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.expr;
  
  import com.alibaba.druid.sql.ast.*;
  import com.alibaba.druid.sql.visitor.SQLASTVisitor;
  
  import java.util.Collections;
  import java.util.List;
  
  public class SQLSequenceExpr extends SQLExprImpl implements SQLReplaceable {
      private SQLName sequence;
      private Function function;
  
      public SQLSequenceExpr() {
      }
  
      public SQLSequenceExpr(SQLName sequence, Function function) {
          this.sequence = sequence;
          this.function = function;
      }
  
      public SQLSequenceExpr clone() {
          SQLSequenceExpr x = new SQLSequenceExpr();
          if (sequence != null) {
              x.setSequence(sequence.clone());
          }
          x.function = function;
          return x;
      }
  
      @Override
      protected void accept0(SQLASTVisitor visitor) {
          if (visitor.visit(this)) {
              if (this.sequence != null) {
                  this.sequence.accept(visitor);
              }
          }
          visitor.endVisit(this);
      }
  
      @Override
      public boolean replace(SQLExpr expr, SQLExpr target) {
          if (this.sequence == expr) {
              setSequence((SQLName) target);
              return true;
          }
          return false;
      }
  
      public static enum Function {
          NextVal("NEXTVAL"), CurrVal("CURRVAL"), PrevVal("PREVVAL");
  
          public final String name;
          public final String nameLCase;
  
          private Function(String name) {
              this.name = name;
              this.nameLCase = name.toLowerCase();
          }
      }
  
      public List<SQLObject> getChildren() {
          return Collections.<SQLObject>singletonList(sequence);
      }
  
      public SQLName getSequence() {
          return sequence;
      }
  
      public void setSequence(SQLName sequence) {
          this.sequence = sequence;
      }
  
      public Function getFunction() {
          return function;
      }
  
      public void setFunction(Function function) {
          this.function = function;
      }
  
      @Override
      public int hashCode() {
          final int prime = 31;
          int result = 1;
          result = prime * result + ((function == null) ? 0 : function.hashCode());
          result = prime * result + ((sequence == null) ? 0 : sequence.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;
          }
          SQLSequenceExpr other = (SQLSequenceExpr) obj;
          if (function != other.function) {
              return false;
          }
          if (sequence == null) {
              if (other.sequence != null) {
                  return false;
              }
          } else if (!sequence.equals(other.sequence)) {
              return false;
          }
          return true;
      }
  
  }
  