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

  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 "cmUseMangledMesaCommand.h"
#include "cmSystemTools.h"

// cmUseMangledMesaCommand
bool cmUseMangledMesaCommand::InitialPass(std::vector<std::string> const& args)
{ 
  // expected two arguments:
  // arguement one: the full path to gl_mangle.h
  // arguement two : directory for output of edited headers
  if(args.size() != 2)
    {
    this->SetError("called with incorrect number of arguments");
    return false;
    }
  const char* inputDir = args[0].c_str();
  std::string glh = inputDir;
  glh += "/";
  glh += "gl.h";
  if(!cmSystemTools::FileExists(glh.c_str()))
    {
    std::string e = "Bad path to Mesa, could not find: ";
    e += glh;
    e += " ";
    this->SetError(e.c_str());
    return false;
    }
  const char* destDir = args[1].c_str();
  std::vector<std::string> files;
  cmSystemTools::Glob(inputDir, "\\.h$", files);
  if(files.size() == 0)
    {
    cmSystemTools::Error("Could not open Mesa Directory ", inputDir);
    return false;
    }
  cmSystemTools::MakeDirectory(destDir);
  for(std::vector<std::string>::iterator i = files.begin();
      i != files.end(); ++i)
    {
    std::string path = inputDir;
    path += "/";
    path += *i;
    this->CopyAndFullPathMesaHeader(path.c_str(), destDir);
    }
  
  return true;
}

void 
cmUseMangledMesaCommand::
CopyAndFullPathMesaHeader(const char* source,
                          const char* outdir)
{
  std::string dir, file;
  cmSystemTools::SplitProgramPath(source, dir, file);
  std::string outFile = outdir;
  outFile += "/";
  outFile += file;
  std::string tempOutputFile = outFile;
  tempOutputFile += ".tmp";
  std::ofstream fout(tempOutputFile.c_str());
  if(!fout)
    {
    cmSystemTools::Error("Could not open file for write in copy operatation: ", 
                         tempOutputFile.c_str(), outdir);
    return;
    }
  std::ifstream fin(source);
  if(!fin)
    {
    cmSystemTools::Error("Could not open file for read in copy operatation",
                         source);
    return;
    }
  // now copy input to output and expand varibles in the
  // input file at the same time
  const int bufSize = 4096;
  char buffer[bufSize];
  std::string inLine;  
  // regular expression for any #include line
  cmRegularExpression includeLine("^[ \t]*#[ \t]*include[ \t]*[<\"]([^\">]+)[\">]");
  // regular expression for gl/ or GL/ in a file (match(1) of above)
  cmRegularExpression glDirLine("(gl|GL)(/|\\\\)([^<\"]+)");
  // regular expression for gl GL or xmesa in a file (match(1) of above)
  cmRegularExpression glLine("(gl|GL|xmesa)");
  while(fin)
    {
    fin.getline(buffer, bufSize);
    if(fin)
      {
      inLine = buffer;
      if(includeLine.find(inLine.c_str()))
        {
        std::string includeFile = includeLine.match(1);
        if(glDirLine.find(includeFile.c_str()))
          {
          std::string gfile = glDirLine.match(3);
          fout << "#include \"" << outdir << "/" << gfile.c_str() << "\"\n";
          }
        else if(glLine.find(includeFile.c_str()))
          {
          fout << "#include \"" << outdir << "/" << includeLine.match(1).c_str() << "\"\n";
          }
        else
          {
          fout << inLine << "\n";
          }
        }
      else
        {
        fout << inLine << "\n";
        }
      }
    }
  // close the files before attempting to copy
  fin.close();
  fout.close();
  cmSystemTools::CopyFileIfDifferent(tempOutputFile.c_str(),
                                     outFile.c_str());
  cmSystemTools::RemoveFile(tempOutputFile.c_str());
}