/*=========================================================================

  Program:   Insight Segmentation & Registration Toolkit
  Module:    $RCSfile$
  Language:  C++
  Date:      $Date$
  Version:   $Revision$

  Copyright (c) 2002 Insight Consortium. All rights reserved.
  See ITKCopyright.txt or http://www.itk.org/HTML/Copyright.htm for details.

     This software is distributed WITHOUT ANY WARRANTY; without even 
     the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR 
     PURPOSE.  See the above copyright notices for more information.

=========================================================================*/
#include "cmVTKMakeInstantiatorCommand.h"
#include "cmCacheManager.h"
#include "cmGeneratedFileStream.h"

bool
cmVTKMakeInstantiatorCommand
::InitialPass(std::vector<std::string> const& args)
{
  if(args.size() < 3)
    {
    this->SetError("called with incorrect number of arguments");
    return false;
    }
  
  m_ClassName = args[0];
  m_Makefile->ExpandVariablesInString(m_ClassName);
  
  std::string outSourceList = args[1];
  m_Makefile->ExpandVariablesInString(outSourceList);
  
  std::vector<cmStdString> inSourceLists;
  m_ExportMacro = "-";
  unsigned int groupSize = 10;
  
  // Find the path of the files to be generated.
  std::string filePath = m_Makefile->GetCurrentOutputDirectory();
  std::string headerPath = filePath;
  
  for(unsigned int i=2;i < args.size();++i)
    {
    if(args[i] == "GROUP_SIZE")
      {
      if(++i < args.size())
        {
        std::string gSize = args[i].c_str();
        m_Makefile->ExpandVariablesInString(gSize);
        groupSize = atoi(gSize.c_str());
        }
      else
        {
        this->SetError("GROUP_SIZE option used without value.");
        return false;
        }
      }
    else if(args[i] == "HEADER_LOCATION")
      {
      if(++i < args.size())
        {
        headerPath = args[i];
        m_Makefile->ExpandVariablesInString(headerPath);
        }
      else
        {
        this->SetError("HEADER_LOCATION option used without value.");
        return false;
        }
      }
    else if(args[i] == "EXPORT_MACRO")
      {
      if(++i < args.size())
        {
        m_ExportMacro = args[i];
        m_Makefile->ExpandVariablesInString(m_ExportMacro);
        }
      else
        {
        this->SetError("EXPORT_MACRO option used without value.");
        return false;
        }
      }
    // If not an option, it must be another input source list name.
    else
      {
      std::string s = args[i];
      m_Makefile->ExpandVariablesInString(s);
      inSourceLists.push_back(s);
      }
    }
  
  if(m_ExportMacro == "-")
    {
    this->SetError("No EXPORT_MACRO option given.");
    return false;
    }
  
  for(std::vector<cmStdString>::const_iterator s = inSourceLists.begin();
      s != inSourceLists.end(); ++s)
    {
    // Find the source list specified.
    cmMakefile::SourceMap::iterator srcListIter =
      m_Makefile->GetSources().find(*s);
    
    if(srcListIter == m_Makefile->GetSources().end())
      {
      std::string errStr = "No source list named " + *s;
      this->SetError(errStr.c_str());
      return false;
      }
    
    std::vector<cmSourceFile>& srcList = srcListIter->second;
    
    // Collect the names of the classes.
    for(std::vector<cmSourceFile>::iterator src = srcList.begin();
        src != srcList.end();++src)
      {
      // Wrap-excluded and abstract classes do not have a New() method.
      // vtkIndent and vtkTimeStamp are special cases and are not
      // vtkObject subclasses.
      if(!src->GetWrapExclude() && !src->GetIsAnAbstractClass()
         && (src->GetSourceName() != "vtkIndent")
         && (src->GetSourceName() != "vtkTimeStamp"))
        {
        m_Classes.push_back(src->GetSourceName());
        }
      }
    }    
  
