/*
   Copyright (C) 2001-2006, William Joseph.
   All Rights Reserved.

   This file is part of GtkRadiant.

   GtkRadiant 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.

   GtkRadiant 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.

   You should have received a copy of the GNU General Public License
   along with GtkRadiant; if not, write to the Free Software
   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */

#if !defined( INCLUDED_DEBUGGING_DEBUGGING_H )
#define INCLUDED_DEBUGGING_DEBUGGING_H

/// \file
/// \brief Debugging macros for fatal error/assert messages.

#include "stream/textstream.h"
#include "warnings.h"
#include "generic/static.h"

#if defined( _MSC_VER ) && defined( _M_IX86 )
#define DEBUGGER_BREAKPOINT() __asm { int 3 }
#elif defined ( __i386__ ) && defined ( __GNUC__ ) && __GNUC__ >= 2
#define DEBUGGER_BREAKPOINT() __asm__ __volatile__ ( "int $03" )
#else
#include <signal.h>

#define DEBUGGER_BREAKPOINT() raise( SIGTRAP );
#endif

#define STR( x )  # x
#define STR2( x ) STR( x )
#define FILE_LINE __FILE__ ":" STR2( __LINE__ )

#if defined( _DEBUG ) || 1
#define DEBUG_ASSERTS
#endif

class DebugMessageHandler
{
public:
virtual TextOutputStream& getOutputStream() = 0;
virtual bool handleMessage() = 0;
};

class NullDebugMessageHandler : public NullOutputStream, public DebugMessageHandler
{
public:
virtual TextOutputStream& getOutputStream(){
	return *this;
}
virtual bool handleMessage(){
	return false;
}
};

class DefaultDebugMessageHandler : public DebugMessageHandler
{
public:
virtual TextOutputStream& getOutputStream(){
	return globalErrorStream();
}
virtual bool handleMessage(){
#if defined( _DEBUG )
	return false; // send debug-break
#else
	return true;
#endif
}
};

class DebugMessageHandlerRef : public DefaultDebugMessageHandler
{
DebugMessageHandler* m_handler;
public:
DebugMessageHandlerRef()
	: m_handler( this ){
}
void setHandler( DebugMessageHandler& handler ){
	m_handler = &handler;
}
DebugMessageHandler& getHandler(){
	return *m_handler;
}
};

typedef Static<DebugMessageHandlerRef> GlobalDebugMessageHandler;

inline DebugMessageHandler& globalDebugMessageHandler(){
	return GlobalDebugMessageHandler::instance().getHandler();
}

#if defined( DEBUG_ASSERTS )

/// \brief Sends a \p message to the current debug-message-handler text-output-stream if \p condition evaluates to false.
#define ASSERT_MESSAGE( condition, message ) do { \
		if ( !( condition ) ) \
		{ \
			globalDebugMessageHandler().getOutputStream() << FILE_LINE "\nassertion failure: " << message << "\n"; \
			if ( !globalDebugMessageHandler().handleMessage() ) { DEBUGGER_BREAKPOINT(); } \
		}} while ( 0 )

/// \brief Sends a \p message to the current debug-message-handler text-output-stream.
#define ERROR_MESSAGE( message ) do { \
		globalDebugMessageHandler().getOutputStream() << FILE_LINE "\nruntime error: " << message << "\n"; \
		if ( !globalDebugMessageHandler().handleMessage() ) { DEBUGGER_BREAKPOINT(); }} while ( 0 )

#define ASSERT_NOTNULL( ptr ) ASSERT_MESSAGE( ptr != 0, "pointer \"" # ptr "\" is null" )

#else

#define ASSERT_MESSAGE( condition, message )
#define ERROR_MESSAGE( message )
#define ASSERT_NOTNULL( ptr )

#endif

#endif