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.DbType;
  import com.alibaba.druid.sql.SQLUtils;
  import com.alibaba.druid.sql.ast.*;
  import com.alibaba.druid.sql.visitor.SQLASTVisitor;
  
  import java.io.Serializable;
  import java.util.ArrayList;
  import java.util.List;
  
  public class SQLCaseExpr extends SQLExprImpl implements SQLReplaceable, Serializable {
      private static final long serialVersionUID = 1L;
      private final List<Item> items = new ArrayList<Item>();
      private SQLExpr valueExpr;
      private SQLExpr elseExpr;
  
      public SQLCaseExpr() {
      }
  
      public SQLExpr getValueExpr() {
          return this.valueExpr;
      }
  
      public void setValueExpr(SQLExpr valueExpr) {
          if (valueExpr != null) {
              valueExpr.setParent(this);
          }
          this.valueExpr = valueExpr;
      }
  
      public SQLExpr getElseExpr() {
          return this.elseExpr;
      }
  
      public void setElseExpr(SQLExpr elseExpr) {
          if (elseExpr != null) {
              elseExpr.setParent(this);
          }
          this.elseExpr = elseExpr;
      }
  
      public List<Item> getItems() {
          return this.items;
      }
  
      public void addItem(Item item) {
          if (item != null) {
              item.setParent(this);
              this.items.add(item);
          }
      }
  
      public void addItem(SQLExpr condition, SQLExpr value) {
          this.addItem(new Item(condition, value));
      }
  
      protected void accept0(SQLASTVisitor visitor) {
          if (visitor.visit(this)) {
              if (valueExpr != null) {
                  valueExpr.accept(visitor);
              }
  
              for (Item item : this.items) {
                  if (item != null) {
                      item.accept(visitor);
                  }
              }
  
              if (elseExpr != null) {
                  elseExpr.accept(visitor);
              }
          }
          visitor.endVisit(this);
      }
  
      @Override
      public List getChildren() {
          List<SQLObject> children = new ArrayList<SQLObject>();
          if (valueExpr != null) {
              children.add(this.valueExpr);
          }
          children.addAll(this.items);
          if (elseExpr != null) {
              children.add(this.elseExpr);
          }
          return children;
      }
  
      @Override
      public boolean replace(SQLExpr expr, SQLExpr target) {
          if (valueExpr == expr) {
              setValueExpr(target);
              return true;
          }
  
          if (elseExpr == expr) {
              setElseExpr(target);
              return true;
          }
  
          return false;
      }
  
      public static class Item extends SQLObjectImpl implements SQLReplaceable, Serializable {
          private static final long serialVersionUID = 1L;
          private SQLExpr conditionExpr;
          private SQLExpr valueExpr;
  
          public Item() {
          }
  
          public Item(SQLExpr conditionExpr, SQLExpr valueExpr) {
              setConditionExpr(conditionExpr);
              setValueExpr(valueExpr);
          }
  
          public SQLExpr getConditionExpr() {
              return this.conditionExpr;
          }
  
          public void setConditionExpr(SQLExpr conditionExpr) {
              if (conditionExpr != null) {
                  conditionExpr.setParent(this);
              }
              this.conditionExpr = conditionExpr;
          }
  
          public SQLExpr getValueExpr() {
              return this.valueExpr;
          }
  
          public void setValueExpr(SQLExpr valueExpr) {
              if (valueExpr != null) {
                  valueExpr.setParent(this);
              }
              this.valueExpr = valueExpr;
          }
  
          protected void accept0(SQLASTVisitor visitor) {
              if (visitor.visit(this)) {
                  if (this.conditionExpr != null) {
                      this.conditionExpr.accept(visitor);
                  }
  
                  if (valueExpr != null) {
                      valueExpr.accept(visitor);
                  }
              }
              visitor.endVisit(this);
          }
  
          @Override
          public int hashCode() {
              final int prime = 31;
              int result = 1;
              result = prime * result + ((conditionExpr == null) ? 0 : conditionExpr.hashCode());
              result = prime * result + ((valueExpr == null) ? 0 : valueExpr.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;
              }
              Item other = (Item) obj;
              if (conditionExpr == null) {
                  if (other.conditionExpr != null) {
                      return false;
                  }
              } else if (!conditionExpr.equals(other.conditionExpr)) {
                  return false;
              }
              if (valueExpr == null) {
                  if (other.valueExpr != null) {
                      return false;
                  }
              } else if (!valueExpr.equals(other.valueExpr)) {
                  return false;
              }
              return true;
          }
  
          public Item clone() {
              Item x = new Item();
              if (conditionExpr != null) {
                  x.setConditionExpr(conditionExpr.clone());
              }
              if (valueExpr != null) {
                  x.setValueExpr(valueExpr.clone());
              }
              return x;
          }
  
          @Override
          public boolean replace(SQLExpr expr, SQLExpr target) {
              if (valueExpr == expr) {
                  setValueExpr(target);
                  return true;
              }
  
              if (conditionExpr == expr) {
                  setConditionExpr(target);
                  return true;
              }
  
              return false;
          }
      }
  
      @Override
      public int hashCode() {
          final int prime = 31;
          int result = 1;
          result = prime * result + ((elseExpr == null) ? 0 : elseExpr.hashCode());
          result = prime * result + items.hashCode();
          result = prime * result + ((valueExpr == null) ? 0 : valueExpr.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;
          }
          SQLCaseExpr other = (SQLCaseExpr) obj;
          if (elseExpr == null) {
              if (other.elseExpr != null) {
                  return false;
              }
          } else if (!elseExpr.equals(other.elseExpr)) {
              return false;
          }
          if (!items.equals(other.items)) {
              return false;
          }
          if (valueExpr == null) {
              if (other.valueExpr != null) {
                  return false;
              }
          } else if (!valueExpr.equals(other.valueExpr)) {
              return false;
          }
          return true;
      }
  
      public SQLCaseExpr clone() {
          SQLCaseExpr x = new SQLCaseExpr();
  
          for (Item item : items) {
              x.addItem(item.clone());
          }
  
          if (valueExpr != null) {
              x.setValueExpr(valueExpr.clone());
          }
  
          if (elseExpr != null) {
              x.setElseExpr(elseExpr.clone());
          }
  
          return x;
      }
  
      public SQLDataType computeDataType() {
          for (Item item : items) {
              SQLExpr expr = item.getValueExpr();
              if (expr != null) {
                  SQLDataType dataType = expr.computeDataType();
                  if (dataType != null) {
                      return dataType;
                  }
              }
          }
  
          if (elseExpr != null) {
              return elseExpr.computeDataType();
          }
  
          return null;
      }
  
      public String toString() {
          return SQLUtils.toSQLString(this, (DbType) null);
      }
  }
  