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


import frappe
from frappe import _
from frappe.utils import DateTimeLikeObject, getdate, today

import erpnext
from erpnext.accounts.utils import get_fiscal_year


def get_columns(filters, trans):
	validate_filters(filters)

	# get conditions for based_on filter cond
	based_on_details = based_wise_columns_query(filters.get("based_on"), trans)
	# get conditions for periodic filter cond
	period_cols, period_select = period_wise_columns_query(filters, trans)
	# get conditions for grouping filter cond
	group_by_cols = group_wise_column(filters.get("group_by"))

	columns = (
		based_on_details["based_on_cols"]
		+ period_cols
		+ [_("Total(Qty)") + ":Float:120", _("Total(Amt)") + ":Currency/currency:120"]
	)
	if group_by_cols:
		columns = (
			based_on_details["based_on_cols"]
			+ group_by_cols
			+ period_cols
			+ [_("Total(Qty)") + ":Float:120", _("Total(Amt)") + ":Currency/currency:120"]
		)

	conditions = {
		"based_on_select": based_on_details["based_on_select"],
		"period_wise_select": period_select,
		"columns": columns,
		"group_by": based_on_details["based_on_group_by"],
		"grbc": group_by_cols,
		"trans": trans,
		"addl_tables": based_on_details["addl_tables"],
		"addl_tables_relational_cond": based_on_details.get("addl_tables_relational_cond", ""),
	}
	conditions["company_currency"] = (
		erpnext.get_company_currency(filters.get("company")) if filters.get("company") else None
	)

	return conditions


def validate_filters(filters):
	if not filters.get("fiscal_year"):
		filters["fiscal_year"] = get_fiscal_year(today())[0]
	if not filters.get("company"):
		filters["company"] = frappe.defaults.get_user_default("Company")
	for f in ["Fiscal Year", "Based On", "Period", "Company"]:
		if not filters.get(f.lower().replace(" ", "_")):
			frappe.throw(_("{0} is mandatory").format(_(f)))

	if not frappe.db.exists("Fiscal Year", filters.get("fiscal_year")):
		frappe.throw(_("Fiscal Year {0} does not exist").format(filters.get("fiscal_year")))

	if filters.get("based_on") == filters.get("group_by"):
		frappe.throw(_("'Based On' and 'Group By' can not be the same"))

	if filters.get("period_based_on") and filters.period_based_on not in ["bill_date", "posting_date"]:
		frappe.throw(
			msg=_("{0} can be either {1} or {2}.").format(
				frappe.bold("Period based On"), frappe.bold("Posting Date"), frappe.bold("Billing Date")
			),
			title=_("Invalid Filter"),
		)


def get_data(filters, conditions):
	data = []
	inc, cond = "", ""
	query_details = conditions["based_on_select"] + conditions["period_wise_select"]

	posting_date = "t1.transaction_date"
	if conditions.get("trans") in [
		"Sales Invoice",
		"Purchase Invoice",
		"Purchase Receipt",
		"Delivery Note",
	]:
		posting_date = "t1.posting_date"
		if filters.period_based_on and conditions.get("trans") in ["Sales Invoice", "Purchase Invoice"]:
			posting_date = "t1." + filters.period_based_on

	if conditions["based_on_select"] in ["t1.project,", "t2.project,"]:
		cond = " and " + conditions["based_on_select"][:-1] + " IS Not NULL"

	if not filters.get("include_closed_orders"):
		if conditions.get("trans") in ["Sales Order", "Purchase Order"]:
			cond += " and t1.status != 'Closed'"

	if conditions.get("trans") == "Quotation" and filters.get("group_by") == "Customer":
		cond += " and t1.quotation_to = 'Customer'"

	year_start_date, year_end_date = frappe.get_cached_value(
		"Fiscal Year", filters.get("fiscal_year"), ["year_start_date", "year_end_date"]
	)

	if filters.get("group_by"):
		sel_col = ""
		ind = conditions["columns"].index(conditions["grbc"][0])

		if filters.get("group_by") == "Item":
			sel_col = "t2.item_code"
		elif filters.get("group_by") == "Customer":
			sel_col = "t1.party_name" if conditions.get("trans") == "Quotation" else "t1.customer"
		elif filters.get("group_by") == "Supplier":
			sel_col = "t1.supplier"

