/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
/*
 * Copyright (c) 2006,2007 INRIA
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation;
 *
 * 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.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 * Author: Mathieu Lacage <mathieu.lacage@sophia.inria.fr>
 */

#ifndef NS3_LOG_H
#define NS3_LOG_H

#include <string>
#include <iostream>
#include <stdint.h>
#include <map>

#include "log-macros-enabled.h"
#include "log-macros-disabled.h"

/**
 * \file
 * \ingroup logging
 * Debug message logging
 */

/**
 * \ingroup debugging
 * \defgroup logging Logging
 *
 * \brief Logging functions and macros
 *
 * LOG functionality: macros which allow developers to
 * send information to the \c std::clog output stream.
 *
 * All logging messages are disabled by default. To enable selected logging 
 * messages, use the ns3::LogComponentEnable
 * function or use the NS_LOG environment variable 
 *
 * Use the environment variable NS_LOG to define a ':'-separated list of
 * logging components to enable. For example (using bash syntax),
 * \code
 *   $ NS_LOG="OlsrAgent" ./waf --run ...
 * \endcode
 * would enable one component at all log levels.
 * \code
 *   $NS_LOG="OlsrAgent:Ipv4L3Protocol" ./waf --run ...
 * \endcode
 * would enable two components, at all log levels, etc.
 * \c NS_LOG="*" will enable all available log components at all levels.
 *
 * To control more selectively the log levels for each component, use
 * this syntax:
 * \code
 *   $ NS_LOG='Component1=func|warn:Component2=error|debug'
 * \endcode
 * This example would enable the \c func, and \c warn log
 * levels for 'Component1' and the \c error and \c debug log levels
 * for 'Component2'.  The wildcard '*' can be used here as well.  For example
 * \c NS_LOG='*=level_all|prefix' would enable all log levels and prefix all
 * prints with the component and function names.
 *
 * A note on NS_LOG_FUNCTION() and NS_LOG_FUNCTION_NOARGS():
 * generally, use of (at least) NS_LOG_FUNCTION(this) is preferred,
 * with the any function parameters added:
 * \code
 *   NS_LOG_FUNCTION (this << arg1 << args);
 * \endcode
 * Use NS_LOG_FUNCTION_NOARGS() only in static functions with no arguments.
 */
/** @{ */


namespace ns3 {

/**
 *  Logging severity classes and levels.
 */
enum LogLevel {
  LOG_NONE           = 0x00000000, //!< No logging.

  LOG_ERROR          = 0x00000001, //!< Serious error messages only.
  LOG_LEVEL_ERROR    = 0x00000001, //!< LOG_ERROR and above.

  LOG_WARN           = 0x00000002, //!< Warning messages.
  LOG_LEVEL_WARN     = 0x00000003, //!< LOG_WARN and above.

  LOG_DEBUG          = 0x00000004, //!< Rare ad-hoc debug messages.
  LOG_LEVEL_DEBUG    = 0x00000007, //!< LOG_DEBUG and above.

  LOG_INFO           = 0x00000008, //!< Informational messages (e.g., banners).
  LOG_LEVEL_INFO     = 0x0000000f, //!< LOG_INFO and above.

  LOG_FUNCTION       = 0x00000010, //!< Function tracing.
  LOG_LEVEL_FUNCTION = 0x0000001f, //!< LOG_FUNCTION and above.

  LOG_LOGIC          = 0x00000020, //!< Control flow tracing within functions.
  LOG_LEVEL_LOGIC    = 0x0000003f, //!< LOG_LOGIC and above.

  LOG_ALL            = 0x0fffffff, //!< Print everything.
  LOG_LEVEL_ALL      = LOG_ALL,    //!< Print everything.

  LOG_PREFIX_FUNC    = 0x80000000, //!< Prefix all trace prints with function.
  LOG_PREFIX_TIME    = 0x40000000, //!< Prefix all trace prints with simulation time.
  LOG_PREFIX_NODE    = 0x20000000, //!< Prefix all trace prints with simulation node.
  LOG_PREFIX_LEVEL   = 0x10000000, //!< Prefix all trace prints with log level (severity).
  LOG_PREFIX_ALL     = 0xf0000000  //!< All prefixes.
};

