/*
 * 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 2011-1-19)
 */
package com.alibaba.cobar.parser.ast.expression.comparison;

import com.alibaba.cobar.parser.ast.expression.BinaryOperatorExpression;
import com.alibaba.cobar.parser.ast.expression.Expression;
import com.alibaba.cobar.parser.ast.expression.ReplacableExpression;
import com.alibaba.cobar.parser.ast.expression.misc.InExpressionList;
import com.alibaba.cobar.parser.ast.expression.misc.QueryExpression;
import com.alibaba.cobar.parser.visitor.SQLASTVisitor;

/**
 * <code>higherPreExpr (NOT)? IN ( '(' expr (',' expr)* ')' | subquery )</code>
 * 
 * @author <a href="mailto:shuo.qius@alibaba-inc.com">QIU Shuo</a>
 */
public class InExpression extends BinaryOperatorExpression implements ReplacableExpression {
    private final boolean not;

    /**
     * @param rightOprand {@link QueryExpression} or {@link InExpressionList}
     */
    public InExpression(boolean not, Expression leftOprand, Expression rightOprand) {
        super(leftOprand, rightOprand, PRECEDENCE_COMPARISION);
        this.not = not;
    }

    public boolean isNot() {
        return not;
    }

    public InExpressionList getInExpressionList() {
        if (rightOprand instanceof InExpressionList) {
            return (InExpressionList) rightOprand;
        }
        return null;
    }

    public QueryExpression getQueryExpression() {
        if (rightOprand instanceof QueryExpression) {
            return (QueryExpression) rightOprand;
        }
        return null;
    }

    @Override
    public String getOperator() {
        return not ? "NOT IN" : "IN";
    }

    private Expression replaceExpr;

    @Override
    public void setReplaceExpr(Expression replaceExpr) {
        this.replaceExpr = replaceExpr;
    }

    @Override
    public void clearReplaceExpr() {
        this.replaceExpr = null;
    }

    @Override
    public void accept(SQLASTVisitor visitor) {
        if (replaceExpr == null)
            visitor.visit(this);
        else
            replaceExpr.accept(visitor);
    }
}