from django.test import TestCase
from .models import CourseInstance, Token, Student
from .auth import auth_and_get_token
from django.contrib.auth.models import User
from .student_functions import sign_up_for_course
from django.core import serializers
import json
from unittest.mock import MagicMock
# https://docs.djangoproject.com/en/3.0/topics/auth/default/


class CourseInstanceTestCase(TestCase):
    def setUp(self):
        u1 = User.objects.create_user('test1')
        u2 = User.objects.create_user('test2')

        s1 = Student.objects.create(user=u1, registration_rights=True)
        s2 = Student.objects.create(user=u2, registration_rights=True)

        CourseInstance.objects.create(
            teacher="Roman Ptak", maxStudents=1)

    def test_sign_up_without_registration_rights(self):
        course = CourseInstance.objects.get(teacher='Roman Ptak')
        user1 = Student.objects.get(user__username='test1')
        user1.registration_rights = False

        user1.save()

        with self.assertRaises(ValueError):
            success = sign_up_for_course(user1, course)

    def test_sign_up_without_registration_rights_mock(self):
        course = CourseInstance.objects.get(teacher='Roman Ptak')

        #TU JEST MOCKUP STUDENTA
        user = Student()
        user.registration_rights = MagicMock(return_value=False)

        user.registration_rights = False

        with self.assertRaises(ValueError):
            success = sign_up_for_course(user, course)

    def test_assign_more_students_than_possible(self):
        user1 = Student.objects.get(user__username='test1')
        user2 = Student.objects.get(user__username='test2')
        course = CourseInstance.objects.get(teacher='Roman Ptak')

        # Sign up the first student,
        # course reaches maximum capacity
        success = sign_up_for_course(user1, course)
        self.assertTrue(success)

        # Sign up the second student,
        # should disallow saving
        success = sign_up_for_course(user2, course)
        self.assertFalse(success)

    def test_sign_up_for_course_check_attendants(self):
        user1 = Student.objects.get(user__username='test1')

        course: CourseInstance = CourseInstance.objects.get(
            teacher='Roman Ptak')
        sign_up_for_course(user1, course)

        self.assertIn(user1, course.attendants.all())

    def test_get_courses_json(self):
        courses = CourseInstance.objects.all()

        data = serializers.serialize("json", courses)
        json.loads(data)  # Try to parse the JSON to see if its valid
        pass # Pass if no exception is thrown


class LoginTestCase(TestCase):
    def setUp(self):
        user = User.objects.create_user(
            'romanptak', 'roman.ptak@pwr.edu.pl', '123')

    def test_log_in_correct_password(self):
        # Check if correct credentials authenticate the user
        token = auth_and_get_token(login='romanptak', password='123')
        self.assertIsNotNone(token)

    def test_log_in_incorrect_password(self):
        # Check if correct credentials authenticate the user
        token = auth_and_get_token(login='romanptak', password='error')
        self.assertIsNone(token)


class TokenTestCase(TestCase):
    def setUp(self):
        user = User.objects.create_user(
            'romanptak', 'roman.ptak@pwr.edu.pl', '123')

    def test_new_token_is_saved(self):
        num_of_tokens_before_login = len(Token.objects.all())
        # Check if correct credentials authenticate the user
        token = auth_and_get_token(login='romanptak', password='123')

        num_of_tokens_after_login = len(Token.objects.all())

        self.assertLess(num_of_tokens_before_login, num_of_tokens_after_login)