/**
 * Enable the logging output associated with that log component.
 *
 * The logging output can be later disabled with a call
 * to ns3::LogComponentDisable.
 *
 * Same as running your program with the NS_LOG environment
 * variable set as NS_LOG='name=level'.
 *
 * \param name The log component name.
 * \param level The logging level.
 */
void LogComponentEnable (char const *name, enum LogLevel level);

/**
 * Enable the logging output for all registered log components.
 *
 * Same as running your program with the NS_LOG environment
 * variable set as NS_LOG='*=level'
 *
 * \param level The logging level.
 */
void LogComponentEnableAll (enum LogLevel level);


/**
 * Disable the logging output associated with that log component.
 *
 * The logging output can be later re-enabled with a call
 * to LogComponentEnable.
 *
 * \param name The log component name.
 * \param level The logging level.
 */
void LogComponentDisable (char const *name, enum LogLevel level);

/**
 * Disable all logging for all components.
 *
 * \param level The logging level.
 */
void LogComponentDisableAll (enum LogLevel level);


} // namespace ns3


/**
 * Define a Log component with a specific name.
 *
 * This macro should be used at the top of every file in which you want 
 * to use the NS_LOG macro. This macro defines a new
 * "log component" which can be later selectively enabled
 * or disabled with the ns3::LogComponentEnable and 
 * ns3::LogComponentDisable functions or with the NS_LOG
 * environment variable.
 *
 * LogComponent names should be simple string tokens, _i.e._,
 * "ArfWifiManager", not "ns3::ArfWifiManager".
 *
 * This macro should be placed within namespace ns3.  If functions
 * outside of namespace ns3 require access to logging, the preferred
 * solution is to add the following 'using' directive at file scope,
 * outside of namespace ns3, and after the inclusion of
 * NS_LOG_COMPONENT_DEFINE, such as follows:
 * \code
 *   namespace ns3 {
 *     NS_LOG_COMPONENT_DEFINE ("...");
 *
 *     // Definitions within the ns3 namespace
 *
 *   } // namespace ns3
 *
 *   using ns3::g_log;
 *
 *   // Further definitions outside of the ns3 namespace
 *\endcode
 *
 * \param name The log component name.
 */
#define NS_LOG_COMPONENT_DEFINE(name)                           \
  static ns3::LogComponent g_log = ns3::LogComponent (name, __FILE__)

/**
 * Define a logging component with a mask.
 *
 * See LogComponent().
 *
 * \param name The log component name.
 * \param mask The default mask.
 */
#define NS_LOG_COMPONENT_DEFINE_MASK(name, mask)                \
  static ns3::LogComponent g_log = ns3::LogComponent (name, __FILE__, mask)

/**
 * Use \ref NS_LOG to output a message of level LOG_ERROR.
 *
 * \param msg The message to log.
 */
#define NS_LOG_ERROR(msg) \
  NS_LOG (ns3::LOG_ERROR, msg)

/**
 * Use \ref NS_LOG to output a message of level LOG_WARN.
 *
 * \param msg The message to log.
 */
#define NS_LOG_WARN(msg) \
  NS_LOG (ns3::LOG_WARN, msg)

/**
 * Use \ref NS_LOG to output a message of level LOG_DEBUG.
 *
 * \param msg The message to log.
 */
#define NS_LOG_DEBUG(msg) \
  NS_LOG (ns3::LOG_DEBUG, msg)

/**
 * Use \ref NS_LOG to output a message of level LOG_INFO.
 *
 * \param msg The message to log.
 */
#define NS_LOG_INFO(msg) \
  NS_LOG (ns3::LOG_INFO, msg)

/**
 * Use \ref NS_LOG to output a message of level LOG_LOGIC
 *
 * \param msg The message to log.
 */
#define NS_LOG_LOGIC(msg) \
  NS_LOG (ns3::LOG_LOGIC, msg)


namespace ns3 {

/**
 * Print the list of logging messages available.
 * Same as running your program with the NS_LOG environment
 * variable set as NS_LOG=print-list
 */
void LogComponentPrintList (void);

/**
 * Function signature for prepending the simulation time
 * to a log message.
 *
 * \param os The output stream to print on.
 */
typedef void (*LogTimePrinter)(std::ostream &os);
/**
 * Function signature for prepending the node id
 * to a log message.
 *
 * \param os The output stream to print on.
 */
typedef void (*LogNodePrinter)(std::ostream &os);

