import frappe
from frappe import _
from lms.lms.utils import check_multicurrency, apply_gst


def get_context(context):
	module = frappe.form_dict.module
	docname = frappe.form_dict.modulename
	doctype = "LMS Course" if module == "course" else "LMS Batch"

	context.module = module
	context.docname = docname
	context.doctype = doctype

	validate_access(doctype, docname, module)
	get_billing_details(context)
	context.amount, context.currency = check_multicurrency(
		context.amount, context.currency
	)

	if context.currency == "INR":
		context.amount, context.gst_applied = apply_gst(context.amount, None)


def validate_access(doctype, docname, module):
	if frappe.session.user == "Guest":
		raise frappe.PermissionError(_("You are not allowed to access this page."))

	if module not in ["course", "batch"]:
		raise ValueError(_("Module is incorrect."))

	if not frappe.db.exists(doctype, docname):
		raise ValueError(_("Module Name is incorrect or does not exist."))

	if doctype == "LMS Course":
		membership = frappe.db.exists(
			"LMS Enrollment", {"member": frappe.session.user, "course": docname}
		)
		if membership:
			raise frappe.PermissionError(_("You are already enrolled for this course"))

	else:
		membership = frappe.db.exists(
			"Batch Student", {"student": frappe.session.user, "parent": docname}
		)
		if membership:
			raise frappe.PermissionError(_("You are already enrolled for this batch."))


def get_billing_details(context):
	if context.doctype == "LMS Course":
		details = frappe.db.get_value(
			"LMS Course",
			context.docname,
			["title", "name", "paid_course", "course_price as amount", "currency"],
			as_dict=True,
		)

		if not details.paid_course:
			raise frappe.PermissionError(_("This course is free."))

	else:
		details = frappe.db.get_value(
			"LMS Batch",
			context.docname,
			["title", "name", "paid_batch", "amount", "currency"],
			as_dict=True,
		)

		if not details.paid_batch:
			raise frappe.PermissionError(
				_("To join this batch, please contact the Administrator.")
			)

	context.title = details.title
	context.amount = details.amount
	context.currency = details.currency