"""RAG 知识库模型。"""

import uuid
from datetime import datetime, timezone

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

from app.core.database import Base


class KnowledgeChunk(Base):
    """知识库分块 — 向量化的月报/报告片段。"""

    __tablename__ = "knowledge_chunks"

    id: Mapped[str] = mapped_column(String(36), primary_key=True, default=lambda: str(uuid.uuid4()))
    tenant_id: Mapped[str] = mapped_column(String(36), ForeignKey("tenants.id"), nullable=False, index=True)
    source_type: Mapped[str] = mapped_column(String(50), nullable=False, comment="report/agreement/board/aar/knowledge_graph")
    source_id: Mapped[str | None] = mapped_column(String(36), nullable=True, comment="来源记录 ID")
    company_id: Mapped[str | None] = mapped_column(String(36), ForeignKey("companies.id"), nullable=True, index=True)
    content: Mapped[str] = mapped_column(Text, nullable=False, comment="文本内容")
    embedding: Mapped[dict | None] = mapped_column(JSON, nullable=True, comment="向量嵌入")
    metadata_json: Mapped[dict | None] = mapped_column(JSON, nullable=True, comment="元数据")
    created_at: Mapped[datetime] = mapped_column(
        DateTime(timezone=True), default=lambda: datetime.now(timezone.utc)
    )