/**
 * Declaration of Log class.
 * 
 * @file
 * @author Mauro E S Muņoz <mauro@cria.org.br>
 * @date   2003-03-28
 * $Id$
 * 
 * LICENSE INFORMATION 
 * 
 * Copyright(c) 2003 by CRIA -
 * Centro de Referencia em Informacao Ambiental
 *
 * http://www.cria.org.br
 * 
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details:
 * 
 * http://www.gnu.org/copyleft/gpl.html
 */

#ifndef _LOGHH_
#define _LOGHH_

#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>


//   Obs: Need to implement compatibility with sockets.


/**************************************************************/
/***************************** Log ****************************/

/** 
 * Class that allows sending of log messages to "stream" devices.
 * A system interface class with more advanced logging 
 * mechanisms (libraries).
 */
class Log
{
public:

  typedef enum {
    Debug, Info, Warn, Error
  } Level;


public:

  /** 
   * @param name File name for 'debug()'output
   * @param pref Prefix to be shown on every message
   * @param overwrite If != 0 truncate the file before first use,
   *                  otherwise begin from the end.
   */
  Log( char *name, char *pref="", int overwrite=0 );

  /** Use Log object as an output for 'debug()'.*/
  Log( Level level=Warn, FILE *log=stdout, char *pref="" );
  ~Log();

  /** Change log level.*/
  void setLevel( Level level )  { f_level = level; }

  /** Change prefix to be shown befeore any message.*/
  void setPrefix( char *pref );


  // Not necessarily printed (depend on current log level).
  //
  int debug( char *format, ... );  ///< 'Debug' level.
  int info ( char *format, ... );  ///< 'Info' level.

  // Are necessarily printed in log.
  int warn ( char *format, ... );  ///< stderr and continue.
  int error( int exit_code, char *format, ... );  ///< stderr and exit.

  /** Print 'size' bytes from memory counting from 'buf'.
   * 'length' informs the number of bytes per line.
   * Available only during 'Debug' level.*/
  int buffer( void *buf, int size, int length=16 );


private:

  FILE  *f_log;
  Level  f_level;
  char  *f_pref;
};


extern Log _log;


#endif