/*
 *  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.normalization;

import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.List;

import com.rapidminer.example.ExampleSet;
import com.rapidminer.operator.OperatorDescription;
import com.rapidminer.operator.OperatorException;
import com.rapidminer.operator.annotation.ResourceConsumptionEstimator;
import com.rapidminer.operator.ports.metadata.AttributeMetaData;
import com.rapidminer.operator.ports.metadata.ExampleSetMetaData;
import com.rapidminer.operator.preprocessing.PreprocessingModel;
import com.rapidminer.operator.preprocessing.PreprocessingOperator;
import com.rapidminer.parameter.ParameterType;
import com.rapidminer.parameter.ParameterTypeCategory;
import com.rapidminer.parameter.UndefinedParameterError;
import com.rapidminer.parameter.conditions.EqualTypeCondition;
import com.rapidminer.tools.Ontology;
import com.rapidminer.tools.OperatorResourceConsumptionHandler;


/**
 * This operator performs a normalization. This can be done between a user
 * defined minimum and maximum value or by a z-transformation, i.e. on mean 0
 * and variance 1. or by a proportional transformation as proportion of the total sum
 * of the respective attribute.
 * 
 * @author Ingo Mierswa, Sebastian Land
 */
public class Normalization extends PreprocessingOperator {

	private static final ArrayList<NormalizationMethod> METHODS = new ArrayList<NormalizationMethod>();
	
	static {
		registerNormalizationMethod(new ZTransformationNormalizationMethod());
		registerNormalizationMethod(new RangeNormalizationMethod());
		registerNormalizationMethod(new ProportionNormalizationMethod());
		registerNormalizationMethod(new IQRNormalizationMethod());
	}
	
	/**
	 * This must not be modified outside this class!
	 */
	public static String[] NORMALIZATION_METHODS;

	public static final int METHOD_Z_TRANSFORMATION = 0;

	public static final int METHOD_RANGE_TRANSFORMATION = 1;

	public static final int METHOD_PROPORTION_TRANSFORMATION = 2;

	public static final String PARAMETER_NORMALIZATION_METHOD = "method";


	/** Creates a new Normalization operator. */
	public Normalization(OperatorDescription description) {
		super(description);
	}

	@Override
	protected Collection<AttributeMetaData> modifyAttributeMetaData(ExampleSetMetaData emd, AttributeMetaData amd) throws UndefinedParameterError {
		if (amd.isNumerical()) {
			amd.setType(Ontology.REAL);
			int method = getParameterAsInt(PARAMETER_NORMALIZATION_METHOD);
			NormalizationMethod normalizationMethod = METHODS.get(method);
			return normalizationMethod.modifyAttributeMetaData(emd, amd, getExampleSetInputPort(), this);
		}
		return Collections.singleton(amd);
	}

	@Override
	public PreprocessingModel createPreprocessingModel(ExampleSet exampleSet) throws OperatorException {
		int method = getParameterAsInt(PARAMETER_NORMALIZATION_METHOD);
		NormalizationMethod normalizationMethod = METHODS.get(method);
		normalizationMethod.init();
		return normalizationMethod.getNormalizationModel(exampleSet, this);
	}

	@Override
	public Class<? extends PreprocessingModel> getPreprocessingModelClass() {
		return AbstractNormalizationModel.class;
	}
	
	/** Returns a list with all parameter types of this model. */
	@Override
	public List<ParameterType> getParameterTypes() {
		List<ParameterType> types = super.getParameterTypes();
		types.add(new ParameterTypeCategory(PARAMETER_NORMALIZATION_METHOD, "Select the normalization method.", NORMALIZATION_METHODS, 0));
		int i = 0; 
		for (NormalizationMethod method: METHODS) {
			for (ParameterType type: method.getParameterTypes(this)) {
				type.registerDependencyCondition(new EqualTypeCondition(this, PARAMETER_NORMALIZATION_METHOD, NORMALIZATION_METHODS, true, new int[] {i}));
				types.add(type);
			}
			i++;
		}
		return types;
	}


	@Override
	protected int[] getFilterValueTypes() {
		return new int[] { Ontology.NUMERICAL };
	}
	
	@Override
	public ResourceConsumptionEstimator getResourceConsumptionEstimator() {
		return OperatorResourceConsumptionHandler.getResourceConsumptionEstimator(getInputPort(), Normalization.class, attributeSelector);
	}
	
	/**
	 * This method can be used for registering additional normalization methods.
	 */
	public static void registerNormalizationMethod(NormalizationMethod newMethod) {
		METHODS.add(newMethod);
		NORMALIZATION_METHODS = new String[METHODS.size()];
		int i = 0;
		for (NormalizationMethod method: METHODS) {
			NORMALIZATION_METHODS[i] = method.getName();
			i++;
		}
	}

}