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

from typing import Optional

import frappe
from frappe import _, msgprint
from frappe.utils import cint, cstr, flt

import erpnext
from erpnext.accounts.utils import get_company_default
from erpnext.controllers.stock_controller import StockController
from erpnext.stock.doctype.batch.batch import get_batch_qty
from erpnext.stock.doctype.serial_no.serial_no import get_serial_nos
from erpnext.stock.utils import get_stock_balance


class OpeningEntryAccountError(frappe.ValidationError):
	pass


class EmptyStockReconciliationItemsError(frappe.ValidationError):
	pass


class StockReconciliation(StockController):
	def __init__(self, *args, **kwargs):
		super(StockReconciliation, self).__init__(*args, **kwargs)
		self.head_row = ["Item Code", "Warehouse", "Quantity", "Valuation Rate"]

	def validate(self):
		if not self.expense_account:
			self.expense_account = frappe.get_cached_value(
				"Company", self.company, "stock_adjustment_account"
			)
		if not self.cost_center:
			self.cost_center = frappe.get_cached_value("Company", self.company, "cost_center")
		self.validate_posting_time()
		self.remove_items_with_no_change()
		self.validate_data()
		self.validate_expense_account()
		self.validate_customer_provided_item()
		self.set_zero_value_for_customer_provided_items()
		self.clean_serial_nos()
		self.set_total_qty_and_amount()
		self.validate_putaway_capacity()

		if self._action == "submit":
			self.make_batches("warehouse")

	def on_submit(self):
		self.update_stock_ledger()
		self.make_gl_entries()
		self.repost_future_sle_and_gle()

		from erpnext.stock.doctype.serial_no.serial_no import update_serial_nos_after_submit

		update_serial_nos_after_submit(self, "items")

	def on_cancel(self):
		self.ignore_linked_doctypes = ("GL Entry", "Stock Ledger Entry", "Repost Item Valuation")
		self.make_sle_on_cancel()
		self.make_gl_entries_on_cancel()
		self.repost_future_sle_and_gle()
		self.delete_auto_created_batches()

	def remove_items_with_no_change(self):
		"""Remove items if qty or rate is not changed"""
		self.difference_amount = 0.0

		def _changed(item):
			item_dict = get_stock_balance_for(
				item.item_code, item.warehouse, self.posting_date, self.posting_time, batch_no=item.batch_no
			)

			if (
				(item.qty is None or item.qty == item_dict.get("qty"))
				and (item.valuation_rate is None or item.valuation_rate == item_dict.get("rate"))
				and (not item.serial_no or (item.serial_no == item_dict.get("serial_nos")))
			):
				return False
			else:
				# set default as current rates
				if item.qty is None:
					item.qty = item_dict.get("qty")

				if item.valuation_rate is None:
					item.valuation_rate = item_dict.get("rate")

				if item_dict.get("serial_nos"):
					item.current_serial_no = item_dict.get("serial_nos")
					if self.purpose == "Stock Reconciliation" and not item.serial_no:
						item.serial_no = item.current_serial_no

				item.current_qty = item_dict.get("qty")
				item.current_valuation_rate = item_dict.get("rate")
				self.difference_amount += flt(item.qty, item.precision("qty")) * flt(
					item.valuation_rate or item_dict.get("rate"), item.precision("valuation_rate")
				) - flt(item_dict.get("qty"), item.precision("qty")) * flt(
					item_dict.get("rate"), item.precision("valuation_rate")
				)
				return True

		items = list(filter(lambda d: _changed(d), self.items))

		if not items:
			frappe.throw(
				_("None of the items have any change in quantity or value."),
				EmptyStockReconciliationItemsError,
			)

		elif len(items) != len(self.items):
			self.items = items
			for i, item in enumerate(self.items):
				item.idx = i + 1
			frappe.msgprint(_("Removed items with no change in quantity or value."))

