package de.ugoe.cs.cpdp.loader;

import java.io.File;
import java.io.IOException;
import java.util.ArrayList;

import weka.core.Attribute;
import weka.core.DenseInstance;
import weka.core.Instances;
import de.ugoe.cs.util.FileTools;

/**
 * Loads the instances for a software version from a CSV file of the PROMISE
 * data set mined by Jurezko and Madeyski.
 * 
 * @author Steffen Herbold
 */
class CSVDataLoader implements SingleVersionLoader {

	/*
	 * (non-Javadoc)
	 * 
	 * @see
	 * de.ugoe.cs.cpdp.loader.AbstractFolderLoader.SingleVersionLoader#load(
	 * java.io.File)
	 */
	@Override
	public Instances load(File file) {
		final String[] lines;
		try {
			lines = FileTools.getLinesFromFile(file.getAbsolutePath());
		} catch (IOException e) {
			throw new RuntimeException(e);
		}

		// configure Instances
		final ArrayList<Attribute> atts = new ArrayList<Attribute>();

		String[] lineSplit = lines[0].split(",");
		for (int j = 0; j < lineSplit.length - 4; j++) {
			atts.add(new Attribute(lineSplit[j + 3]));
		}
		final ArrayList<String> classAttVals = new ArrayList<String>();
		classAttVals.add("0");
		classAttVals.add("1");
		final Attribute classAtt = new Attribute("bug", classAttVals);
		atts.add(classAtt);

		final Instances data = new Instances(file.getName(), atts, 0);
		data.setClass(classAtt);

		// fetch data
		for (int i = 1; i < lines.length; i++) {
			lineSplit = lines[i].split(",");
			double[] values = new double[lineSplit.length - 3];
			for (int j = 0; j < values.length - 1; j++) {
				values[j] = Double.parseDouble(lineSplit[j + 3].trim());
			}
			values[values.length - 1] = lineSplit[lineSplit.length - 1].trim()
					.equals("0") ? 0 : 1;
			data.add(new DenseInstance(1.0, values));
		}

		return data;
	}

	/*
	 * (non-Javadoc)
	 * 
	 * @see de.ugoe.cs.cpdp.loader.AbstractFolderLoader.SingleVersionLoader#
	 * filenameFilter(java.lang.String)
	 */
	@Override
	public boolean filenameFilter(String filename) {
		return filename.endsWith(".csv");
	}

}