"""Models for user preferences."""
from __future__ import annotations

from flask_sqlalchemy import BaseQuery
from sqlalchemy import Column, ForeignKey, Integer, String, UniqueConstraint
from sqlalchemy.orm import backref, relation

from abilian.core.extensions import db
from abilian.core.models.subjects import User
from abilian.core.sqlalchemy import JSON


class UserPreference(db.Model):
    """An atom of user preference."""

    __tablename__ = "user_preference"
    __table_args__ = (UniqueConstraint("user_id", "key"),)

    #: Unique id for this preference.
    id = Column(Integer, primary_key=True, autoincrement=True)

    #: The user who set this preference.
    user = relation(
        User, backref=backref("preferences", cascade="all, delete, delete-orphan")
    )
    user_id = Column(ForeignKey(User.id))

    #: The key
    key = Column(String, nullable=False)

    #: The value
    value = Column(JSON, nullable=False)

    query: BaseQuery
