refactor: 重构neo4j服务

backend/internal/service/graph_simple.go

@@ -0,0 +1,64 @@
+package service
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/neo4j/neo4j-go-driver/v5/neo4j"
+
+	"knowledge-graph-backend/internal/model"
+)
+
+// GetSimpleGraphData 获取简化的图数据，仅保留核心信息，适合 LLM 处理
+func (s *Neo4jService) GetSimpleGraphData() model.SimpleGraphData {
+	ctx := context.Background()
+	var nodes []model.SimpleNode
+	var edges []model.SimpleEdge
+
+	nodeResult, err := neo4j.ExecuteQuery(ctx, s.driver,
+		"MATCH (n) RETURN n",
+		map[string]any{},
+		neo4j.EagerResultTransformer,
+	)
+	if err != nil {
+		fmt.Printf("Error querying nodes: %v\n", err)
+		return model.SimpleGraphData{}
+	}
+	for _, record := range nodeResult.Records {
+		if v, ok := record.Get("n"); ok {
+			if n, ok := v.(neo4j.Node); ok {
+				props := n.Props
+				node := model.SimpleNode{ID: getStr(props, "id"), Label: getStr(props, "label"), Type: getStr(props, "type")}
+				nodes = append(nodes, node)
+			}
+		}
+	}
+
+	edgeResult, err := neo4j.ExecuteQuery(ctx, s.driver,
+		"MATCH (a)-[r]->(b) RETURN a.id AS source, b.id AS target, r",
+		map[string]any{},
+		neo4j.EagerResultTransformer,
+	)
+	if err != nil {
+		fmt.Printf("Error querying edges: %v\n", err)
+		return model.SimpleGraphData{Nodes: nodes}
+	}
+	for _, record := range edgeResult.Records {
+		source, _ := record.Get("source")
+		target, _ := record.Get("target")
+		v, _ := record.Get("r")
+		if rel, ok := v.(neo4j.Relationship); ok {
+			props := rel.Props
+			edge := model.SimpleEdge{Source: getStr(props, "source"), Target: getStr(props, "target"), Type: rel.Type, Label: getStr(props, "label")}
+			if s, ok := source.(string); ok {
+				edge.Source = s
+			}
+			if t, ok := target.(string); ok {
+				edge.Target = t
+			}
+			edges = append(edges, edge)
+		}
+	}
+
+	return model.SimpleGraphData{Nodes: nodes, Edges: edges}
+}