package org.jbpm.internal.log;

import java.io.PrintWriter;
import java.io.StringWriter;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.HashMap;
import java.util.Map;
import java.util.logging.Formatter;
import java.util.logging.Level;
import java.util.logging.LogRecord;

public class LogFormatter extends Formatter {
  
  static final String NEWLINE = System.getProperty("line.separator");
  static final DateFormat dateTimeFormat = new SimpleDateFormat("HH:mm:ss,SSS");
  static final Map<Level, String> levels = new HashMap<Level, String>();
  private static Map<Integer, Integer> indentations = new HashMap<Integer, Integer>();

  
  static {
    levels.put(Level.ALL,     "ALL");
    levels.put(Level.CONFIG,  "CFG");
    levels.put(Level.FINE,    "FIN");
    levels.put(Level.FINER,   "FNR");
    levels.put(Level.FINEST,  "FST");
    levels.put(Level.INFO,    "INF");
    levels.put(Level.OFF,     "OFF");
    levels.put(Level.SEVERE,  "SEV");
    levels.put(Level.WARNING, "WRN");
  }

  public String format(LogRecord logRecord) {
    StringWriter msg = new StringWriter();
    if (logRecord.getThrown()!=null) {
      msg.append("### EXCEPTION ###########################################");
      msg.append(NEWLINE);
    }
    msg.append(dateTimeFormat.format(new Date()));
    msg.append(" ");
    msg.append(levels.get(logRecord.getLevel()));
    msg.append(" ");

    int threadId = logRecord.getThreadID();
    for (int i=0; i<getIndentation(threadId); i++) {
      msg.append("  ");
    }
    
    msg.append("| [");
    
    String loggerName = logRecord.getLoggerName();
    int dotIndex = loggerName.lastIndexOf('.');
    if (dotIndex!=-1) {
      loggerName = loggerName.substring(dotIndex+1);
    }
    msg.append(loggerName);
    
    msg.append("] ");
    
    msg.append(logRecord.getMessage());
    if (logRecord.getThrown()!=null) {
      msg.append(NEWLINE);
      logRecord.getThrown().printStackTrace(new PrintWriter(msg));
      msg.append("### EXCEPTION ###########################################");
    }
    msg.append(NEWLINE);
    return msg.toString();
  }

  private int getIndentation(int threadId) {
    Integer indentation = indentations.get(threadId);
    if (indentation==null) {
      indentation = indentations.size();
      indentations.put(threadId, indentation);
    }
    return indentation;
  }

  public static void resetIndentation() {
    indentations = new HashMap<Integer, Integer>();
  }
}