/*
 *  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;

import java.util.List;

import com.rapidminer.example.ExampleSet;
import com.rapidminer.example.set.Partition;
import com.rapidminer.example.set.SplittedExampleSet;
import com.rapidminer.operator.OperatorDescription;
import com.rapidminer.operator.OperatorException;
import com.rapidminer.operator.UserError;
import com.rapidminer.operator.annotation.ResourceConsumptionEstimator;
import com.rapidminer.operator.ports.metadata.ExampleSetMetaData;
import com.rapidminer.operator.ports.metadata.ExampleSetSizePrecondition;
import com.rapidminer.operator.ports.metadata.MetaData;
import com.rapidminer.operator.preprocessing.AbstractDataProcessing;
import com.rapidminer.parameter.ParameterType;
import com.rapidminer.parameter.ParameterTypeBoolean;
import com.rapidminer.parameter.ParameterTypeInt;
import com.rapidminer.parameter.UndefinedParameterError;
import com.rapidminer.tools.OperatorResourceConsumptionHandler;

/**
 * This operator keeps only the examples of a given range (including the borders). The other examples will be removed
 * from the input example set.
 * 
 * @author Ingo Mierswa
 */
public class ExampleRangeFilter extends AbstractDataProcessing {

	/** The parameter name for "The first example of the resulting example set." */
	public static final String PARAMETER_FIRST_EXAMPLE = "first_example";

	/** The parameter name for "The last example of the resulting example set." */
	public static final String PARAMETER_LAST_EXAMPLE = "last_example";

	public static final String PARAMETER_INVERT_FILTER = "invert_filter";

	public ExampleRangeFilter(OperatorDescription description) {
		super(description);

		getExampleSetInputPort().addPrecondition(new ExampleSetSizePrecondition(getExampleSetInputPort(), this, PARAMETER_FIRST_EXAMPLE, PARAMETER_LAST_EXAMPLE));
	}

	@Override
	protected MetaData modifyMetaData(ExampleSetMetaData metaData) throws UndefinedParameterError {
		if (metaData.getNumberOfExamples().isKnown()) {
			int difference = getParameterAsInt(PARAMETER_LAST_EXAMPLE) - getParameterAsInt(PARAMETER_FIRST_EXAMPLE);
			if (getParameterAsBoolean(PARAMETER_INVERT_FILTER))
				difference = metaData.getNumberOfExamples().getValue() - difference - 1;
			metaData.setNumberOfExamples(difference);
		}
		return metaData;
	}

	@Override
	public ExampleSet apply(ExampleSet exampleSet) throws OperatorException {
		int[] partition = new int[exampleSet.size()];
		int startIndex = getParameterAsInt(PARAMETER_FIRST_EXAMPLE);
		int endIndex = getParameterAsInt(PARAMETER_LAST_EXAMPLE);

		if (endIndex < startIndex)
			throw new UserError(this, 210, "last_example", "first_example");

		for (int i = 0; i < partition.length; i++) {
			if ((i >= startIndex - 1) && (i <= endIndex - 1)) {
				partition[i] = 0;
			} else {
				partition[i] = 1;
			}
		}

		SplittedExampleSet result = new SplittedExampleSet(exampleSet, new Partition(partition, 2));
		if (getParameterAsBoolean(PARAMETER_INVERT_FILTER))
			result.selectSingleSubset(1);
		else
			result.selectSingleSubset(0);

		return result;
	}

	@Override
	public List<ParameterType> getParameterTypes() {
		List<ParameterType> parameterTypes = super.getParameterTypes();
		parameterTypes.add(new ParameterTypeInt(PARAMETER_FIRST_EXAMPLE, "The first example of the resulting example set.", 1, Integer.MAX_VALUE, false));
		parameterTypes.add(new ParameterTypeInt(PARAMETER_LAST_EXAMPLE, "The last example of the resulting example set.", 1, Integer.MAX_VALUE, false));
		parameterTypes.add(new ParameterTypeBoolean(PARAMETER_INVERT_FILTER, "Indicates if the filter should be inverted.", false));
		return parameterTypes;
	}
	
	@Override
	public boolean writesIntoExistingData() {
		return false;
	}
	
	@Override
	public ResourceConsumptionEstimator getResourceConsumptionEstimator() {
		return OperatorResourceConsumptionHandler.getResourceConsumptionEstimator(getInputPort(), ExampleRangeFilter.class, null);
	}
}