	def validate_data(self):
		def _get_msg(row_num, msg):
			return _("Row # {0}:").format(row_num + 1) + " " + msg

		self.validation_messages = []
		item_warehouse_combinations = []

		default_currency = frappe.db.get_default("currency")

		for row_num, row in enumerate(self.items):
			# find duplicates
			key = [row.item_code, row.warehouse]
			for field in ["serial_no", "batch_no"]:
				if row.get(field):
					key.append(row.get(field))

			if key in item_warehouse_combinations:
				self.validation_messages.append(
					_get_msg(row_num, _("Same item and warehouse combination already entered."))
				)
			else:
				item_warehouse_combinations.append(key)

			self.validate_item(row.item_code, row)

			# validate warehouse
			if not frappe.db.get_value("Warehouse", row.warehouse):
				self.validation_messages.append(_get_msg(row_num, _("Warehouse not found in the system")))

			# if both not specified
			if row.qty in ["", None] and row.valuation_rate in ["", None]:
				self.validation_messages.append(
					_get_msg(row_num, _("Please specify either Quantity or Valuation Rate or both"))
				)

			# do not allow negative quantity
			if flt(row.qty) < 0:
				self.validation_messages.append(_get_msg(row_num, _("Negative Quantity is not allowed")))

			# do not allow negative valuation
			if flt(row.valuation_rate) < 0:
				self.validation_messages.append(_get_msg(row_num, _("Negative Valuation Rate is not allowed")))

			if row.qty and row.valuation_rate in ["", None]:
				row.valuation_rate = get_stock_balance(
					row.item_code, row.warehouse, self.posting_date, self.posting_time, with_valuation_rate=True
				)[1]
				if not row.valuation_rate:
					# try if there is a buying price list in default currency
					buying_rate = frappe.db.get_value(
						"Item Price",
						{"item_code": row.item_code, "buying": 1, "currency": default_currency},
						"price_list_rate",
					)
					if buying_rate:
						row.valuation_rate = buying_rate

					else:
						# get valuation rate from Item
						row.valuation_rate = frappe.get_value("Item", row.item_code, "valuation_rate")

		# throw all validation messages
		if self.validation_messages:
			for msg in self.validation_messages:
				msgprint(msg)

			raise frappe.ValidationError(self.validation_messages)

	def validate_item(self, item_code, row):
		from erpnext.stock.doctype.item.item import (
			validate_cancelled_item,
			validate_end_of_life,
			validate_is_stock_item,
		)

		# using try except to catch all validation msgs and display together

		try:
			item = frappe.get_doc("Item", item_code)

			# end of life and stock item
			validate_end_of_life(item_code, item.end_of_life, item.disabled)
			validate_is_stock_item(item_code, item.is_stock_item)

			# item should not be serialized
			if item.has_serial_no and not row.serial_no and not item.serial_no_series:
				raise frappe.ValidationError(
					_("Serial no(s) required for serialized item {0}").format(item_code)
				)

			# item managed batch-wise not allowed
			if item.has_batch_no and not row.batch_no and not item.create_new_batch:
				raise frappe.ValidationError(_("Batch no is required for batched item {0}").format(item_code))

			# docstatus should be < 2
			validate_cancelled_item(item_code, item.docstatus)

		except Exception as e:
			self.validation_messages.append(_("Row #") + " " + ("%d: " % (row.idx)) + cstr(e))

	def update_stock_ledger(self):
		"""find difference between current and expected entries
		and create stock ledger entries based on the difference"""
		from erpnext.stock.stock_ledger import get_previous_sle

		sl_entries = []
		has_serial_no = False
		has_batch_no = False
		for row in self.items:
			item = frappe.get_doc("Item", row.item_code)
			if item.has_batch_no:
				has_batch_no = True

			if item.has_serial_no or item.has_batch_no:
				has_serial_no = True
				self.get_sle_for_serialized_items(row, sl_entries, item)
			else:
				if row.serial_no or row.batch_no:
					frappe.throw(
						_(
							"Row #{0}: Item {1} is not a Serialized/Batched Item. It cannot have a Serial No/Batch No against it."
						).format(row.idx, frappe.bold(row.item_code))
					)

				previous_sle = get_previous_sle(
					{
						"item_code": row.item_code,
						"warehouse": row.warehouse,
						"posting_date": self.posting_date,
						"posting_time": self.posting_time,
					}
				)

