content: /*
   * Copyright 1999-2017 Alibaba Group Holding Ltd.
   *
   * 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.druid.sql.ast.statement;
  
  import com.alibaba.druid.sql.ast.*;
  import com.alibaba.druid.sql.ast.expr.SQLIntegerExpr;
  import com.alibaba.druid.sql.visitor.SQLASTVisitor;
  
  import java.util.List;
  
  public final class SQLSelectOrderByItem extends SQLExprImpl implements SQLReplaceable {
      protected SQLExpr expr;
      protected String collate;
      protected SQLExpr opclass;
  
      protected SQLOrderingSpecification type;
      protected NullsOrderType nullsOrderType;
  
      protected transient SQLSelectItem resolvedSelectItem;
  
      public SQLSelectOrderByItem() {
      }
  
      public SQLSelectOrderByItem(SQLExpr expr) {
          this.setExpr(expr);
      }
  
      public SQLSelectOrderByItem(SQLExpr expr, SQLOrderingSpecification type) {
          this.setExpr(expr);
          this.type = type;
      }
  
      public SQLExpr getExpr() {
          return this.expr;
      }
  
      public void setExpr(SQLExpr expr) {
          if (expr != null) {
              expr.setParent(this);
          }
          this.expr = expr;
      }
  
      public String getCollate() {
          return collate;
      }
  
      public void setCollate(String collate) {
          this.collate = collate;
      }
  
      public SQLExpr getOpclass() {
          return opclass;
      }
  
      public void setOpclass(SQLExpr opclass) {
          this.opclass = opclass;
      }
  
      public SQLOrderingSpecification getType() {
          return this.type;
      }
  
      public void setType(SQLOrderingSpecification type) {
          this.type = type;
      }
  
      public NullsOrderType getNullsOrderType() {
          return this.nullsOrderType;
      }
  
      public void setNullsOrderType(NullsOrderType nullsOrderType) {
          this.nullsOrderType = nullsOrderType;
      }
  
      protected void accept0(SQLASTVisitor v) {
          if (v.visit(this)) {
              if (expr != null) {
                  expr.accept(v);
              }
          }
  
          v.endVisit(this);
      }
  
      @Override
      public int hashCode() {
          final int prime = 31;
          int result = 1;
          result = prime * result + ((collate == null) ? 0 : collate.hashCode());
          result = prime * result + ((expr == null) ? 0 : expr.hashCode());
          result = prime * result + ((type == null) ? 0 : type.hashCode());
          return result;
      }
  
      @Override
      public boolean equals(Object obj) {
          if (this == obj) {
              return true;
          }
          if (obj == null) {
              return false;
          }
          if (getClass() != obj.getClass()) {
              return false;
          }
          SQLSelectOrderByItem other = (SQLSelectOrderByItem) obj;
          if (collate == null) {
              if (other.collate != null) {
                  return false;
              }
          } else if (!collate.equals(other.collate)) {
              return false;
          }
          if (expr == null) {
              if (other.expr != null) {
                  return false;
              }
          } else if (!expr.equals(other.expr)) {
              return false;
          }
          if (type != other.type) {
              return false;
          }
          return true;
      }
  
      @Override
      public boolean replace(SQLExpr expr, SQLExpr target) {
          if (this.expr == expr) {
              if (target instanceof SQLIntegerExpr && parent instanceof SQLOrderBy) {
                  ((SQLOrderBy) parent).getItems().remove(this);
              }
              this.setExpr(target);
              return true;
          }
          return false;
      }
  
      public static enum NullsOrderType {
          NullsFirst, NullsLast;
  
          public String toFormalString() {
              if (NullsFirst.equals(this)) {
                  return "NULLS FIRST";
              }
  
              if (NullsLast.equals(this)) {
                  return "NULLS LAST";
              }
  
              throw new IllegalArgumentException();
          }
      }
  
      public SQLSelectOrderByItem clone() {
          SQLSelectOrderByItem x = new SQLSelectOrderByItem();
          if (expr != null) {
              x.setExpr(expr.clone());
          }
          x.collate = collate;
          x.type = type;
          x.nullsOrderType = nullsOrderType;
          return x;
      }
  
      public SQLSelectItem getResolvedSelectItem() {
          return resolvedSelectItem;
      }
  
      public void setResolvedSelectItem(SQLSelectItem resolvedSelectItem) {
          this.resolvedSelectItem = resolvedSelectItem;
      }
  
      public boolean isClusterBy() {
          if (parent instanceof SQLCreateTableStatement) {
              List<SQLSelectOrderByItem> clusteredBy = ((SQLCreateTableStatement) parent).getClusteredBy();
              return clusteredBy.indexOf(this) != -1;
          }
  
          if (parent instanceof SQLSelectQueryBlock) {
              List<SQLSelectOrderByItem> clusterBy = ((SQLSelectQueryBlock) parent).getClusterByDirect();
              return clusterBy != null && clusterBy.indexOf(this) != -1;
          }
  
          return false;
      }
  
      public boolean isSortBy() {
          if (parent instanceof SQLCreateTableStatement) {
              List<SQLSelectOrderByItem> sortedBy = ((SQLCreateTableStatement) parent).getSortedBy();
              return sortedBy.indexOf(this) != -1;
          }
  
          if (parent instanceof SQLSelectQueryBlock) {
              List<SQLSelectOrderByItem> sortedBy = ((SQLSelectQueryBlock) parent).getSortByDirect();
              return sortedBy != null && sortedBy.indexOf(this) != -1;
          }
  
          return false;
      }
  
      public boolean isDistributeBy() {
          if (parent instanceof SQLSelectQueryBlock) {
              List<SQLSelectOrderByItem> distributeBy = ((SQLSelectQueryBlock) parent).getDistributeBy();
              return distributeBy.indexOf(this) != -1;
          }
  
          return false;
      }
  }
  