# Copyright © 2022 Aravinth Manivannan <realaravinth@batsense.net>
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as
# published by the Free Software Foundation, either version 3 of the
# License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
import time
from io import StringIO

from django.contrib.auth import get_user_model
from django.core.management import call_command
from django.urls import reverse
from django.test import TestCase, Client, override_settings
from django.utils.http import urlencode
from django.contrib.auth import authenticate
from django.conf import settings

from payments import get_payment_model, RedirectNeeded, PaymentStatus

from accounts.tests import register_util, login_util
from dash.tests import create_configurations, create_instance_util

from .models import Payment


class BillingTest(TestCase):
    """
    Tests billing system
    """

    def setUp(self):
        self.username = "billing_user"
        register_util(t=self, username=self.username)
        create_configurations(t=self)

    def test_payments(self):
        c = Client()
        login_util(self, c, "accounts.home")
        instance_name = "test_create_instance_renders"
        create_instance_util(
            t=self, c=c, instance_name=instance_name, config=self.instance_config[0]
        )

        payment_uri = reverse("billing.invoice.generate", args=(instance_name,))

        # generate invoice
        resp = c.get(payment_uri)
        self.assertEqual(resp.status_code, 302)
        invoice_uri = resp.headers["Location"]
        self.assertEqual("invoice/payment/" in invoice_uri, True)

        # try to generate duplicate invoice, but should get redirected to previous invoice
        resp = c.get(payment_uri)
        self.assertEqual(resp.status_code, 302)
        self.assertEqual(invoice_uri == resp.headers["Location"], True)

        # check if invoice details page is displaying the invoice
        # if payment is yet to be made:
        #   template will show payment button
        # else:
        #   template will show payment date
        resp = c.get(invoice_uri)
        self.assertEqual(str.encode(instance_name) in resp.content, True)
        self.assertEqual(
            str.encode(str(self.instance_config[0].rent)) in resp.content, True
        )
        self.assertEqual(str.encode("Paid on") in resp.content, False)

        # check if the unpaid invoice is displayed in the pending invoice view
        resp = c.get(reverse("billing.invoice.pending"))
        self.assertEqual(str.encode(invoice_uri) in resp.content, True)

        # simulate payment. There's probably a better way to do this
        payment = get_payment_model().objects.get(paid_by=self.user)
        payment.status = PaymentStatus.CONFIRMED
        payment.save()

        # check if paid invoice is listed in paid invoice list view
        resp = c.get(reverse("billing.invoice.paid"))
        self.assertEqual(str.encode(invoice_uri) in resp.content, True)

        # check if the paid invoice is displayed in the pending invoice view, should not be displayed
        resp = c.get(reverse("billing.invoice.pending"))
        self.assertEqual(str.encode(invoice_uri) in resp.content, False)

        # check if the invoice details view is rendering paid invoice version
        resp = c.get(invoice_uri)
        self.assertEqual(str.encode(instance_name) in resp.content, True)
        self.assertEqual(
            str.encode(str(self.instance_config[0].rent)) in resp.content, True
        )
        self.assertEqual(str.encode("Paid on") in resp.content, True)

        # try to generate an invoice for the second time on the same VM
        # shouldn't be possible since payment is already made for the duration
        resp = c.get(payment_uri)
        self.assertEqual(resp.status_code, 400)

        ## payment success page; no real functionality but user is redirected here
        # by stripe if payment is successful
        resp = c.get(reverse("billing.invoice.success", args=(payment.public_ref,)))
        self.assertEqual(b"success" in resp.content, True)

        ## payment failure page; no real functionality but user is redirected here
        # by stripe if payment is successful
        resp = c.get(reverse("billing.invoice.fail", args=(payment.public_ref,)))
        self.assertEqual(b"failed" in resp.content, True)