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

  Program:   Visualization Toolkit
  Module:    vtkObjectFactory.cxx
  Language:  C++
  Date:      $Date$
  Version:   $Revision$

  Copyright (c) 1993-2002 Ken Martin, Will Schroeder, Bill Lorensen 
  All rights reserved.
  See Copyright.txt or http://www.kitware.com/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 notice for more information.

=========================================================================*/
#include "vtkObjectFactory.h"

#include "vtkDebugLeaks.h"
#include "vtkDirectory.h"
#include "vtkDynamicLoader.h"
#include "vtkObjectFactoryCollection.h"
#include "vtkOverrideInformation.h"
#include "vtkOverrideInformationCollection.h"
#include "vtkVersion.h"

#include <ctype.h>

vtkCxxRevisionMacro(vtkObjectFactory, "1.36");

vtkObjectFactoryCollection* vtkObjectFactory::RegisteredFactories = 0;


class vtkCleanUpObjectFactory
{
public:
  inline void Use() 
    {
    }
  ~vtkCleanUpObjectFactory()
    {
      vtkObjectFactory::UnRegisterAllFactories();
    }  
};

static vtkCleanUpObjectFactory vtkCleanUpObjectFactoryGlobal;

// Create an instance of a named vtk object using the loaded
// factories

vtkObject* vtkObjectFactory::CreateInstance(const char* vtkclassname)
{
  if(!vtkObjectFactory::RegisteredFactories)
    {
    vtkObjectFactory::Init();
    }
  
  vtkObjectFactory* factory = 0;
  
  for(vtkObjectFactory::RegisteredFactories->InitTraversal();
      (factory = vtkObjectFactory::RegisteredFactories->GetNextItem());)
    {
    vtkObject* newobject = factory->CreateObject(vtkclassname);
    if(newobject)
      {
      return newobject;
      }
    }
  // if the factory does not create the object, then
  // the object will be created with the name passed in,
  // so register the construction
#ifdef VTK_DEBUG_LEAKS
  vtkDebugLeaks::ConstructClass(vtkclassname);
#endif

  return 0;
}




// A one time initialization method.   
void vtkObjectFactory::Init()
{
  vtkCleanUpObjectFactoryGlobal.Use();
  // Don't do anything if we are already initialized
  if(vtkObjectFactory::RegisteredFactories)
    {
    return;
    }
  
  vtkObjectFactory::RegisteredFactories = vtkObjectFactoryCollection::New();
  vtkObjectFactory::RegisterDefaults();
  vtkObjectFactory::LoadDynamicFactories();
}


// Register any factories that are always present in VTK like
// the OpenGL factory, currently this is not done.

void vtkObjectFactory::RegisterDefaults()
{
}


// Load all libraries in VTK_AUTOLOAD_PATH

void vtkObjectFactory::LoadDynamicFactories()
{
  // follow PATH convensions
#ifdef _WIN32
  char PathSeparator = ';';
#else
  char PathSeparator = ':';
#endif

  char* LoadPath = 0;

#ifndef _WIN32_WCE
  LoadPath = getenv("VTK_AUTOLOAD_PATH");
#endif
  if(LoadPath == 0)
    {
    return;
    }
  
  char* CurrentPath = new char[strlen(LoadPath)+1];
  char* SeparatorPosition = LoadPath; // initialize to env variable
  while(SeparatorPosition)
    {
    int PathLength =0;
    // find PathSeparator in LoadPath
    SeparatorPosition = strchr(LoadPath, PathSeparator);
    // if not found then use the whole string
    if(SeparatorPosition == 0)
      {
      PathLength = static_cast<int>(strlen(LoadPath));
      }
    else
      {
      PathLength = SeparatorPosition - LoadPath;
      }
    // copy the path out of LoadPath into CurrentPath
    strncpy(CurrentPath, LoadPath, PathLength);
    // add a null terminator
    CurrentPath[PathLength] = 0;
    // Get ready for the next path 
    LoadPath = SeparatorPosition+1;
    // Load the libraries in the current path
    vtkObjectFactory::LoadLibrariesInPath(CurrentPath);
    }
  // clean up memory
  delete [] CurrentPath;
}

