/*! \file
 
  \brief Class creaMessageManager and Macros for outputing messages in crea

  There are 4 kinds of messages :
  - Messages (normal messages)
  - Debug messages (not compiled in release)
  - Warnings 
  - Errors
  There are also "types" of messages which are strings which identify the nature of the message 
  (for example : "Kernel" messages are generated by the core classes of the library, there can be a type of 
  message for each type of Node, and so on...)
  A type of message must be declared by registering it into the MessageManager. This is done by a line like :
  crea::MessageManager::RegisterMessageType("Kernel","Messages generated by the core classes of the library",5);
  where : 
  -The first string is the type of the message (the category which will be used to generate a message of this type)
  -The second string is help string
  -The integer is the initial level for the messages of this type (see below).
  
  To generate a message of a known type then use one of the macros :
  creaMessage, creaDebugMessage, creaWarning, creaError or their variants.

  example :

  creaMessage("Kernel",4,"problem with "<<GetName()<<creaendl);

  will push the 3rd argument in std::cout if the message level of "Kernel" messages is greater or equal to 4.
  which means that it generates a message of level 4 (0 : very important/always displayed ... 9 : deep debug message).

  At run time, one is able to change the level of the messages displayed by using a command like :
  
  crea::MessageManager::SetMessageLevel("Kernel",5); 
  
  which tells the manager to display all Kernel messages of level up to 5.

  Variants :

  crea*Cont : continues a previous creaMessage on the same line (without rewriting the type and level)
  crea*Inc / Dec : displays the message and then increments/decrement the messages tabulation 

*/
  //===========================================================
  /**
     \class crea::MessageManager
     \brief Manages the messages displayed by crea
  */


#ifndef __creaMessageManager_h__
#define __creaMessageManager_h__

// The do { } while(0) statement in macros is made to "swallow the semicolon" 
// see http://gcc.gnu.org/onlinedocs/cpp/Swallowing-the-Semicolon.html#Swallowing-the-Semicolon

#include "creaSystem.h"
#include "creaRTTI.h" // for CREA_GET_CURRENT_OBJECT_NAME

#include <string>
#include <map>
#include <iostream>
#include <sstream>

// Comment out these symbols to prevent compilation 
//#define CREA_COMPILE_MESSAGES
//#define CREA_COMPILE_DEBUG_MESSAGES
//#define CREA_COMPILE_WARNING_MESSAGES
//#define CREA_COMPILE_ERROR_MESSAGES


#define creaOnMessageLevel(key,value)			\
  int __creaOnMessageLevelVariable =			\
    crea::MessageManager::GetMessageLevel(key);		\
  if ( __creaOnMessageLevelVariable<0)			\
    {							\
      creaWarning("message type '"<<key<<"' unknown");	\
    }							\
  else if (value<= __creaOnMessageLevelVariable) 

#ifdef CREA_PREPEND_MESSAGE_WITH_CODE
#define creaMessageCode				\
  key[0] << key[1] << key[2] << value << " "
#else 
#define creaMessageCode ""
#endif 

#ifdef CREA_PREPEND_MESSAGE_WITH_TAB
#define creaMessageTab				\
  crea::MessageManager::GetTab()
#else 
#define creaMessageTab ""
#endif

//#define CREA_PREPEND_MESSAGE_WITH_SPACE
#ifdef CREA_PREPEND_MESSAGE_WITH_SPACE
#define creaMessageSpace(value)			\
  crea::MessageManager::GetSpace(value)
#else 
#define creaMessageSpace(value) ""
#endif
 

//===========================================================
#ifdef CREA_COMPILE_MESSAGES

// Macro for messages
#define creaMessage(key,value,MESSAGE)			\
  do {							\
    creaOnMessageLevel(key,value)			\
      {							\
	std::ostringstream s;				\
	s << creaMessageCode				\
	  << creaMessageTab				\
	  << creaMessageSpace(value)			\
	  << MESSAGE;					\
	crea::MessageManager::SendMessage(key,s.str());	\
      }							\
  }							\
  while (0)

