from django.db import models
from django.conf import settings
from django.utils import timezone

class SoftDeleteManager(models.Manager):
    """
    Custom manager that automatically filters out soft deleted records.
    Use this manager for models that have a 'deleted' field.
    """
    
    def get_queryset(self):
        """Override get_queryset to exclude deleted records by default"""
        return super().get_queryset().filter(deleted=False)
    
    def all_with_deleted(self):
        """Get all records including deleted ones"""
        return super().get_queryset()
    
    def deleted_only(self):
        """Get only deleted records"""
        return super().get_queryset().filter(deleted=True)

class SoftDeleteModel(models.Model):
    """
    Abstract base model that provides soft delete functionality.
    Models inheriting from this will have a 'deleted' field and custom manager.
    """
    
    deleted = models.BooleanField(default=False)
    deleted_by = models.ForeignKey(settings.AUTH_USER_MODEL, on_delete=models.SET_NULL, null=True, blank=True, related_name='+')
    deleted_at = models.DateTimeField(null=True, blank=True)

    # Default manager excludes deleted records
    objects = SoftDeleteManager()

    # Manager that includes all records (including deleted)
    all_objects = models.Manager()

    class Meta:
        abstract = True

    def soft_delete(self, user=None):
        """Soft delete this instance"""
        self.deleted = True
        self.deleted_at = timezone.now()
        if user is not None:
            self.deleted_by = user
        self.save()

    def restore(self):
        """Restore a soft deleted instance"""
        self.deleted = False
        self.deleted_at = None
        self.deleted_by = None
        self.save()