package de.ugoe.cs.cpdp.dataprocessing;

import java.util.ArrayList;

import org.apache.commons.collections4.list.SetUniqueList;

import weka.core.Instances;

/**
 * Removes attributes from all data sets, except the one defined, using their name. 
 * @author Fabian Trautsch
 */
public class AttributeNonRemoval implements ISetWiseProcessingStrategy, IProcessesingStrategy {

	/**
	 * names of the attributes to be kept (determined by {@link #setParameter(String)}) 
	 */
	private ArrayList<String> attributeNames = new ArrayList<String>();
	
	/**
	 * Sets that attributes that will be kept. The string contains the blank-separated names of the attributes to be kept.
	 * <br><br>
	 * Note, that keeping of attributes with blanks is currently not supported!
	 * @param parameters string with the blank-separated attribute names
	 */
	@Override
	public void setParameter(String parameters) {
		if( parameters!=null ) {
			String[] attributeNamesArray = parameters.split(" ");
			for(String attributeName : attributeNamesArray) {
				attributeNames.add(attributeName);
			}
		}
	}

	/**
	 * @see de.ugoe.cs.cpdp.dataprocessing.SetWiseProcessingStrategy#apply(weka.core.Instances, org.apache.commons.collections4.list.SetUniqueList)
	 */
	@Override
	public void apply(Instances testdata, SetUniqueList<Instances> traindataSet) {
		for( String attributeName : attributeNames ) {
			for( int i=0 ; i<testdata.numAttributes() ; i++ ) {
				if(!attributeName.equals(testdata.attribute(i).name()) ) {
					testdata.deleteAttributeAt(i);
					for( Instances traindata : traindataSet ) {
						traindata.deleteAttributeAt(i);
					}
				}
			}
		}
	}

	/**
	 * @see de.ugoe.cs.cpdp.dataprocessing.ProcessesingStrategy#apply(weka.core.Instances, weka.core.Instances)
	 */
	@Override
	public void apply(Instances testdata, Instances traindata) {
		for(int i=testdata.numAttributes()-1; i>=0; i--) {
			if(!attributeNames.contains(testdata.attribute(i).name())) {
				testdata.deleteAttributeAt(i);
				traindata.deleteAttributeAt(i);
			}
		}
	}
}