# 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, json
from frappe.utils.nestedset import get_root_of
from frappe.utils import cint
from erpnext.accounts.doctype.pos_profile.pos_profile import get_item_groups

from six import string_types

@frappe.whitelist()
def get_items(start, page_length, price_list, item_group, search_value="", pos_profile=None):
	data = dict()
	warehouse = ""
	display_items_in_stock = 0

	if pos_profile:
		warehouse, display_items_in_stock = frappe.db.get_value('POS Profile', pos_profile, ['warehouse', 'display_items_in_stock'])

	if not frappe.db.exists('Item Group', item_group):
		item_group = get_root_of('Item Group')

	if search_value:
		data = search_serial_or_batch_or_barcode_number(search_value)

	item_code = data.get("item_code") if data.get("item_code") else search_value
	serial_no = data.get("serial_no") if data.get("serial_no") else ""
	batch_no = data.get("batch_no") if data.get("batch_no") else ""
	barcode = data.get("barcode") if data.get("barcode") else ""

	condition = get_conditions(item_code, serial_no, batch_no, barcode)

	if pos_profile:
		condition += get_item_group_condition(pos_profile)

	lft, rgt = frappe.db.get_value('Item Group', item_group, ['lft', 'rgt'])
	# locate function is used to sort by closest match from the beginning of the value

	result = []

	items_data = frappe.db.sql("""
		SELECT
			name AS item_code,
			item_name,
			stock_uom,
			image AS item_image,
			idx AS idx,
			is_stock_item
		FROM
			`tabItem`
		WHERE
			disabled = 0
				AND has_variants = 0
				AND is_sales_item = 1
				AND item_group in (SELECT name FROM `tabItem Group` WHERE lft >= {lft} AND rgt <= {rgt})
				AND {condition}
		ORDER BY
			idx desc
		LIMIT
			{start}, {page_length}"""
		.format(
			start=start,
			page_length=page_length,
			lft=lft,
			rgt=rgt,
			condition=condition
		), as_dict=1)

	if items_data:
		items = [d.item_code for d in items_data]
		item_prices_data = frappe.get_all("Item Price",
			fields = ["item_code", "price_list_rate", "currency"],
			filters = {'price_list': price_list, 'item_code': ['in', items]})

		item_prices, bin_data = {}, {}
		for d in item_prices_data:
			item_prices[d.item_code] = d

		# prepare filter for bin query
		bin_filters = {'item_code': ['in', items]}
		if warehouse:
			bin_filters['warehouse'] = warehouse
		if display_items_in_stock:
			bin_filters['actual_qty'] = [">", 0]

		# query item bin
		bin_data = frappe.get_all(
			'Bin', fields=['item_code', 'sum(actual_qty) as actual_qty'],
			filters=bin_filters, group_by='item_code'
		)

		# convert list of dict into dict as {item_code: actual_qty}
		bin_dict = {}
		for b in bin_data:
			bin_dict[b.get('item_code')] = b.get('actual_qty')

		for item in items_data:
			item_code = item.item_code
			item_price = item_prices.get(item_code) or {}
			item_stock_qty = bin_dict.get(item_code)

			if display_items_in_stock and not item_stock_qty:
				pass
			else:
				row = {}
				row.update(item)
				row.update({
					'price_list_rate': item_price.get('price_list_rate'),
					'currency': item_price.get('currency'),
					'actual_qty': item_stock_qty,
				})
				result.append(row)

	res = {
		'items': result
	}

	if serial_no:
		res.update({
			'serial_no': serial_no
		})

	if batch_no:
		res.update({
			'batch_no': batch_no
		})

	if barcode:
		res.update({
			'barcode': barcode
		})

	return res

@frappe.whitelist()
def search_serial_or_batch_or_barcode_number(search_value):
	# search barcode no
	barcode_data = frappe.db.get_value('Item Barcode', {'barcode': search_value}, ['barcode', 'parent as item_code'], as_dict=True)
	if barcode_data:
		return barcode_data

	# search serial no
	serial_no_data = frappe.db.get_value('Serial No', search_value, ['name as serial_no', 'item_code'], as_dict=True)
	if serial_no_data:
		return serial_no_data

	# search batch no
	batch_no_data = frappe.db.get_value('Batch', search_value, ['name as batch_no', 'item as item_code'], as_dict=True)
	if batch_no_data:
		return batch_no_data

	return {}

def get_conditions(item_code, serial_no, batch_no, barcode):
	if serial_no or batch_no or barcode:
		return "name = {0}".format(frappe.db.escape(item_code))

	return """(name like {item_code}
		or item_name like {item_code})""".format(item_code = frappe.db.escape('%' + item_code + '%'))

def get_item_group_condition(pos_profile):
	cond = "and 1=1"
	item_groups = get_item_groups(pos_profile)
	if item_groups:
		cond = "and item_group in (%s)"%(', '.join(['%s']*len(item_groups)))

	return cond % tuple(item_groups)

def item_group_query(doctype, txt, searchfield, start, page_len, filters):
	item_groups = []
	cond = "1=1"
	pos_profile= filters.get('pos_profile')

	if pos_profile:
		item_groups = get_item_groups(pos_profile)

		if item_groups:
			cond = "name in (%s)"%(', '.join(['%s']*len(item_groups)))
			cond = cond % tuple(item_groups)

	return frappe.db.sql(""" select distinct name from `tabItem Group`
			where {condition} and (name like %(txt)s) limit {start}, {page_len}"""
		.format(condition = cond, start=start, page_len= page_len),
			{'txt': '%%%s%%' % txt})

@frappe.whitelist()
def get_pos_fields():
	return frappe.get_all("POS Field", fields=["label", "fieldname",
		"fieldtype", "default_value", "reqd", "read_only", "options"])