/*
 *  RapidMiner
 *
 *  Copyright (C) 2001-2011 by Rapid-I and the contributors
 *
 *  Complete list of developers available at our web site:
 *
 *       http://rapid-i.com
 *
 *  This program is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU Affero General Public License as published by
 *  the Free Software Foundation, either version 3 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 Affero General Public License for more details.
 *
 *  You should have received a copy of the GNU Affero General Public License
 *  along with this program.  If not, see http://www.gnu.org/licenses/.
 */
package com.rapidminer.operator.features.transformation;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;

import com.rapidminer.example.Attribute;
import com.rapidminer.example.AttributeRole;
import com.rapidminer.example.Attributes;
import com.rapidminer.example.Example;
import com.rapidminer.example.ExampleSet;
import com.rapidminer.example.table.AttributeFactory;
import com.rapidminer.example.table.DataRow;
import com.rapidminer.example.table.DoubleArrayDataRow;
import com.rapidminer.example.table.MemoryExampleTable;
import com.rapidminer.operator.AbstractModel;
import com.rapidminer.operator.OperatorException;
import com.rapidminer.tools.Ontology;

/**
 * This class is completely unnecessary and is only kept for compatibility reasons.
 * The class hierarchy is complete nonsense and will be dropped with one of the next
 * versions. So if you implement using this class, please implement this little code fragment
 * below again or build a more fitting class hierarchy.
 * 
 * The model for the generic dimensionality reducer.
 * 
 * @author Ingo Mierswa
 */
@Deprecated
public class DimensionalityReducerModel extends AbstractModel {

    private static final long serialVersionUID = 1036161585615738268L;

    private int dimensions;

    private double[][] p;

    protected DimensionalityReducerModel(ExampleSet exampleSet, double[][] p, int dimensions) {
        super(exampleSet);
        this.p = p;
        this.dimensions = dimensions;
    }

    @Override
    public ExampleSet apply(ExampleSet exampleSet) throws OperatorException {
        List<Attribute> attributes = new ArrayList<Attribute>();
        for (int i = 0; i < dimensions; i++) {
            Attribute att = AttributeFactory.createAttribute("d" + i, Ontology.REAL);
            attributes.add(att);
        }

        Map<String, Attribute> newSpecialAttributes = new HashMap<String, Attribute>();
        Map<String, Attribute> oldSpecialAttributes = new HashMap<String, Attribute>();
        Iterator<AttributeRole> s = exampleSet.getAttributes().specialAttributes();
        while (s.hasNext()) {
            AttributeRole role = s.next();
            Attribute att = AttributeFactory.createAttribute(role.getAttribute());
            newSpecialAttributes.put(role.getSpecialName(), att);
            oldSpecialAttributes.put(role.getSpecialName(), role.getAttribute());
            attributes.add(att);
        }
        MemoryExampleTable table = new MemoryExampleTable(attributes);

        // Apply build the instances
        int i = 0;
        for (Example oldExample : exampleSet) {
            DataRow row = new DoubleArrayDataRow(new double[attributes.size()]);
            for (int j = 0; j < dimensions; j++)
                row.set(attributes.get(j), p[i][j]);

            for (String specialAttributeRole: newSpecialAttributes.keySet()) {
                Attribute attribute = newSpecialAttributes.get(specialAttributeRole);
                row.set(attribute, oldExample.getValue(oldSpecialAttributes.get(specialAttributeRole)));
            }

            table.addDataRow(row);
            i++;
        }

        ExampleSet resultSet = table.createExampleSet();
        // set special roles
        Attributes newAttributes = resultSet.getAttributes();
        for (Entry<String, Attribute> specialEntry: newSpecialAttributes.entrySet()) {
            newAttributes.setSpecialAttribute(specialEntry.getValue(), specialEntry.getKey());
        }

        return resultSet;
    }

    @Override
    public String getName() {
        return "Dimensionality Reduction";
    }

    @Override
    public String toString() {
        return "This model reduces the number of dimensions to " + dimensions + ".";
    }
}