/*
 *  RapidMiner
 *
 *  Copyright (C) 2001-2008 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.preprocessing.filter;

import java.util.List;

import com.rapidminer.example.Attribute;
import com.rapidminer.example.AttributeRole;
import com.rapidminer.operator.OperatorDescription;
import com.rapidminer.operator.OperatorException;
import com.rapidminer.parameter.ParameterType;
import com.rapidminer.parameter.ParameterTypeCategory;
import com.rapidminer.tools.Ontology;


/**
 * This operator switches off all features whose value type matches the one
 * given in the parameter <code>skip_features_of_type</code>. This can be
 * useful e.g. for learning schemes that can handle only nominal attributes.
 * 
 * @author Buelent Moeller, Ingo Mierswa
 * @version $Id: FeatureValueTypeFilter.java,v 1.7 2006/04/05 08:57:27
 *          ingomierswa Exp $
 */
public class FeatureValueTypeFilter extends FeatureFilter {

	/** The parameter name for "All features of this type will be deselected." */
	public static final String PARAMETER_SKIP_FEATURES_OF_TYPE = "skip_features_of_type";

	/** The parameter name for "All features of this type will not be deselected." */
	public static final String PARAMETER_EXCEPT_FEATURES_OF_TYPE = "except_features_of_type";
	
	public FeatureValueTypeFilter(OperatorDescription description) {
		super(description);
	}

	/**
	 * Implements the method required by the superclass. For features whose type
	 * is a subtype of the one given as a parameter for this operator, TRUE is
	 * returned (otherwise FALSE). If no parameter was provided, FALSE is always
	 * returned, so no feature is switched off.
	 * 
	 * @param role
	 *            Feature to check.
	 * @return TRUE if this feature should <b>not</b> be active in the output
	 *         example set of this operator. FALSE otherwise.
	 */
	public boolean switchOffFeature(AttributeRole role) throws OperatorException {
		Attribute feature = role.getAttribute();
		
        // first type (most general) was omitted in parameters 
		int type = getParameterAsInt(PARAMETER_SKIP_FEATURES_OF_TYPE) + 1;
        
        int exceptionType = getParameterAsInt(PARAMETER_EXCEPT_FEATURES_OF_TYPE);
        if (exceptionType == 0) {
            return Ontology.ATTRIBUTE_VALUE_TYPE.isA(feature.getValueType(), type);
        } else {
            return 
                Ontology.ATTRIBUTE_VALUE_TYPE.isA(feature.getValueType(), type) &&
                !Ontology.ATTRIBUTE_VALUE_TYPE.isA(feature.getValueType(), exceptionType);
        }
	}

	public List<ParameterType> getParameterTypes() {
		List<ParameterType> types = super.getParameterTypes();
        // omitt first (most general) type
		String[] valueTypes = new String[Ontology.VALUE_TYPE_NAMES.length - 1];
		for (int i = 0; i < valueTypes.length; i++)
			valueTypes[i] = Ontology.VALUE_TYPE_NAMES[i + 1];
		ParameterType type = new ParameterTypeCategory(PARAMETER_SKIP_FEATURES_OF_TYPE, "All features of this type will be deselected.", valueTypes, 0);
		type.setExpert(false);
		types.add(type);
        
        String[] exceptionValueTypes = new String[valueTypes.length + 1];
        exceptionValueTypes[0] = "none";
        System.arraycopy(valueTypes, 0, exceptionValueTypes, 1, valueTypes.length);
        types.add(new ParameterTypeCategory(PARAMETER_EXCEPT_FEATURES_OF_TYPE, "All features of this type will not be deselected.", exceptionValueTypes, 0));
		return types;
	}
}