content: /*****************************************************************
   *   Licensed to the Apache Software Foundation (ASF) under one
   *  or more contributor license agreements.  See the NOTICE file
   *  distributed with this work for additional information
   *  regarding copyright ownership.  The ASF licenses this file
   *  to you 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
   *
   *    https://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 org.apache.cayenne.access.translator.ejbql;
  
  import org.apache.cayenne.ejbql.EJBQLBaseVisitor;
  import org.apache.cayenne.ejbql.EJBQLExpression;
  import org.apache.cayenne.ejbql.parser.EJBQLFromItem;
  import org.apache.cayenne.ejbql.parser.EJBQLJoin;
  
  /**
   * @since 3.0
   */
  public class EJBQLFromTranslator extends EJBQLBaseVisitor {
  
      protected EJBQLTranslationContext context;
      private String lastId;
      private EJBQLJoinAppender joinAppender;
  
      public EJBQLFromTranslator(EJBQLTranslationContext context) {
          super(true);
          this.context = context;
          this.joinAppender = context.getTranslatorFactory().getJoinAppender(context);
      }
  
      @Override
      public boolean visitFrom(EJBQLExpression expression, int finishedChildIndex) {
          if (finishedChildIndex + 1 == expression.getChildrenCount()) {
              if (lastId != null) {
                  context.markCurrentPosition(EJBQLJoinAppender.makeJoinTailMarker(lastId));
              }
          }
  
          return true;
      }
  
      @Override
      public boolean visitFromItem(EJBQLFromItem expression, int finishedChildIndex) {
  
          String id = expression.getId();
          
          if (lastId != null) {
              context.append(',');
              context.markCurrentPosition(EJBQLJoinAppender.makeJoinTailMarker(lastId));
          }
  
          this.lastId = id;
          joinAppender.appendTable(new EJBQLTableId(id));
          return false;
      }
  
      @Override
      public boolean visitInnerFetchJoin(EJBQLJoin join) {
          joinAppender.appendInnerJoin(
                  null,
                  new EJBQLTableId(join.getLeftHandSideId()),
                  new EJBQLTableId(join.getRightHandSideId()));
  
          context.markCurrentPosition(EJBQLJoinAppender
                  .makeJoinTailMarker(join.getRightHandSideId()));
          return false;
      }
  
      @Override
      public boolean visitInnerJoin(EJBQLJoin join) {
          joinAppender.appendInnerJoin(
                  null,
                  new EJBQLTableId(join.getLeftHandSideId()),
                  new EJBQLTableId(join.getRightHandSideId()));
          
          //fix 1341-mark current join position for probable future joins to this join
          context.markCurrentPosition(EJBQLJoinAppender.makeJoinTailMarker(join.getRightHandSideId()));
          return false;
      }
  
      @Override
      public boolean visitOuterFetchJoin(EJBQLJoin join) {
          joinAppender.appendOuterJoin(
                  null,
                  new EJBQLTableId(join.getLeftHandSideId()),
                  new EJBQLTableId(join.getRightHandSideId()));
  
          context.markCurrentPosition(EJBQLJoinAppender
                  .makeJoinTailMarker(join.getRightHandSideId()));
          return false;
      }
  
      @Override
      public boolean visitOuterJoin(EJBQLJoin join) {
          joinAppender.appendOuterJoin(
                  null,
                  new EJBQLTableId(join.getLeftHandSideId()),
                  new EJBQLTableId(join.getRightHandSideId()));
          context.markCurrentPosition(EJBQLJoinAppender.makeJoinTailMarker(join.getRightHandSideId()));
          return false;
      }
  }
  