from django.db import models


from apps.account.models import StudentUser, User
from apps.course.models import Course


class Participant(models.Model):
    student = models.ForeignKey(
        StudentUser,
        on_delete=models.CASCADE,
        related_name='participated_courses'
    )
    course = models.ForeignKey(
        Course,
        on_delete=models.CASCADE,
        related_name='participants'
    )
    joined_date = models.DateTimeField(auto_now_add=True)
    unread_messages_count = models.IntegerField(default=0)
    
    class Meta:
        unique_together = ('student', 'course')