/*
 Copyright (C) 2007 Richard Gomes

 This source code is release under the BSD License.

 This file is part of JQuantLib, a free-software/open-source library
 for financial quantitative analysts and developers - http://jquantlib.org/

 JQuantLib is free software: you can redistribute it and/or modify it
 under the terms of the JQuantLib license.  You should have received a
 copy of the license along with this program; if not, please email
 . The license is also available online at
 .

 This program is distributed in the hope that it will be useful, but WITHOUT
 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 FOR A PARTICULAR PURPOSE.  See the license for more details.

 JQuantLib is based on QuantLib. http://quantlib.org/
 When applicable, the original copyright notice follows this notice.
 */

/*
 Copyright (C) 2003, 2006 Ferdinando Ametrano
 Copyright (C) 2006 StatPro Italia srl

 This file is part of QuantLib, a free-software/open-source library
 for financial quantitative analysts and developers - http://quantlib.org/

 QuantLib is free software: you can redistribute it and/or modify it
 under the terms of the QuantLib license.  You should have received a
 copy of the license along with this program; if not, please email
 . The license is also available online at
 .

 This program is distributed in the hope that it will be useful, but WITHOUT
 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
 FOR A PARTICULAR PURPOSE.  See the license for more details.
 */

package org.jquantlib.instruments;

import org.jquantlib.lang.exceptions.LibraryException;
import org.jquantlib.util.PolymorphicVisitable;
import org.jquantlib.util.PolymorphicVisitor;
import org.jquantlib.util.Visitor;

/**
 * Abstract base class for option payoffs
 *
 * @author Richard Gomes
 */
public abstract class Payoff implements PolymorphicVisitable {

    //
    // protected static final
    //

    /**
	 * This protected constant is declared for convenience of extended classes
	 */
    protected static final String UNKNOWN_OPTION_TYPE = "unknown option type";


    //
    // public abstract methods
    //

    /**
     * @warning This method is used for output and comparison between payoffs.
     * It is not meant to be used for writing switch-on-type code.
     */
    public abstract String name() /* @ReadOnly */ ;

    public abstract String description() /* @ReadOnly */ ;

    /**
     * Returns the value of an {@link Instrument} at maturity under {@link Payoff} conditions
     */
    public abstract double get(double price) /* @ReadOnly */;


    //
    // overrides Object
    //

    @Override
    public String toString() {
        return description();
    }


	//
	// implements PolymorphicVisitable
	//

	@Override
	public void accept(final PolymorphicVisitor pv) {
		final Visitor v = (pv!=null) ? pv.visitor(this.getClass()) : null;
        if (v != null) {
            v.visit(this);
        } else {
            throw new LibraryException("null payoff visitor"); // TODO: message
        }
	}

}