# 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 webnotes
from webnotes import _, throw
from webnotes.utils import flt, cint
import json

def get_customer_list(doctype, txt, searchfield, start, page_len, filters):
	if webnotes.conn.get_default("cust_master_name") == "Customer Name":
		fields = ["name", "customer_group", "territory"]
	else:
		fields = ["name", "customer_name", "customer_group", "territory"]
		
	return webnotes.conn.sql("""select %s from `tabCustomer` where docstatus < 2 
		and (%s like %s or customer_name like %s) order by 
		case when name like %s then 0 else 1 end,
		case when customer_name like %s then 0 else 1 end,
		name, customer_name limit %s, %s""" % 
		(", ".join(fields), searchfield, "%s", "%s", "%s", "%s", "%s", "%s"), 
		("%%%s%%" % txt, "%%%s%%" % txt, "%%%s%%" % txt, "%%%s%%" % txt, start, page_len))
		
@webnotes.whitelist()
def get_item_details(args):
	"""
		args = {
			"item_code": "",
			"warehouse": None,
			"customer": "",
			"conversion_rate": 1.0,
			"selling_price_list": None,
			"price_list_currency": None,
			"plc_conversion_rate": 1.0
		}
	"""

	if isinstance(args, basestring):
		args = json.loads(args)
	args = webnotes._dict(args)
	
	if args.barcode:
		args.item_code = _get_item_code(barcode=args.barcode)
	elif not args.item_code and args.serial_no:
		args.item_code = _get_item_code(serial_no=args.serial_no)
	
	item_bean = webnotes.bean("Item", args.item_code)
	
	_validate_item_details(args, item_bean.doc)
	
	meta = webnotes.get_doctype(args.doctype)

	# hack! for Sales Order Item
	warehouse_fieldname = "warehouse"
	if meta.get_field("reserved_warehouse", parentfield=args.parentfield):
		warehouse_fieldname = "reserved_warehouse"
	
	out = _get_basic_details(args, item_bean, warehouse_fieldname)
	
	if meta.get_field("currency"):
		out.base_ref_rate = out.basic_rate = out.ref_rate = out.export_rate = 0.0
		
		if args.selling_price_list and args.price_list_currency:
			out.update(_get_price_list_rate(args, item_bean, meta))
		
	out.update(_get_item_discount(out.item_group, args.customer))
	
	if out.get(warehouse_fieldname):
		out.update(get_available_qty(args.item_code, out.get(warehouse_fieldname)))
	
	out.customer_item_code = _get_customer_item_code(args, item_bean)
	
	if cint(args.is_pos):
		pos_settings = get_pos_settings(args.company)
		if pos_settings:
			out.update(apply_pos_settings(pos_settings, out))
		
	if args.doctype in ("Sales Invoice", "Delivery Note"):
		if item_bean.doc.has_serial_no == "Yes" and not args.serial_no:
			out.serial_no = _get_serial_nos_by_fifo(args, item_bean)
		
	return out

def _get_serial_nos_by_fifo(args, item_bean):
	return "\n".join(webnotes.conn.sql_list("""select name from `tabSerial No` 
		where item_code=%(item_code)s and warehouse=%(warehouse)s and status='Available' 
		order by timestamp(purchase_date, purchase_time) asc limit %(qty)s""", {
			"item_code": args.item_code,
			"warehouse": args.warehouse,
			"qty": cint(args.qty)
		}))

def _get_item_code(barcode=None, serial_no=None):
	if barcode:
		input_type = "Barcode"
		item_code = webnotes.conn.sql_list("""select name from `tabItem` where barcode=%s""", barcode)
	elif serial_no:
		input_type = "Serial No"
		item_code = webnotes.conn.sql_list("""select item_code from `tabSerial No` 
			where name=%s""", serial_no)
			
	if not item_code:
		throw(_("No Item found with ") + input_type + ": %s" % (barcode or serial_no))
	
	return item_code[0]
	
def _validate_item_details(args, item):
	from erpnext.utilities.transaction_base import validate_item_fetch
	validate_item_fetch(args, item)
	
	# validate if sales item or service item
	if args.order_type == "Maintenance":
		if item.is_service_item != "Yes":
			throw(_("Item") + (" %s: " % item.name) + 
				_("not a service item.") +
				_("Please select a service item or change the order type to Sales."))
		