				if previous_sle:
					if row.qty in ("", None):
						row.qty = previous_sle.get("qty_after_transaction", 0)

					if row.valuation_rate in ("", None):
						row.valuation_rate = previous_sle.get("valuation_rate", 0)

				if row.qty and not row.valuation_rate and not row.allow_zero_valuation_rate:
					frappe.throw(
						_("Valuation Rate required for Item {0} at row {1}").format(row.item_code, row.idx)
					)

				if (
					previous_sle
					and row.qty == previous_sle.get("qty_after_transaction")
					and (row.valuation_rate == previous_sle.get("valuation_rate") or row.qty == 0)
				) or (not previous_sle and not row.qty):
					continue

				sl_entries.append(self.get_sle_for_items(row))

		if sl_entries:
			if has_serial_no:
				sl_entries = self.merge_similar_item_serial_nos(sl_entries)

			allow_negative_stock = False
			if has_batch_no:
				allow_negative_stock = True

			self.make_sl_entries(sl_entries, allow_negative_stock=allow_negative_stock)

		if has_serial_no and sl_entries:
			self.update_valuation_rate_for_serial_no()

	def get_sle_for_serialized_items(self, row, sl_entries, item):
		from erpnext.stock.stock_ledger import get_previous_sle

		serial_nos = get_serial_nos(row.serial_no)

		# To issue existing serial nos
		if row.current_qty and (row.current_serial_no or row.batch_no):
			args = self.get_sle_for_items(row)
			args.update(
				{
					"actual_qty": -1 * row.current_qty,
					"serial_no": row.current_serial_no,
					"batch_no": row.batch_no,
					"valuation_rate": row.current_valuation_rate,
				}
			)

			if row.current_serial_no:
				args.update(
					{
						"qty_after_transaction": 0,
					}
				)

			sl_entries.append(args)

		qty_after_transaction = 0
		for serial_no in serial_nos:
			args = self.get_sle_for_items(row, [serial_no])

			previous_sle = get_previous_sle(
				{
					"item_code": row.item_code,
					"posting_date": self.posting_date,
					"posting_time": self.posting_time,
					"serial_no": serial_no,
				}
			)

			if previous_sle and row.warehouse != previous_sle.get("warehouse"):
				# If serial no exists in different warehouse

				warehouse = previous_sle.get("warehouse", "") or row.warehouse

				if not qty_after_transaction:
					qty_after_transaction = get_stock_balance(
						row.item_code, warehouse, self.posting_date, self.posting_time
					)

				qty_after_transaction -= 1

				new_args = args.copy()
				new_args.update(
					{
						"actual_qty": -1,
						"qty_after_transaction": qty_after_transaction,
						"warehouse": warehouse,
						"valuation_rate": previous_sle.get("valuation_rate"),
					}
				)

				sl_entries.append(new_args)

		if row.qty:
			args = self.get_sle_for_items(row)

			if item.has_serial_no and item.has_batch_no:
				args["qty_after_transaction"] = row.qty

			args.update(
				{
					"actual_qty": row.qty,
					"incoming_rate": row.valuation_rate,
					"valuation_rate": row.valuation_rate,
				}
			)

			sl_entries.append(args)

		if serial_nos == get_serial_nos(row.current_serial_no):
			# update valuation rate
			self.update_valuation_rate_for_serial_nos(row, serial_nos)

	def update_valuation_rate_for_serial_no(self):
		for d in self.items:
			if not d.serial_no:
				continue

			serial_nos = get_serial_nos(d.serial_no)
			self.update_valuation_rate_for_serial_nos(d, serial_nos)

	def update_valuation_rate_for_serial_nos(self, row, serial_nos):
		valuation_rate = row.valuation_rate if self.docstatus == 1 else row.current_valuation_rate
		if valuation_rate is None:
			return

		for d in serial_nos:
			frappe.db.set_value("Serial No", d, "purchase_rate", valuation_rate)

	def get_sle_for_items(self, row, serial_nos=None):
		"""Insert Stock Ledger Entries"""