		# first column of the multi-column group_by = the based-on key the detail queries equate against
		based_on_key = conditions["group_by"].split(",")[0].strip()

		if filters.get("based_on") in ["Customer", "Supplier"]:
			inc = 3
		elif filters.get("based_on") in ["Item"]:
			inc = 2
		else:
			inc = 1

		data1 = frappe.db.sql(
			""" select {} from `tab{}` t1, `tab{} Item` t2 {}
					where t2.parent = t1.name and t1.company = {} and {} between {} and {} and
					t1.docstatus = 1 {} {}
					group by {}
				""".format(
				query_details,
				conditions["trans"],
				conditions["trans"],
				conditions["addl_tables"],
				"%s",
				posting_date,
				"%s",
				"%s",
				conditions.get("addl_tables_relational_cond"),
				cond,
				conditions["group_by"],
			),
			(filters.get("company"), year_start_date, year_end_date),
			as_list=1,
		)

		for d in range(len(data1)):
			# to add blanck column
			dt = data1[d]
			dt.insert(ind, "")
			data.append(dt)

			# to get distinct value of col specified by group_by in filter
			row = frappe.db.sql(
				"""select DISTINCT({}) from `tab{}` t1, `tab{} Item` t2 {}
						where t2.parent = t1.name and t1.company = {} and {} between {} and {}
						and t1.docstatus = 1 and {} = {} {} {}
					""".format(
					sel_col,
					conditions["trans"],
					conditions["trans"],
					conditions["addl_tables"],
					"%s",
					posting_date,
					"%s",
					"%s",
					based_on_key,
					"%s",
					conditions.get("addl_tables_relational_cond"),
					cond,
				),
				(filters.get("company"), year_start_date, year_end_date, data1[d][0]),
				as_list=1,
			)

			for i in range(len(row)):
				des = ["" for q in range(len(conditions["columns"]))]

				# get data for group_by filter
				row1 = frappe.db.sql(
					""" select t4.default_currency AS currency , {} , {} from `tab{}` t1, `tab{} Item` t2 {}
							where t2.parent = t1.name and t1.company = {} and {} between {} and {}
							and t1.docstatus = 1 and {} = {} and {} = {} {} {}
							group by t4.default_currency, {}
						""".format(
						sel_col,
						conditions["period_wise_select"],
						conditions["trans"],
						conditions["trans"],
						conditions["addl_tables"],
						"%s",
						posting_date,
						"%s",
						"%s",
						sel_col,
						"%s",
						based_on_key,
						"%s",
						conditions.get("addl_tables_relational_cond"),
						cond,
						sel_col,
					),
					(filters.get("company"), year_start_date, year_end_date, row[i][0], data1[d][0]),
					as_list=1,
				)

				if not row1:
					continue

				des[ind] = row[i][0]
				des[ind - 1] = row1[0][0]

				for j in range(1, len(conditions["columns"]) - inc):
					des[j + inc] = row1[0][j]

				data.append(des)

		total_row = calculate_total_row(data1, conditions["columns"], conditions.get("company_currency"))
		data.append(total_row)
	else:
		data = frappe.db.sql(
			""" select {} from `tab{}` t1, `tab{} Item` t2 {}
					where t2.parent = t1.name and t1.company = {} and {} between {} and {} and
					t1.docstatus = 1 {} {}
					group by {}
				""".format(
				query_details,
				conditions["trans"],
				conditions["trans"],
				conditions["addl_tables"],
				"%s",
				posting_date,
				"%s",
				"%s",
				cond,
				conditions.get("addl_tables_relational_cond", ""),
				conditions["group_by"],
			),
			(filters.get("company"), year_start_date, year_end_date),
			as_list=1,
		)

		total_row = calculate_total_row(data, conditions["columns"], conditions.get("company_currency"))
		data.append(total_row)

	return data


def calculate_total_row(data, columns, company_currency=None):
	def wrap_in_quotes(label):
		return f"'{label}'"

	total_values = {}
	currency_col_idx = None
	for i, col in enumerate(columns):
		if "Float" in col or "Currency/currency" in col:
			total_values[i] = 0
		if "Link/Currency" in col:
			currency_col_idx = i

	for row in data:
		for i in total_values.keys():
			total_values[i] += row[i] if row[i] is not None else 0

	total_row = [wrap_in_quotes(_("Total"))]
	for i in range(1, len(columns)):
		total_row.append(total_values.get(i, None))

	if currency_col_idx is not None:
		total_row[currency_col_idx] = company_currency

	return total_row


def get_mon(dt):
	return getdate(dt).strftime("%b")


