/***************************************************************************
                          message.h  -  Print messages
                             -------------------
    begin                : Wed Sep 15 2004
    copyright            : (C) 2004 by Jan Rheinlaender
    email                : jrheinlaender@users.sourceforge.net
 ***************************************************************************/

/***************************************************************************
 *                                                                         *
 *   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.                                   *
 *                                                                         *
 ***************************************************************************/

#ifndef MESSAGE_H
#define MESSAGE_H

#include <iostream>
#include <fstream>
#include <string>

enum message_mode { // *** added in 1.3.1
  m_stdc, // Use std::c streams 
  m_func,  // Use a user-defined function
  m_ostream // Use a user-defined output stream
};

enum message_type {
  t_msg_error, // Stream type for printing error messages
  t_msg_warn,  // warning messages
  t_msg_info,  // progress messages
  t_msg_null   // Rubbish bin
};

typedef void (*msgfuncp)(const std::string&, const std::string&);

#define OUTPUTF *outputfunctionp

#define CONSTRUCTOR \
message::message(msgfuncp f, const message_type t, const int l) { \
  mode = m_func; \
  type = t; \
  level = l; \
  strm = new std::ostringstream; \
  outputfunctionp = f; \
} \

#define INITDECL static void init(msgfuncp f);

#define INIT \
void msg::init(msgfuncp f) { \
  msg_error = message(f, t_msg_error, 1); \
  msg_warn = message(f, t_msg_warn, 1); \
  msg_info = message(f, t_msg_info, -1); \
  devnullstream.open("/dev/null"); \
  devnull = message(devnullstream, t_msg_info, 0); \
} \

/// Helper class to initialize class message
class message;
class message_init {
public:
  message_init();
private:
  /// A boolean used to ensure that init() is only called once in the lifetime of the class
  static bool called;
  static message_init message_initializer;
};

enum manip_type {
  endline,   // End of line
  endstring  // End of string
};

/** *** added in 0.7
  Every stream has a priority level, where smaller numbers mean higher priority.
  Messages are printed when their priority is smaller or equal to the priority level of the
  stream. For example: Stream message::msg_err() has priority 1. This
  means that a message with priority 1 will be printed, but a message with priority 2 not.

  There are 8 priority levels (0 to 7). Larger priority levels are interpreted in such a way
  that, for example, a stream with priority 9 prints messages of level 9 and 1 (9 modulo 1).
  @author Jan Rheinlaender
  @short Class for printing messages: Errors, warnings and info
**/

class message {
  friend class message_init;
public:
  /**
   * Create a message stream of the given type that will output messages of priority level
   * or less. This construction uses the std::cerr etc. output streams
   * @param t The type of the messages that will be printed
   * @param l The priority level up to which messages will be printed
   */
  message(const message_type t, const int l);

  /**
   * Create a message stream using a user-defined output file stream
   * @param t The type of the messages that will be printed
   * @param l The priority level up to which messages will be printed
   */
  message(std::ostream& of, const message_type t, const int l); // *** added in 1.3.1

  /**
   * Create a message stream using a user-defined output function
   * @param t The type of the messages that will be printed
   * @param l The priority level up to which messages will be printed
   */
  message(msgfuncp f, const message_type t, const int l); // *** added in 1.3.1

  /// Clean up
  ~message();
  
  /// Set the priority level of the stream
  void setlevel(const int l);

  /// Return the underlying stream. Use only if absolutely necessary!
  //inline std::ostream &stream() { return *strm; } // *** removed in 1.3.1

  /**
    Return the stream to print messages of priority p. Returns the /dev/null stream
    if the priority is not high enough
    @param p The priority of the messages
    @returns This object
  */
  //  message& prio(const int p); *** removed in 1.3.1

 /**
  Check if messages of a certain priority will be printed on this stream. Returns true
  if (p % 8) <= the priority level of the stream.
  @param p The priority
  @returns True or false
  */

  inline const bool checkprio(const int p) const { // *** changed in 0.8, inlined in 1.0
    if ((level >> 3) > 0) // i.e. level > 7 *** changed in 1.0
      return ((p % 8) <= (level % 8));
    else
      return (p <= level);
  }

  /// Print a message on the stream
  message &operator<<(const char *cp);

  /// Print an unsigned int on the stream
  message &operator<<(const unsigned int i);
  
  /// Print a long unsigned int on the stream
  message &operator<<(const long unsigned int i);

  /// Print a signed int on the stream
  message &operator<<(const int i);

  /// Print a long int on the stream
  message &operator<<(const long int i);

  /// Print a double on the stream
  message &operator<<(const double d);

  /// Print a string on the stream
   message &operator<<(const std::string &s);

  /// manipulators
  // TODO: Is there a better way to implement this?
  // compare std::ostream & dflt(std::ostream & os); from GiNac
  message &operator<<(manip_type m);
  /// endline manipulator
  message &endl(message &m) { (*strm) << std::endl; return m; } // *** added in 0.9

private:
  /// The messaging mode
  
  message_mode mode;
  /// The type of the stream
  message_type type;

  /// The priority level of the stream
  int level;

  /// The underlying stream for printing the messages
  std::ostream *strm;
  
  /// The user-defined output function
  msgfuncp outputfunctionp;

// Class methods
private:
  /// Initialize
  static void init();
};

// Global message printing streams *** removed in 1.3.1
//extern message msg_error;
//extern message msg_warn;
//extern message msg_info;

#endif