  // Generate the header with the class declaration.
  {
  std::string fileName = m_ClassName + ".h";
  std::string fullName = headerPath+"/"+fileName;
  
  // Generate the output file with copy-if-different.
  cmGeneratedFileStream fout(fullName.c_str());
  
  // Actually generate the code in the file.
  this->GenerateHeaderFile(fout.GetStream());
  }
  
  // Generate the implementation file.
  {
  std::string fileName = m_ClassName + ".cxx";
  std::string fullName = filePath+"/"+fileName;
  
  // Generate the output file with copy-if-different.
  {
  cmGeneratedFileStream fout(fullName.c_str());
  
  // Actually generate the code in the file.
  this->GenerateImplementationFile(fout.GetStream());
  }
  
  // Add the generated source file into the source list.
  cmSourceFile file;
  file.SetWrapExclude(true);
  file.SetIsAnAbstractClass(false);
  file.SetName(fileName.c_str(), filePath.c_str(),
               m_Makefile->GetSourceExtensions(),
               m_Makefile->GetHeaderExtensions());
  m_Makefile->AddSource(file, outSourceList.c_str());
  }

  unsigned int numClasses = m_Classes.size();
  unsigned int numFullBlocks = numClasses / groupSize;
  unsigned int lastBlockSize = numClasses % groupSize;
  unsigned int numBlocks = numFullBlocks + ((lastBlockSize>0)? 1:0);

  // Generate the files with the ::New() calls to each class.  These
  // are done in groups to keep the translation unit size smaller.
  for(unsigned int block=0; block < numBlocks;++block)
    {
    std::string fileName = this->GenerateCreationFileName(block);    
    std::string fullName = filePath+"/"+fileName;
    
    // Generate the output file with copy-if-different.
    {
    cmGeneratedFileStream fout(fullName.c_str());
    
    unsigned int thisBlockSize =
      (block < numFullBlocks)? groupSize:lastBlockSize;
    
    // Actually generate the code in the file.
    this->GenerateCreationFile(fout.GetStream(),
                               block*groupSize, thisBlockSize);
    }
    
    // Add the generated source file into the source list.
    cmSourceFile file;
    file.SetWrapExclude(true);
    file.SetIsAnAbstractClass(false);
    file.SetName(fileName.c_str(), filePath.c_str(),
                 m_Makefile->GetSourceExtensions(),
                 m_Makefile->GetHeaderExtensions());
    m_Makefile->AddSource(file, outSourceList.c_str());
    }

  return true;
}

std::string
cmVTKMakeInstantiatorCommand::GenerateCreationFileName(unsigned int block)
{
  std::strstream nameStr;
  nameStr << m_ClassName.c_str() << block << ".cxx" << std::ends;
  std::string result = nameStr.str();
  nameStr.rdbuf()->freeze(0);
  return result;
}

// Generates the class header file with the definition of the class
// and its initializer class.
void
cmVTKMakeInstantiatorCommand
::GenerateHeaderFile(std::ostream& os)
{
  os <<
    "#ifndef __" << m_ClassName.c_str() << "_h\n"
    "#define __" << m_ClassName.c_str() << "_h\n"
    "\n"
    "#include \"vtkInstantiator.h\"\n"
    "\n"
    "class " << m_ClassName.c_str() << "Initialize;\n"
    "\n"
    "class " << m_ExportMacro.c_str() << " " << m_ClassName.c_str() << "\n"
    "{\n"
    "  friend class " << m_ClassName.c_str() << "Initialize;\n"
    "\n"
    "  static void ClassInitialize();\n"
    "  static void ClassFinalize();\n"
    "\n";
  
  for(unsigned int i=0;i < m_Classes.size();++i)
    {
    os << "  static vtkObject* Create_" << m_Classes[i].c_str() << "();\n";
    }
  
