense_account,
							"against": warehouse_account[sle.warehouse],
							"cost_center": detail.cost_center,
							"remarks": self.get("remarks") or "Accounting Entry for Stock",
							"credit": stock_value_difference
						}))
					elif sle.warehouse not in warehouse_with_no_account:
						warehouse_with_no_account.append(sle.warehouse)

		if warehouse_with_no_account:
			msgprint(_("No accounting entries for the following warehouses") + ": \n" +
				"\n".join(warehouse_with_no_account))

		return process_gl_map(gl_list)

	def get_voucher_details(self, default_expense_account, default_cost_center, sle_map):
		if self.doctype == "Stock Reconciliation":
			return [frappe._dict({ "name": voucher_detail_no, "expense_account": default_expense_account,
				"cost_center": default_cost_center }) for voucher_detail_no, sle in sle_map.items()]
		else:
			details = self.get(self.fname)

			if default_expense_account or default_cost_center:
				for d in details:
					if default_expense_account and not d.get("expense_account"):
						d.expense_account = default_expense_account
					if default_cost_center and not d.get("cost_center"):
						d.cost_center = default_cost_center

			return details

	def get_items_and_warehouses(self):
		items, warehouses = [], []

		if hasattr(self, "fname"):
			item_doclist = self.get(self.fname)
		elif self.doctype == "Stock Reconciliation":
			import json
			item_doclist = []
			data = json.loads(self.reconciliation_json)
			for row in data[data.index(self.head_row)+1:]:
				d = frappe._dict(zip(["item_code", "warehouse", "qty", "valuation_rate"], row))
				item_doclist.append(d)

		if item_doclist:
			for d in item_doclist:
				if d.item_code and d.item_code not in items:
					items.append(d.item_code)

				if d.get("warehouse") and d.warehouse not in warehouses:
					warehouses.append(d.warehouse)

				if self.doctype == "Stock Entry":
					if d.get("s_warehouse") and d.s_warehouse not in warehouses:
						warehouses.append(d.s_warehouse)
					if d.get("t_warehouse") and d.t_warehouse not in warehouses:
						warehouses.append(d.t_warehouse)

		return items, warehouses

	def get_stock_ledger_details(self):
		stock_ledger = {}
		for sle in frappe.db.sql("""select warehouse, stock_value_difference,
			voucher_detail_no, item_code, posting_date, actual_qty
			from `tabStock Ledger Entry` where voucher_type=%s and voucher_no=%s""",
			(self.doctype, self.name), as_dict=True):
				stock_ledger.setdefault(sle.voucher_detail_no, []).append(sle)
		return stock_ledger

	def make_adjustment_entry(self, expected_gle, voucher_obj):
		from erpnext.accounts.utils import get_stock_and_account_difference
		account_list = [d.account for d in expected_gle]
		acc_diff = get_stock_and_account_difference(account_list, expected_gle[0].posting_date)

		cost_center = self.get_company_default("cost_center")
		stock_adjustment_account = self.get_company_default("stock_adjustment_account")

		gl_entries = []
		for account, diff in acc_diff.items():
			if diff:
				gl_entries.append([
					# stock in hand account
					voucher_obj.get_gl_dict({
						"account": account,
						"against": stock_adjustment_account,
						"debit": diff,
						"remarks": "Adjustment Accounting Entry for Stock",
					}),

					# account against stock in hand
					voucher_obj.get_gl_dict({
						"account": stock_adjustment_account,
						"against": account,
						"credit": diff,
						"cost_center": cost_center or None,
						"remarks": "Adjustment Accounting Entry for Stock",
					}),
				])

		if gl_entries:
			from erpnext.accounts.general_ledger import make_gl_entries
			make_gl_entries(gl_entries)

	def check_expense_account(self, item):
		if not item.get("expense_account"):
			frappe.throw(_("Expense or Difference account is mandatory for Item {0} as it impacts overall stock value").format(item.item_code))

		else:
			is_expense_account = frappe.db.get_value("Account",
				item.get("expense_account"), "report_type")=="Profit and Loss"
			if self.doctype not in ("Purchase Receipt", "Stock Reconciliation") and not is_expense_account:
				frappe.throw(_("Expense / Difference account ({0}) must be a 'Profit or Loss' account")
					.format(item.get("expense_account")))
			if is_expense_account and not item.get("cost_center"):
				frappe.throw(_("{0} {1}: Cost Center is mandatory for Item {2}").format(
					_(self.doctype), self.name, item.get("item_code")))

	def get_sl_entries(self, d, args):
		sl_dict = {
			"item_code": d.get("item_code", None),
			"warehouse": d.get("warehouse", None),
			"posting_date": self.posting_date,
			"posting_time": self.posting_time,
			"voucher_type": self.doctype,
			"voucher_no": self.name,
			"voucher_detail_no": d.name,
			"actual_qty": (self.docstatus==1 and 1 or -1)*flt(d.get("stock_qty")),
			"stock_uom": d.get("stock_uom"),
			"incoming_rate": 0,
			"company": self.company,
			"fiscal_year": self.fiscal_year,
			"batch_no": cstr(d.get("batch_no")).strip(),
			"serial_no": d.get("serial_no"),
			"project": d.get("project_name"),
			"is_cancelled": self.docstatus==2 and "Yes" or "No"
		}

