/*
 *  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.join;

import java.util.Arrays;

import com.rapidminer.example.ExampleSet;
import com.rapidminer.operator.Operator;
import com.rapidminer.operator.OperatorCreationException;
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.InputPort;
import com.rapidminer.operator.ports.OutputPort;
import com.rapidminer.operator.ports.metadata.ExampleSetUnionRule;
import com.rapidminer.tools.OperatorResourceConsumptionHandler;
import com.rapidminer.tools.OperatorService;

/**
 * This operator performs two steps: first, it build the union set / superset of features of both 
 * input example sets where common features are kept and both feature sets are extended in a way
 * that the feature sets are equal for both example sets. The second step then merges both example
 * sets and will deliver the resulting example set.
 * 
 * @author Ingo Mierswa
 */
public class ExampleSetUnion extends Operator {

	private InputPort exampleSet1Input = getInputPorts().createPort("example set 1", ExampleSet.class);
	private InputPort exampleSet2Input = getInputPorts().createPort("example set 2", ExampleSet.class);
	private OutputPort unionOutput = getOutputPorts().createPort("union");
	
	public ExampleSetUnion(OperatorDescription description) {
		super(description);
//		exampleSet1Input.addPrecondition(new ExampleSetPrecondition(exampleSet1Input, -1, Attributes.ID_NAME));
//		exampleSet2Input.addPrecondition(new ExampleSetPrecondition(exampleSet2Input, -1, Attributes.ID_NAME));
		getTransformer().addRule(new ExampleSetUnionRule(exampleSet1Input, exampleSet2Input, unionOutput, null));
	}

	@Override
	public void doWork() throws OperatorException {
		ExampleSet exampleSet1 = (ExampleSet) exampleSet1Input.getData(ExampleSet.class).clone();
		ExampleSet exampleSet2 = (ExampleSet) exampleSet2Input.getData(ExampleSet.class).clone();
		try {
			ExampleSetSuperset supersetOperator = OperatorService.createOperator(ExampleSetSuperset.class);
			supersetOperator.setParameter(ExampleSetSuperset.PARAMETER_INCLUDE_SPECIAL_ATTRIBUTES, "true");
			ExampleSetMerge mergeOperator = OperatorService.createOperator(ExampleSetMerge.class);
			
			supersetOperator.superset(exampleSet1, exampleSet2);
			unionOutput.deliver(mergeOperator.merge(Arrays.asList(new ExampleSet[] { exampleSet1, exampleSet2} )));
			
		} catch (OperatorCreationException e) {
			throw new UserError(this, 904, "inner operator", e.getMessage());
		}
	}
	
	@Override
	public ResourceConsumptionEstimator getResourceConsumptionEstimator() {
		return OperatorResourceConsumptionHandler.getResourceConsumptionEstimator(getInputPorts().getPortByIndex(0), ExampleSetUnion.class, null);
	}
}