added RaG

web/backend/app/services/rag/models.py

@@ -0,0 +1,71 @@
+"""RAG models: sources and chunks with pgvector embeddings."""
+
+from __future__ import annotations
+
+from datetime import datetime
+from typing import Any, Optional
+
+from sqlalchemy import (
+    DateTime,
+    ForeignKey,
+    Integer,
+    JSON,
+    String,
+    Text,
+    UniqueConstraint,
+    func,
+)
+from sqlalchemy.orm import Mapped, mapped_column, relationship
+
+from app.core.database import Base
+
+try:
+    from pgvector.sqlalchemy import Vector
+
+    EMBEDDING_DIM = 1536
+    _VectorType = Vector(EMBEDDING_DIM)
+except Exception:  # pragma: no cover
+    EMBEDDING_DIM = 1536
+    _VectorType = JSON  # type: ignore[misc, assignment]
+
+
+class RagSource(Base):
+    __tablename__ = "rag_sources"
+
+    id: Mapped[int] = mapped_column(Integer, primary_key=True)
+    scope: Mapped[str] = mapped_column(String(16), nullable=False, index=True)  # global | project
+    project_id: Mapped[Optional[int]] = mapped_column(
+        ForeignKey("projects.id", ondelete="CASCADE"), nullable=True, index=True
+    )
+    kind: Mapped[str] = mapped_column(String(16), nullable=False)  # upload | url
+    title: Mapped[str] = mapped_column(String(512), default="")
+    uri: Mapped[Optional[str]] = mapped_column(String(2048), nullable=True)
+    path: Mapped[Optional[str]] = mapped_column(String(2048), nullable=True)
+    gost_id: Mapped[Optional[str]] = mapped_column(String(128), nullable=True, index=True)
+    status: Mapped[str] = mapped_column(String(32), default="pending")  # pending|indexing|ready|error
+    error_message: Mapped[Optional[str]] = mapped_column(Text, nullable=True)
+    meta: Mapped[Optional[dict]] = mapped_column(JSON, nullable=True)
+    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), server_default=func.now())
+    updated_at: Mapped[datetime] = mapped_column(
+        DateTime(timezone=True), server_default=func.now(), onupdate=func.now()
+    )
+
+    chunks: Mapped[list[RagChunk]] = relationship(
+        back_populates="source", cascade="all, delete-orphan"
+    )
+
+
+class RagChunk(Base):
+    __tablename__ = "rag_chunks"
+    __table_args__ = (UniqueConstraint("source_id", "chunk_index", name="uq_rag_chunk_source_idx"),)
+
+    id: Mapped[int] = mapped_column(Integer, primary_key=True)
+    source_id: Mapped[int] = mapped_column(
+        ForeignKey("rag_sources.id", ondelete="CASCADE"), index=True, nullable=False
+    )
+    chunk_index: Mapped[int] = mapped_column(Integer, default=0)
+    text: Mapped[str] = mapped_column(Text, default="")
+    embedding: Mapped[Optional[Any]] = mapped_column(_VectorType, nullable=True)
+    meta: Mapped[Optional[dict]] = mapped_column(JSON, nullable=True)
+
+    source: Mapped[RagSource] = relationship(back_populates="chunks")