/* Copyright (c) 2008, Avian Contributors

   Permission to use, copy, modify, and/or distribute this software
   for any purpose with or without fee is hereby granted, provided
   that the above copyright notice and this permission notice appear
   in all copies.

   There is NO WARRANTY for this software.  See license.txt for
   details. */

package java.util.logging;

import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.List;

public class Logger {
  private final String name;
  private static final ArrayList<Handler> handlers;
  static {
    handlers = new ArrayList<Handler>();
    handlers.add(new DefaultHandler());
  }

  public static Logger getLogger(String name) {
    return new Logger(name);
  }

  private Logger(String name) {
    this.name = name;
  }

  public List<Handler> getHandlers() {
    return new ArrayList<Handler>(handlers);
  }

  public void addHandler(Handler handler) {
    handlers.add(handler);
  }

  public void removeHandler(Handler handler) {
    handlers.remove(handler);
  }

  public void fine(String message) {
    log(Level.FINE, Method.getCaller(), message, null);
  }

  public void info(String message) {
    log(Level.INFO, Method.getCaller(), message, null);
  }

  public void warning(String message) {
    log(Level.WARNING, Method.getCaller(), message, null);
  }

  public void severe(String message) {
    log(Level.SEVERE, Method.getCaller(), message, null);
  }

  public void log(Level level, String message) {
    log(level, Method.getCaller(), message, null);
  }

  public void log(Level level, String message, Throwable exception) {
    log(level, Method.getCaller(), message, exception);
  }

  private void log(Level level, Method caller, String message,
                   Throwable exception) {
    LogRecord r = new LogRecord(name, caller.getName(), level, message,
                                exception);
    for (Handler h : handlers) {
      h.publish(r);
    }
  }

  public void setLevel(Level level) {
    // Currently ignored
  }

  private static class DefaultHandler extends Handler {
    private static final int NAME_WIDTH = 14;
    private static final int METHOD_WIDTH = 15;
    private static final int LEVEL_WIDTH = 8;
    private final String newline;

    public DefaultHandler() {
      newline = System.getProperty("line.separator");
    }

    public Object clone() { return this; }
    public void close() { }
    public void flush() { }

    private void maybeLogThrown(StringBuilder sb, Throwable t) {
      if (t != null) {
        sb.append("\nCaused by: ");
        sb.append(t.getClass().getName());
        sb.append(": ");
        sb.append(t.getMessage());
        sb.append(newline);

        for (StackTraceElement elt : t.getStackTrace()) {
          sb.append('\t');
          sb.append(elt.getClassName());
          sb.append('.');
          sb.append(elt.getMethodName());
          sb.append("(line");
          sb.append(':');
	  int lineNumber = elt.getLineNumber();
	  if (lineNumber == -2) {
	    sb.append("unknown");
	  } else if (lineNumber == -1) {
	    sb.append("native");
	  } else {
	    sb.append(lineNumber);
	  }
          sb.append(')');
          sb.append(newline);
        }
        maybeLogThrown(sb, t.getCause());
      }
    }

    private void indent(StringBuilder sb, int amount) {
      do {
        sb.append(' ');
      } while (--amount > 0);
    }

    public void publish(LogRecord r) {
      StringBuilder sb = new StringBuilder();
      sb.append(r.getLoggerName());
      indent(sb, NAME_WIDTH - r.getLoggerName().length());
      sb.append(r.getSourceMethodName());
      indent(sb, METHOD_WIDTH - r.getSourceMethodName().length());
      sb.append(r.getLevel().getName());
      indent(sb, LEVEL_WIDTH - r.getLevel().getName().length());
      sb.append(r.getMessage());
      maybeLogThrown(sb, r.getThrown());
      System.out.println(sb.toString());
    }
  }

}