# Copyright (c) 2015, Frappe Technologies Pvt. Ltd. and Contributors
# MIT License. See license.txt

# For license information, please see license.txt


import json

import frappe
from frappe.model.document import Document
from frappe.utils import flt

from erpnext.stock.get_item_details import get_item_details, get_price_list_rate


class PackedItem(Document):
	pass


def make_packing_list(doc):
	"Make/Update packing list for Product Bundle Item."
	if doc.get("_action") and doc._action == "update_after_submit":
		return

	parent_items_price, reset = {}, False
	set_price_from_children = frappe.db.get_single_value(
		"Selling Settings", "editable_bundle_item_rates"
	)

	stale_packed_items_table = get_indexed_packed_items_table(doc)

	reset = reset_packing_list(doc)

	for item_row in doc.get("items"):
		if is_product_bundle(item_row.item_code):
			for bundle_item in get_product_bundle_items(item_row.item_code):
				pi_row = add_packed_item_row(
					doc=doc,
					packing_item=bundle_item,
					main_item_row=item_row,
					packed_items_table=stale_packed_items_table,
					reset=reset,
				)
				item_data = get_packed_item_details(bundle_item.item_code, doc.company)
				update_packed_item_basic_data(item_row, pi_row, bundle_item, item_data)
				update_packed_item_stock_data(item_row, pi_row, bundle_item, item_data, doc)
				update_packed_item_price_data(pi_row, item_data, doc)
				update_packed_item_from_cancelled_doc(item_row, bundle_item, pi_row, doc)

				if set_price_from_children:  # create/update bundle item wise price dict
					update_product_bundle_rate(parent_items_price, pi_row, item_row)

	if parent_items_price:
		set_product_bundle_rate_amount(doc, parent_items_price)  # set price in bundle item


def is_product_bundle(item_code: str) -> bool:
	return bool(frappe.db.exists("Product Bundle", {"new_item_code": item_code}))


def get_indexed_packed_items_table(doc):
	"""
	Create dict from stale packed items table like:
	{(Parent Item 1, Bundle Item 1, ae4b5678): {...}, (key): {value}}

	Use: to quickly retrieve/check if row existed in table instead of looping n times
	"""
	indexed_table = {}
	for packed_item in doc.get("packed_items"):
		key = (packed_item.parent_item, packed_item.item_code, packed_item.parent_detail_docname)
		indexed_table[key] = packed_item

	return indexed_table


def reset_packing_list(doc):
	"Conditionally reset the table and return if it was reset or not."
	reset_table = False
	doc_before_save = doc.get_doc_before_save()

	if doc_before_save:
		# reset table if:
		# 1. items were deleted
		# 2. if bundle item replaced by another item (same no. of items but different items)
		# we maintain list to track recurring item rows as well
		items_before_save = [item.item_code for item in doc_before_save.get("items")]
		items_after_save = [item.item_code for item in doc.get("items")]
		reset_table = items_before_save != items_after_save
	else:
		# reset: if via Update Items OR
		# if new mapped doc with packed items set (SO -> DN)
		# (cannot determine action)
		reset_table = True

	if reset_table:
		doc.set("packed_items", [])
	return reset_table


def get_product_bundle_items(item_code):
	product_bundle = frappe.qb.DocType("Product Bundle")
	product_bundle_item = frappe.qb.DocType("Product Bundle Item")

	query = (
		frappe.qb.from_(product_bundle_item)
		.join(product_bundle)
		.on(product_bundle_item.parent == product_bundle.name)
		.select(
			product_bundle_item.item_code,
			product_bundle_item.qty,
			product_bundle_item.uom,
			product_bundle_item.description,
		)
		.where(product_bundle.new_item_code == item_code)
		.orderby(product_bundle_item.idx)
	)
	return query.run(as_dict=True)


def add_packed_item_row(doc, packing_item, main_item_row, packed_items_table, reset):
	"""Add and return packed item row.
	doc: Transaction document
	packing_item (dict): Packed Item details
	main_item_row (dict): Items table row corresponding to packed item
	packed_items_table (dict): Packed Items table before save (indexed)
	reset (bool): State if table is reset or preserved as is
	"""
	exists, pi_row = False, {}

	# check if row already exists in packed items table
	key = (main_item_row.item_code, packing_item.item_code, main_item_row.name)
	if packed_items_table.get(key):
		pi_row, exists = packed_items_table.get(key), True

	if not exists:
		pi_row = doc.append("packed_items", {})
	elif reset:  # add row if row exists but table is reset
		pi_row.idx, pi_row.name = None, None
		pi_row = doc.append("packed_items", pi_row)

	return pi_row


def get_packed_item_details(item_code, company):
	item = frappe.qb.DocType("Item")
	item_default = frappe.qb.DocType("Item Default")
	query = (
		frappe.qb.from_(item)
		.left_join(item_default)
		.on((item_default.parent == item.name) & (item_default.company == company))
		.select(
			item.item_name,
			item.is_stock_item,
			item.description,
			item.stock_uom,
			item.valuation_rate,
			item_default.default_warehouse,
		)
		.where(item.name == item_code)
	)
	return query.run(as_dict=True)[0]