// A file scope helper function to concat path and file into
// a full path
static char* CreateFullPath(const char* path, const char* file)
{
  int lenpath = static_cast<int>(strlen(path));
  char* ret = new char[lenpath + strlen(file)+2];
#ifdef _WIN32
  const char sep = '\\';
#else
  const char sep = '/';
#endif
  // make sure the end of path is a separator
  strcpy(ret, path);
  if(ret[lenpath-1] != sep)
    {
    ret[lenpath] = sep;
    ret[lenpath+1] = 0;
    }
  strcat(ret, file);
  return ret;
}

// A file scope typedef to make the cast code to the load
// function cleaner to read.
typedef vtkObjectFactory* (* VTK_LOAD_FUNCTION)();
typedef const char* (* VTK_VERSION_FUNCTION)();
typedef const char* (* VTK_COMPILER_FUNCTION)();


// A file scoped function to determine if a file has
// the shared library extension in its name, this converts name to lower
// case before the compare, vtkDynamicLoader always uses
// lower case for LibExtension values. 

inline int vtkNameIsSharedLibrary(const char* name)
{
  int len = static_cast<int>(strlen(name));
  char* copy = new char[len+1];
  
  for(int i = 0; i < len; i++)
    {
    copy[i] = tolower(name[i]);
    }
  copy[len] = 0;
  char* ret = strstr(copy, vtkDynamicLoader::LibExtension());
  delete [] copy;
  return (ret != NULL);
}

void vtkObjectFactory::LoadLibrariesInPath(const char* path)
{
  vtkDirectory* dir = vtkDirectory::New();
  if(!dir->Open(path))
    {
    dir->Delete();
    return;
    }
  
  // Attempt to load each file in the directory as a shared library
  for(int i = 0; i < dir->GetNumberOfFiles(); i++)
    {
    const char* file = dir->GetFile(i);
    // try to make sure the file has at least the extension
    // for a shared library in it.
    if(vtkNameIsSharedLibrary(file))
      {
      char* fullpath = CreateFullPath(path, file);
      vtkLibHandle lib = vtkDynamicLoader::OpenLibrary(fullpath);
      if(lib)
        {
        // Look for the symbol vtkLoad, vtkGetFactoryCompilerUsed,
        // and vtkGetFactoryVersion in the library
        VTK_LOAD_FUNCTION loadfunction
          = (VTK_LOAD_FUNCTION)
          vtkDynamicLoader::GetSymbolAddress(lib,
                                             "vtkLoad");
        VTK_COMPILER_FUNCTION compilerFunction
          = (VTK_COMPILER_FUNCTION)
          vtkDynamicLoader::GetSymbolAddress(lib,
                                             "vtkGetFactoryCompilerUsed");
        VTK_VERSION_FUNCTION versionFunction
          = (VTK_VERSION_FUNCTION)
          vtkDynamicLoader::GetSymbolAddress(lib,
                                             "vtkGetFactoryVersion");
        // if the symbol is found call it to create the factory
        // from the library
        if(loadfunction && compilerFunction && versionFunction)
          {
          const char* compiler = (*compilerFunction)();
          const char* version = (*versionFunction)();
          if(strcmp(compiler, VTK_CXX_COMPILER) ||
             strcmp(version, vtkVersion::GetVTKSourceVersion()))
            {
            vtkGenericWarningMacro(
              << "Incompatible factory rejected:"   
              << "\nRunning VTK compiled with: " <<  VTK_CXX_COMPILER
              << "\nFactory compiled with: " << compiler
              << "\nRunning VTK version: " << vtkVersion::GetVTKSourceVersion()
              << "\nFactory version: " << version 
              << "\nPath to rejected factory: " << fullpath << "\n");
            }
          else
            {
            vtkObjectFactory* newfactory = (*loadfunction)();
            newfactory->LibraryVTKVersion = 
              strcpy(new char[strlen(version)+1], version);
            newfactory->LibraryCompilerUsed = 
              strcpy(new char[strlen(compiler)+1], compiler);
            // initialize class members if load worked
            newfactory->LibraryHandle = (void*)lib;
            newfactory->LibraryPath = 
              strcpy(new char[strlen(fullpath)+1], fullpath);
            vtkObjectFactory::RegisterFactory(newfactory);
            newfactory->Delete();
            }
          }
        // if only the loadfunction is found, then warn
        else if (loadfunction)
          {
          vtkGenericWarningMacro("Old Style Factory not loaded.  Shared object has vtkLoad, but is missing vtkGetFactoryCompilerUsed and vtkGetFactoryVersion.  Recompile factory: " << fullpath << ", and use VTK_FACTORY_INTERFACE_IMPLEMENT macro.");
          }
        }
      delete [] fullpath;
      }
    }
  dir->Delete();
}