	elif item.is_sales_item != "Yes":
		throw(_("Item") + (" %s: " % item.name) + _("not a sales item"))
			
def _get_basic_details(args, item_bean, warehouse_fieldname):
	item = item_bean.doc
	
	from webnotes.defaults import get_user_default_as_list
	user_default_warehouse_list = get_user_default_as_list('warehouse')
	user_default_warehouse = user_default_warehouse_list[0] \
		if len(user_default_warehouse_list)==1 else ""
	
	out = webnotes._dict({
			"item_code": item.name,
			"description": item.description_html or item.description,
			warehouse_fieldname: user_default_warehouse or item.default_warehouse \
				or args.get(warehouse_fieldname),
			"income_account": item.default_income_account or args.income_account \
				or webnotes.conn.get_value("Company", args.company, "default_income_account"),
			"expense_account": item.purchase_account or args.expense_account \
				or webnotes.conn.get_value("Company", args.company, "default_expense_account"),
			"cost_center": item.default_sales_cost_center or args.cost_center,
			"qty": 1.0,
			"export_amount": 0.0,
			"amount": 0.0,
			"batch_no": None,
			"item_tax_rate": json.dumps(dict(([d.tax_type, d.tax_rate] for d in 
				item_bean.doclist.get({"parentfield": "item_tax"})))),
		})
	
	for fieldname in ("item_name", "item_group", "barcode", "brand", "stock_uom"):
		out[fieldname] = item.fields.get(fieldname)
			
	return out
	
def _get_price_list_rate(args, item_bean, meta):
	ref_rate = webnotes.conn.sql("""select ref_rate from `tabItem Price` 
		where price_list=%s and item_code=%s and selling=1""", 
		(args.selling_price_list, args.item_code), as_dict=1)

	if not ref_rate:
		return {}
	
	# found price list rate - now we can validate
	from erpnext.utilities.transaction_base import validate_currency
	validate_currency(args, item_bean.doc, meta)
	
	return {"ref_rate": flt(ref_rate[0].ref_rate) * flt(args.plc_conversion_rate) / flt(args.conversion_rate)}
	
def _get_item_discount(item_group, customer):
	parent_item_groups = [x[0] for x in webnotes.conn.sql("""SELECT parent.name 
		FROM `tabItem Group` AS node, `tabItem Group` AS parent 
		WHERE parent.lft <= node.lft and parent.rgt >= node.rgt and node.name = %s
		GROUP BY parent.name 
		ORDER BY parent.lft desc""", (item_group,))]
		
	discount = 0
	for d in parent_item_groups:
		res = webnotes.conn.sql("""select discount, name from `tabCustomer Discount` 
			where parent = %s and item_group = %s""", (customer, d))
		if res:
			discount = flt(res[0][0])
			break
			
	return {"adj_rate": discount}

@webnotes.whitelist()
def get_available_qty(item_code, warehouse):
	return webnotes.conn.get_value("Bin", {"item_code": item_code, "warehouse": warehouse}, 
		["projected_qty", "actual_qty"], as_dict=True) or {}
		
def _get_customer_item_code(args, item_bean):
	customer_item_code = item_bean.doclist.get({"parentfield": "item_customer_details",
		"customer_name": args.customer})
	
	return customer_item_code and customer_item_code[0].ref_code or None
	
def get_pos_settings(company):
	pos_settings = webnotes.conn.sql("""select * from `tabPOS Setting` where user = %s 
		and company = %s""", (webnotes.session['user'], company), as_dict=1)
	
	if not pos_settings:
		pos_settings = webnotes.conn.sql("""select * from `tabPOS Setting` 
			where ifnull(user,'') = '' and company = %s""", company, as_dict=1)
			
	return pos_settings and pos_settings[0] or None
	
def apply_pos_settings(pos_settings, opts):
	out = {}
	
	for fieldname in ("income_account", "cost_center", "warehouse", "expense_account"):
		if not opts.get(fieldname):
			out[fieldname] = pos_settings.get(fieldname)
			
	if out.get("warehouse"):
		out["actual_qty"] = get_available_qty(opts.item_code, out.get("warehouse")).get("actual_qty")
	
	return out