content: /*
   * Copyright 2020 Alibaba Group Holding Limited.
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   * http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package com.alibaba.graphscope.common.ir.rel;
  
  import com.alibaba.graphscope.common.ir.rel.graph.*;
  import com.alibaba.graphscope.common.ir.rel.graph.match.GraphLogicalMultiMatch;
  import com.alibaba.graphscope.common.ir.rel.graph.match.GraphLogicalSingleMatch;
  import com.google.common.base.Preconditions;
  
  import org.apache.calcite.rel.RelNode;
  import org.apache.calcite.rel.RelShuttleImpl;
  import org.apache.calcite.rel.core.TableScan;
  import org.apache.calcite.rel.logical.LogicalFilter;
  import org.apache.calcite.rel.logical.LogicalJoin;
  
  /**
   * a wrapper of {@code GraphRelShuttle} and re-implement {@code RelShuttleImpl} to visit our self-defined operators ({@code GraphLogicalXX})
   */
  public class GraphRelShuttleWrapper extends RelShuttleImpl {
      protected final GraphRelShuttle relShuttle;
  
      public GraphRelShuttleWrapper(GraphRelShuttle relShuttle) {
          this.relShuttle = relShuttle;
      }
  
      @Override
      public RelNode visit(TableScan tableScan) {
          Preconditions.checkArgument(
                  tableScan instanceof AbstractBindableTableScan,
                  "tableScan should be " + AbstractBindableTableScan.class);
          if (tableScan instanceof GraphLogicalSource) {
              return relShuttle.visit((GraphLogicalSource) tableScan);
          } else if (tableScan instanceof GraphLogicalExpand) {
              return relShuttle.visit((GraphLogicalExpand) tableScan);
          } else { // GraphLogicalGetV
              return relShuttle.visit((GraphLogicalGetV) tableScan);
          }
      }
  
      @Override
      public RelNode visit(LogicalFilter filter) {
          return relShuttle.visit(filter);
      }
  
      @Override
      public RelNode visit(LogicalJoin join) {
          return relShuttle.visit(join);
      }
  
      @Override
      public RelNode visit(RelNode relNode) {
          if (relNode instanceof GraphLogicalProject) {
              return relShuttle.visit((GraphLogicalProject) relNode);
          } else if (relNode instanceof GraphLogicalAggregate) {
              return relShuttle.visit((GraphLogicalAggregate) relNode);
          } else if (relNode instanceof GraphLogicalSort) {
              return relShuttle.visit((GraphLogicalSort) relNode);
          } else if (relNode instanceof GraphLogicalSingleMatch) {
              return relShuttle.visit((GraphLogicalSingleMatch) relNode);
          } else if (relNode instanceof GraphLogicalMultiMatch) {
              return relShuttle.visit((GraphLogicalMultiMatch) relNode);
          } else if (relNode instanceof GraphLogicalPathExpand) {
              return relShuttle.visit((GraphLogicalPathExpand) relNode);
          } else if (relNode instanceof GraphLogicalDedupBy) {
              return relShuttle.visit((GraphLogicalDedupBy) relNode);
          } else {
              throw new UnsupportedOperationException(
                      "relNode " + relNode.getClass() + " can not be visited in shuttle");
          }
      }
  }
  