def period_wise_columns_query(filters, trans):
	query_details = ""
	pwc = []
	bet_dates = get_period_date_ranges(filters.get("period"), filters.get("fiscal_year"))

	if trans in ["Purchase Receipt", "Delivery Note", "Purchase Invoice", "Sales Invoice"]:
		trans_date = "posting_date"
		if filters.period_based_on and trans in ["Purchase Invoice", "Sales Invoice"]:
			trans_date = filters.period_based_on
	else:
		trans_date = "transaction_date"

	if filters.get("period") != "Yearly":
		for dt in bet_dates:
			get_period_wise_columns(dt, filters.get("period"), pwc)
			query_details = get_period_wise_query(dt, trans_date, query_details)
	else:
		pwc = [
			_(filters.get("fiscal_year")) + " (" + _("Qty") + "):Float:120",
			_(filters.get("fiscal_year")) + " (" + _("Amt") + "):Currency/currency:120",
		]
		query_details = " SUM(t2.stock_qty), SUM(t2.base_net_amount),"

	query_details += "SUM(t2.stock_qty), SUM(t2.base_net_amount)"
	return pwc, query_details


def get_period_wise_columns(bet_dates, period, pwc):
	if period == "Monthly":
		pwc += [
			_(get_mon(bet_dates[0])) + " (" + _("Qty") + "):Float:120",
			_(get_mon(bet_dates[0])) + " (" + _("Amt") + "):Currency/currency:120",
		]
	else:
		pwc += [
			_(get_mon(bet_dates[0])) + "-" + _(get_mon(bet_dates[1])) + " (" + _("Qty") + "):Float:120",
			_(get_mon(bet_dates[0]))
			+ "-"
			+ _(get_mon(bet_dates[1]))
			+ " ("
			+ _("Amt")
			+ "):Currency/currency:120",
		]


def get_period_wise_query(bet_dates, trans_date, query_details):
	query_details += """SUM(CASE WHEN t1.{trans_date} BETWEEN '{sd}' AND '{ed}' THEN t2.stock_qty ELSE NULL END),
					SUM(CASE WHEN t1.{trans_date} BETWEEN '{sd}' AND '{ed}' THEN t2.base_net_amount ELSE NULL END),
				""".format(
		trans_date=trans_date,
		sd=bet_dates[0],
		ed=bet_dates[1],
	)
	return query_details


@frappe.whitelist()
def get_period_date_ranges(
	period: str, fiscal_year: str | None = None, year_start_date: DateTimeLikeObject | None = None
):
	from dateutil.relativedelta import relativedelta

	if not year_start_date:
		year_start_date, year_end_date = frappe.get_cached_value(
			"Fiscal Year", fiscal_year, ["year_start_date", "year_end_date"]
		)

	increment = {"Monthly": 1, "Quarterly": 3, "Half-Yearly": 6, "Yearly": 12}.get(period)

	period_date_ranges = []
	for _i in range(1, 13, increment):
		period_end_date = getdate(year_start_date) + relativedelta(months=increment, days=-1)
		if period_end_date > getdate(year_end_date):
			period_end_date = year_end_date
		period_date_ranges.append([year_start_date, period_end_date])
		year_start_date = period_end_date + relativedelta(days=1)
		if period_end_date == year_end_date:
			break

	return period_date_ranges


def get_period_month_ranges(period, fiscal_year):
	from dateutil.relativedelta import relativedelta

	period_month_ranges = []

	for start_date, end_date in get_period_date_ranges(period, fiscal_year):
		months_in_this_period = []
		while start_date <= end_date:
			months_in_this_period.append(start_date.strftime("%B"))
			start_date += relativedelta(months=1)
		period_month_ranges.append(months_in_this_period)

	return period_month_ranges


def quotation_party_name_expr():
	"""Resolve a Quotation's party label from its dynamic link, mirroring set_customer_name()."""
	customer_branch = (
		"when t1.quotation_to = 'Customer' then "
		"(select c.customer_name from `tabCustomer` c where c.name = t1.party_name)"
	)
	lead_branch = (
		"when t1.quotation_to = 'Lead' then "
		"(select coalesce(nullif(l.company_name, ''), l.lead_name) from `tabLead` l "
		"where l.name = t1.party_name)"
	)
	prospect_branch = "when t1.quotation_to = 'Prospect' then t1.party_name"
	branches = [customer_branch, lead_branch, prospect_branch]
	# CRM Deal ships with the CRM app; skip the branch when its table is absent
	if frappe.db.table_exists("CRM Deal"):
		branches.append(
			"when t1.quotation_to = 'CRM Deal' then "
			"(select d.organization from `tabCRM Deal` d where d.name = t1.party_name)"
		)