		if not serial_nos and row.serial_no:
			serial_nos = get_serial_nos(row.serial_no)

		data = frappe._dict(
			{
				"doctype": "Stock Ledger Entry",
				"item_code": row.item_code,
				"warehouse": row.warehouse,
				"posting_date": self.posting_date,
				"posting_time": self.posting_time,
				"voucher_type": self.doctype,
				"voucher_no": self.name,
				"voucher_detail_no": row.name,
				"company": self.company,
				"stock_uom": frappe.db.get_value("Item", row.item_code, "stock_uom"),
				"is_cancelled": 1 if self.docstatus == 2 else 0,
				"serial_no": "\n".join(serial_nos) if serial_nos else "",
				"batch_no": row.batch_no,
				"valuation_rate": flt(row.valuation_rate, row.precision("valuation_rate")),
			}
		)

		if not row.batch_no:
			data.qty_after_transaction = flt(row.qty, row.precision("qty"))

		if self.docstatus == 2 and not row.batch_no:
			if row.current_qty:
				data.actual_qty = -1 * row.current_qty
				data.qty_after_transaction = flt(row.current_qty)
				data.previous_qty_after_transaction = flt(row.qty)
				data.valuation_rate = flt(row.current_valuation_rate)
				data.stock_value = data.qty_after_transaction * data.valuation_rate
				data.stock_value_difference = -1 * flt(row.amount_difference)
			else:
				data.actual_qty = row.qty
				data.qty_after_transaction = 0.0
				data.valuation_rate = flt(row.valuation_rate)
				data.stock_value_difference = -1 * flt(row.amount_difference)

		return data

	def make_sle_on_cancel(self):
		sl_entries = []

		has_serial_no = False
		for row in self.items:
			if row.serial_no or row.batch_no or row.current_serial_no:
				has_serial_no = True
				serial_nos = ""
				if row.current_serial_no:
					serial_nos = get_serial_nos(row.current_serial_no)

				sl_entries.append(self.get_sle_for_items(row, serial_nos))
			else:
				sl_entries.append(self.get_sle_for_items(row))

		if sl_entries:
			if has_serial_no:
				sl_entries = self.merge_similar_item_serial_nos(sl_entries)

			sl_entries.reverse()
			allow_negative_stock = cint(
				frappe.db.get_single_value("Stock Settings", "allow_negative_stock")
			)
			self.make_sl_entries(sl_entries, allow_negative_stock=allow_negative_stock)

	def merge_similar_item_serial_nos(self, sl_entries):
		# If user has put the same item in multiple row with different serial no
		new_sl_entries = []
		merge_similar_entries = {}

		for d in sl_entries:
			if not d.serial_no or flt(d.get("actual_qty")) < 0:
				new_sl_entries.append(d)
				continue

			key = (d.item_code, d.warehouse)
			if key not in merge_similar_entries:
				d.total_amount = flt(d.actual_qty) * d.valuation_rate
				merge_similar_entries[key] = d
			elif d.serial_no:
				data = merge_similar_entries[key]
				data.actual_qty += d.actual_qty
				data.qty_after_transaction += d.qty_after_transaction

				data.total_amount += d.actual_qty * d.valuation_rate
				data.valuation_rate = (data.total_amount) / data.actual_qty
				data.serial_no += "\n" + d.serial_no

				data.incoming_rate = (data.total_amount) / data.actual_qty

		for key, value in merge_similar_entries.items():
			new_sl_entries.append(value)

		return new_sl_entries

	def get_gl_entries(self, warehouse_account=None):
		if not self.cost_center:
			msgprint(_("Please enter Cost Center"), raise_exception=1)

		return super(StockReconciliation, self).get_gl_entries(
			warehouse_account, self.expense_account, self.cost_center
		)

	def validate_expense_account(self):
		if not cint(erpnext.is_perpetual_inventory_enabled(self.company)):
			return

