/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */

/*

 * Copyright (c) 2008 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

 *

 * Authors: Mathieu Lacage <mathieu.lacage@sophia.inria.fr>

 */

#include "global-value.h"

#include "fatal-error.h"

#include "attribute.h"

#include "string.h"

#include "uinteger.h"

#include "log.h"

#include "ns3/core-config.h"

#ifdef HAVE_STDLIB_H

#include <cstdlib>

#endif

/**

 * \file

 * \ingroup core

 * ns3::GlobalValue implementation.

 */

namespace ns3 {

NS_LOG_COMPONENT_DEFINE ("GlobalValue");

GlobalValue::GlobalValue (std::string name, std::string help,

                          const AttributeValue &initialValue,

                          Ptr<const AttributeChecker> checker)

  : m_name (name),

    m_help (help),

    m_initialValue (0),

    m_currentValue (0),

    m_checker (checker)

{

  NS_LOG_FUNCTION (name << help << &initialValue << checker);

  if (m_checker == 0)

    {

      NS_FATAL_ERROR ("Checker should not be zero on " << name );

    }

  m_initialValue = m_checker->CreateValidValue (initialValue);

  m_currentValue = m_initialValue;

  if (m_initialValue == 0)

    {

      NS_FATAL_ERROR ("Value set by user on " << name << " is invalid.");

    }

  GetVector ()->push_back (this);

  InitializeFromEnv ();

}

void

GlobalValue::InitializeFromEnv (void)

{

  NS_LOG_FUNCTION (this);

#ifdef HAVE_GETENV

  char *envVar = getenv ("NS_GLOBAL_VALUE");

  if (envVar == 0)

    {

      return;

    }

  std::string env = std::string (envVar);

  std::string::size_type cur = 0;

  std::string::size_type next = 0;

  while (next != std::string::npos)

    {

      next = env.find (";", cur);

      std::string tmp = std::string (env, cur, next-cur);

      std::string::size_type equal = tmp.find ("=");

      if (equal != std::string::npos)

        {

          std::string name = tmp.substr (0, equal);

          std::string value = tmp.substr (equal+1, tmp.size () - equal - 1);

          if (name == m_name)

            {

              Ptr<AttributeValue> v = m_checker->CreateValidValue (StringValue (value));

              if (v != 0)

                {

                  m_initialValue = v;

                  m_currentValue = v;

                }

              return;

            }

        }

      cur = next + 1;

    }

#endif /* HAVE_GETENV */

}

std::string 

GlobalValue::GetName (void) const

{

  NS_LOG_FUNCTION_NOARGS ();

  return m_name;

}

std::string 

GlobalValue::GetHelp (void) const

{

  NS_LOG_FUNCTION_NOARGS ();

  return m_help;

}

void

GlobalValue::GetValue (AttributeValue &value) const

{

  NS_LOG_FUNCTION (&value);

  bool ok = m_checker->Copy (*m_currentValue, value);

  if (ok)

    {

      return;

    }

  StringValue *str = dynamic_cast<StringValue *> (&value);

  if (str == 0)

    {

      NS_FATAL_ERROR ("GlobalValue name="<<m_name<<": input value is not a string");

    }

  str->Set (m_currentValue->SerializeToString (m_checker));

}

Ptr<const AttributeChecker> 

GlobalValue::GetChecker (void) const

{

  NS_LOG_FUNCTION (this);

  return m_checker;

}

bool

GlobalValue::SetValue (const AttributeValue &value)

{

  NS_LOG_FUNCTION (&value);

  Ptr<AttributeValue> v = m_checker->CreateValidValue (value);

  if (v == 0)

    {

      return 0;

    }

  m_currentValue = v;

  return true;

}

void 

GlobalValue::Bind (std::string name, const AttributeValue &value)

{

  NS_LOG_FUNCTION (name << &value);

  for (Iterator i = Begin (); i != End (); i++)

    {

      if ((*i)->GetName () == name)

        {

          if (!(*i)->SetValue (value))

            {

              NS_FATAL_ERROR ("Invalid new value for global value: "<<name);

            }

          return;

        }

    }

  NS_FATAL_ERROR ("Non-existant global value: "<<name);

}

bool 

GlobalValue::BindFailSafe (std::string name, const AttributeValue &value)

{

  NS_LOG_FUNCTION (name << &value);

  for (Iterator i = Begin (); i != End (); i++)

    {

      if ((*i)->GetName () == name)

        {

          return (*i)->SetValue (value);

        }

    }

  return false;

}

GlobalValue::Iterator 

GlobalValue::Begin (void)

{

  NS_LOG_FUNCTION_NOARGS ();

  return GetVector ()->begin ();

}

GlobalValue::Iterator 

GlobalValue::End (void)

{

  NS_LOG_FUNCTION_NOARGS ();

  return GetVector ()->end ();

}

void 

GlobalValue::ResetInitialValue (void)

{

  NS_LOG_FUNCTION (this);

  m_currentValue = m_initialValue;

}

bool

GlobalValue::GetValueByNameFailSafe (std::string name, AttributeValue &value)

{

  NS_LOG_FUNCTION (name << &value);

  for (GlobalValue::Iterator gvit = GlobalValue::Begin (); gvit != GlobalValue::End (); ++gvit)

    {

      if ((*gvit)->GetName () == name)

        {

          (*gvit)->GetValue (value);

          return true;

        }

    } 

  return false; // not found

}

void

GlobalValue::GetValueByName (std::string name, AttributeValue &value)

{

  NS_LOG_FUNCTION (name << &value);

  if (!GetValueByNameFailSafe (name, value))

    {

      NS_FATAL_ERROR ("Could not find GlobalValue named \"" << name << "\"");

    }

}

GlobalValue::Vector *

GlobalValue::GetVector (void)

{

  NS_LOG_FUNCTION_NOARGS ();

  static Vector vector;

  return &vector;

}

} // namespace ns3