/*
 * ConstantPopulationModel.java
 *
 * Copyright (C) 2002-2009 Alexei Drummond and Andrew Rambaut
 *
 * This file is part of BEAST.
 * See the NOTICE file distributed with this work for additional
 * information regarding copyright ownership and licensing.
 *
 * BEAST is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * BEAST 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
 * GNU Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with BEAST; if not, write to the
 * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
 * Boston, MA  02110-1301  USA
 */

package dr.evomodel.coalescent;

import dr.evolution.coalescent.ConstantPopulation;
import dr.evolution.coalescent.DemographicFunction;
import dr.evoxml.XMLUnits;
import dr.inference.model.Parameter;
import dr.xml.*;

/**
 * A wrapper for ConstantPopulation.
 *
 * @author Andrew Rambaut
 * @author Alexei Drummond
 * @version $Id: ConstantPopulationModel.java,v 1.10 2005/05/24 20:25:57 rambaut Exp $
 */
public class ConstantPopulationModel extends DemographicModel {
    //
    // Public stuff
    //

    public static String CONSTANT_POPULATION_MODEL = "constantSize";
    public static String POPULATION_SIZE = "populationSize";

    /**
     * Construct demographic model with default settings
     */
    public ConstantPopulationModel(Parameter N0Parameter, Type units) {

        this(CONSTANT_POPULATION_MODEL, N0Parameter, units);
    }

    /**
     * Construct demographic model with default settings
     */
    public ConstantPopulationModel(String name, Parameter N0Parameter, Type units) {

        super(name);

        constantPopulation = new ConstantPopulation(units);

        this.N0Parameter = N0Parameter;
        addVariable(N0Parameter);
        N0Parameter.addBounds(new Parameter.DefaultBounds(Double.POSITIVE_INFINITY, 0.0, 1));
        setUnits(units);
    }

    // general functions

    public DemographicFunction getDemographicFunction() {
        constantPopulation.setN0(N0Parameter.getParameterValue(0));
        return constantPopulation;
    }

    /**
     * Parses an element from an DOM document into a ConstantPopulation.
     */
    public static XMLObjectParser PARSER = new AbstractXMLObjectParser() {

        public String getParserName() {
            return CONSTANT_POPULATION_MODEL;
        }

        public Object parseXMLObject(XMLObject xo) throws XMLParseException {

            Type units = XMLUnits.Utils.getUnitsAttr(xo);

            XMLObject cxo = xo.getChild(POPULATION_SIZE);
            Parameter N0Param = (Parameter) cxo.getChild(Parameter.class);


            return new ConstantPopulationModel(N0Param, units);
        }


        //************************************************************************
        // AbstractXMLObjectParser implementation
        //************************************************************************

        public String getParserDescription() {
            return "A demographic model representing a constant population size through time.";
        }

        public Class getReturnType() {
            return ConstantPopulationModel.class;
        }

        public XMLSyntaxRule[] getSyntaxRules() {
            return rules;
        }

        private XMLSyntaxRule[] rules = new XMLSyntaxRule[]{
                XMLUnits.UNITS_RULE,
                new ElementRule(POPULATION_SIZE,
                        new XMLSyntaxRule[]{new ElementRule(Parameter.class)})
        };
    };


    //
    // protected stuff
    //

    private Parameter N0Parameter;
    private ConstantPopulation constantPopulation = null;
}
