/*
 * Software License Agreement (BSD License)
 *
 *  Copyright (c) 2008-2014, Willow Garage, Inc.
 *  Copyright (c) 2014-2015, Open Source Robotics Foundation
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 *
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 *     notice, this list of conditions and the following disclaimer.
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 *     copyright notice, this list of conditions and the following
 *     disclaimer in the documentation and/or other materials provided
 *     with the distribution.
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 *     contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
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/* Author Ioan Sucan */

#ifndef FCL_UTIL_PROFILER
#define FCL_UTIL_PROFILER

#define ENABLE_PROFILING 1

#ifndef ENABLE_PROFILING

/// The ENABLE_PROFILING macro can be set externally. If it is not, profiling is enabled by default, unless NDEBUG is defined.

#  ifdef NDEBUG
#    define ENABLE_PROFILING 0
#  else
#    define ENABLE_PROFILING 1
#  endif

#endif

#if ENABLE_PROFILING

#include <map>
#include <string>
#include <iostream>
#include <boost/thread.hpp>
#include <boost/noncopyable.hpp>
#include <boost/date_time/posix_time/posix_time.hpp>

namespace fcl
{

/// @brief Namespace containing time datatypes and time operations
namespace time
{

/// @brief Representation of a point in time
typedef boost::posix_time::ptime         point;

/// @brief Representation of a time duration
typedef boost::posix_time::time_duration duration;

/// @brief Get the current time point
inline point now(void)
{
  return boost::posix_time::microsec_clock::universal_time();
}

/// @brief Return the time duration representing a given number of seconds
inline duration seconds(double sec)
{
  long s  = (long)sec;
  long us = (long)((sec - s) * 1000000);
  return boost::posix_time::seconds(s) + boost::posix_time::microseconds(us);
}

/// @brief Return the number of seconds that a time duration represents
inline double seconds(const duration &d)
{
  return (double)d.total_microseconds() / 1000000.0;
}

}

namespace tools
{

/// @brief This is a simple thread-safe tool for counting time
/// spent in various chunks of code. This is different from
/// external profiling tools in that it allows the user to count
/// time spent in various bits of code (sub-function granularity)
/// or count how many times certain pieces of code are executed.
class Profiler : private boost::noncopyable
{
public:

  /// @brief This instance will call Profiler::begin() when constructed and Profiler::end() when it goes out of scope.
  class ScopedBlock
  {
  public:
    /// @brief Start counting time for the block named \e name of the profiler \e prof
    ScopedBlock(const std::string &name, Profiler &prof = Profiler::Instance()) : name_(name), prof_(prof)
    {
      prof_.begin(name);
    }

    ~ScopedBlock(void)
    {
      prof_.end(name_);
    }

  private:

    std::string  name_;
    Profiler    &prof_;
  };

  /// @brief This instance will call Profiler::start() when constructed and Profiler::stop() when it goes out of scope.
  /// If the profiler was already started, this block's constructor and destructor take no action
  class ScopedStart
  {
  public:

    /// @brief Take as argument the profiler instance to operate on (\e prof)
    ScopedStart(Profiler &prof = Profiler::Instance()) : prof_(prof), wasRunning_(prof_.running())
    {
      if (!wasRunning_)
        prof_.start();
    }

    ~ScopedStart(void)
    {
      if (!wasRunning_)
        prof_.stop();
    }

  private:

    Profiler &prof_;
    bool      wasRunning_;
  };

  /// @brief Return an instance of the class 
  static Profiler& Instance(void);

  /// @brief Constructor. It is allowed to separately instantiate this
  /// class (not only as a singleton) 
  Profiler(bool printOnDestroy = false, bool autoStart = false) : running_(false), printOnDestroy_(printOnDestroy)
  {
    if (autoStart)
      start();
  }

  /// @brief Destructor 
  ~Profiler(void)
  {
    if (printOnDestroy_ && !data_.empty())
      status();
  }

  /// @brief Start counting time 
  static void Start(void)
  {
    Instance().start();
  }

  /// @brief Stop counting time 
  static void Stop(void)
  {
    Instance().stop();
  }

  /// @brief Clear counted time and events 
  static void Clear(void)
  {
    Instance().clear();
  }

  /// @brief Start counting time 
  void start(void);

  /// @brief Stop counting time 
  void stop(void);

  /// @brief Clear counted time and events 
  void clear(void);

  /// @brief Count a specific event for a number of times 
  static void Event(const std::string& name, const unsigned int times = 1)
  {
    Instance().event(name, times);
  }

  /// @brief Count a specific event for a number of times 
  void event(const std::string &name, const unsigned int times = 1);

  /// @brief Maintain the average of a specific value 
  static void Average(const std::string& name, const double value)
  {
    Instance().average(name, value);
  }