// Macro for continuing a message (when one wants to split the macro
// call into multiple lines)
#define creaMessageCont(key,value,MESSAGE)		\
  do							\
    {							\
      creaOnMessageLevel(key,value)			\
	{						\
	std::ostringstream s;				\
	s << MESSAGE;					\
	crea::MessageManager::SendMessage(key,s.str());	\
	}						\
    }							\
  while (0)

#define creaMessageInc(key,value,MESSAGE)		\
  do							\
    {							\
	std::ostringstream s;				\
	s << creaMessageCode				\
	  << creaMessageTab				\
	  << creaMessageSpace(value)			\
	  << MESSAGE;					\
	crea::MessageManager::SendMessage(key,s.str());	\
	crea::MessageManager::IncTab();			\
	}						\
    }							\
  while (0)

#define creaMessageDec(key,value,MESSAGE)			\
  do								\
    {								\
      creaOnMessageLevel(key,value)				\
	{							\
	  crea::MessageManager::DecTab();			\
	  std::ostringstream s;					\
	  s << creaMessageCode					\
	    << creaMessageTab					\
	    << creaMessageSpace(value)				\
	    << MESSAGE;						\
	  crea::MessageManager::SendMessage(key,s.str());	\
	}							\
    }								\
  while (0)

#define creaDecTab(key,value)			\
  do						\
    {						\
      creaOnMessageLevel(key,value)		\
	{					\
	  crea::MessageManager::DecTab();	\
	}					\
    }						\
  while (0)

#define creaIncTab(key,value)			\
  do						\
    {						\
      creaOnMessageLevel(key,value)		\
	{					\
	  crea::MessageManager::IncTab();	\
	}					\
    }						\
  while (0)

#define creaResetTab()				\
  do						\
    {						\
      crea::MessageManager::ResetTab();		\
    }						\
  while (0)

#else
#define creaMessage(key,value,MESSAGE)
#define creaMessageInc(key,value,MESSAGE)
#define creaMessageDec(key,value,MESSAGE)
#define creaMessageCont(key,value,MESSAGE)
#define creaDecTab(key,value)
#define creaIncTab(key,value)
#define creaResetTab()
#endif
//===========================================================



//===========================================================
// Macros for debug messages
#ifdef CREA_COMPILE_DEBUG_MESSAGES
#define creaDebugMessage(key,value,MESSAGE) creaMessage(key,value,MESSAGE)
#define creaDebugMessageCont(key,value,MESSAGE)	creaMessageCont(key,value,MESSAGE)
#define creaDebugMessageInc(key,value,MESSAGE) creaMessageInc(key,value,MESSAGE)  
#define creaDebugMessageDec(key,value,MESSAGE) creaMessageDec(key,value,MESSAGE)
#define creaDebugDecTab(key,value) creaDecTab(key,value)
#define creaDebugIncTab(key,value) creaIncTab(key,value)
#define creaDebugResetTab() creaResetTab()
#else
#define creaDebugMessage(key,value,MESSAGE) 
#define creaDebugMessageCont(key,value,MESSAGE) 
#define creaDebugMessageInc(key,value,MESSAGE)
#define creaDebugMessageDec(key,value,MESSAGE) 
#define creaDebugDecTab(key,value)
#define creaDebugIncTab(key,value)
#endif
//===========================================================

//===========================================================
#ifdef CREA_COMPILE_WARNING_MESSAGES
#define creaWarning(MESSAGE)						\
  do									\
    {									\
      int lev = crea::MessageManager::GetMessageLevel("warning");	\
      if (lev >0)							\
	{								\
	  std::cerr << "!! WARNING !! " << MESSAGE << std::endl;	\
	  if (lev >1)							\
	    {								\
	      std::cerr << "!! WARNING !! In file '"<<__FILE__		\
			<<"' ; Line "<<__LINE__<<std::endl;		\
	    }								\
	}								\
    }									\
  while (0) 

