# Copyright (c) 2013, 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.utils import cint, cstr
from erpnext.accounts.report.financial_statements import (get_period_list, get_columns, get_data)
from erpnext.accounts.report.profit_and_loss_statement.profit_and_loss_statement import get_net_profit_loss
from erpnext.accounts.utils import get_fiscal_year
from six import iteritems


def execute(filters=None):
	if cint(frappe.db.get_single_value('Accounts Settings', 'use_custom_cash_flow')):
		from erpnext.accounts.report.cash_flow.custom_cash_flow import execute as execute_custom
		return execute_custom(filters=filters)

	period_list = get_period_list(filters.from_fiscal_year, filters.to_fiscal_year,
		filters.period_start_date, filters.period_end_date, filters.filter_based_on,
		filters.periodicity, company=filters.company)

	cash_flow_accounts = get_cash_flow_accounts()

	# compute net profit / loss
	income = get_data(filters.company, "Income", "Credit", period_list, filters=filters,
		accumulated_values=filters.accumulated_values, ignore_closing_entries=True, ignore_accumulated_values_for_fy= True)
	expense = get_data(filters.company, "Expense", "Debit", period_list, filters=filters,
		accumulated_values=filters.accumulated_values, ignore_closing_entries=True, ignore_accumulated_values_for_fy= True)

	net_profit_loss = get_net_profit_loss(income, expense, period_list, filters.company)

	data = []
	summary_data = {}
	company_currency = frappe.get_cached_value('Company',  filters.company,  "default_currency")

	for cash_flow_account in cash_flow_accounts:
		section_data = []
		data.append({
			"account_name": cash_flow_account['section_header'],
			"parent_account": None,
			"indent": 0.0,
			"account": cash_flow_account['section_header']
		})

		if len(data) == 1:
			# add first net income in operations section
			if net_profit_loss:
				net_profit_loss.update({
					"indent": 1,
					"parent_account": cash_flow_accounts[0]['section_header']
				})
				data.append(net_profit_loss)
				section_data.append(net_profit_loss)

		for account in cash_flow_account['account_types']:
			account_data = get_account_type_based_data(filters.company,
				account['account_type'], period_list, filters.accumulated_values, filters)
			account_data.update({
				"account_name": account['label'],
				"account": account['label'],
				"indent": 1,
				"parent_account": cash_flow_account['section_header'],
				"currency": company_currency
			})
			data.append(account_data)
			section_data.append(account_data)

		add_total_row_account(data, section_data, cash_flow_account['section_footer'],
			period_list, company_currency, summary_data)

	add_total_row_account(data, data, _("Net Change in Cash"), period_list, company_currency, summary_data)
	columns = get_columns(filters.periodicity, period_list, filters.accumulated_values, filters.company)

	chart = get_chart_data(columns, data)

	report_summary = get_report_summary(summary_data, company_currency)

	return columns, data, None, chart, report_summary

def get_cash_flow_accounts():
	operation_accounts = {
		"section_name": "Operations",
		"section_footer": _("Net Cash from Operations"),
		"section_header": _("Cash Flow from Operations"),
		"account_types": [
			{"account_type": "Depreciation", "label": _("Depreciation")},
			{"account_type": "Receivable", "label": _("Net Change in Accounts Receivable")},
			{"account_type": "Payable", "label": _("Net Change in Accounts Payable")},
			{"account_type": "Stock", "label": _("Net Change in Inventory")}
		]
	}

	investing_accounts = {
		"section_name": "Investing",
		"section_footer": _("Net Cash from Investing"),
		"section_header": _("Cash Flow from Investing"),
		"account_types": [
			{"account_type": "Fixed Asset", "label": _("Net Change in Fixed Asset")}
		]
	}

	financing_accounts = {
		"section_name": "Financing",
		"section_footer": _("Net Cash from Financing"),
		"section_header": _("Cash Flow from Financing"),
		"account_types": [
			{"account_type": "Equity", "label": _("Net Change in Equity")}
		]
	}

	# combine all cash flow accounts for iteration
	return [operation_accounts, investing_accounts, financing_accounts]

def get_account_type_based_data(company, account_type, period_list, accumulated_values, filters):
	data = {}
	total = 0
	for period in period_list:
		start_date = get_start_date(period, accumulated_values, company)

		amount = get_account_type_based_gl_data(company, start_date,
			period['to_date'], account_type, filters)

		if amount and account_type == "Depreciation":
			amount *= -1

		total += amount
		data.setdefault(period["key"], amount)

	data["total"] = total
	return data

def get_account_type_based_gl_data(company, start_date, end_date, account_type, filters={}):
	cond = ""
	filters = frappe._dict(filters)

	if filters.include_default_book_entries:
		company_fb = frappe.db.get_value("Company", company, 'default_finance_book')
		cond = """ AND (finance_book in (%s, %s, '') OR finance_book IS NULL)
			""" %(frappe.db.escape(filters.finance_book), frappe.db.escape(company_fb))
	else:
		cond = " AND (finance_book in (%s, '') OR finance_book IS NULL)" %(frappe.db.escape(cstr(filters.finance_book)))


	gl_sum = frappe.db.sql_list("""
		select sum(credit) - sum(debit)
		from `tabGL Entry`
		where company=%s and posting_date >= %s and posting_date <= %s
			and voucher_type != 'Period Closing Voucher'
			and account in ( SELECT name FROM tabAccount WHERE account_type = %s) {cond}
	""".format(cond=cond), (company, start_date, end_date, account_type))

	return gl_sum[0] if gl_sum and gl_sum[0] else 0

def get_start_date(period, accumulated_values, company):
	if not accumulated_values and period.get('from_date'):
		return period['from_date']

	start_date = period["year_start_date"]
	if accumulated_values:
		start_date = get_fiscal_year(period.to_date, company=company)[1]

	return start_date

def add_total_row_account(out, data, label, period_list, currency, summary_data, consolidated = False):
	total_row = {
		"account_name": "'" + _("{0}").format(label) + "'",
		"account": "'" + _("{0}").format(label) + "'",
		"currency": currency
	}
	for row in data:
		if row.get("parent_account"):
			for period in period_list:
				key = period if consolidated else period['key']
				total_row.setdefault(key, 0.0)
				total_row[key] += row.get(key, 0.0)

			total_row.setdefault("total", 0.0)
			total_row["total"] += row["total"]

	out.append(total_row)
	out.append({})

	summary_data[label] = total_row["total"]

def get_report_summary(summary_data, currency):
	report_summary = []

	for label, value in iteritems(summary_data):
		report_summary.append(
			{
				"value": value,
				"label": label,
				"datatype": "Currency",
				"currency": currency
			}
		)

	return report_summary


def get_chart_data(columns, data):
	labels = [d.get("label") for d in columns[2:]]
	datasets = [{'name':account.get('account').replace("'", ""), 'values': [account.get('total')]}  for account in data if account.get('parent_account') == None and account.get('currency')]
	datasets = datasets[:-1]

	chart = {
		"data": {
			'labels': labels,
			'datasets': datasets
		},
		"type": "bar"
	}

	chart["fieldtype"] = "Currency"

	return chart