// Recheck the VTK_AUTOLOAD_PATH for new libraries

void vtkObjectFactory::ReHash()
{
  vtkObjectFactory::UnRegisterAllFactories();
  vtkObjectFactory::Init();
}

// initialize class members
vtkObjectFactory::vtkObjectFactory()
{
  this->LibraryHandle = 0;
  this->LibraryPath = 0;
  this->OverrideArray = 0;
  this->OverrideClassNames = 0;
  this->SizeOverrideArray = 0;
  this->OverrideArrayLength = 0;
  this->LibraryVTKVersion = 0;
  this->LibraryCompilerUsed = 0;
}


// Unload the library and free the path string
vtkObjectFactory::~vtkObjectFactory()
{
  delete [] this->LibraryVTKVersion;
  delete [] this->LibraryCompilerUsed;
  delete [] this->LibraryPath;
  this->LibraryPath = 0;
  
  for(int i =0; i < this->OverrideArrayLength; i++)
    {
    delete [] this->OverrideClassNames[i];
    delete [] this->OverrideArray[i].Description;
    delete [] this->OverrideArray[i].OverrideWithName;
    }
  delete [] this->OverrideArray;
  delete [] this->OverrideClassNames;
  this->OverrideArray = NULL;
  this->OverrideClassNames = NULL;
}

// Add a factory to the registered list
void vtkObjectFactory::RegisterFactory(vtkObjectFactory* factory)
{
  if(factory->LibraryHandle == 0)
    {
    const char* nonDynamicName = "Non-Dynamicly loaded factory";
    factory->LibraryPath = strcpy(new char[strlen(nonDynamicName)+1], 
                                  nonDynamicName);
    factory->LibraryCompilerUsed = 
      strcpy(new char[strlen(VTK_CXX_COMPILER)+1], VTK_CXX_COMPILER);
    factory->LibraryVTKVersion = 
      strcpy(new char[strlen(vtkVersion::GetVTKSourceVersion())+1],
             vtkVersion::GetVTKSourceVersion());
    }
  else 
    {
    if(strcmp(factory->LibraryCompilerUsed,
              VTK_CXX_COMPILER) != 0)
      {
      vtkGenericWarningMacro(<< "Possible incompatible factory load:" 
      << "\nRunning vtk compiled with :\n" <<  VTK_CXX_COMPILER
      << "\nLoaded Factory compiled with:\n" << factory->LibraryCompilerUsed
      << "\nRejecting factory:\n" << factory->LibraryPath << "\n");
      return;
      }
    if(strcmp(factory->LibraryVTKVersion, 
              vtkVersion::GetVTKSourceVersion()) != 0)
        {
        vtkGenericWarningMacro(<< "Possible incompatible factory load:" 
        << "\nRunning vtk version :\n" << vtkVersion::GetVTKSourceVersion() 
        << "\nLoaded Factory version:\n" << factory->LibraryVTKVersion
        << "\nRejecting factory:\n" << factory->LibraryPath << "\n");
        return;
        }
    if(strcmp(factory->GetVTKSourceVersion(), 
              vtkVersion::GetVTKSourceVersion()) != 0)
      {
      vtkGenericWarningMacro(<< "Possible incompatible factory load:" 
      << "\nRunning vtk version :\n" << vtkVersion::GetVTKSourceVersion() 
      << "\nLoaded Factory version:\n" << factory->GetVTKSourceVersion()
      << "\nRejecting factory:\n" << factory->LibraryPath << "\n");
      return;
      }
    }
  
  vtkObjectFactory::Init();
  vtkObjectFactory::RegisteredFactories->AddItem(factory);
}

