import datetime
from django.utils import timezone
from django.test import TestCase
from unittest.mock import patch
from django.core.files.uploadedfile import SimpleUploadedFile

from dj_language.models import Language
from apps.account.models import StudentUser, User, Notification
from apps.course.models.course import Course, CourseCategory
from apps.quiz.models import Quiz, QuizParticipant
from apps.account.tasks import check_low_quiz_results_task

class QuizNotificationFlowTests(TestCase):
    def setUp(self):
        # Create languages
        self.lang_ru, _ = Language.objects.update_or_create(
            code='ru',
            defaults={'name': 'Russian', 'status': True, 'countries': []}
        )
        self.lang_en, _ = Language.objects.update_or_create(
            code='en',
            defaults={'name': 'English', 'status': True, 'countries': []}
        )

        # Create category
        self.category = CourseCategory.objects.create(
            name=[{"title": "Category", "language_code": "en"}],
            slug=[{"title": "category", "language_code": "en"}]
        )
        
        # Create student user
        self.student = StudentUser.objects.create(
            email='student_quiz@example.com',
            username='student_quiz',
            fullname='Quiz Student',
            language=self.lang_ru,
            fcm='token_quiz_student'
        )
        
        # Create Course
        thumbnail = SimpleUploadedFile('thumb.jpg', b'filecontent', content_type='image/jpeg')
        self.course = Course.objects.create(
            title=[
                {"title": "Course 1", "language_code": "en"},
                {"title": "Курс 1", "language_code": "ru"}
            ],
            slug=[{"title": "course-1", "language_code": "en"}],
            category=self.category,
            thumbnail=thumbnail,
            video_type=Course.VedioTypeChoices.YOUTUBE_LINK,
            video_link='https://example.com/video',
            is_online=False,
            level=Course.LevelChoices.BEGINNER,
            duration=10,
            lessons_count=0,
            description='Description',
            short_description='Short description',
            status=[{"title": "ongoing", "language_code": "en"}],
            is_free=True,
        )

        # Create Quiz
        self.quiz = Quiz.objects.create(
            course=self.course,
            title=[
                {"title": "Quiz A", "language_code": "en"},
                {"title": "Тест А", "language_code": "ru"}
            ],
            each_question_timing=60,
            status=True
        )

    @patch('apps.account.notification_service.send_notification')
    def test_low_quiz_result_triggers_on_intervals(self, mock_send):
        # Event: Low Quiz Result (score < 70)
        # Create failed attempt exactly 2 days ago
        attempt_2_days = QuizParticipant.objects.create(
            quiz=self.quiz,
            user=self.student,
            started_at=timezone.now() - datetime.timedelta(days=2, hours=1),
            ended_at=timezone.now() - datetime.timedelta(days=2),
            total_timing=300,
            question_score=50,
            timing_score=0,
            total_score=50
        )
        
        # Run periodic task
        check_low_quiz_results_task()
        
        # Verify reminder sent to the student (Russian template check)
        notif = Notification.objects.filter(user=self.student, title="Предложение пересдать тест").first()
        self.assertIsNotNone(notif)
        self.assertIn("Тест А", notif.message)
        self.assertTrue(mock_send.called)

    @patch('apps.account.notification_service.send_notification')
    def test_no_reminder_if_passed_initially(self, mock_send):
        # Create successful attempt exactly 2 days ago (score = 80)
        QuizParticipant.objects.create(
            quiz=self.quiz,
            user=self.student,
            started_at=timezone.now() - datetime.timedelta(days=2, hours=1),
            ended_at=timezone.now() - datetime.timedelta(days=2),
            total_timing=300,
            question_score=80,
            timing_score=0,
            total_score=80
        )
        
        check_low_quiz_results_task()
        
        self.assertFalse(Notification.objects.filter(user=self.student, title="Предложение пересдать тест").exists())
        self.assertFalse(mock_send.called)

    @patch('apps.account.notification_service.send_notification')
    def test_no_reminder_if_retaken_and_passed(self, mock_send):
        # Create failed attempt exactly 7 days ago
        attempt_failed = QuizParticipant.objects.create(
            quiz=self.quiz,
            user=self.student,
            started_at=timezone.now() - datetime.timedelta(days=7, hours=1),
            ended_at=timezone.now() - datetime.timedelta(days=7),
            total_timing=300,
            question_score=40,
            timing_score=0,
            total_score=40
        )
        
        # Create a newer successful attempt 3 days ago
        QuizParticipant.objects.create(
            quiz=self.quiz,
            user=self.student,
            started_at=timezone.now() - datetime.timedelta(days=3, hours=1),
            ended_at=timezone.now() - datetime.timedelta(days=3),
            total_timing=300,
            question_score=90,
            timing_score=0,
            total_score=90
        )
        
        check_low_quiz_results_task()
        
        # Should not suggest retake since they passed subsequently
        self.assertFalse(Notification.objects.filter(user=self.student, title="Предложение пересдать тест").exists())

    @patch('apps.account.notification_service.send_notification')
    def test_no_reminder_if_already_retaken_even_if_failed(self, mock_send):
        # Create failed attempt exactly 21 days ago
        attempt_failed = QuizParticipant.objects.create(
            quiz=self.quiz,
            user=self.student,
            started_at=timezone.now() - datetime.timedelta(days=21, hours=1),
            ended_at=timezone.now() - datetime.timedelta(days=21),
            total_timing=300,
            question_score=30,
            timing_score=0,
            total_score=30
        )
        
        # Create a newer attempt 10 days ago (also failed, e.g. score = 50)
        # Since they already attempted a retake 10 days ago, we shouldn't trigger the 21-day reminder of the first failure.
        QuizParticipant.objects.create(
            quiz=self.quiz,
            user=self.student,
            started_at=timezone.now() - datetime.timedelta(days=10, hours=1),
            ended_at=timezone.now() - datetime.timedelta(days=10),
            total_timing=300,
            question_score=50,
            timing_score=0,
            total_score=50
        )
        
        check_low_quiz_results_task()
        
        self.assertFalse(Notification.objects.filter(user=self.student, title="Предложение пересдать тест").exists())