from typing import TYPE_CHECKING

from sqlalchemy import String, Text
from sqlalchemy.orm import Mapped, mapped_column, relationship

from src.models.base import Base, UUIDMixin

if TYPE_CHECKING:
    from src.models.question import Question


class Category(Base, UUIDMixin):
    """Question category (e.g., Arrays, Strings, Trees)."""

    __tablename__ = "categories"

    name: Mapped[str] = mapped_column(String(100), unique=True, nullable=False)
    slug: Mapped[str] = mapped_column(String(100), unique=True, nullable=False)
    description: Mapped[str | None] = mapped_column(Text, nullable=True)

    # Relationships
    questions: Mapped[list["Question"]] = relationship(
        secondary="question_categories",
        back_populates="categories",
    )