from datetime import datetime

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

from app.db.session import Base
from app.models.catalog import Versioned


class KnowledgeItem(Versioned, Base):
    __tablename__ = "knowledge_items"
    __table_args__ = (
        CheckConstraint(
            "verification_status IN ('pending', 'verified', 'rejected')",
            name="ck_knowledge_verification_status",
        ),
    )
    id: Mapped[int] = mapped_column(Integer, primary_key=True, index=True)
    title: Mapped[str] = mapped_column(String(250), nullable=False, index=True)
    category: Mapped[str] = mapped_column(String(80), nullable=False, default="未分类")
    content: Mapped[str] = mapped_column(Text, nullable=False)
    source_url: Mapped[str | None] = mapped_column(String(1000), nullable=True)
    verification_status: Mapped[str] = mapped_column(String(30), nullable=False, default="pending")
    source_id: Mapped[int | None] = mapped_column(ForeignKey("sources.id"), index=True)
    document_id: Mapped[int | None] = mapped_column(ForeignKey("documents.id"), index=True)
    collected_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True))
    reviewer: Mapped[str | None] = mapped_column(String(100))
    reviewed_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True))
    verification_notes: Mapped[str | None] = mapped_column(Text)