  // Write the initializer class to make sure the creation functions
  // get registered when this generated header is included.
  os <<
    "};\n"
    "\n"
    "class " << m_ExportMacro.c_str() << " " << m_ClassName.c_str() << "Initialize\n"
    "{\n"
    "public:\n"
    "  " << m_ClassName.c_str() << "Initialize();\n"
    "  ~" << m_ClassName.c_str() << "Initialize();\n"
    "private:\n"
    "  static unsigned int Count;\n"
    "};\n"
    "\n"
    "static " << m_ClassName.c_str() << "Initialize " << m_ClassName.c_str() << "Initializer;\n"
    "\n"
    "#endif\n";  
}

// Generates the file with the implementation of the class.  All
// methods except the actual object creation functions are generated
// here.
void
cmVTKMakeInstantiatorCommand
::GenerateImplementationFile(std::ostream& os)
{
  // Write the ClassInitialize method to register all the creation functions.
  os <<
    "#include \"" << m_ClassName.c_str() << ".h\"\n"
    "\n"
    "void " << m_ClassName.c_str() << "::ClassInitialize()\n"
    "{\n";
    
  for(unsigned int i=0;i < m_Classes.size();++i)
    {
    os << "  vtkInstantiator::RegisterInstantiator(\""
       << m_Classes[i].c_str() << "\", " << m_ClassName.c_str() << "::Create_"
       << m_Classes[i].c_str() << ");\n";
    }
  
  // Write the ClassFinalize method to unregister all the creation functions.
  os <<
    "}\n"
    "\n"
    "void " << m_ClassName.c_str() << "::ClassFinalize()\n"
    "{\n";
  
  for(unsigned int i=0;i < m_Classes.size();++i)
    {
    os << "  vtkInstantiator::UnRegisterInstantiator(\""
       << m_Classes[i].c_str() << "\", " << m_ClassName.c_str() << "::Create_"
       << m_Classes[i].c_str() << ");\n";
    }
  
  // Write the constructor and destructor of the initializer class to
  // call the ClassInitialize and ClassFinalize methods at the right
  // time.
  os <<
    "}\n"
    "\n" <<
    m_ClassName.c_str() << "Initialize::" << m_ClassName.c_str() << "Initialize()\n"
    "{\n"
    "  if(++" << m_ClassName.c_str() << "Initialize::Count == 1)\n"
    "    { " << m_ClassName.c_str() << "::ClassInitialize(); }\n"
    "}\n"
    "\n" <<
    m_ClassName.c_str() << "Initialize::~" << m_ClassName.c_str() << "Initialize()\n"
    "{\n"
    "  if(--" << m_ClassName.c_str() << "Initialize::Count == 0)\n"
    "    { " << m_ClassName.c_str() << "::ClassFinalize(); }\n"
    "}\n"
    "\n"
    "// Number of translation units that include this class's header.\n"
    "// Purposely not initialized.  Default is static initialization to 0.\n"
    "unsigned int " << m_ClassName.c_str() << "Initialize::Count;\n";
}

// Generates a file that includes the headers of the classes it knows
// how to create and provides functions which create the classes with
// the New() method.
void
cmVTKMakeInstantiatorCommand
::GenerateCreationFile(std::ostream& os, unsigned int groupStart,
                       unsigned int groupSize)
{
  // Need to include header of generated class.
  os <<
    "#include \"" << m_ClassName.c_str() << ".h\"\n"
    "\n";
  
  // Include class files.
  for(unsigned int i=0;i < groupSize;++i)
    {
    os << "#include \"" << m_Classes[groupStart+i].c_str() << ".h\"\n";
    }

  os <<
    "\n";

  // Write the create function implementations.
  for(unsigned int i=0;i < groupSize;++i)
    {
    os << "vtkObject* " << m_ClassName.c_str() << "::Create_"
       << m_Classes[groupStart+i].c_str() << "() { return "
       << m_Classes[groupStart+i].c_str() << "::New(); }\n";
    }
}