// print ivars to stream
void vtkObjectFactory::PrintSelf(ostream& os, vtkIndent indent)
{
  this->Superclass::PrintSelf(os, indent);
  os << indent 
     << "Factory DLL path: " << this->LibraryPath << "\n";
  os << indent << "Library version: " << this->LibraryVTKVersion << "\n";
  os << indent << "Compiler used: " << this->LibraryCompilerUsed << "\n";
  os << indent << "Factory description: " << this->GetDescription() << endl;
  int num = this->GetNumberOfOverrides();
  os << indent << "Factory overides " << num << " classes:" << endl;
  indent = indent.GetNextIndent();
  for(int i =0; i < num; i++)
  {
    os << indent << "Class : " <<  this->GetClassOverrideName(i) << endl;
    os << indent << "Overriden with: " <<  this->GetClassOverrideWithName(i) 
       << endl;
    os << indent << "Enable flag: " <<  this->GetEnableFlag(i) << endl;
    os << endl;
  }
}

// Remove a factory from the list of registered factories.
void vtkObjectFactory::UnRegisterFactory(vtkObjectFactory* factory)
{ 
  void* lib = factory->LibraryHandle;
  vtkObjectFactory::RegisteredFactories->RemoveItem(factory);
  if(lib)
    {
    vtkDynamicLoader::CloseLibrary((vtkLibHandle)lib);
    }
}

// unregister all factories and delete the RegisteredFactories list
void vtkObjectFactory::UnRegisterAllFactories()
{
  // do not do anything if this is null
  if( ! vtkObjectFactory::RegisteredFactories )
    {
    return;
    }
  int num = vtkObjectFactory::RegisteredFactories->GetNumberOfItems();
  // collect up all the library handles so they can be closed
  // AFTER the factory has been deleted.
  void** libs = new void*[num+1];
  vtkObjectFactory* factory = 0;
  vtkObjectFactory::RegisteredFactories->InitTraversal();
  int index = 0;
  while((factory =
         vtkObjectFactory::RegisteredFactories->GetNextItem()))
    {
    libs[index++] = factory->LibraryHandle;
    }
  // delete the factory list and its factories
  vtkObjectFactory::RegisteredFactories->Delete();
  vtkObjectFactory::RegisteredFactories = 0;
  // now close the libraries
  for(int i = 0; i < num; i++)
    {
    void* lib = libs[i];
    if(lib)
      {
      vtkDynamicLoader::CloseLibrary(reinterpret_cast<vtkLibHandle>(lib));
      }
    }
  delete [] libs;
}


// Register an override function with a factory.
void vtkObjectFactory::RegisterOverride(const char* classOverride,
                                        const char* subclass,
                                        const char* description,
                                        int enableFlag,
                                        CreateFunction createFunction)
{
  this->GrowOverrideArray();
  int nextIndex = this->OverrideArrayLength;
  this->OverrideArrayLength++;
  char* override = strcpy(new char[strlen(classOverride)+1], classOverride);
  char* desc = strcpy(new char[strlen(description)+1], description);
  char* ocn =  strcpy(new char[strlen(subclass)+1], 
                      subclass);
  this->OverrideClassNames[nextIndex] = override;
  this->OverrideArray[nextIndex].Description = desc;
  this->OverrideArray[nextIndex].OverrideWithName = ocn;
  this->OverrideArray[nextIndex].EnabledFlag = enableFlag;
  this->OverrideArray[nextIndex].CreateCallback = createFunction;
}

// Create an instance of an object
vtkObject* vtkObjectFactory::CreateObject(const char* vtkclassname)
{
  for(int i=0; i < this->OverrideArrayLength; i++)
  {
    if(this->OverrideArray[i].EnabledFlag &&
       strcmp(this->OverrideClassNames[i], vtkclassname) == 0)
    {
      return (*this->OverrideArray[i].CreateCallback)();
    }
  }
  return 0;
}
  
