/**
 * Logger is a convenience API (using the Facade design pattern) for
 * logging LogRecords in Logs.  We expect this to be extended with
 * new kinds of events to log.
 */
public class Logger {
  private Log log;

  /**
   * Constructor that takes the Log to use.
   */
  public Logger(Log log) {
    this.log = log;
  }
  
  /**
   * Accessor method for making use of the Log directly.
   */
  public Log getLog() { return log; }

  /**
   * Prints events returned from getAll().
   */
  public void printAll(long windowMS) {
    LogRecord[] records = log.getAll(windowMS);
    for (int i = 0; i<records.length; i++)
      System.out.println(records[i]);
  }
  
  /**
   * Logs a "method entry" event.
   */
  public void addMethodEntry(Object instance, String method) {
    if (instance == null)
      log.add(new LogRecord("Entering: "+method));
    else
      log.add(new LogRecord("Entering: "+instance+"."+method));
  }
  
  /**
   * Logs a "method exit" event.
   */
  public void addMethodExit(Object instance, String method) {
    if (instance == null)
      log.add(new LogRecord("Exiting: "+method));
    else
      log.add(new LogRecord("Exiting: "+instance+"."+method));
  }
}