[UNI-218] refactor : 길 찾기 상세경로 좌회전,우회전 로직 수정 (#185)

* [UNI-218] refactor : 방향 비교할 때 i-1, i, i+1 비교가 아닌 i-2, i, i+2를 비교하도록 변경

* [UNI-218] refactor : 메서드 2개를 하나로 병합

uniro_backend/src/main/java/com/softeer5/uniro_backend/map/service/RouteCalculator.java

@@ -275,14 +275,30 @@ private boolean isBuildingRoute(Route route){
     }
 
     // 두 route 간의 각도를 통한 계산으로 방향성을 정하는 메서드
-    private DirectionType calculateDirection(Node secondNode, Route inBoundRoute, Route outBoundRoute) {
-        Node firstNode = inBoundRoute.getNode1().equals(secondNode) ? inBoundRoute.getNode2() : inBoundRoute.getNode1();
-        Node thirdNode = outBoundRoute.getNode1().equals(secondNode) ? outBoundRoute.getNode2() : outBoundRoute.getNode1();
+    private DirectionType calculateDirection(Node secondNode, List<Route> shortestRoutes, int idx) {
+        Node firstNode = shortestRoutes.get(idx).getNode1().equals(secondNode) ?
+                shortestRoutes.get(idx).getNode2() : shortestRoutes.get(idx).getNode1();
+        Node thirdNode = shortestRoutes.get(idx+1).getNode2().equals(secondNode) ?
+                shortestRoutes.get(idx+1).getNode1() : shortestRoutes.get(idx+1).getNode2();
+
+        if(idx-1 >= 0){
+            firstNode = shortestRoutes.get(idx-1).getNode1().equals(secondNode) ?
+                    shortestRoutes.get(idx-1).getNode2() : shortestRoutes.get(idx-1).getNode1();
+        }
+
+        if(idx+2 <= shortestRoutes.size()-1){
+            thirdNode = shortestRoutes.get(idx+2).getNode2().equals(secondNode) ?
+                    shortestRoutes.get(idx+2).getNode1() : shortestRoutes.get(idx+2).getNode2();
+        }
 
         Point p1 = firstNode.getCoordinates();
         Point p2 = secondNode.getCoordinates();
         Point p3 = thirdNode.getCoordinates();
 
+        return calculateAngle(p1, p2, p3);
+    }
+
+    private DirectionType calculateAngle(Point p1, Point p2, Point p3) {
         double v1x = p2.getX() - p1.getX();
         double v1y = p2.getY() - p1.getY();
 
@@ -366,7 +382,8 @@ private List<RouteDetailResDTO> getRouteDetail(Node startNode, Node endNode, Lis
                 break;
             }
             if(nxt.isCore()){
-                DirectionType directionType = calculateDirection(nxt, nowRoute, shortestRoutes.get(i+1));
+                DirectionType directionType = calculateDirection(nxt, shortestRoutes, i);
+
                 if(directionType == DirectionType.STRAIGHT){
                     now = nxt;
                     continue;