# Copyright (c) 2013, Frappe Technologies Pvt. Ltd. and contributors
# License: MIT. See LICENSE

import frappe
from frappe import _
from frappe.utils import getdate


def execute(filters=None):
	columns = get_columns()
	data = get_data(filters)
	chart = get_chart_data(data)
	report_summary = get_report_summary(data)

	return columns, data, None, chart, report_summary

def get_columns():
	return [
		{
			'label': _('Employee'),
			'fieldname': 'employee',
			'fieldtype': 'Link',
			'options': 'Employee',
			'width': 150
		},
		{
			'label': _('Employee Name'),
			'fieldname': 'employee_name',
			'fieldtype': 'Data',
			'width': 150
		},
		{
			'label': _('Date of Joining'),
			'fieldname': 'date_of_joining',
			'fieldtype': 'Date',
			'width': 100
		},
		{
			'label': _('Relieving Date'),
			'fieldname': 'relieving_date',
			'fieldtype': 'Date',
			'width': 100
		},
		{
			'label': _('Department'),
			'fieldname': 'department',
			'fieldtype': 'Link',
			'options': 'Department',
			'width': 120
		},
		{
			'label': _('Designation'),
			'fieldname': 'designation',
			'fieldtype': 'Link',
			'options': 'Designation',
			'width': 120
		},
		{
			'label': _('Reports To'),
			'fieldname': 'reports_to',
			'fieldtype': 'Link',
			'options': 'Employee',
			'width': 120
		},
		{
			'label': _('Exit Interview'),
			'fieldname': 'exit_interview',
			'fieldtype': 'Link',
			'options': 'Exit Interview',
			'width': 98
		},
		{
			'label': _('Interview Status'),
			'fieldname': 'interview_status',
			'fieldtype': 'Data',
			'width': 98
		},
		{
			'label': _('Final Decision'),
			'fieldname': 'employee_status',
			'fieldtype': 'Data',
			'width': 98
		},
		{
			'label': _('Full and Final Statement'),
			'fieldname': 'full_and_final_statement',
			'fieldtype': 'Link',
			'options': 'Full and Final Statement',
			'width': 150
		}
	]

def get_data(filters):
	data = []

	employee = frappe.qb.DocType('Employee')
	interview = frappe.qb.DocType('Exit Interview')
	fnf = frappe.qb.DocType('Full and Final Statement')

	query = (
		frappe.qb.from_(employee)
			.left_join(interview).on(interview.employee == employee.name)
			.left_join(fnf).on(fnf.employee == employee.name)
			.select(
				employee.name.as_('employee'), employee.employee_name.as_('employee_name'),
				employee.date_of_joining.as_('date_of_joining'), employee.relieving_date.as_('relieving_date'),
				employee.department.as_('department'), employee.designation.as_('designation'),
				employee.reports_to.as_('reports_to'), interview.name.as_('exit_interview'),
				interview.status.as_('interview_status'), interview.employee_status.as_('employee_status'),
				interview.reference_document_name.as_('questionnaire'), fnf.name.as_('full_and_final_statement')
			).distinct()
			.where(
				((employee.relieving_date.isnotnull()) | (employee.relieving_date != ''))
				& ((interview.name.isnull()) | ((interview.name.isnotnull()) & (interview.docstatus != 2)))
				& ((fnf.name.isnull()) | ((fnf.name.isnotnull()) & (fnf.docstatus != 2)))
			)
	)

	query = get_conditions(filters, query, employee, interview, fnf)
	result = query.run(as_dict=True)

	return result


def get_conditions(filters, query, employee, interview, fnf):
	if filters.get('from_date') and filters.get('to_date'):
		query = query.where(employee.relieving_date[getdate(filters.get('from_date')):getdate(filters.get('to_date'))])

	elif filters.get('from_date'):
		query = query.where(employee.relieving_date >= filters.get('from_date'))

	elif filters.get('to_date'):
		query = query.where(employee.relieving_date <= filters.get('to_date'))

	if filters.get('company'):
		query = query.where(employee.company == filters.get('company'))

	if filters.get('department'):
		query = query.where(employee.department == filters.get('department'))

	if filters.get('designation'):
		query = query.where(employee.designation == filters.get('designation'))

	if filters.get('employee'):
		query = query.where(employee.name == filters.get('employee'))

	if filters.get('reports_to'):
		query = query.where(employee.reports_to == filters.get('reports_to'))

	if filters.get('interview_status'):
		query = query.where(interview.status == filters.get('interview_status'))

	if filters.get('final_decision'):
		query = query.where(interview.employee_status == filters.get('final_decision'))

	if filters.get('exit_interview_pending'):
		query = query.where((interview.name == '') | (interview.name.isnull()))

	if filters.get('questionnaire_pending'):
		query = query.where((interview.reference_document_name == '') | (interview.reference_document_name.isnull()))

	if filters.get('fnf_pending'):
		query = query.where((fnf.name == '') | (interview.name.isnull()))

	return query


def get_chart_data(data):
	if not data:
		return None

	retained = 0
	exit_confirmed = 0
	pending = 0

	for entry in data:
		if entry.employee_status == 'Employee Retained':
			retained += 1
		elif entry.employee_status == 'Exit Confirmed':
			exit_confirmed += 1
		else:
			pending += 1

	chart = {
		'data': {
			'labels': [_('Retained'), _('Exit Confirmed'), _('Decision Pending')],
			'datasets': [{'name': _('Employee Status'), 'values': [retained, exit_confirmed, pending]}]
		},
		'type': 'donut',
		'colors': ['green', 'red', 'blue'],
	}

	return chart


def get_report_summary(data):
	if not data:
		return None

	total_resignations = len(data)
	interviews_pending = len([entry.name for entry in data if not entry.exit_interview])
	fnf_pending = len([entry.name for entry in data if not entry.full_and_final_statement])
	questionnaires_pending = len([entry.name for entry in data if not entry.questionnaire])

	return [
		{
			'value': total_resignations,
			'label': _('Total Resignations'),
			'indicator': 'Red' if total_resignations > 0 else 'Green',
			'datatype': 'Int',
		},
		{
			'value': interviews_pending,
			'label': _('Pending Interviews'),
			'indicator': 'Blue' if interviews_pending > 0 else 'Green',
			'datatype': 'Int',
		},
		{
			'value': fnf_pending,
			'label': _('Pending FnF'),
			'indicator': 'Blue' if fnf_pending > 0 else 'Green',
			'datatype': 'Int',
		},
		{
			'value': questionnaires_pending,
			'label': _('Pending Questionnaires'),
			'indicator': 'Blue' if questionnaires_pending > 0 else 'Green',
			'datatype': 'Int'
		},
	]