#else
#define creaWarning(MESSAGE) 
#endif
//===========================================================


//===========================================================
#ifdef CREA_COMPILE_ERROR_MESSAGES
//#include "creaWx.h"
#define creaError(MESSAGE)				\
  do							\
    {							\
      std::ostringstream s;				\
      s << MESSAGE;					\
      std::ostringstream f;				\
      f << __FILE__ << " (l."<<__LINE__<<")";		\
      crea::Exception e( CREA_GET_CURRENT_OBJECT_NAME,	\
			f.str(),			\
			s.str());			\
      throw e;						\
    }							\
  while (0) 

#define creaGlobalError(MESSAGE)				\
  do							\
    {							\
      std::ostringstream s;				\
      s << MESSAGE;					\
      std::ostringstream f;				\
      f << __FILE__ << " (l."<<__LINE__<<")";		\
      crea::Exception e( "global scope",		\
			f.str(),			\
			s.str());			\
      throw e;						\
    }							\
  while (0) 

#define CREA_INTERNAL_ERROR_MESSAGE \
  "\n\n***********************************************\n**** THIS IS AN INTERNAL ERROR TO crea     ****\n**** Please send a full bug report to :    ****\n****  creatools@creatis.insa-lyon.fr ****\n***********************************************\n\n"

#define creaInternalError(MESSAGE)			\
  do							\
    {							\
      std::ostringstream s;				\
      s << MESSAGE << CREA_INTERNAL_ERROR_MESSAGE;	\
      std::ostringstream f;				\
      f << __FILE__ << " (l."<<__LINE__<<")";		\
      crea::Exception e( CREA_GET_CURRENT_OBJECT_NAME,	\
			 f.str(),			\
			 s.str());			\
      throw e;						\
    }							\
  while (0) 

#else
#define creaError(MESSAGE)
#define creaGlobalError(MESSAGE)
#define creaInternalError(MESSAGE)
#endif
//===========================================================

//===========================================================
#define creaendl std::endl
//===========================================================

// Signal/slot mechanism for message events
#include <boost/signal.hpp>
#include <boost/bind.hpp>

namespace crea 
{
  
  class CREA_EXPORT MessageManager
  {
  public:
    //=============================================
    typedef boost::signal<void (const std::string&)>  MessageSignalType;
    typedef MessageSignalType::slot_function_type MessageCallbackType;
    //=============================================
    ///
    MessageManager();
    ///
    ~MessageManager();
    ///
    static MessageManager* GetInstance();
    ///
    static void RegisterMessageType(const std::string& key, 
                                    const std::string& help,
                                    unsigned char default_level = 9);
    ///
    static void SetMessageLevel(const std::string& key, unsigned char level);
    ///
    static int GetMessageLevel(const std::string& key);
    ///  
    static void SendMessage(const std::string& key, const std::string& mess);
    ///
    static void AddMessageObserver(const std::string& key, MessageCallbackType callback );
    ///
    static void SendMessagesToCout(bool v = true);
    ///
    static std::string& GetTab() { static std::string s; return s; }
    ///
    static std::string GetSpace(int n) { 
      std::string s; s.insert(0,"                ",n); return s; }
    ///
    static void IncTab() { GetTab() += std::string(" "); }
    ///
    static void DecTab() { GetTab() = GetTab().substr(0,GetTab().length()-1); }
    ///
    static void ResetTab() { GetTab() = std::string(""); }
    ///
    static void PrintInfo();
    /// 
    
  private:
    struct MessageType
    {
      MessageType(int l, const std::string& h) : Level(l), Help(h) {}
      int Level;
      std::string Help;
      MessageSignalType Signal;
    };
    typedef std::map<std::string,MessageType*> MessageMapType;
    MessageMapType mMessageMap;
    unsigned int mMaxMessageLength;
    bool mSendToCout;
  };
  //===========================================================
  
}

#include "creaException.h"

#endif