refactor: 重构neo4j服务

2026-04-28 12:53:01 +08:00
parent 3ff8f3951a
commit f998f78c80
10 changed files with 654 additions and 795 deletions
@@ -0,0 +1,195 @@
+package service
+
+import (
+	"context"
+	"fmt"
+	"strings"
+
+	"github.com/neo4j/neo4j-go-driver/v5/neo4j"
+
+	"knowledge-graph-backend/internal/model"
+)
+
+// CreateNode 创建新节点
+func (s *Neo4jService) CreateNode(req model.CreateNodeRequest) (model.Node, error) {
+	ctx := context.Background()
+
+	if req.ID == "" {
+		return model.Node{}, fmt.Errorf("node id is required")
+	}
+	if req.Label == "" {
+		return model.Node{}, fmt.Errorf("node label is required")
+	}
+
+	if _, found, err := s.fetchNodeByID(req.ID); err != nil {
+		return model.Node{}, err
+	} else if found {
+		return model.Node{}, fmt.Errorf("node with id %s already exists", req.ID)
+	}
+
+	props := buildNodeProps(req)
+	nodeType := sanitizeLabel(req.Type)
+	if nodeType == "" {
+		nodeType = "Node"
+	}
+
+	query := fmt.Sprintf(`
+		CREATE (n:%s)
+		SET n = $props
+		RETURN n`, nodeType)
+
+	result, err := neo4j.ExecuteQuery(ctx, s.driver, query, map[string]any{"props": props}, neo4j.EagerResultTransformer)
+	if err != nil {
+		return model.Node{}, fmt.Errorf("failed to create node: %w", err)
+	}
+	if len(result.Records) == 0 {
+		return model.Node{}, fmt.Errorf("failed to create node: no result returned")
+	}
+
+	v, _ := result.Records[0].Get("n")
+	if n, ok := v.(neo4j.Node); ok {
+		return neo4jNodeToModel(n), nil
+	}
+	return model.Node{}, fmt.Errorf("unexpected result type while creating node")
+}
+
+// UpdateNode 更新节点
+func (s *Neo4jService) UpdateNode(id string, req model.UpdateNodeRequest) (model.Node, error) {
+	ctx := context.Background()
+
+	if _, found, err := s.fetchNodeByID(id); err != nil {
+		return model.Node{}, err
+	} else if !found {
+		return model.Node{}, fmt.Errorf("node with id %s not found", id)
+	}
+
+	setClauses := []string{}
+	params := map[string]any{"id": id}
+
+	if req.Label != "" {
+		setClauses = append(setClauses, "n.label = $label")
+		params["label"] = req.Label
+	}
+	if req.Type != "" {
+		setClauses = append(setClauses, "n.type = $type")
+		params["type"] = req.Type
+	}
+	if req.X != nil {
+		setClauses = append(setClauses, "n.x = $x")
+		params["x"] = *req.X
+	}
+	if req.Y != nil {
+		setClauses = append(setClauses, "n.y = $y")
+		params["y"] = *req.Y
+	}
+
+	for key, value := range req.Properties {
+		if isReservedNodeProperty(key) {
+			continue
+		}
+		safeKey := sanitizeLabel(key)
+		setClauses = append(setClauses, fmt.Sprintf("n.%s = $%s", safeKey, safeKey))
+		params[safeKey] = value
+	}
+
+	query := `MATCH (n {id: $id})`
+	if len(setClauses) > 0 {
+		query += ` SET ` + strings.Join(setClauses, ", ")
+	}
+	query += ` RETURN n`
+
+	result, err := neo4j.ExecuteQuery(ctx, s.driver, query, params, neo4j.EagerResultTransformer)
+	if err != nil {
+		return model.Node{}, err
+	}
+	if len(result.Records) == 0 {
+		return model.Node{}, fmt.Errorf("failed to update node")
+	}
+
+	v, _ := result.Records[0].Get("n")
+	if n, ok := v.(neo4j.Node); ok {
+		return neo4jNodeToModel(n), nil
+	}
+	return model.Node{}, fmt.Errorf("unexpected result type while updating node")
+}
+
+// DeleteNode 删除节点
+func (s *Neo4jService) DeleteNode(id string) error {
+	ctx := context.Background()
+
+	if _, found, err := s.fetchNodeByID(id); err != nil {
+		return err
+	} else if !found {
+		return fmt.Errorf("node with id %s not found", id)
+	}
+
+	_, err := neo4j.ExecuteQuery(ctx, s.driver, `
+		MATCH (n {id: $id})
+		DETACH DELETE n`, map[string]any{"id": id}, neo4j.EagerResultTransformer)
+	return err
+}
+
+// CreateEdge 创建新边
+func (s *Neo4jService) CreateEdge(req model.CreateEdgeRequest) (model.Edge, error) {
+	ctx := context.Background()
+
+	if req.Source == "" || req.Target == "" {
+		return model.Edge{}, fmt.Errorf("source and target are required")
+	}
+	if _, found, err := s.fetchNodeByID(req.Source); err != nil {
+		return model.Edge{}, err
+	} else if !found {
+		return model.Edge{}, fmt.Errorf("source node with id %s not found", req.Source)
+	}
+	if _, found, err := s.fetchNodeByID(req.Target); err != nil {
+		return model.Edge{}, err
+	} else if !found {
+		return model.Edge{}, fmt.Errorf("target node with id %s not found", req.Target)
+	}
+
+	props := buildEdgeProps(req)
+	relationType := sanitizeRelationshipType(req.Type)
+	if relationType == "" {
+		relationType = "RELATED_TO"
+	}
+
+	query := fmt.Sprintf(`
+		MATCH (a {id: $source}), (b {id: $target})
+		CREATE (a)-[r:%s]->(b)
+		SET r = $props
+		RETURN r`, relationType)
+
+	params := map[string]any{
+		"source": req.Source,
+		"target": req.Target,
+		"props":  props,
+	}
+
+	result, err := neo4j.ExecuteQuery(ctx, s.driver, query, params, neo4j.EagerResultTransformer)
+	if err != nil {
+		return model.Edge{}, err
+	}
+	if len(result.Records) == 0 {
+		return model.Edge{}, fmt.Errorf("failed to create edge")
+	}
+
+	v, _ := result.Records[0].Get("r")
+	if r, ok := v.(neo4j.Relationship); ok {
+		edge := neo4jRelToModel(r)
+		edge.Source = req.Source
+		edge.Target = req.Target
+		return edge, nil
+	}
+	return model.Edge{}, fmt.Errorf("unexpected result type while creating edge")
+}
+
+// DeleteEdge 删除边
+func (s *Neo4jService) DeleteEdge(edgeID string) error {
+	ctx := context.Background()
+
+	_, err := neo4j.ExecuteQuery(ctx, s.driver, `
+		MATCH ()-[r]-()
+		WHERE r.id = $id
+		DELETE r`, map[string]any{"id": edgeID}, neo4j.EagerResultTransformer)
+	return err
+}