content: /*
   * Copyright 1999-2012 Alibaba Group.
   *  
   * 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.
   */
  /**
   * (created at 2011-1-23)
   */
  package com.alibaba.cobar.parser.ast.expression.primary.function.groupby;
  
  import java.util.ArrayList;
  import java.util.Collections;
  import java.util.List;
  
  import com.alibaba.cobar.parser.ast.expression.Expression;
  import com.alibaba.cobar.parser.ast.expression.primary.function.FunctionExpression;
  import com.alibaba.cobar.parser.visitor.SQLASTVisitor;
  
  /**
   * @author <a href="mailto:shuo.qius@alibaba-inc.com">QIU Shuo</a>
   */
  public class GroupConcat extends FunctionExpression {
      private final boolean distinct;
      private final Expression orderBy;
      private final boolean isDesc;
      private final List<Expression> appendedColumnNames;
      private final String separator;
  
      public GroupConcat(boolean distinct, List<Expression> exprList, Expression orderBy, boolean isDesc,
                         List<Expression> appendedColumnNames, String separator) {
          super("GROUP_CONCAT", exprList);
          this.distinct = distinct;
          this.orderBy = orderBy;
          this.isDesc = isDesc;
          if (appendedColumnNames == null || appendedColumnNames.isEmpty()) {
              this.appendedColumnNames = Collections.emptyList();
          } else if (appendedColumnNames instanceof ArrayList) {
              this.appendedColumnNames = appendedColumnNames;
          } else {
              this.appendedColumnNames = new ArrayList<Expression>(appendedColumnNames);
          }
          this.separator = separator == null ? "," : separator;
      }
  
      public boolean isDistinct() {
          return distinct;
      }
  
      public Expression getOrderBy() {
          return orderBy;
      }
  
      public boolean isDesc() {
          return isDesc;
      }
  
      public List<Expression> getAppendedColumnNames() {
          return appendedColumnNames;
      }
  
      public String getSeparator() {
          return separator;
      }
  
      @Override
      public FunctionExpression constructFunction(List<Expression> arguments) {
          throw new UnsupportedOperationException("function of char has special arguments");
      }
  
      @Override
      public void accept(SQLASTVisitor visitor) {
          visitor.visit(this);
      }
  }
  