/*
 *  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.ports.metadata;

import com.rapidminer.example.ExampleSet;
import com.rapidminer.operator.ProcessSetupError.Severity;
import com.rapidminer.operator.ports.InputPort;
import com.rapidminer.parameter.ParameterHandler;
import com.rapidminer.parameter.UndefinedParameterError;
import com.rapidminer.tools.Ontology;
import com.rapidminer.tools.math.similarity.DistanceMeasures;

/**
 * This precondition must be added to the exampleset input port, if a distance measure might be chosen by the user. It
 * will check if the example set contains only compatible values.
 * 
 * @author Sebastian Land
 */
public class DistanceMeasurePrecondition extends AbstractPrecondition {

	private ParameterHandler parameterHandler;

	public DistanceMeasurePrecondition(InputPort inputPort, ParameterHandler handler) {
		super(inputPort);
		this.parameterHandler = handler;
	}

	@Override
	public void check(MetaData metaData) {
		if (metaData instanceof ExampleSetMetaData) {
			ExampleSetMetaData emd = (ExampleSetMetaData) metaData;
			try {
				switch (this.parameterHandler.getParameterAsInt(DistanceMeasures.PARAMETER_MEASURE_TYPES)) {
				case DistanceMeasures.NOMINAL_MEASURES_TYPE:
					if (!containsOnlyType(emd, Ontology.NOMINAL, false)) {
						createError(Severity.ERROR, "measures.nominal", parameterHandler.getParameterAsString(DistanceMeasures.PARAMETER_NOMINAL_MEASURE));
					}
					break;
				case DistanceMeasures.NUMERICAL_MEASURES_TYPE:
					if (!containsOnlyType(emd, Ontology.NUMERICAL, false)) {
						createError(Severity.ERROR, "measures.numerical", parameterHandler.getParameterAsString(DistanceMeasures.PARAMETER_NUMERICAL_MEASURE));
					}
					break;
				case DistanceMeasures.DIVERGENCES_TYPE:
					if (!containsOnlyType(emd, Ontology.NUMERICAL, false)) {
						createError(Severity.ERROR, "measures.numerical", parameterHandler.getParameterAsString(DistanceMeasures.PARAMETER_DIVERGENCE));
					}
					break;
				}
			} catch (UndefinedParameterError e) {
			}
		}
	}

	private boolean containsOnlyType(ExampleSetMetaData emd, int type, boolean includeSpecial) {
		for (AttributeMetaData amd : emd.getAllAttributes()) {
			if (!amd.isSpecial() || includeSpecial) {
				if (!Ontology.ATTRIBUTE_VALUE_TYPE.isA(amd.getValueType(), type))
					return false;
			}
		}
		return true;
	}

	@Override
	public void assumeSatisfied() {
		getInputPort().receiveMD(new ExampleSetMetaData());
	}

	@Override
	public String getDescription() {
		return "<em>expects:</em> ExampleSet";
	}

	@Override
	public boolean isCompatible(MetaData input, CompatibilityLevel level) {
		return ExampleSet.class.isAssignableFrom(input.getObjectClass());
	}

	@Override
	public MetaData getExpectedMetaData() {
		return new ExampleSetMetaData();
	}

}