"""study_topic_subject_notes ORM (PR-9) — 분야 설명 캐시.

(user, study_topic, subject, scope) 단위 unique. AI 즉석 생성 + 캐시.
사용자가 풀이 결과 화면에서 "모르겠음" 카드 클릭 시 호출.

status: none/pending/ready/failed/stale (PR-3 패턴 동일).
"""

from datetime import datetime

from sqlalchemy import BigInteger, DateTime, ForeignKey, String, Text
from sqlalchemy.orm import Mapped, mapped_column

from core.database import Base


class StudyTopicSubjectNote(Base):
    __tablename__ = "study_topic_subject_notes"

    id: Mapped[int] = mapped_column(BigInteger, primary_key=True)
    user_id: Mapped[int] = mapped_column(
        BigInteger, ForeignKey("users.id", ondelete="CASCADE"), nullable=False
    )
    study_topic_id: Mapped[int] = mapped_column(
        BigInteger, ForeignKey("study_topics.id", ondelete="CASCADE"), nullable=False
    )
    subject: Mapped[str] = mapped_column(String(120), nullable=False)
    scope: Mapped[str] = mapped_column(String(200), nullable=False, default="")
    content: Mapped[str | None] = mapped_column(Text)
    status: Mapped[str] = mapped_column(String(20), default="none", nullable=False)
    generated_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True))
    model: Mapped[str | None] = mapped_column(String(120))
    created_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), default=datetime.now, nullable=False
    )
    updated_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), default=datetime.now, onupdate=datetime.now, nullable=False
    )