self-constructing_graph/graph/router/dify_kb.py

from fastapi import APIRouter, UploadFile, File, HTTPException, Depends, Header
from typing import List, Optional
from pydantic import BaseModel
from models.response import StandardResponse

from db.database import get_db
from sqlalchemy.orm import Session
from sqlalchemy import text
from db.schemas  import *
from db.models import *
from utils.response import resp_200

router = APIRouter(prefix="/dify", tags=["Dify Knowledge Base"])


# --- Data Models ---
class RetrievalSetting(BaseModel):
    top_k: int
    score_threshold: float

class MetadataCondition(BaseModel):
    name: List[str]
    comparison_operator: str
    value: Optional[str] = None

class MetadataFilter(BaseModel):
    logical_operator: str = "and"
    conditions: List[MetadataCondition]

class DifyRetrievalRequest(BaseModel):
    knowledge_id: str
    query: str
    retrieval_setting: RetrievalSetting
    metadata_condition: Optional[MetadataFilter] = None

class KnowledgeRecord(BaseModel):
    content: str
    score: float
    title: str
    metadata: dict

# --- Authentication ---
async def verify_api_key(authorization: str = Header(...)):
    if not authorization.startswith("Bearer "):
        raise HTTPException(
            status_code=403,
            detail=StandardResponse(
                success=False,
                error_code=1001,
                error_msg="Invalid Authorization header format"
            )
        )
    api_key = authorization[7:]
    # TODO: Implement actual API key validation logic
    if not api_key:
        raise HTTPException(
            status_code=403,
            detail=StandardResponse(
                success=False,
                error_code=1002,
                error_msg="Authorization failed"
            )
        )
    return api_key

@router.post("/retrieval", response_model=StandardResponse)
async def dify_retrieval(
    request: DifyRetrievalRequest,
    api_key: str = Depends(verify_api_key),
    db: Session = Depends(get_db)
):
    """
    实现Dify外部知识库检索接口
    """
    print("dify_retrieval start")
    try:            
        # 检查知识库是否存在
        kb_exists = db.query(DbKgGraphs).filter(DbKgGraphs.id == request.knowledge_id).count()
        
        if kb_exists == 0:
            raise HTTPException(
                status_code=404,
                detail=StandardResponse(
                    success=False,
                    error_code=2001,
                    error_msg="The knowledge does not exist"
                )
            )
        print("知识库存在")
        # 构建基础查询
        query = """
        select id,name,category,version from kg_nodes as node where node.graph_id = :graph_id and node.name = :node_name
        """

        # 添加元数据过滤条件
        if request.metadata_condition:
            conditions = []
            for cond in request.metadata_condition.conditions:
                operator_map = {
                    "contains": "CONTAINS",
                    "not contains": "NOT CONTAINS",
                    "start with": "STARTS WITH", 
                    "end with": "ENDS WITH",
                    "is": "=",
                    "is not": "<>",
                    "empty": "IS NULL",
                    "not empty": "IS NOT NULL",
                    ">": ">",
                    "<": "<",
                    "≥": ">=",
                    "≤": "<=",
                    "before": "<",
                    "after": ">"
                }
                cypher_op = operator_map.get(cond.comparison_operator, "=")
                
                for field in cond.name:
                    if cond.comparison_operator in ["empty", "not empty"]:
                        conditions.append(f"node.{field} {cypher_op}")
                    else:
                        conditions.append(
                            f"node.{field} {cypher_op} ${field}_value"
                        )

            where_clause = " AND ".join(conditions)
            query += f" AND {where_clause}"

        query += """           
        ORDER BY node.name DESC
        LIMIT :top_k
        """
        params = {'graph_id': request.knowledge_id, 'node_name': request.query,'top_k':request.retrieval_setting.top_k}
        supply_params = {f"{cond.name}_value": cond.value for cond in request.metadata_condition.conditions} if request.metadata_condition else {}
        # 执行查询
        

        result = db.execute(text(query), 
                            {
                                **params, 
                                **supply_params
                            }    )           
                                
     
        data_returned = []
        for record in result:
            id,name,category,version = record
            doc_node = {
                "id": id,
                "name": name,
                "category": category,
                "version": version
            }
            
            data_returned.append({
                "content": "",
                "score": float(1.0),
                "title": doc_node.get("name", "Untitled"),
                "metadata": {
                    "id": doc_node.get("id", 0),
                    "category": doc_node.get("category", "")                    
                }
            })
        
        for data in data_returned:
            id = data['metadata']['id']
            result = db.execute(text("""
            select prop_title, prop_value from kg_props as prop where prop.category=1 and prop.ref_id =:node_id
            """),{'node_id':id})
            content = []
            for record in result:
                prop_title, prop_value = record
                content.append(f"{prop_title}:{prop_value}\n")
            data['content']="\n".join(content)
        response_data = StandardResponse(
            success=True,
            records=data_returned
        )
        return response_data

    except HTTPException:
        raise
    except Exception as e:
        print(e)
        raise HTTPException(
            status_code=500,
            detail=StandardResponse(
                success=False,
                error_code=500,
                error_msg=str(e)
            )
        )

dify_kb_router = router