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

 Program:   Visualization Toolkit
 Module:    VTXSchemaManager.cxx

 Copyright (c) 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.

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

/*
 * VTXSchemaManager.cxx
 *
 *  Created on: May 31, 2019
 *      Author: William F Godoy godoywf@ornl.gov
 */

#include "VTXSchemaManager.h"

#include "schema/vtk/VTXvtkVTI.h"
#include "schema/vtk/VTXvtkVTU.h"

#include <vtk_pugixml.h>
#include <vtksys/SystemTools.hxx>

#include "common/VTXHelper.h"

namespace vtx
{

// PUBLIC
void VTXSchemaManager::Update(
  const std::string& streamName, const size_t /*step*/, const std::string& schemaName)
{
  // can't do it in the constructor as it need MPI initialized
  if (!this->ADIOS)
  {
    this->ADIOS.reset(new adios2::ADIOS(helper::MPIGetComm()));
  }

  if (!this->IO && !this->Engine)
  {
    this->StreamName = streamName;
    this->SchemaName = schemaName;

    const std::string fileName = helper::GetFileName(this->StreamName);
    this->IO = this->ADIOS->DeclareIO(fileName);
    this->IO.SetEngine(helper::GetEngineType(fileName));
    this->Engine = this->IO.Open(fileName, adios2::Mode::Read);
    InitReader();
  }
  else
  {
    // TODO: check if variables changed
  }
}

void VTXSchemaManager::Fill(vtkMultiBlockDataSet* multiBlock, const size_t step)
{
  this->Reader->Fill(multiBlock, step);
}

// PRIVATE
const std::set<std::string> VTXSchemaManager::SupportedTypes = { "ImageData", "UnstructuredGrid" };
// TODO: , "StructuredGrid", "PolyData" };

void VTXSchemaManager::InitReader()
{
  if (InitReaderXMLVTK())
  {
    return;
  }
  // else if( InitReaderOther() ) {}
  // here we can make it extensible by trying to find other schema types
  // for now we stick with VTK XML schemas
}

bool VTXSchemaManager::InitReaderXMLVTK()
{
  pugi::xml_document xmlDocument;
  std::string xmlContents;

  bool isSchemaFile = false;

  // check if it's file, not optimizing with MPI_Bcast
  std::string xmlFileName;

  if (vtksys::SystemTools::FileIsDirectory(this->Engine.Name())) // BP4
  {
    xmlFileName = this->Engine.Name() + "/" + this->SchemaName;
  }
  else if (vtksys::SystemTools::FileIsDirectory(this->Engine.Name() + ".dir")) // BP3
  {
    xmlFileName = this->Engine.Name() + ".dir/" + this->SchemaName;
  }

  if (!xmlFileName.empty())
  {
    if (vtksys::SystemTools::FileExists(xmlFileName))
    {
      xmlContents = helper::FileToString(xmlFileName);
      xmlDocument =
        helper::XMLDocument(xmlContents, true, "when reading " + this->SchemaName + " file");
      isSchemaFile = true;
    }
  }

  if (!isSchemaFile)
  {
    const adios2::Attribute<std::string> vtkXMLAttribute =
      this->IO.InquireAttribute<std::string>(this->SchemaName);

    if (!vtkXMLAttribute)
    {
      throw std::runtime_error("ERROR: neither " + this->SchemaName +
        " file or bp attribute was found in " + this->Engine.Name() + "\n");
    }

    const std::vector<std::string> vtkAttributes = vtkXMLAttribute.Data();

    xmlContents = vtkAttributes.front();
    xmlDocument =
      helper::XMLDocument(xmlContents, true, "when reading " + this->SchemaName + " attribute");
  }

  constexpr bool isDebug = true;
  constexpr bool isMandatory = true;
  constexpr bool isUnique = true;

  const pugi::xml_node vtkXMLFileNode = helper::XMLNode("VTKFile", xmlDocument, isDebug,
    "when reading VTKFile node in " + this->Engine.Name(), isMandatory, isUnique);

  const pugi::xml_attribute typeXML = helper::XMLAttribute("type", vtkXMLFileNode, true,
    "when reading type xml attribute in vtk.xml " + this->Engine.Name(), isMandatory);

  const std::string type = std::string(typeXML.value());

  if (VTXSchemaManager::SupportedTypes.count(type) == 0)
  {
    throw std::runtime_error("ERROR: ADIOS2Reader only supports types= " +
      helper::SetToCSV(VTXSchemaManager::SupportedTypes) + " when reading type xml attribute in " +
      this->SchemaName + " from " + this->Engine.Name() + "\n");
  }

  if (type == "ImageData")
  {
    this->Reader.reset(new schema::VTXvtkVTI(xmlContents, this->IO, this->Engine));
  }
  else if (type == "UnstructuredGrid")
  {
    this->Reader.reset(new schema::VTXvtkVTU(xmlContents, this->IO, this->Engine));
  }

  const bool success = static_cast<bool>(this->Reader);
  return success;
}

} // end var namespace