	return "case " + " ".join(branches) + " end"


def quotation_territory_expr():
	"""Only Customer and Lead carry a territory; other party types have none."""
	return (
		"case "
		"when t1.quotation_to = 'Customer' then "
		"(select c.territory from `tabCustomer` c where c.name = t1.party_name) "
		"when t1.quotation_to = 'Lead' then "
		"(select l.territory from `tabLead` l where l.name = t1.party_name) "
		"end"
	)


def based_wise_columns_query(based_on, trans):
	based_on_details = {}

	# based_on_cols, based_on_select, based_on_group_by, addl_tables
	if based_on == "Item":
		based_on_details["based_on_cols"] = [
			{"label": _("Item"), "fieldtype": "Link", "options": "Item", "width": 120, "fieldname": "item"},
			{"label": _("Item Name"), "fieldtype": "Data", "width": 120, "fieldname": "item_name"},
		]
		# item_name is stored per line and editable, so it is not functionally dependent on item_code
		# and Max() over it is a sort -- which MariaDB and PostgreSQL resolve differently. Read it
		# from the Item master instead: that IS functionally dependent on the grouped item_code, so
		# it can be grouped without splitting rows and is identical on both engines by construction.
		based_on_details["based_on_select"] = "t2.item_code, item_master.item_name as item_name,"
		based_on_details["based_on_group_by"] = "t2.item_code, item_master.item_name"
		based_on_details["addl_tables"] = ",`tabItem` item_master"
		based_on_details["addl_tables_relational_cond"] = " and t2.item_code = item_master.name"

	elif based_on == "Item Group":
		based_on_details["based_on_cols"] = [
			{
				"label": _("Item Group"),
				"fieldtype": "Link",
				"options": "Item Group",
				"width": 120,
				"fieldname": "item_group",
			}
		]
		based_on_details["based_on_select"] = "t2.item_group,"
		based_on_details["based_on_group_by"] = "t2.item_group"
		based_on_details["addl_tables"] = ""

	elif based_on == "Customer":
		if trans == "Quotation":
			based_on_details["based_on_cols"] = [
				{
					"label": _("Party"),
					"fieldtype": "Link",
					"options": "Customer",
					"width": 120,
					"fieldname": "party",
				},
				{"label": _("Party Name"), "fieldtype": "Data", "width": 120, "fieldname": "party_name"},
				{
					"label": _("Territory"),
					"fieldtype": "Link",
					"options": "Territory",
					"width": 120,
					"fieldname": "territory",
				},
			]
			# a Quotation's party_name is a dynamic link, so no single master can be joined. Resolve
			# it through the quotation_to discriminator, mirroring Quotation.set_customer_name, and
			# group by it too: two parties of different types can share a name, and merging them
			# under one row was never right. Correlated only on grouped columns, so the query stays
			# valid under GROUP BY and free of any text sort.
			based_on_details["based_on_select"] = (
				f"t1.party_name, {quotation_party_name_expr()} as customer_name, "
				f"{quotation_territory_expr()} as territory,"
			)
			based_on_details["based_on_group_by"] = "t1.party_name, t1.quotation_to"
			based_on_details["addl_tables"] = ""
		else:
			based_on_details["based_on_cols"] = [
				{
					"label": _("Customer"),
					"fieldtype": "Link",
					"options": "Customer",
					"width": 120,
					"fieldname": "customer",
				},
				{
					"label": _("Customer Name"),
					"fieldtype": "Data",
					"width": 120,
					"fieldname": "customer_name",
				},
				{
					"label": _("Territory"),
					"fieldtype": "Link",
					"options": "Territory",
					"width": 120,
					"fieldname": "territory",
				},
			]
			# customer_name and territory are stored per transaction and editable, so they are not
			# functionally dependent on the customer and Max() over them is a text sort, which the
			# engines resolve differently. The Customer master's values ARE dependent on the grouped
			# key, so they can be grouped without splitting rows and agree on both engines.
			based_on_details["based_on_select"] = (
				"t1.customer, customer_master.customer_name as customer_name, "
				"customer_master.territory as territory,"
			)
			based_on_details[
				"based_on_group_by"
			] = "t1.customer, customer_master.customer_name, customer_master.territory"
			based_on_details["addl_tables"] = ",`tabCustomer` customer_master"
			based_on_details["addl_tables_relational_cond"] = " and t1.customer = customer_master.name"