		if not self.expense_account:
			frappe.throw(_("Please enter Expense Account"))
		elif self.purpose == "Opening Stock" or not frappe.db.sql(
			"""select name from `tabStock Ledger Entry` limit 1"""
		):
			if frappe.db.get_value("Account", self.expense_account, "report_type") == "Profit and Loss":
				frappe.throw(
					_(
						"Difference Account must be a Asset/Liability type account, since this Stock Reconciliation is an Opening Entry"
					),
					OpeningEntryAccountError,
				)

	def set_zero_value_for_customer_provided_items(self):
		changed_any_values = False

		for d in self.get("items"):
			is_customer_item = frappe.db.get_value("Item", d.item_code, "is_customer_provided_item")
			if is_customer_item and d.valuation_rate:
				d.valuation_rate = 0.0
				changed_any_values = True

		if changed_any_values:
			msgprint(
				_("Valuation rate for customer provided items has been set to zero."),
				title=_("Note"),
				indicator="blue",
			)

	def set_total_qty_and_amount(self):
		for d in self.get("items"):
			d.amount = flt(d.qty, d.precision("qty")) * flt(d.valuation_rate, d.precision("valuation_rate"))
			d.current_amount = flt(d.current_qty, d.precision("current_qty")) * flt(
				d.current_valuation_rate, d.precision("current_valuation_rate")
			)

			d.quantity_difference = flt(d.qty) - flt(d.current_qty)
			d.amount_difference = flt(d.amount) - flt(d.current_amount)

	def get_items_for(self, warehouse):
		self.items = []
		for item in get_items(warehouse, self.posting_date, self.posting_time, self.company):
			self.append("items", item)

	def submit(self):
		if len(self.items) > 100:
			msgprint(
				_(
					"The task has been enqueued as a background job. In case there is any issue on processing in background, the system will add a comment about the error on this Stock Reconciliation and revert to the Draft stage"
				)
			)
			self.queue_action("submit", timeout=4600)
		else:
			self._submit()

	def cancel(self):
		if len(self.items) > 100:
			msgprint(
				_(
					"The task has been enqueued as a background job. In case there is any issue on processing in background, the system will add a comment about the error on this Stock Reconciliation and revert to the Submitted stage"
				)
			)
			self.queue_action("cancel", timeout=2000)
		else:
			self._cancel()


@frappe.whitelist()
def get_items(
	warehouse, posting_date, posting_time, company, item_code=None, ignore_empty_stock=False
):
	ignore_empty_stock = cint(ignore_empty_stock)
	items = [frappe._dict({"item_code": item_code, "warehouse": warehouse})]

	if not item_code:
		items = get_items_for_stock_reco(warehouse, company)

	res = []
	itemwise_batch_data = get_itemwise_batch(warehouse, posting_date, company, item_code)

	for d in items:
		if d.item_code in itemwise_batch_data:
			valuation_rate = get_stock_balance(
				d.item_code, d.warehouse, posting_date, posting_time, with_valuation_rate=True
			)[1]

			for row in itemwise_batch_data.get(d.item_code):
				if ignore_empty_stock and not row.qty:
					continue

				args = get_item_data(row, row.qty, valuation_rate)
				res.append(args)
		else:
			stock_bal = get_stock_balance(
				d.item_code,
				d.warehouse,
				posting_date,
				posting_time,
				with_valuation_rate=True,
				with_serial_no=cint(d.has_serial_no),
			)
			qty, valuation_rate, serial_no = (
				stock_bal[0],
				stock_bal[1],
				stock_bal[2] if cint(d.has_serial_no) else "",
			)

			if ignore_empty_stock and not stock_bal[0]:
				continue

			args = get_item_data(d, qty, valuation_rate, serial_no)

			res.append(args)

	return res


def get_items_for_stock_reco(warehouse, company):
	lft, rgt = frappe.db.get_value("Warehouse", warehouse, ["lft", "rgt"])
	items = frappe.db.sql(
		f"""
		select
			i.name as item_code, i.item_name, bin.warehouse as warehouse, i.has_serial_no, i.has_batch_no
		from
			`tabBin` bin, `tabItem` i
		where
			i.name = bin.item_code
			and IFNULL(i.disabled, 0) = 0
			and i.is_stock_item = 1
			and i.has_variants = 0
			and exists(
				select name from `tabWarehouse` where lft >= {lft} and rgt <= {rgt} and name = bin.warehouse
			)
	""",
		as_dict=1,
	)

