package com.randomnoun.common.log4j2;
   
   import java.io.IOException;
   import java.io.InputStreamReader;
   import java.io.OutputStream;
   import java.io.PipedInputStream;
   import java.io.PipedOutputStream;
   import java.nio.charset.Charset;
   
  import org.apache.logging.log4j.Logger;
  
  /** An outputstream that writes to a log4j Logger.
   * 
   * Lines are terminated by CRLF or LF. 
   *
   * @author knoxg
   */
  public class LoggingOutputStream extends OutputStream {
  	Logger logger;
  	StringBuffer line = new StringBuffer();
  	PipedOutputStream pos;
  	PipedInputStream pis;
  	InputStreamReader isr;
  	boolean wasCr; // last character was a CR (to convert CRLFs)
  	
  	public LoggingOutputStream(Logger logger, Charset charset) throws IOException {
  		this.logger = logger;
  		this.pos = new PipedOutputStream();
  		this.pis = new PipedInputStream(pos);
  		this.isr = new InputStreamReader(pis, charset);
  	}
  	public LoggingOutputStream(Logger logger, String charsetName) throws IOException {
  		this(logger, Charset.forName(charsetName));
  	}
  	public LoggingOutputStream(Logger logger) throws IOException {
  		this(logger, Charset.defaultCharset());
  	}
  	
  	@Override
  	public void write(int b) throws IOException {
  		pos.write(b);
  		int ch = isr.read();
  		if (ch == -1) {
  			// EOF
  		} else if (ch == 13) { // \r
  			logger.info(line); line.setLength(0);
  			wasCr = true;
  		} else if (ch == 10) { // \n
  			if (!wasCr) {
  				logger.info(line); line.setLength(0);
  			}
  			wasCr = false;
  		} else { 
  			line.append((char) b);
  			wasCr = false;
  		}
  	}
  }