restore planutils after merge

Signed-off-by: Selina Song <[email protected]>

Author: Selina Song

core/src/main/java/org/opensearch/sql/calcite/utils/PlanUtils.java

@@ -358,6 +358,43 @@ static RexNode derefMapCall(RexNode rexNode) {
     return rexNode;
   }
 
+  /** Check if contains RexOver */
+  static boolean containsRowNumberDedup(LogicalProject project) {
+    return project.getProjects().stream()
+        .anyMatch(p -> p instanceof RexOver && p.getKind() == SqlKind.ROW_NUMBER);
+  }
+
+  /** Get all RexWindow list from LogicalProject */
+  static List<RexWindow> getRexWindowFromProject(LogicalProject project) {
+    final List<RexWindow> res = new ArrayList<>();
+    final RexVisitorImpl<Void> visitor =
+        new RexVisitorImpl<>(true) {
+          @Override
+          public Void visitOver(RexOver over) {
+            res.add(over.getWindow());
+            return null;
+          }
+        };
+    visitor.visitEach(project.getProjects());
+    return res;
+  }
+
+  static List<Integer> getSelectColumns(List<RexNode> rexNodes) {
+    final List<Integer> selectedColumns = new ArrayList<>();
+    final RexVisitorImpl<Void> visitor =
+        new RexVisitorImpl<Void>(true) {
+          @Override
+          public Void visitInputRef(RexInputRef inputRef) {
+            if (!selectedColumns.contains(inputRef.getIndex())) {
+              selectedColumns.add(inputRef.getIndex());
+            }
+            return null;
+          }
+        };
+    visitor.visitEach(rexNodes);
+    return selectedColumns;
+  }
+
   /**
    * Reverses the direction of a RelCollation.
    *