import frappe


def get_course(course_name=None):
	course_name = course_name or frappe.form_dict["course"]
	return course_name and get_doc("LMS Course", course_name)


def get_doc(doctype, name):
	try:
		return frappe.get_doc(doctype, name)
	except frappe.exceptions.DoesNotExistError:
		return


def get_cohort(course, cohort_slug):
	name = frappe.get_value("Cohort", {"course": course.name, "slug": cohort_slug})
	return name and frappe.get_doc("Cohort", name)


def get_subgroup(cohort, subgroup_slug):
	name = frappe.get_value(
		"Cohort Subgroup", {"cohort": cohort.name, "slug": subgroup_slug}
	)
	return name and frappe.get_doc("Cohort Subgroup", name)


def add_nav(context, title, href):
	"""Adds a breadcrumb to the navigation."""
	nav = context.setdefault("nav", [])
	nav.append({"title": title, "href": href})