// grow the array if the length is greater than the size.
void vtkObjectFactory::GrowOverrideArray()
{
  if(this->OverrideArrayLength+1 > this->SizeOverrideArray)
  {
    int newLength = this->OverrideArrayLength + 50;
    OverrideInformation* newArray = new OverrideInformation[newLength];
    char** newNameArray = new char*[newLength];
    for(int i =0; i < this->OverrideArrayLength; i++)
    {
      newNameArray[i] = this->OverrideClassNames[i];
      newArray[i] = this->OverrideArray[i];
    }
    delete [] this->OverrideClassNames;
    this->OverrideClassNames = newNameArray;
    delete [] this->OverrideArray;
    this->OverrideArray = newArray;
  }
}

int vtkObjectFactory::GetNumberOfOverrides()
{
  return this->OverrideArrayLength;
}

const char* vtkObjectFactory::GetClassOverrideName(int index)
{
  return this->OverrideClassNames[index];
}

const char* vtkObjectFactory::GetClassOverrideWithName(int index)
{
  return this->OverrideArray[index].OverrideWithName;
}
  
int vtkObjectFactory::GetEnableFlag(int index)
{
  return this->OverrideArray[index].EnabledFlag;
}

const char* vtkObjectFactory::GetOverrideDescription(int index)
{
  return this->OverrideArray[index].Description;
}

// Set the enable flag for a class / subclassName pair
void vtkObjectFactory::SetEnableFlag(int flag,
                                     const char* className,
                                     const char* subclassName)
{
  for(int i =0; i < this->OverrideArrayLength; i++)
    {
    if(strcmp(this->OverrideClassNames[i], className) == 0)
      {
      // if subclassName is null, then set on className match
      if(!subclassName)
        {
        this->OverrideArray[i].EnabledFlag = flag;
        }
      else 
        {
        if(strcmp(this->OverrideArray[i].OverrideWithName, subclassName) == 0)
          {
          this->OverrideArray[i].EnabledFlag = flag;
          }
        }
      }
    }
}

// Get the enable flag for a className/subclassName pair
int vtkObjectFactory::GetEnableFlag(const char* className,
                                    const char* subclassName)
{
  for(int i =0; i < this->OverrideArrayLength; i++)
  {
    if(strcmp(this->OverrideClassNames[i], className) == 0)
    {
      if(strcmp(this->OverrideArray[i].OverrideWithName, subclassName) == 0)
      {
        return this->OverrideArray[i].EnabledFlag;
      }
    }
  }
  return 0;
}

// Set the EnabledFlag to 0 for a given classname
void vtkObjectFactory::Disable(const char* className)
{
  for(int i =0; i < this->OverrideArrayLength; i++)
  {
    if(strcmp(this->OverrideClassNames[i], className) == 0)
    {
      this->OverrideArray[i].EnabledFlag = 0;
    }
  }
}

// 1,0 is the class overriden by className
int vtkObjectFactory::HasOverride(const char* className)
{
  for(int i =0; i < this->OverrideArrayLength; i++)
    {
    if(strcmp(this->OverrideClassNames[i], className) == 0)
      {
      return 1;
      }
    }
  return 0;
}

// 1,0 is the class overriden by className/subclassName pair
int vtkObjectFactory::HasOverride(const char* className, 
                                  const char* subclassName)
{
  for(int i =0; i < this->OverrideArrayLength; i++)
    {
    if(strcmp(this->OverrideClassNames[i], className) == 0)
      { 
      if(strcmp(this->OverrideArray[i].OverrideWithName, subclassName) == 0)
        {
        return 1;
        }
      }
    }
  return 0;
}


vtkObjectFactoryCollection* vtkObjectFactory::GetRegisteredFactories()
{
  if(!vtkObjectFactory::RegisteredFactories)
    {
    vtkObjectFactory::Init();
    }

  return vtkObjectFactory::RegisteredFactories;
}


// 1,0 is the className overriden by any registered factories
int vtkObjectFactory::HasOverrideAny(const char* className)
{
  vtkObjectFactory* factory = 0;
  for(vtkObjectFactory::RegisteredFactories->InitTraversal();
      (factory = vtkObjectFactory::RegisteredFactories->GetNextItem());)
    {
    if(factory->HasOverride(className))
      {
      return 1;
      }
    }
  return 0;
}

