"""QA 会话语义状态模型。"""

from __future__ import annotations

from typing import Any, Optional

from sqlalchemy import ForeignKey, Integer, TIMESTAMP, VARCHAR
from sqlalchemy.orm import Mapped, mapped_column

from .base import Base
from .types import JSONB


class QASessionState(Base):
    __tablename__ = "qa_session_states"

    id: Mapped[int] = mapped_column(Integer, primary_key=True, autoincrement=True)
    session_id: Mapped[int] = mapped_column(
        Integer,
        ForeignKey("qa_sessions.id", ondelete="CASCADE"),
        nullable=False,
        unique=True,
        index=True,
    )
    last_subject: Mapped[Optional[str]] = mapped_column(VARCHAR(255), nullable=True, index=True)
    last_entity_ids: Mapped[Optional[Any]] = mapped_column(JSONB, nullable=True)
    last_intent: Mapped[Optional[str]] = mapped_column(VARCHAR(20), nullable=True, index=True)
    ambiguity: Mapped[Optional[str]] = mapped_column(VARCHAR(20), nullable=True, index=True)
    rewrite_history: Mapped[Optional[Any]] = mapped_column(JSONB, nullable=True)
    pending_clarification: Mapped[Optional[Any]] = mapped_column(JSONB, nullable=True)
    pending_clarification_expires_at: Mapped[Optional[TIMESTAMP]] = mapped_column(TIMESTAMP, nullable=True, index=True)