/**
    * Logback: the reliable, generic, fast and flexible logging framework.
    * Copyright (C) 1999-2011, QOS.ch. All rights reserved.
    *
    * This program and the accompanying materials are dual-licensed under
    * either the terms of the Eclipse Public License v1.0 as published by
    * the Eclipse Foundation
    *
    *   or (per the licensee's choosing)
   *
   * under the terms of the GNU Lesser General Public License version 2.1
   * as published by the Free Software Foundation.
   */
  package ch.qos.logback.classic.pattern;
  
  import ch.qos.logback.classic.spi.ILoggingEvent;
  
  public abstract class NamedConverter extends ClassicConverter {
  
    Abbreviator abbreviator = null;
  
    /**
     * Gets fully qualified name from event.
     * 
     * @param event
     *          The LoggingEvent to process, cannot not be null.
     * @return name, must not be null.
     */
    protected abstract String getFullyQualifiedName(final ILoggingEvent event);
  
    public void start() {
      String optStr = getFirstOption();
      if (optStr != null) {
        try {
          int targetLen = Integer.parseInt(optStr);
          if (targetLen == 0) {
            abbreviator = new ClassNameOnlyAbbreviator();
          } else if (targetLen > 0) {
            abbreviator = new TargetLengthBasedClassNameAbbreviator(targetLen);
          }
        } catch (NumberFormatException nfe) {
          // FIXME: better error reporting
        }
      }
    }
  
    public String convert(ILoggingEvent event) {
      String fqn = getFullyQualifiedName(event);
  
      if (abbreviator == null) {
        return fqn;
      } else {
        return abbreviator.abbreviate(fqn);
      }
    }
  }