# Copyright (c) 2013, Frappe Technologies Pvt. Ltd. and contributors
# For license information, please see license.txt

from __future__ import unicode_literals
import frappe
import erpnext
from frappe import _
from frappe.utils import flt
from erpnext.accounts.report.financial_statements import get_period_list

def execute(filters=None):
	filters = frappe._dict(filters or {})

	columns = get_columns()
	data = get_vehicle_log_data(filters)
	chart = get_chart_data(data, filters)

	return columns, data, None, chart

def get_columns():
	return [
		{
			'fieldname': 'vehicle',
			'fieldtype': 'Link',
			'label': _('Vehicle'),
			'options': 'Vehicle',
			'width': 150
		},
		{
			'fieldname': 'make',
			'fieldtype': 'Data',
			'label': _('Make'),
			'width': 100
		},
		{
			'fieldname': 'model',
			'fieldtype': 'Data',
			'label': _('Model'),
			'width': 80
		},
		{
			'fieldname': 'location',
			'fieldtype': 'Data',
			'label': _('Location'),
			'width': 100
		},
		{
			'fieldname': 'log_name',
			'fieldtype': 'Link',
			'label': _('Vehicle Log'),
			'options': 'Vehicle Log',
			'width': 100
		},
		{
			'fieldname': 'odometer',
			'fieldtype': 'Int',
			'label': _('Odometer Value'),
			'width': 120
		},
		{
			'fieldname': 'date',
			'fieldtype': 'Date',
			'label': _('Date'),
			'width': 100
		},
		{
			'fieldname': 'fuel_qty',
			'fieldtype': 'Float',
			'label': _('Fuel Qty'),
			'width': 80
		},
		{
			'fieldname': 'fuel_price',
			'fieldtype': 'Float',
			'label': _('Fuel Price'),
			'width': 100
		},
		{
			'fieldname': 'fuel_expense',
			'fieldtype': 'Currency',
			'label': _('Fuel Expense'),
			'width': 150
		},
		{
			'fieldname': 'service_expense',
			'fieldtype': 'Currency',
			'label': _('Service Expense'),
			'width': 150
		},
		{
			'fieldname': 'employee',
			'fieldtype': 'Link',
			'label': _('Employee'),
			'options': 'Employee',
			'width': 150
		}
	]

	return columns


def get_vehicle_log_data(filters):
	start_date, end_date = get_period_dates(filters)
	conditions, values = get_conditions(filters)

	data = frappe.db.sql("""
		SELECT
			vhcl.license_plate as vehicle, vhcl.make, vhcl.model,
			vhcl.location, log.name as log_name, log.odometer,
			log.date, log.employee, log.fuel_qty,
			log.price as fuel_price,
			log.fuel_qty * log.price as fuel_expense
		FROM
			`tabVehicle` vhcl,`tabVehicle Log` log
		WHERE
			vhcl.license_plate = log.license_plate
			and log.docstatus = 1
			and date between %(start_date)s and %(end_date)s
			{0}
		ORDER BY date""".format(conditions), values, as_dict=1)

	for row in data:
		row['service_expense'] = get_service_expense(row.log_name)

	return data


def get_conditions(filters):
	conditions = ''

	start_date, end_date = get_period_dates(filters)
	values = {
		'start_date': start_date,
		'end_date': end_date
	}

	if filters.employee:
		conditions += ' and log.employee = %(employee)s'
		values['employee'] = filters.employee

	if filters.vehicle:
		conditions += ' and vhcl.license_plate = %(vehicle)s'
		values['vehicle'] = filters.vehicle

	return conditions, values


def get_period_dates(filters):
	if filters.filter_based_on == 'Fiscal Year' and filters.fiscal_year:
		fy = frappe.db.get_value('Fiscal Year', filters.fiscal_year,
			['year_start_date', 'year_end_date'], as_dict=True)
		return fy.year_start_date, fy.year_end_date
	else:
		return filters.from_date, filters.to_date


def get_service_expense(logname):
	expense_amount = frappe.db.sql("""
		SELECT sum(expense_amount)
		FROM
			`tabVehicle Log` log, `tabVehicle Service` service
		WHERE
			service.parent=log.name and log.name=%s
	""", logname)

	return flt(expense_amount[0][0]) if expense_amount else 0.0


def get_chart_data(data, filters):
	period_list = get_period_list(filters.fiscal_year, filters.fiscal_year,
		filters.from_date, filters.to_date, filters.filter_based_on, 'Monthly')

	fuel_data, service_data = [], []

	for period in period_list:
		total_fuel_exp = 0
		total_service_exp = 0

		for row in data:
			if row.date <= period.to_date and row.date >= period.from_date:
				total_fuel_exp += flt(row.fuel_expense)
				total_service_exp += flt(row.service_expense)

		fuel_data.append([period.key, total_fuel_exp])
		service_data.append([period.key, total_service_exp])

	labels = [period.label for period in period_list]
	fuel_exp_data= [row[1] for row in fuel_data]
	service_exp_data= [row[1] for row in service_data]

	datasets = []
	if fuel_exp_data:
		datasets.append({
			'name': _('Fuel Expenses'),
			'values': fuel_exp_data
		})

	if service_exp_data:
		datasets.append({
			'name': _('Service Expenses'),
			'values': service_exp_data
		})

	chart = {
		'data': {
			'labels': labels,
			'datasets': datasets
		},
		'type': 'line',
		'fieldtype': 'Currency'
	}

	return chart