// Create a helper class to get around
// only being able to iterate a list only once at the
// same time.
class vtkObjectFactoryCollectionIterator : public vtkCollection
{
public:
  vtkObjectFactoryCollectionIterator(vtkCollection* source)
    {
      Source = source;
#ifdef VTK_DEBUG_LEAKS
      vtkDebugLeaks::ConstructClass("vtkCollection");
#endif
    }
  vtkObjectFactory* GetNextItem() 
    {
      return vtkObjectFactory::SafeDownCast(this->GetNextItemAsObject());
    }
  
  void InitTraversal()
    { 
      this->Current = this->Top = 
        ((vtkObjectFactoryCollectionIterator*)this->Source)->Top;
    }
  vtkCollection* Source;
private:
  vtkObjectFactoryCollectionIterator(const vtkObjectFactoryCollectionIterator&);
  void operator=(const vtkObjectFactoryCollectionIterator&);
};


// collect up information about current registered factories  
void
vtkObjectFactory::GetOverrideInformation(const char* name,
                                         vtkOverrideInformationCollection* 
                                         ret)
{
  // create the collection to return
  vtkOverrideInformation* overInfo = 0; // info object pointer
  vtkObjectFactory* factory = 0; // factory pointer for traversal
  vtkObjectFactoryCollectionIterator* it = 
    new vtkObjectFactoryCollectionIterator(vtkObjectFactory::RegisteredFactories);
  for(it->InitTraversal();
      (factory = it->GetNextItem());)
    {
    for(int i =0; i < factory->OverrideArrayLength; i++)
      {
      if( strcmp(name, factory->OverrideClassNames[i]) == 0)
        {
        // Create a new override info class
        overInfo = vtkOverrideInformation::New();
        // Set the class name
        overInfo->SetClassOverrideName(factory->OverrideClassNames[i]);
        // Set the override class name
        overInfo->SetClassOverrideWithName(
          factory->OverrideArray[i].OverrideWithName);
        // Set the Description for the override
        overInfo->SetDescription(factory->OverrideArray[i].Description);
        // Set the factory for the override
        overInfo->SetObjectFactory(factory);
        // add the item to the collection
        ret->AddItem(overInfo);
        overInfo->Delete();
        }
      }
    }
  it->Delete();
}

// set enable flag for all registered factories for the given className
void vtkObjectFactory::SetAllEnableFlags(int flag, 
                                         const char* className)
{
  vtkObjectFactory* factory = 0;
  for(vtkObjectFactory::RegisteredFactories->InitTraversal();
      (factory = vtkObjectFactory::RegisteredFactories->GetNextItem());)
    {
    factory->SetEnableFlag(flag, className, 0);
    }
  
}

// set enable flag for the first factory that that
// has an override for className/subclassName pair
void vtkObjectFactory::SetAllEnableFlags(int flag,
                                         const char* className,
                                         const char* subclassName)
{
  vtkObjectFactory* factory = 0;
  for(vtkObjectFactory::RegisteredFactories->InitTraversal();
      (factory = vtkObjectFactory::RegisteredFactories->GetNextItem());)
    {
    factory->SetEnableFlag(flag, className, subclassName);
    }
}




  
void vtkObjectFactory::CreateAllInstance(const char* vtkclassname,
                                               vtkCollection* retList)
{
  vtkObjectFactory* f;
  vtkObjectFactoryCollection* collection
    = vtkObjectFactory::GetRegisteredFactories();
  for(collection->InitTraversal(); (f = collection->GetNextItem()); )
    {
    vtkObject* o = f->CreateObject(vtkclassname);
    if(o)
      {
      retList->AddItem(o);
      o->Delete();
      }
    }
}

