/*
 *  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.preprocessing.filter.attributes;

import java.util.LinkedList;
import java.util.List;

import com.rapidminer.example.Attribute;
import com.rapidminer.example.set.ConditionCreationException;
import com.rapidminer.operator.Operator;
import com.rapidminer.operator.UserError;
import com.rapidminer.operator.ports.InputPort;
import com.rapidminer.operator.ports.metadata.AttributeMetaData;
import com.rapidminer.operator.ports.metadata.MetaDataInfo;
import com.rapidminer.parameter.ParameterHandler;
import com.rapidminer.parameter.ParameterType;
import com.rapidminer.parameter.ParameterTypeAttribute;


/**
 * @author Tobias Malbrecht
 */
public class SingleAttributeFilter extends AbstractAttributeFilterCondition {

	public static final String PARAMETER_ATTRIBUTE = "attribute";

	private String attributeName;

	@Override
	public void init(ParameterHandler operator) throws UserError, ConditionCreationException {
		attributeName = operator.getParameterAsString(PARAMETER_ATTRIBUTE);
		if ((attributeName == null) || (attributeName.length() == 0))
			throw new UserError((operator instanceof Operator) ? (Operator) operator: null, 904, "The condition for a single attribute needs a non-empty attribute parameter string.");
	}

	public MetaDataInfo isFilteredOutMetaData(AttributeMetaData attribute, ParameterHandler handler) throws ConditionCreationException {
		if ((attributeName == null) || (attributeName.length() == 0))
			throw new ConditionCreationException("The condition for a single attribute needs a non-empty attribute parameter string.");
		return attribute.getName().equals(attributeName) ? MetaDataInfo.NO: MetaDataInfo.YES;
	}

	public ScanResult beforeScanCheck(Attribute attribute) throws UserError {
		if (attribute.getName().equals(attributeName))
			return ScanResult.KEEP;
		else
			return ScanResult.REMOVE;
	}

	@Override
	public List<ParameterType> getParameterTypes(ParameterHandler operator, InputPort inPort, int...valueTypes) {
		List<ParameterType> types = new LinkedList<ParameterType>();
		ParameterType type = new ParameterTypeAttribute(PARAMETER_ATTRIBUTE, "The attribute which should be chosen.", inPort, true, valueTypes);
		type.setExpert(false);
		types.add(type);
		return types;
	}
}