"""Trackable mixin."""
from db import db
from sqlalchemy.ext.declarative import declared_attr
from sqlalchemy.sql import func


class TrackableMixin:
    """Track create/edit dates/users for tables."""

    created_at = db.Column(db.TIMESTAMP(timezone=True), nullable=False, server_default=func.current_timestamp())

    updated_at = db.Column(db.TIMESTAMP(timezone=True), nullable=False, server_default=func.current_timestamp())

    @declared_attr
    def create_user_id(cls):
        return db.Column(db.Integer, db.ForeignKey("User.id"), nullable=False)

    @declared_attr
    def edit_user_id(cls):
        return db.Column(db.Integer, db.ForeignKey("User.id"), nullable=False)

    @declared_attr
    def create_user(cls):
        return db.relationship("User", foreign_keys=[cls.create_user_id])

    @declared_attr
    def edit_user(cls):
        return db.relationship("User", foreign_keys=[cls.edit_user_id])