# Copyright (c) 2015, Frappe Technologies Pvt. Ltd. and Contributors
# License: GNU General Public License v3. See license.txt

from __future__ import unicode_literals
import calendar
import frappe
from frappe import _
from frappe.utils import cint, cstr, getdate

def execute(filters=None):
	common_columns = [
		{
			'label': _('New Customers'),
			'fieldname': 'new_customers',
			'fieldtype': 'Int',
			'default': 0,
			'width': 125
		},
		{
			'label': _('Repeat Customers'),
			'fieldname': 'repeat_customers',
			'fieldtype': 'Int',
			'default': 0,
			'width': 125
		},
		{
			'label': _('Total'),
			'fieldname': 'total',
			'fieldtype': 'Int',
			'default': 0,
			'width': 100
		},
		{
			'label': _('New Customer Revenue'),
			'fieldname': 'new_customer_revenue',
			'fieldtype': 'Currency',
			'default': 0.0,
			'width': 175
		},
		{
			'label': _('Repeat Customer Revenue'),
			'fieldname': 'repeat_customer_revenue',
			'fieldtype': 'Currency',
			'default': 0.0,
			'width': 175
		},
		{
			'label': _('Total Revenue'),
			'fieldname': 'total_revenue',
			'fieldtype': 'Currency',
			'default': 0.0,
			'width': 175
		}
	]
	if filters.get('view_type') == 'Monthly':
		return get_data_by_time(filters, common_columns)
	else:
		return get_data_by_territory(filters, common_columns)

def get_data_by_time(filters, common_columns):
	# key yyyy-mm
	columns = [
		{
			'label': _('Year'),
			'fieldname': 'year',
			'fieldtype': 'Data',
			'width': 100
		},
		{
			'label': _('Month'),
			'fieldname': 'month',
			'fieldtype': 'Data',
			'width': 100
		},
	]
	columns += common_columns

	customers_in = get_customer_stats(filters)

	# time series
	from_year, from_month, temp = filters.get('from_date').split('-')
	to_year, to_month, temp = filters.get('to_date').split('-')

	from_year, from_month, to_year, to_month = \
		cint(from_year), cint(from_month), cint(to_year), cint(to_month)

	out = []
	for year in range(from_year, to_year+1):
		for month in range(from_month if year==from_year else 1, (to_month+1) if year==to_year else 13):
			key = '{year}-{month:02d}'.format(year=year, month=month)
			data = customers_in.get(key)
			new = data['new'] if data else [0, 0.0]
			repeat = data['repeat'] if data else [0, 0.0]
			out.append({
				'year': cstr(year),
				'month': calendar.month_name[month],
				'new_customers': new[0],
				'repeat_customers': repeat[0],
				'total': new[0] + repeat[0],
				'new_customer_revenue': new[1],
				'repeat_customer_revenue': repeat[1],
				'total_revenue': new[1] + repeat[1]
			})
	return columns, out

def get_data_by_territory(filters, common_columns):
	columns = [{
		'label': 'Territory',
		'fieldname': 'territory',
		'fieldtype': 'Link',
		'options': 'Territory',
		'width': 150
	}]
	columns += common_columns

	customers_in = get_customer_stats(filters, tree_view=True)

	territory_dict = {}
	for t in frappe.db.sql('''SELECT name, lft, parent_territory, is_group FROM `tabTerritory` ORDER BY lft''', as_dict=1):
		territory_dict.update({
			t.name: {
				'parent': t.parent_territory,
				'is_group': t.is_group
			}
		})

	depth_map = frappe._dict()
	for name, info in territory_dict.items():
		default = depth_map.get(info['parent']) + 1 if info['parent'] else 0
		depth_map.setdefault(name, default)

	data = []
	for name, indent in depth_map.items():
		condition = customers_in.get(name)
		new = customers_in[name]['new'] if condition else [0, 0.0]
		repeat = customers_in[name]['repeat'] if condition else [0, 0.0]
		temp = {
			'territory': name,
			'parent_territory': territory_dict[name]['parent'],
			'indent': indent,
			'new_customers': new[0],
			'repeat_customers': repeat[0],
			'total': new[0] + repeat[0],
			'new_customer_revenue': new[1],
			'repeat_customer_revenue': repeat[1],
			'total_revenue': new[1] + repeat[1],
			'bold': 0 if indent else 1
		}
		data.append(temp)

	loop_data = sorted(data, key=lambda k: k['indent'], reverse=True)

	for ld in loop_data:
		if ld['parent_territory']:
			parent_data = [x for x in data if x['territory'] == ld['parent_territory']][0]
			for key in parent_data.keys():
				if key not in  ['indent', 'territory', 'parent_territory', 'bold']:
					parent_data[key] += ld[key]

	return columns, data, None, None, None, 1

def get_customer_stats(filters, tree_view=False):
	""" Calculates number of new and repeated customers and revenue. """
	company_condition = ''
	if filters.get('company'):
		company_condition = ' and company=%(company)s'

	customers = []
	customers_in = {}

	for si in frappe.db.sql('''select territory, posting_date, customer, base_grand_total from `tabSales Invoice`
		where docstatus=1 and posting_date <= %(to_date)s
		{company_condition} order by posting_date'''.format(company_condition=company_condition),
		filters, as_dict=1):

		key = si.territory if tree_view else si.posting_date.strftime('%Y-%m')
		new_or_repeat = 'new' if si.customer not in customers else 'repeat'
		customers_in.setdefault(key, {'new': [0, 0.0], 'repeat': [0, 0.0]})

		# if filters.from_date <= si.posting_date.strftime('%Y-%m-%d'):
		if getdate(filters.from_date) <= getdate(si.posting_date):
				customers_in[key][new_or_repeat][0] += 1
				customers_in[key][new_or_repeat][1] += si.base_grand_total
		if new_or_repeat == 'new':
			customers.append(si.customer)

	return customers_in