  /// @brief Maintain the average of a specific value 
  void average(const std::string &name, const double value);

  /// @brief Begin counting time for a specific chunk of code 
  static void Begin(const std::string &name)
  {
    Instance().begin(name);
  }

  /// @brief Stop counting time for a specific chunk of code 
  static void End(const std::string &name)
  {
    Instance().end(name);
  }

  /// @brief Begin counting time for a specific chunk of code 
  void begin(const std::string &name);

  /// @brief Stop counting time for a specific chunk of code 
  void end(const std::string &name);

  /// @brief Print the status of the profiled code chunks and
  /// events. Optionally, computation done by different threads
  /// can be printed separately. 
  static void Status(std::ostream &out = std::cout, bool merge = true)
  {
    Instance().status(out, merge);
  }

  /// @brief Print the status of the profiled code chunks and
  /// events. Optionally, computation done by different threads
  /// can be printed separately. 
  void status(std::ostream &out = std::cout, bool merge = true);

  /// @brief Check if the profiler is counting time or not 
  bool running(void) const
  {
    return running_;
  }

  /// @brief Check if the profiler is counting time or not 
  static bool Running(void)
  {
    return Instance().running();
  }

private:

  /// @brief Information about time spent in a section of the code 
  struct TimeInfo
  {
    TimeInfo(void) : total(0, 0, 0, 0), shortest(boost::posix_time::pos_infin), longest(boost::posix_time::neg_infin), parts(0)
    {
    }

    /// @brief Total time counted. 
    time::duration    total;

    /// @brief The shortest counted time interval 
    time::duration    shortest;

    /// @brief The longest counted time interval 
    time::duration    longest;

    /// @brief Number of times a chunk of time was added to this structure 
    unsigned long int parts;

    /// @brief The point in time when counting time started 
    time::point       start;

    /// @brief Begin counting time 
    void set(void)
    {
      start = time::now();
    }

    /// @brief Add the counted time to the total time 
    void update(void)
    {
      const time::duration &dt = time::now() - start;
      if (dt > longest)
        longest = dt;
      if (dt < shortest)
        shortest = dt;
      total = total + dt;
      ++parts;
    }
  };

  /// @brief Information maintained about averaged values 
  struct AvgInfo
  {
    /// @brief The sum of the values to average 
    double            total;

    /// @brief The sub of squares of the values to average 
    double            totalSqr;

    /// @brief Number of times a value was added to this structure 
    unsigned long int parts;
  };

  /// @brief Information to be maintained for each thread 
  struct PerThread
  {
    /// @brief The stored events 
    std::map<std::string, unsigned long int> events;

    /// @brief The stored averages 
    std::map<std::string, AvgInfo>           avg;

    /// @brief The amount of time spent in various places 
    std::map<std::string, TimeInfo>          time;
  };

  void printThreadInfo(std::ostream &out, const PerThread &data);

  boost::mutex                           lock_;
  std::map<boost::thread::id, PerThread> data_;
  TimeInfo                               tinfo_;
  bool                                   running_;
  bool                                   printOnDestroy_;

};
}
}

#else

#include <string>
#include <iostream>

/// If profiling is disabled, provide empty implementations for the public functions 
namespace fcl
{

namespace tools
{

class Profiler
{
public:

  class ScopedBlock
  {
  public:

    ScopedBlock(const std::string &, Profiler & = Profiler::Instance())
    {
    }

    ~ScopedBlock(void)
    {
    }
  };

  class ScopedStart
  {
  public:

    ScopedStart(Profiler & = Profiler::Instance())
    {
    }

    ~ScopedStart(void)
    {
    }
  };

  static Profiler& Instance(void);

  Profiler(bool = true, bool = true)
  {
  }

  ~Profiler(void)
  {
  }

  static void Start(void)
  {
  }

  static void Stop(void)
  {
  }

  static void Clear(void)
  {
  }

  void start(void)
  {
  }

  void stop(void)
  {
  }

  void clear(void)
  {
  }

  static void Event(const std::string&, const unsigned int = 1)
  {
  }

  void event(const std::string &, const unsigned int = 1)
  {
  }

  static void Average(const std::string&, const double)
  {
  }

  void average(const std::string &, const double)
  {
  }

  static void Begin(const std::string &)
  {
  }

  static void End(const std::string &)
  {
  }

  void begin(const std::string &)
  {
  }

  void end(const std::string &)
  {
  }

  static void Status(std::ostream & = std::cout, bool = true)
  {
  }

  void status(std::ostream & = std::cout, bool = true)
  {
  }

  bool running(void) const
  {
    return false;
  }

  static bool Running(void)
  {
    return false;
  }
};
}
}

#endif

#endif