		sl_dict.update(args)
		return sl_dict

	def make_sl_entries(self, sl_entries, is_amended=None):
		from erpnext.stock.stock_ledger import make_sl_entries
		make_sl_entries(sl_entries, is_amended)

	def make_gl_entries_on_cancel(self):
		if frappe.db.sql("""select name from `tabGL Entry` where voucher_type=%s
			and voucher_no=%s""", (self.doctype, self.name)):
				self.make_gl_entries()

	def get_serialized_items(self):
		serialized_items = []
		item_codes = list(set([d.item_code for d in self.get(self.fname)]))
		if item_codes:
			serialized_items = frappe.db.sql_list("""select name from `tabItem`
				where has_serial_no='Yes' and name in ({})""".format(", ".join(["%s"]*len(item_codes))),
				tuple(item_codes))

		return serialized_items

def update_gl_entries_after(posting_date, posting_time, for_warehouses=None, for_items=None,
		warehouse_account=None, allow_negative_stock=False):
	def _delete_gl_entries(voucher_type, voucher_no):
		frappe.db.sql("""delete from `tabGL Entry`
			where voucher_type=%s and voucher_no=%s""", (voucher_type, voucher_no))

	if not warehouse_account:
		warehouse_account = get_warehouse_account()

	future_stock_vouchers = get_future_stock_vouchers(posting_date, posting_time, for_warehouses, for_items)
	gle = get_voucherwise_gl_entries(future_stock_vouchers, posting_date)

	for voucher_type, voucher_no in future_stock_vouchers:
		existing_gle = gle.get((voucher_type, voucher_no), [])
		voucher_obj = frappe.get_doc(voucher_type, voucher_no)
		expected_gle = voucher_obj.get_gl_entries(warehouse_account, allow_negative_stock=allow_negative_stock)
		if expected_gle:
			if not existing_gle or not compare_existing_and_expected_gle(existing_gle,
				expected_gle):
					_delete_gl_entries(voucher_type, voucher_no)
					voucher_obj.make_gl_entries(repost_future_gle=False, allow_negative_stock=allow_negative_stock)
		else:
			_delete_gl_entries(voucher_type, voucher_no)

def compare_existing_and_expected_gle(existing_gle, expected_gle):
	matched = True
	for entry in expected_gle:
		for e in existing_gle:
			if entry.account==e.account and entry.against_account==e.against_account \
				and entry.cost_center==e.cost_center \
				and (entry.debit != e.debit or entry.credit != e.credit):
					matched = False
					break
	return matched

def get_future_stock_vouchers(posting_date, posting_time, for_warehouses=None, for_items=None):
	future_stock_vouchers = []

	values = []
	condition = ""
	if for_items:
		condition += " and item_code in ({})".format(", ".join(["%s"] * len(for_items)))
		values += for_items

	if for_warehouses:
		condition += " and warehouse in ({})".format(", ".join(["%s"] * len(for_warehouses)))
		values += for_warehouses

	for d in frappe.db.sql("""select distinct sle.voucher_type, sle.voucher_no
		from `tabStock Ledger Entry` sle
		where timestamp(sle.posting_date, sle.posting_time) >= timestamp(%s, %s) {condition}
		order by timestamp(sle.posting_date, sle.posting_time) asc, name asc""".format(condition=condition),
		tuple([posting_date, posting_time] + values), as_dict=True):
			future_stock_vouchers.append([d.voucher_type, d.voucher_no])

	return future_stock_vouchers

def get_voucherwise_gl_entries(future_stock_vouchers, posting_date):
	gl_entries = {}
	if future_stock_vouchers:
		for d in frappe.db.sql("""select * from `tabGL Entry`
			where posting_date >= %s and voucher_no in (%s)""" %
			('%s', ', '.join(['%s']*len(future_stock_vouchers))),
			tuple([posting_date] + [d[1] for d in future_stock_vouchers]), as_dict=1):
				gl_entries.setdefault((d.voucher_type, d.voucher_no), []).append(d)

	return gl_entries

def get_warehouse_account():
	warehouse_account = dict(frappe.db.sql("""select master_name, name from tabAccount
		where account_type = 'Warehouse' and ifnull(master_name, '') != ''"""))
	return warehouse_account

def block_negative_stock(allow_negative_stock=False):
	if cint(frappe.defaults.get_global_default("auto_accounting_for_stock")) and not allow_negative_stock:
		if cint(frappe.db.get_value("Stock Settings", None, "allow_negative_stock")):
			frappe.throw(_("Negative stock is not allowed in case of Perpetual Inventory, please disable it from Stock Settings"))

def get_valuation_rate(item_code, warehouse, posting_date):
	last_valuation_rate = frappe.db.sql("""select valuation_rate
		from `tabStock Ledger Entry`
		where item_code = %s and warehouse = %s
		and ifnull(qty_after_transaction, 0) > 0 and posting_date < %s
		order by posting_date desc limit 1""", (item_code, warehouse, posting_date))

	valuation_rate = flt(last_valuation_rate[0][0]) if last_valuation_rate else 0

	if not valuation_rate:
		valuation_rate = frappe.db.get_value("Item Price", {"item_code": item_code, "buying": 1}, "price_list_rate")

	return valuation_rate