	elif based_on == "Customer Group":
		based_on_details["based_on_cols"] = [
			{
				"label": _("Customer Group"),
				"fieldtype": "Link",
				"options": "Customer Group",
				"fieldname": "customer_group",
			}
		]
		based_on_details["based_on_select"] = "t1.customer_group,"
		based_on_details["based_on_group_by"] = "t1.customer_group"
		based_on_details["addl_tables"] = ""

	elif based_on == "Supplier":
		based_on_details["based_on_cols"] = [
			{
				"label": _("Supplier"),
				"fieldtype": "Link",
				"options": "Supplier",
				"width": 120,
				"fieldname": "supplier",
			},
			{"label": _("Supplier Name"), "fieldtype": "Data", "width": 120, "fieldname": "supplier_name"},
			{
				"label": _("Supplier Group"),
				"fieldtype": "Link",
				"options": "Supplier Group",
				"width": 140,
				"fieldname": "supplier_group",
			},
		]
		# supplier_name is stored per transaction and editable, so Max() over it is a text sort that
		# the engines resolve differently. The Supplier master is already joined here as t3 and its
		# columns are functionally dependent on the grouped supplier, so both can simply be grouped:
		# no row split, and identical on both engines by construction.
		based_on_details["based_on_select"] = "t1.supplier, t3.supplier_name, t3.supplier_group,"
		based_on_details["based_on_group_by"] = "t1.supplier, t3.supplier_name, t3.supplier_group"
		based_on_details["addl_tables"] = ",`tabSupplier` t3"
		based_on_details["addl_tables_relational_cond"] = " and t1.supplier = t3.name"

	elif based_on == "Supplier Group":
		based_on_details["based_on_cols"] = [
			{
				"label": _("Supplier Group"),
				"fieldtype": "Link",
				"options": "Supplier Group",
				"width": 140,
				"fieldname": "supplier_group",
			}
		]
		based_on_details["based_on_select"] = "t3.supplier_group,"
		based_on_details["based_on_group_by"] = "t3.supplier_group"
		based_on_details["addl_tables"] = ",`tabSupplier` t3"
		based_on_details["addl_tables_relational_cond"] = " and t1.supplier = t3.name"

	elif based_on == "Territory":
		based_on_details["based_on_cols"] = [
			{
				"label": _("Territory"),
				"fieldtype": "Link",
				"options": "Territory",
				"width": 120,
				"fieldname": "territory",
			}
		]
		based_on_details["based_on_select"] = "t1.territory,"
		based_on_details["based_on_group_by"] = "t1.territory"
		based_on_details["addl_tables"] = ""

	elif based_on == "Project":
		if trans in ["Sales Invoice", "Delivery Note", "Sales Order"]:
			based_on_details["based_on_cols"] = [
				{
					"label": _("Project"),
					"fieldtype": "Link",
					"options": "Project",
					"width": 120,
					"fieldname": "project",
				}
			]
			based_on_details["based_on_select"] = "t1.project,"
			based_on_details["based_on_group_by"] = "t1.project"
			based_on_details["addl_tables"] = ""
		elif trans in ["Purchase Order", "Purchase Invoice", "Purchase Receipt"]:
			based_on_details["based_on_cols"] = [
				{
					"label": _("Project"),
					"fieldtype": "Link",
					"options": "Project",
					"width": 120,
					"fieldname": "project",
				}
			]
			based_on_details["based_on_select"] = "t2.project,"
			based_on_details["based_on_group_by"] = "t2.project"
			based_on_details["addl_tables"] = ""
		else:
			frappe.throw(_("Project-wise data is not available for Quotation"))

	based_on_details["based_on_select"] += "t4.default_currency as currency,"
	based_on_details["based_on_group_by"] += ", t4.default_currency"
	based_on_details["based_on_cols"].append(
		{
			"label": _("Currency"),
			"fieldtype": "Link",
			"options": "Currency",
			"width": 120,
			"fieldname": "currency",
		}
	)
	based_on_details["addl_tables"] += ", `tabCompany` t4"
	based_on_details["addl_tables_relational_cond"] = (
		based_on_details.get("addl_tables_relational_cond", "") + " and t1.company = t4.name"
	)

	return based_on_details


def group_wise_column(group_by):
	if group_by:
		return [
			{
				"label": _(group_by),
				"fieldtype": "Link",
				"options": group_by,
				"width": 120,
				"fieldname": frappe.scrub(group_by),
			}
		]
	else:
		return []