"""好友之树模型"""

from datetime import datetime

from sqlalchemy import String, Integer, DateTime, ForeignKey, UniqueConstraint
from sqlalchemy.orm import Mapped, mapped_column, relationship

from app.database import Base


class FriendshipTree(Base):
    __tablename__ = "friendship_trees"
    __table_args__ = (
        UniqueConstraint("user_a_id", "user_b_id", name="uq_friendship_tree"),
    )

    id: Mapped[str] = mapped_column(String(36), primary_key=True)
    user_a_id: Mapped[str] = mapped_column(String(36), ForeignKey("users.id", ondelete="CASCADE"))
    user_b_id: Mapped[str] = mapped_column(String(36), ForeignKey("users.id", ondelete="CASCADE"))
    water_count: Mapped[int] = mapped_column(Integer, default=0)
    last_watered_at: Mapped[datetime | None] = mapped_column(DateTime, nullable=True)
    created_at: Mapped[datetime] = mapped_column(DateTime, default=lambda: datetime.utcnow())

    user_a = relationship("User", foreign_keys=[user_a_id])
    user_b = relationship("User", foreign_keys=[user_b_id])