def update_packed_item_basic_data(main_item_row, pi_row, packing_item, item_data):
	pi_row.parent_item = main_item_row.item_code
	pi_row.parent_detail_docname = main_item_row.name
	pi_row.item_code = packing_item.item_code
	pi_row.item_name = item_data.item_name
	pi_row.uom = item_data.stock_uom
	pi_row.qty = flt(packing_item.qty) * flt(main_item_row.stock_qty)
	pi_row.conversion_factor = main_item_row.conversion_factor

	if not pi_row.description:
		pi_row.description = packing_item.get("description")


def update_packed_item_stock_data(main_item_row, pi_row, packing_item, item_data, doc):
	# TODO batch_no, actual_batch_qty, incoming_rate
	if not pi_row.warehouse and not doc.amended_from:
		fetch_warehouse = doc.get("is_pos") or item_data.is_stock_item or not item_data.default_warehouse
		pi_row.warehouse = (
			main_item_row.warehouse
			if (fetch_warehouse and main_item_row.warehouse)
			else item_data.default_warehouse
		)

	if not pi_row.target_warehouse:
		pi_row.target_warehouse = main_item_row.get("target_warehouse")

	bin = get_packed_item_bin_qty(packing_item.item_code, pi_row.warehouse)
	pi_row.actual_qty = flt(bin.get("actual_qty"))
	pi_row.projected_qty = flt(bin.get("projected_qty"))


def update_packed_item_price_data(pi_row, item_data, doc):
	"Set price as per price list or from the Item master."
	if pi_row.rate:
		return

	item_doc = frappe.get_cached_doc("Item", pi_row.item_code)
	row_data = pi_row.as_dict().copy()
	row_data.update(
		{
			"company": doc.get("company"),
			"price_list": doc.get("selling_price_list"),
			"currency": doc.get("currency"),
			"conversion_rate": doc.get("conversion_rate"),
		}
	)
	rate = get_price_list_rate(row_data, item_doc).get("price_list_rate")

	pi_row.rate = rate or item_data.get("valuation_rate") or 0.0


def update_packed_item_from_cancelled_doc(main_item_row, packing_item, pi_row, doc):
	"Update packed item row details from cancelled doc into amended doc."
	prev_doc_packed_items_map = None
	if doc.amended_from:
		prev_doc_packed_items_map = get_cancelled_doc_packed_item_details(doc.packed_items)

	if prev_doc_packed_items_map and prev_doc_packed_items_map.get(
		(packing_item.item_code, main_item_row.item_code)
	):
		prev_doc_row = prev_doc_packed_items_map.get((packing_item.item_code, main_item_row.item_code))
		pi_row.batch_no = prev_doc_row[0].batch_no
		pi_row.serial_no = prev_doc_row[0].serial_no
		pi_row.warehouse = prev_doc_row[0].warehouse


def get_packed_item_bin_qty(item, warehouse):
	bin_data = frappe.db.get_values(
		"Bin",
		fieldname=["actual_qty", "projected_qty"],
		filters={"item_code": item, "warehouse": warehouse},
		as_dict=True,
	)

	return bin_data[0] if bin_data else {}


def get_cancelled_doc_packed_item_details(old_packed_items):
	prev_doc_packed_items_map = {}
	for items in old_packed_items:
		prev_doc_packed_items_map.setdefault((items.item_code, items.parent_item), []).append(
			items.as_dict()
		)
	return prev_doc_packed_items_map


def update_product_bundle_rate(parent_items_price, pi_row, item_row):
	"""
	Update the price dict of Product Bundles based on the rates of the Items in the bundle.

	Stucture:
	{(Bundle Item 1, ae56fgji): 150.0, (Bundle Item 2, bc78fkjo): 200.0}
	"""
	key = (pi_row.parent_item, pi_row.parent_detail_docname)
	rate = parent_items_price.get(key)
	if not rate:
		parent_items_price[key] = 0.0

	parent_items_price[key] += flt((pi_row.rate * pi_row.qty) / item_row.stock_qty)


def set_product_bundle_rate_amount(doc, parent_items_price):
	"Set cumulative rate and amount in bundle item."
	for item in doc.get("items"):
		bundle_rate = parent_items_price.get((item.item_code, item.name))
		if bundle_rate and bundle_rate != item.rate:
			item.rate = bundle_rate
			item.amount = flt(bundle_rate * item.qty)


def on_doctype_update():
	frappe.db.add_index("Packed Item", ["item_code", "warehouse"])


@frappe.whitelist()
def get_items_from_product_bundle(row):
	row, items = json.loads(row), []

	bundled_items = get_product_bundle_items(row["item_code"])
	for item in bundled_items:
		row.update({"item_code": item.item_code, "qty": flt(row["quantity"]) * flt(item.qty)})
		items.append(get_item_details(row))

	return items