/*]  Copyright (c) 2009-2010, Charles McGarvey  [**************************
**]  All rights reserved.
*
* vi:ts=4 sw=4 tw=75
*
* Distributable under the terms and conditions of the 2-clause BSD license;
* see the file COPYING for a complete text of the license.
*
**************************************************************************/

#ifndef _MOOF_LOG_H_
#define _MOOF_LOG_H_

/**
 * @file log.h
 * Functions related to logging the process.
 * The logging functions are logError(), logWarning(), and logInfo(),
 * listed from most critical to least critical.
 */

#include <cstdlib>		// exit
#include <iostream>


/**
 * Macro which tests an assertion and issues an logError() and exits if
 * false.
 * @param X test to perform
 */

#undef ASSERT

#if NDEBUG
#define ASSERT(X)
#else
#define ASSERT(X) if (!(X)) Mf::logError \
	<< "false assertion at " << __FILE__ << ":" << __LINE__ << ", " \
	<< #X, exit(1)
#endif


namespace Mf {


class Log
{
public:

	enum Level
	{
		NONE		= 0,		///< Disable all logging.
		ERRORR		= 1,		///< Log only errors.
		WARNING		= 2,		///< Log warnings and errors.
		INFO		= 3,		///< Log everything.
	};

	static void setLevel(Level level);
	static Level getLevel();


	Log(Level level, const char* type) :
		mLevel(level),
		mType(type) /* only pass literal strings */ {}


	template <class T>
	void operator () (const T& item)
	{
		*this << item << std::endl;
	}

private:

	template <class T> friend std::ostream& operator << (Log&, const T&);

	static Level	gLevel;

	Level			mLevel;
	const char*		mType;
};


extern std::ostream&	log;
extern std::ostream&	nullLog;

extern Log logError;
extern Log logWarning;
extern Log logInfo;


template <class T>
inline std::ostream& operator << (Log& logObj, const T& item)
{
	if (Log::gLevel < logObj.mLevel) return nullLog;
	return log << logObj.mType << item;
}


class Script;
void importLogFunctions(Script& script);


} // namespace Mf

#endif // _MOOF_LOG_H_