"""项目分类模型

支持树形分类结构
"""

from typing import Optional, List

from sqlalchemy import BigInteger, String, Integer, Boolean, ForeignKey
from sqlalchemy.orm import Mapped, mapped_column, relationship

from app.models.base import BaseModel


class Category(BaseModel):
    """项目分类表"""
    
    __tablename__ = "categories"
    
    category_name: Mapped[str] = mapped_column(
        String(50),
        nullable=False,
        comment="分类名称"
    )
    parent_id: Mapped[Optional[int]] = mapped_column(
        BigInteger,
        ForeignKey("categories.id"),
        nullable=True,
        comment="父分类ID"
    )
    sort_order: Mapped[int] = mapped_column(
        Integer,
        nullable=False,
        default=0,
        comment="排序"
    )
    is_active: Mapped[bool] = mapped_column(
        Boolean,
        nullable=False,
        default=True,
        comment="是否启用"
    )
    
    # 关系
    parent: Mapped[Optional["Category"]] = relationship(
        "Category",
        remote_side="Category.id",
        back_populates="children"
    )
    children: Mapped[List["Category"]] = relationship(
        "Category",
        back_populates="parent"
    )
    projects: Mapped[List["Project"]] = relationship(
        "Project",
        back_populates="category"
    )


# 避免循环导入
from app.models.project import Project