/*
 ***************************************************************************************
 *  Copyright (C) 2006 EsperTech, Inc. All rights reserved.                            *
 *  http://www.espertech.com/esper                                                     *
 *  http://www.espertech.com                                                           *
 *  ---------------------------------------------------------------------------------- *
 *  The software in this package is published under the terms of the GPL license       *
 *  a copy of which has been included with this distribution in the license.txt file.  *
 ***************************************************************************************
 */
package com.espertech.esper.client.soda;

import java.io.StringWriter;

/**
 * Represents the "firstever" aggregation function.
 */
public class FirstEverProjectionExpression extends ExpressionBase {
    private static final long serialVersionUID = 4793677355945144559L;

    private boolean distinct;

    /**
     * Ctor.
     */
    public FirstEverProjectionExpression() {
    }

    /**
     * Ctor.
     *
     * @param isDistinct true for distinct
     */
    public FirstEverProjectionExpression(boolean isDistinct) {
        this.distinct = isDistinct;
    }

    /**
     * Ctor.
     *
     * @param expression to aggregate
     * @param isDistinct true for distinct
     */
    public FirstEverProjectionExpression(Expression expression, boolean isDistinct) {
        this.distinct = isDistinct;
        this.getChildren().add(expression);
    }

    public ExpressionPrecedenceEnum getPrecedence() {
        return ExpressionPrecedenceEnum.UNARY;
    }

    public void toPrecedenceFreeEPL(StringWriter writer) {
        ExpressionBase.renderAggregation(writer, "firstever", distinct, this.getChildren());
    }

    /**
     * Returns true for distinct.
     *
     * @return boolean indicating distinct or not
     */
    public boolean isDistinct() {
        return distinct;
    }

    /**
     * Returns true for distinct.
     *
     * @return boolean indicating distinct or not
     */
    public boolean getDistinct() {
        return distinct;
    }

    /**
     * Set to true for distinct.
     *
     * @param distinct indicating distinct or not
     */
    public void setDistinct(boolean distinct) {
        this.distinct = distinct;
    }
}