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/*
 *  streams library
 *
 *  Copyright (C) 2011-2014 by Christian Bockermann, Hendrik Blom
 * 
 *  streams is a library, API and runtime environment for processing high
 *  volume data streams. It is composed of three submodules "stream-api",
 *  "stream-core" and "stream-runtime".
 *
 *  The streams library (and its submodules) 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.
 *
 *  The stream.ai library (and its submodules) 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 stream.io;

import java.io.File;
import java.io.FileOutputStream;
import java.io.OutputStream;
import java.io.PrintStream;
import java.io.Serializable;
import java.util.HashMap;
import java.util.Map;

import stream.Data;
import stream.data.DataUtils;

/**
 * 
 * @author Christian Bockermann <[email protected]>
 * @deprecated
 */
public class SvmLightWriter extends CsvWriter {

	/*
	 * This map provides a mapping of features to indexes features with a
	 * numeric (integer) name will be mapped to their value directly
	 */
	Map indexes = new HashMap();
	Integer largestIndex = 0;
	boolean includeAnnotations = true;

	public SvmLightWriter() {
	}

	public SvmLightWriter(OutputStream out) {
		super(out);
	}

	@Override
	public void writeHeader(Data datum) {
	}

	@Override
	public void write(Data datum) {

		Serializable label = datum.get("@label");
		if (label == null) {
			log.error("SvmLightStreamWriter does only support writing labeled data!");
			log.error("Skipping datum {}", datum);
			return;
		}

		p.print(label);

		StringBuffer annotation = new StringBuffer();

		for (String key : DataUtils.getKeys(datum)) {

			try {
				Double value = new Double(datum.get(key).toString());
				p.print(" ");
				Integer index = -1;
				if (key.matches("\\d+")) {
					index = new Integer(key);
				} else {
					index = this.indexes.get(key);
					if (index == null) {
						index = largestIndex + 1;
						indexes.put(key, index);
					}
				}

				if (largestIndex < index)
					largestIndex = index;

				p.print(index);
				p.print(":");
				p.print(value);
			} catch (Exception e) {
				log.debug("Skipping non-numerical feature '{}'", key);
				annotation.append(" ");
				annotation.append(key);
				annotation.append(":'");
				annotation.append(lineEscape(datum.get(key)));
				annotation.append("'");
			}
		}
		if (includeAnnotations && annotation.length() > 0) {
			p.print(" #");
			p.print(annotation.toString());
		}

		p.println();
	}

	/**
	 * @return the includeAnnotations
	 */
	public boolean isIncludeAnnotations() {
		return includeAnnotations;
	}

	/**
	 * @param includeAnnotations
	 *            the includeAnnotations to set
	 */
	public void setIncludeAnnotations(boolean includeAnnotations) {
		this.includeAnnotations = includeAnnotations;
	}

	protected String lineEscape(Serializable val) {
		if (val == null)
			return "";

		String str = val.toString();
		return str.replaceAll("'", ",").replaceAll("\\n", " ");
	}

	public void printMapping(File file) throws Exception {
		FileOutputStream fos = new FileOutputStream(file);
		printMapping(fos);
		fos.close();
	}

	public void printMapping(OutputStream out) {
		PrintStream p = new PrintStream(out);
		p.println("#feature,index");
		for (String key : indexes.keySet()) {
			p.println(key + "," + indexes.get(key));
		}
		p.flush();
		p.close();
	}
}