from __future__ import annotations

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

from .models import UserProfile


ROLE_GROUP_MAP = {
    UserProfile.ROLE_OWNER: "owner",
    UserProfile.ROLE_MANAGER: "manager",
    UserProfile.ROLE_DRIVER: "driver",
    UserProfile.ROLE_CUSTOMER: "customer",
    UserProfile.ROLE_AUDITOR: "auditor",
}

MANAGED_GROUPS = set(ROLE_GROUP_MAP.values())


@receiver(post_save, sender=UserProfile)
def sync_profile_role_to_groups(sender, instance: UserProfile, created: bool, **kwargs):
    """Keep Django Group membership in sync with the profile role.

    - Removes the user from managed role groups (owner/manager/driver/customer/auditor)
    - Adds the user to the group mapped from the current role
    - Lazily creates the Group if missing
    """
    user = instance.user
    if user is None or not getattr(user, "pk", None):
        return

    # Remove from managed groups first (do not touch other unrelated groups)
    current_managed = user.groups.filter(name__in=MANAGED_GROUPS)
    if current_managed.exists():
        user.groups.remove(*current_managed)

    # Add target group for role
    group_name = ROLE_GROUP_MAP.get(instance.role)
    if not group_name:
        return
    group, _ = Group.objects.get_or_create(name=group_name)
    user.groups.add(group)