from datetime import datetime

from sqlalchemy import Column, func
from sqlalchemy.orm import declarative_mixin

from tofu_api.common.database import Col
from tofu_api.common.database.types import TzDateTime

__all__ = [
    'TimestampMixin'
]


@declarative_mixin
class TimestampMixin:
    """
    Mixin for database models that provides the "created_at" and "modified_at" columns.
    """
    # Created timestamp (automatically set to NOW() once on object creation)
    created_at: Col[datetime] = Column(TzDateTime, nullable=False, server_default=func.now())

    # Modified timestamp (automatically set to NOW() on each update)
    modified_at: Col[datetime] = Column(TzDateTime, nullable=False, server_default=func.now(), onupdate=func.now())