import uuid
from django.db import models
from django.utils import timezone

class UUIDModel(models.Model):
    """Abstract model with a UUID primary key."""
    id = models.UUIDField(primary_key=True, default=uuid.uuid4, editable=False)

    class Meta:
        abstract = True

class TimeStampedModel(models.Model):
    """Abstract model with created_at and updated_at timestamps."""
    created_at = models.DateTimeField(auto_now_add=True, db_index=True)
    updated_at = models.DateTimeField(auto_now=True)

    class Meta:
        abstract = True

class TenantScopedModel(UUIDModel, TimeStampedModel):
    """Abstract model scoped to an organization (tenant)."""
    tenant_id = models.UUIDField(db_index=True, help_text="Organization / Tenant ID")

    class Meta:
        abstract = True

class SoftDeleteModel(models.Model):
    """Abstract model supporting soft-deletion."""
    is_deleted = models.BooleanField(default=False, db_index=True)
    deleted_at = models.DateTimeField(null=True, blank=True)

    def soft_delete(self):
        self.is_deleted = True
        self.deleted_at = timezone.now()
        self.save(update_fields=['is_deleted', 'deleted_at'])

    def restore(self):
        self.is_deleted = False
        self.deleted_at = None
        self.save(update_fields=['is_deleted', 'deleted_at'])

    class Meta:
        abstract = True