/**
 * Set the LogTimePrinter function to be used
 * to prepend log messages with the simulation time.
 *
 * \param lp The LogTimePrinter function.
 */
void LogSetTimePrinter (LogTimePrinter lp);
/**
 * Get the LogTimePrinter function currently in use.
 * \returns The LogTimePrinter function.
 */
LogTimePrinter LogGetTimePrinter (void);

/**
 * Set the LogNodePrinter function to be used
 * to prepend log messages with the node id.
 *
 * \param np The LogNodePrinter function.
 */
void LogSetNodePrinter (LogNodePrinter np);
/**
 * Get the LogNodePrinter function currently in use.
 * \returns The LogNodePrinter function.
 */
LogNodePrinter LogGetNodePrinter (void);


/**
 * A single log component configuration.
 */
class LogComponent
{
public:
  /**
   * Constructor.
   *
   * \param [in] name The user-visible name for this component.
   * \param [in] file The source code file which defined this LogComponent.
   * \param [in] mask LogLevels blocked for this LogComponent.  Blocking
   *                  a log level helps prevent recursion by logging in
   *                  functions which help implement the logging facility.
   */
  LogComponent (const std::string & name,
                const std::string & file,
                const enum LogLevel mask = LOG_NONE);
  /**
   * Check if this LogComponent is enabled for \c level
   *
   * \param [in] level The level to check for.
   * \return \c true if we are enabled at \c level.
   */
  bool IsEnabled (const enum LogLevel level) const;
  /**
   * Check if all levels are disabled.
   *
   * \return \c true if all levels are disabled.
   */
  bool IsNoneEnabled (void) const;
  /**
   * Enable this LogComponent at \c level
   *
   * \param [in] level The LogLevel to enable.
   */
  void Enable (const enum LogLevel level);
  /**
   * Disable logging at \c level for this LogComponent.
   *
   * \param [in] level The LogLevel to disable.
   */
  void Disable (const enum LogLevel level);
  /**
   * Get the name of this LogComponent.
   *
   * \return The name of this LogComponent.
   */
  char const *Name (void) const;
  /**
   * Get the compilation unit defining this LogComponent.
   * \returns The file name.
   */
  std::string File (void) const;
  /**
   * Get the string label for the given LogLevel.
   *
   * \param [in] level The LogLevel to get the label for.
   * \return The string label for \c level.
   */
  static std::string GetLevelLabel(const enum LogLevel level);
  /**
   * Prevent the enabling of a specific LogLevel.
   *
   * \param level The LogLevel to block.
   */
  void SetMask (const enum LogLevel level);

  /**
   * LogComponent name map.
   *
   * \internal
   * This should really be considered an internal API.
   * It is exposed here to allow print-introspected-doxygen.cc
   * to generate a list of all LogComponents.
   */
  typedef std::map<std::string, LogComponent *> ComponentList;

  /**
   * Get the list of LogComponnents.
   *
   * \internal
   * This should really be considered an internal API.
   * It is exposed here to allow print-introspected-doxygen.cc
   * to generate a list of all LogComponents.
   *
   * \returns The list of LogComponents.
   */
  static ComponentList *GetComponentList (void);

  
private:
  /**
   * Parse the `NS_LOG` environment variable for options relating to this
   * LogComponent.
   */
  void EnvVarCheck (void);
  
  int32_t     m_levels;  //!< Enabled LogLevels.
  int32_t     m_mask;    //!< Blocked LogLevels.
  std::string m_name;    //!< LogComponent name.
  std::string m_file;    //!< File defining this LogComponent.

};  // class LogComponent

  
/**
 * Insert `, ` when streaming function arguments.
 */
class ParameterLogger
{
  bool m_first;        //!< First argument flag, doesn't get `, `.
  std::ostream &m_os;  //!< Underlying output stream.
public:
  /**
   * Constructor.
   *
   * \param [in] os Underlying output stream.
   */
  ParameterLogger (std::ostream &os);

  /**
   * Write a function parameter on the output stream,
   * separating parameters after the first by `,` strings.
   *
   * \param [in] param The function parameter.
   * \return This ParameterLogger, so it's chainable.
   */
  template<typename T>
  ParameterLogger& operator<< (T param)
  {
    if (m_first)
      {
        m_os << param;
        m_first = false;
      }
    else
      {
        m_os << ", " << param;
      }
    return *this;
  }
};

} // namespace ns3

/**@}*/  // \ingroup logging

#endif /* NS3_LOG_H */