	items += frappe.db.sql(
		"""
		select
			i.name as item_code, i.item_name, id.default_warehouse as warehouse, i.has_serial_no, i.has_batch_no
		from
			`tabItem` i, `tabItem Default` id
		where
			i.name = id.parent
			and exists(
				select name from `tabWarehouse` where lft >= %s and rgt <= %s and name=id.default_warehouse
			)
			and i.is_stock_item = 1
			and i.has_variants = 0
			and IFNULL(i.disabled, 0) = 0
			and id.company = %s
		group by i.name
	""",
		(lft, rgt, company),
		as_dict=1,
	)

	# remove duplicates
	# check if item-warehouse key extracted from each entry exists in set iw_keys
	# and update iw_keys
	iw_keys = set()
	items = [
		item
		for item in items
		if [
			(item.item_code, item.warehouse) not in iw_keys,
			iw_keys.add((item.item_code, item.warehouse)),
		][0]
	]

	return items


def get_item_data(row, qty, valuation_rate, serial_no=None):
	return {
		"item_code": row.item_code,
		"warehouse": row.warehouse,
		"qty": qty,
		"item_name": row.item_name,
		"valuation_rate": valuation_rate,
		"current_qty": qty,
		"current_valuation_rate": valuation_rate,
		"current_serial_no": serial_no,
		"serial_no": serial_no,
		"batch_no": row.get("batch_no"),
	}


def get_itemwise_batch(warehouse, posting_date, company, item_code=None):
	from erpnext.stock.report.batch_wise_balance_history.batch_wise_balance_history import execute

	itemwise_batch_data = {}

	filters = frappe._dict(
		{"warehouse": warehouse, "from_date": posting_date, "to_date": posting_date, "company": company}
	)

	if item_code:
		filters.item_code = item_code

	columns, data = execute(filters)

	for row in data:
		itemwise_batch_data.setdefault(row[0], []).append(
			frappe._dict(
				{
					"item_code": row[0],
					"warehouse": warehouse,
					"qty": row[8],
					"item_name": row[1],
					"batch_no": row[4],
				}
			)
		)

	return itemwise_batch_data


@frappe.whitelist()
def get_stock_balance_for(
	item_code: str,
	warehouse: str,
	posting_date: str,
	posting_time: str,
	batch_no: Optional[str] = None,
	with_valuation_rate: bool = True,
):
	frappe.has_permission("Stock Reconciliation", "write", throw=True)

	item_dict = frappe.get_cached_value(
		"Item", item_code, ["has_serial_no", "has_batch_no"], as_dict=1
	)

	if not item_dict:
		# In cases of data upload to Items table
		msg = _("Item {} does not exist.").format(item_code)
		frappe.throw(msg, title=_("Missing"))

	serial_nos = None
	has_serial_no = bool(item_dict.get("has_serial_no"))
	has_batch_no = bool(item_dict.get("has_batch_no"))

	if not batch_no and has_batch_no:
		# Not enough information to fetch data
		return {"qty": 0, "rate": 0, "serial_nos": None}

	# TODO: fetch only selected batch's values
	data = get_stock_balance(
		item_code,
		warehouse,
		posting_date,
		posting_time,
		with_valuation_rate=with_valuation_rate,
		with_serial_no=has_serial_no,
	)

	if has_serial_no:
		qty, rate, serial_nos = data
	else:
		qty, rate = data

	if item_dict.get("has_batch_no"):
		qty = (
			get_batch_qty(batch_no, warehouse, posting_date=posting_date, posting_time=posting_time) or 0
		)

	return {"qty": qty, "rate": rate, "serial_nos": serial_nos}


@frappe.whitelist()
def get_difference_account(purpose, company):
	if purpose == "Stock Reconciliation":
		account = get_company_default(company, "stock_adjustment_account")
	else:
		account = frappe.db.get_value(
			"Account", {"is_group": 0, "company": company, "account_type": "Temporary"}, "name"
		)

	return account