# -*- coding: utf-8 -*-
# Copyright (c) 2018, Frappe Technologies Pvt. Ltd. and contributors
# For license information, please see license.txt

from __future__ import unicode_literals
import frappe
from frappe import _
from frappe.model.document import Document
from frappe.utils import formatdate, getdate

class OverlapError(frappe.ValidationError): pass

class ShiftRequest(Document):
	def validate(self):
		self.validate_dates()
		self.validate_shift_request_overlap_dates()
		self.validate_approver()
		self.validate_default_shift()

	def on_submit(self):
		if self.status not in ["Approved", "Rejected"]:
			frappe.throw(_("Only Shift Request with status 'Approved' and 'Rejected' can be submitted"))
		if self.status == "Approved":
			assignment_doc = frappe.new_doc("Shift Assignment")
			assignment_doc.company = self.company
			assignment_doc.shift_type = self.shift_type
			assignment_doc.employee = self.employee
			assignment_doc.start_date = self.from_date
			if self.to_date:
				assignment_doc.end_date = self.to_date
			assignment_doc.shift_request = self.name
			assignment_doc.insert()
			assignment_doc.submit()

			frappe.msgprint(_("Shift Assignment: {0} created for Employee: {1}").format(frappe.bold(assignment_doc.name), frappe.bold(self.employee)))

	def on_cancel(self):
		shift_assignment_list = frappe.get_list("Shift Assignment", {'employee': self.employee, 'shift_request': self.name})
		if shift_assignment_list:
			for shift in shift_assignment_list:
				shift_assignment_doc = frappe.get_doc("Shift Assignment", shift['name'])
				shift_assignment_doc.cancel()

	def validate_default_shift(self):
		default_shift = frappe.get_value("Employee", self.employee, "default_shift")
		if self.shift_type == default_shift:
			frappe.throw(_("You can not request for your Default Shift: {0}").format(frappe.bold(self.shift_type)))

	def validate_approver(self):
		department = frappe.get_value("Employee", self.employee, "department")
		shift_approver = frappe.get_value("Employee", self.employee, "shift_request_approver")
		approvers = frappe.db.sql("""select approver from `tabDepartment Approver` where parent= %s and parentfield = 'shift_request_approver'""", (department))
		approvers = [approver[0] for approver in approvers]
		approvers.append(shift_approver)
		if self.approver not in approvers:
			frappe.throw(_("Only Approvers can Approve this Request."))

	def validate_dates(self):
		if self.from_date and self.to_date and (getdate(self.to_date) < getdate(self.from_date)):
			frappe.throw(_("To date cannot be before from date"))

	def validate_shift_request_overlap_dates(self):
			if not self.name:
				self.name = "New Shift Request"

			d = frappe.db.sql("""
				select
					name, shift_type, from_date, to_date
				from `tabShift Request`
				where employee = %(employee)s and docstatus < 2
				and ((%(from_date)s >= from_date
					and %(from_date)s <= to_date) or
					( %(to_date)s >= from_date
					and %(to_date)s <= to_date ))
				and name != %(name)s""", {
					"employee": self.employee,
					"shift_type": self.shift_type,
					"from_date": self.from_date,
					"to_date": self.to_date,
					"name": self.name
				}, as_dict=1)

			for date_overlap in d:
				if date_overlap ['name']:
					self.throw_overlap_error(date_overlap)

	def throw_overlap_error(self, d):
		msg = _("Employee {0} has already applied for {1} between {2} and {3} : ").format(self.employee,
			d['shift_type'], formatdate(d['from_date']), formatdate(d['to_date'])) \
			+ """ <b><a href="#Form/Shift Request/{0}">{0}</a></b>""".format(d["name"])
		frappe.throw(msg, OverlapError)