/*
 *  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.parameter;

import org.w3c.dom.Element;

import com.rapidminer.io.process.XMLTools;
import com.rapidminer.tools.XMLException;

/**
 * A parameter type for categories. These are several Strings and one of these
 * is the default value. Operators ask for the index of the selected value with
 * {@link com.rapidminer.operator.Operator#getParameterAsInt(String)}.
 * 
 * @author Ingo Mierswa, Simon Fischer
 */
public class ParameterTypeCategory extends ParameterTypeSingle {

    private static final long serialVersionUID = 5747692587025691591L;

    private static final String ATTRIBUTE_DEFAULT = "default";

    private static final String ELEMENT_VALUES = "Values";

    private static final String ELEMENT_VALUE = "Value";

    private int defaultValue = 0;

    private String[] categories = new String[0];

    public ParameterTypeCategory(Element element) throws XMLException {
        super(element);

        defaultValue = Integer.parseInt(element.getAttribute(ATTRIBUTE_DEFAULT));
        categories = XMLTools.getChildTagsContentAsStringArray(XMLTools.getChildElement(element, ELEMENT_VALUES, true), ELEMENT_VALUE);
    }

    public ParameterTypeCategory(String key, String description, String[] categories, int defaultValue, boolean expert) {
        this(key, description, categories, defaultValue);
        setExpert(expert);
    }

    public ParameterTypeCategory(String key, String description, String[] categories, int defaultValue) {
        super(key, description);
        this.categories = categories;
        this.defaultValue = defaultValue;
    }

    public int getDefault() {
        return defaultValue;
    }

    @Override
    public Object getDefaultValue() {
        if (defaultValue == -1) {
            return null;
        } else {
            return categories[defaultValue];
        }
    }

    @Override
    public void setDefaultValue(Object defaultValue) {
        this.defaultValue = (Integer) defaultValue;
    }

    /** Returns false. */
    @Override
    public boolean isNumerical() {
        return false;
    }

    public String getCategory(int index) {
        return categories[index];
    }

    public int getIndex(String string) {
        for (int i = 0; i < categories.length; i++) {
            if (categories[i].equals(string)) {
                return Integer.valueOf(i);
            }
        }
        // try to interpret string as number
        try {
            return Integer.parseInt(string);
        } catch (NumberFormatException e) {
            return -1;
        }
    }

    @Override
    public String toString(Object value) {
        try {
            if (value == null)
                return null;
            int index = Integer.parseInt(value.toString());
            if (index >= categories.length)
                return "";
            return super.toString(categories[index]);
        } catch (NumberFormatException e) {
            return super.toString(value);
        }
    }

    public String[] getValues() {
        return categories;
    }

    @Override
    public String getRange() {
        StringBuffer values = new StringBuffer();
        for (int i = 0; i < categories.length; i++) {
            if (i > 0)
                values.append(", ");
            values.append(categories[i]);
        }
        return values.toString() + "; default: " + categories[defaultValue];
    }

    public int getNumberOfCategories() {
        return categories.length;
    }

    @Override
    protected void writeDefinitionToXML(Element typeElement) {
        typeElement.setAttribute(ATTRIBUTE_DEFAULT, defaultValue + "");

        Element valuesElement = XMLTools.addTag(typeElement, ELEMENT_VALUES);
        for (String category : categories) {
            XMLTools.addTag(valuesElement, ELEMENT_VALUE, category);
        }
    }
}