/*============================================================================
  CMake - Cross Platform Makefile Generator
  Copyright 2000-2009 Kitware, Inc., Insight Software Consortium

  Distributed under the OSI-approved BSD License (the "License");
  see accompanying file Copyright.txt for details.

  This software is distributed WITHOUT ANY WARRANTY; without even the
  implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  See the License for more information.
============================================================================*/
#include "cmCMakeMinimumRequired.h"

#include "cmVersion.h"

// cmCMakeMinimumRequired
bool cmCMakeMinimumRequired
::InitialPass(std::vector<std::string> const& args, cmExecutionStatus &)
{
  // Process arguments.
  std::string version_string;
  bool doing_version = false;
  for(unsigned int i=0; i < args.size(); ++i)
    {
    if(args[i] == "VERSION")
      {
      doing_version = true;
      }
    else if(args[i] == "FATAL_ERROR")
      {
      if(doing_version)
        {
        this->SetError("called with no value for VERSION.");
        return false;
        }
      doing_version = false;
      }
    else if(doing_version)
      {
      doing_version = false;
      version_string = args[i];
      }
    else
      {
      this->UnknownArguments.push_back(args[i]);
      }
    }
  if(doing_version)
    {
    this->SetError("called with no value for VERSION.");
    return false;
    }

  // Make sure there was a version to check.
  if(version_string.empty())
    {
    return this->EnforceUnknownArguments();
    }

  // Save the required version string.
  this->Makefile->AddDefinition("CMAKE_MINIMUM_REQUIRED_VERSION",
                                version_string.c_str());


  // Get the current version number.
  int current_major = cmVersion::GetMajorVersion();
  int current_minor = cmVersion::GetMinorVersion();
  int current_patch = cmVersion::GetPatchVersion();
  int current_tweak = cmVersion::GetTweakVersion();

  // Parse at least two components of the version number.
  // Use zero for those not specified.
  int required_major = 0;
  int required_minor = 0;
  int required_patch = 0;
  int required_tweak = 0;
  if(sscanf(version_string.c_str(), "%u.%u.%u.%u",
            &required_major, &required_minor,
            &required_patch, &required_tweak) < 2)
    {
    cmOStringStream e;
    e << "could not parse VERSION \"" << version_string.c_str() << "\".";
    this->SetError(e.str().c_str());
    return false;
    }

  // Compare the version numbers.
  if((current_major < required_major) ||
     (current_major == required_major &&
      current_minor < required_minor) ||
     (current_major == required_major &&
      current_minor == required_minor &&
      current_patch < required_patch) ||
     (current_major == required_major &&
      current_minor == required_minor &&
      current_patch == required_patch &&
      current_tweak < required_tweak))
    {
    // The current version is too low.
    cmOStringStream e;
    e << "CMake " << version_string.c_str()
      << " or higher is required.  You are running version "
      << cmVersion::GetCMakeVersion();
    this->Makefile->IssueMessage(cmake::FATAL_ERROR, e.str());
    cmSystemTools::SetFatalErrorOccured();
    return true;
    }

  // The version is not from the future, so enforce unknown arguments.
  if(!this->EnforceUnknownArguments())
    {
    return false;
    }

  if (required_major < 2 || (required_major == 2 && required_minor < 4))
  {
    this->Makefile->SetPolicyVersion("2.4");
  }
  else
  {
    this->Makefile->SetPolicyVersion(version_string.c_str());
  }
  
  return true;
}

//----------------------------------------------------------------------------
bool cmCMakeMinimumRequired::EnforceUnknownArguments()
{
  if(!this->UnknownArguments.empty())
    {
    cmOStringStream e;
    e << "called with unknown argument \""
      << this->UnknownArguments[0] << "\".";
    this->SetError(e.str().c_str());
    return false;
    }
  return true;
}