///////////////////////////////////////////////////////////////////////////////
// For information as to what this class does, see the Javadoc, below.       //
// Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006,       //
// 2007, 2008, 2009, 2010, 2014, 2015 by Peter Spirtes, Richard Scheines, Joseph   //
// Ramsey, and Clark Glymour.                                                //
//                                                                           //
// This program is free software; you can redistribute it and/or modify      //
// it under the terms of the GNU General Public License as published by      //
// the Free Software Foundation; either version 2 of the License, or         //
// (at your option) any later version.                                       //
//                                                                           //
// 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             //
// GNU General Public License for more details.                              //
//                                                                           //
// You should have received a copy of the GNU General Public License         //
// along with this program; if not, write to the Free Software               //
// Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA //
///////////////////////////////////////////////////////////////////////////////

package edu.cmu.tetrad.data;

import edu.cmu.tetrad.util.TetradSerializable;

import java.io.IOException;
import java.io.ObjectInputStream;
import java.util.ArrayList;
import java.util.List;

/**
 * Specifies how a column (continuous or discrete) should be discretized. For a
 * discrete column the mapping is int[] remap; for a continuous column the
 * mapping is double[] cutoffs. The categories are the string labels for the
 * categories. This is just a small immutable class that columns can map to in
 * order to remember how discretizations were done so that the user doesn't have
 * to keep typing in information over and over again.
 *
 * @author Joseph Ramsey
 */
public final class ContinuousDiscretizationSpec implements TetradSerializable, DiscretizationSpec {
    static final long serialVersionUID = 23L;

    /**
     * Breakpoints, for continuous data.
     *
     * @serial
     */
    private final double[] breakpoints;

    /**
     * @serial
     */
    private final List<String> categories;


    /**
     * The method used.
     */
    private int method;


    /**
     * The types of discretization
     */
    public static final int EVENLY_DISTRIBUTED_VALUES = 1;
    public static final int EVENLY_DISTRIBUTED_INTERVALS = 2;
    public static final int NONE = 3;

    //============================CONSTRUCTORS==========================//

    public ContinuousDiscretizationSpec(double[] breakpoints, List<String> categories) {
        this(breakpoints, categories, EVENLY_DISTRIBUTED_INTERVALS);
    }


    @SuppressWarnings({"SameParameterValue"})
    public ContinuousDiscretizationSpec(double[] breakpoints, List<String> categories, int method) {
        if (breakpoints == null) {
            throw new NullPointerException();
        }
        if (method != EVENLY_DISTRIBUTED_VALUES && method != EVENLY_DISTRIBUTED_INTERVALS && method != NONE) {
            throw new IllegalArgumentException();
        }
        this.breakpoints = breakpoints;
        this.categories = categories;
        this.method = method;
    }


    /**
     * Generates a simple exemplar of this class to test serialization.
     */
    @SuppressWarnings({"ZeroLengthArrayAllocation"})
    public static DiscretizationSpec serializableInstance() {
        return new ContinuousDiscretizationSpec(new double[0], new ArrayList<String>());
    }

    //============================PUBLIC METHODS========================//


    public int getMethod() {
        return this.method;
    }

    public void setMethod(int method) {
        if (method != EVENLY_DISTRIBUTED_VALUES && method != EVENLY_DISTRIBUTED_INTERVALS && method != NONE) {
            throw new IllegalArgumentException();
        }
        this.method = method;
    }

    public List<String> getCategories() {
        return categories;
    }

    public double[] getBreakpoints() {
        return breakpoints;
    }

    /**
     * Adds semantic checks to the default deserialization method. This method
     * must have the standard signature for a readObject method, and the body of
     * the method must begin with "s.defaultReadObject();". Other than that, any
     * semantic checks can be specified and do not need to stay the same from
     * version to version. A readObject method of this form may be added to any
     * class, even if Tetrad sessions were previously saved out using a version
     * of the class that didn't include it. (That's what the
     * "s.defaultReadObject();" is for. See J. Bloch, Effective Java, for help.
     *
     * @throws java.io.IOException
     * @throws ClassNotFoundException
     */
    private void readObject(ObjectInputStream s)
            throws IOException, ClassNotFoundException {
        s.defaultReadObject();

        if (breakpoints == null) {
            throw new NullPointerException();
        }

        if (categories == null) {
            throw new NullPointerException();
        }

        if (method != EVENLY_DISTRIBUTED_VALUES && method != EVENLY_DISTRIBUTED_INTERVALS) {
            this.method = EVENLY_DISTRIBUTED_INTERVALS;
        }
    }
}