/**
 * Alipay.com Inc.
 * Copyright (c) 2004-2012 All Rights Reserved.
 */
package com.alipay.zdal.parser.sql.ast.expr;

import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;

import com.alipay.zdal.parser.sql.ast.SQLExpr;
import com.alipay.zdal.parser.sql.ast.SQLExprImpl;
import com.alipay.zdal.parser.sql.visitor.SQLASTVisitor;

/**
 * 
 * @author xiaoqing.zhouxq
 * @version $Id: SQLAggregateExpr.java, v 0.1 2012-11-17 ����3:14:24 xiaoqing.zhouxq Exp $
 */
public class SQLAggregateExpr extends SQLExprImpl implements Serializable {

    private static final long     serialVersionUID = 1L;
    protected String              methodName;
    protected Option              option;
    protected final List<SQLExpr> arguments        = new ArrayList<SQLExpr>();

    public SQLAggregateExpr(String methodName) {

        this.methodName = methodName;
    }

    public SQLAggregateExpr(String methodName, Option option) {
        this.methodName = methodName;
        this.option = option;
    }

    public String getMethodName() {
        return this.methodName;
    }

    public void setMethodName(String methodName) {
        this.methodName = methodName;
    }

    public Option getOption() {
        return this.option;
    }

    public void setOption(Option option) {
        this.option = option;
    }

    public List<SQLExpr> getArguments() {
        return this.arguments;
    }

    public void output(StringBuffer buf) {
        buf.append(this.methodName);
        buf.append("(");
        int i = 0;
        for (int size = this.arguments.size(); i < size; ++i) {
            ((SQLExpr) this.arguments.get(i)).output(buf);
        }
        buf.append(")");
    }

    @Override
    protected void accept0(SQLASTVisitor visitor) {
        if (visitor.visit(this)) {
            acceptChild(visitor, this.arguments);
        }

        visitor.endVisit(this);
    }

    @Override
    public int hashCode() {
        final int prime = 31;
        int result = 1;
        result = prime * result + ((arguments == null) ? 0 : arguments.hashCode());
        result = prime * result + ((methodName == null) ? 0 : methodName.hashCode());
        result = prime * result + ((option == null) ? 0 : option.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;
        }
        SQLAggregateExpr other = (SQLAggregateExpr) obj;
        if (arguments == null) {
            if (other.arguments != null) {
                return false;
            }
        } else if (!arguments.equals(other.arguments)) {
            return false;
        }
        if (methodName == null) {
            if (other.methodName != null) {
                return false;
            }
        } else if (!methodName.equals(other.methodName)) {
            return false;
        }
        if (option != other.option) {
            return false;
        }
        return true;
    }

    public static enum Option {
        DISTINCT, ALL, UNIQUE
    }
}