from django.db.models.signals import post_save
from django.dispatch import receiver
from django.contrib.auth.models import User
from django.contrib.auth.models import Group
from .models.students import Student


# Create a Django user every time a new student is created
@receiver(post_save, sender=Student)
def create_user_for_student(sender: Student, instance: Student, created, **kwargs):
    if created and not instance.user:
        print("_____ SAVING USER _____")
        username = f"{instance.name.lower()}.{instance.surname.lower()}"
        # Avoid username conflict with progressive number
        base_username = username
        counter = 1
        while User.objects.filter(username=username).exists():
            username = f"{base_username}{counter}"
            counter += 1
        # Generate standard password for every student
        password = f"{instance.name.lower()[0]}{instance.surname.lower()}{instance.id}"
        # Create user
        user = User.objects.create_user(
            username=username,
            email=instance.email,
            password=password
        )

        student_group, _ = Group.objects.get_or_create(name="StudentGroup")
        user.groups.add(student_group)

        print(f"User: {user.username}\tPassword: {password}")
        instance.user = user
        instance.save()