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

 medInria

 Copyright (c) INRIA 2013 - 2020. All rights reserved.
 See LICENSE.txt for details.

  This software is distributed WITHOUT ANY WARRANTY; without even
  the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
  PURPOSE.

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

#include <map>
#include <string>
#include <vector>

#include "vtkDataManagerReader.h"

#include "vtkCompositeDataPipeline.h"
#include "vtkDataSet.h"
// #include "vtkMultiGroupDataSet.h"
#include "vtkInformation.h"
#include "vtkInformationVector.h"
#include "vtkObjectFactory.h"
#include "vtkSmartPointer.h"
#include "vtkXMLDataElement.h"
#include "vtkXMLImageDataReader.h"
#include "vtkXMLPolyDataReader.h"
#include "vtkXMLRectilinearGridReader.h"
#include "vtkXMLStructuredGridReader.h"
#include "vtkXMLUnstructuredGridReader.h"

#include <vtkDataSetReader.h>

#include <vtkUnstructuredGrid.h>
#include <vtkPolyData.h>
#include <vtkRectilinearGrid.h>
#include <vtkStructuredGrid.h>

#include <vtkDataManager.h>
#include <vtkMetaSurfaceMesh.h>
#include <vtkMetaVolumeMesh.h>
#include <vtkMetaDataSetSequence.h>
#include <vtkDataSet.h>

#include <vtkDataManager.h>

vtkStandardNewMacro(vtkDataManagerReader);

struct vtkDataManagerReaderEntry
{
    const char *extension;
    const char *name;
};

struct vtkDataManagerReaderInternals
{
    vtkXMLDataElement *MetaDataInformation;
    std::vector<vtkXMLDataElement*> MetaDataSets;
    typedef std::map<std::string, vtkSmartPointer<vtkXMLReader> > ReadersType;
    ReadersType Readers;
    static const vtkDataManagerReaderEntry ReaderList[];
};

//----------------------------------------------------------------------------
vtkDataManagerReader::vtkDataManagerReader()
{
    this->Internal = new vtkDataManagerReaderInternals;
    this->Output = vtkDataManager::New();
}

//----------------------------------------------------------------------------
vtkDataManagerReader::~vtkDataManagerReader()
{
    this->Output->Delete();

    delete this->Internal;
}

//----------------------------------------------------------------------------
void vtkDataManagerReader::PrintSelf(ostream& os, vtkIndent indent)
{
    this->Superclass::PrintSelf(os, indent);
}

//----------------------------------------------------------------------------
void vtkDataManagerReader::SetupEmptyOutput()
{
}

//----------------------------------------------------------------------------
const char*vtkDataManagerReader::GetDataSetName()
{
    return "vtkDataManager";
}

//----------------------------------------------------------------------------
int vtkDataManagerReader::FillOutputPortInformation(
    int vtkNotUsed(port), vtkInformation *info)
{
    info->Set(vtkDataObject::DATA_TYPE_NAME(), "vtkDataObject");
    return 1;
}

//----------------------------------------------------------------------------
vtkExecutive*vtkDataManagerReader::CreateDefaultExecutive()
{
    return vtkCompositeDataPipeline::New();
}

//----------------------------------------------------------------------------
vtkDataManager*vtkDataManagerReader::GetOutput()
{
    return this->Output;
}

//----------------------------------------------------------------------------
int vtkDataManagerReader::ReadPrimaryElement(vtkXMLDataElement *ePrimary)
{
    if(!this->Superclass::ReadPrimaryElement(ePrimary)) { return 0; }

    int numNested = ePrimary->GetNumberOfNestedElements();
    int i;
    this->Internal->MetaDataSets.clear();
    for(i=0; i < numNested; ++i)
    {
        vtkXMLDataElement *eNested = ePrimary->GetNestedElement(i);
        if(strcmp(eNested->GetName(), "vtkMetaDataSet") == 0)
        {
            this->Internal->MetaDataSets.push_back(eNested);
        }
    }


    return 1;
}

template<typename T>
vtkDataSet*FileToDataSet_helper(const std::string& filename)
{
    T *reader = T::New();
    reader->SetFileName(filename.c_str());
    reader->Update();
    vtkDataSet *output = reader->GetOutputAsDataSet();
    vtkDataSet *outputCopy = output->NewInstance();
    outputCopy->DeepCopy(output);
    reader->Delete();
    return outputCopy;
}

template<typename T>
vtkDataSet*FileToDataSet_helper2(const std::string& filename)
{
    T *reader = T::New();
    reader->SetFileName(filename.c_str());
    reader->Update();
    vtkDataSet *output = reader->GetOutput();
    vtkDataSet *outputCopy = output->NewInstance();
    outputCopy->DeepCopy(output);
    reader->Delete();
    return outputCopy;
}

//----------------------------------------------------------------------------
vtkDataSet*vtkDataManagerReader::FileToDataSet(const char *type, const std::string& filename)
{
    vtkDataSet *output = 0;
    if (strcmp(type, "vtkXMLImageDataReader") == 0) {
        output = FileToDataSet_helper<vtkXMLImageDataReader>(filename);
    } else if (strcmp(type, "vtkXMLUnstructuredGridReader") == 0) {
        output = FileToDataSet_helper<vtkXMLUnstructuredGridReader>(filename);
    } else if (strcmp(type, "vtkXMLPolyDataReader") == 0) {
        output = FileToDataSet_helper<vtkXMLPolyDataReader>(filename);
    } else if (strcmp(type, "vtkXMLRectilinearGridReader") == 0) {
        output = FileToDataSet_helper<vtkXMLRectilinearGridReader>(filename);
    } else if (strcmp(type, "vtkXMLStructuredGridReader") == 0) {
        output = FileToDataSet_helper<vtkXMLStructuredGridReader>(filename);
    } else if (strcmp(type, "vtkDataSetReader") == 0) {
        output = FileToDataSet_helper2<vtkDataSetReader>(filename);
    }

    return output;
}

//----------------------------------------------------------------------------
vtkMetaDataSet*vtkDataManagerReader::CreateMetaDataSetFromXMLElement (vtkXMLDataElement *element)
{
    vtkMetaDataSet *metadataset = nullptr;

    int type = 0;
    const char *name;
    double time = 0;
    const char *tag;

    std::string filePath = this->FileName;
    std::string::size_type pos = filePath.find_last_of("/\\");
    if(pos != filePath.npos)
    {
        filePath = filePath.substr(0, pos);
    }
    else
    {
        filePath = "";
    }

    if (!element->GetScalarAttribute("type", type))
    {
        vtkErrorMacro (<<"no type for this dataset : cannot handle"<<endl);
        return nullptr;
    }

    int numberofnested = element->GetNumberOfNestedElements();
    std::vector<vtkXMLDataElement*> frames;
    std::vector<vtkXMLDataElement*> flags;
    vtkXMLDataElement *data = nullptr;

    for(int i=0; i < numberofnested; ++i)
    {
        vtkXMLDataElement *eNested = element->GetNestedElement(i);
        if(strcmp(eNested->GetName(), "vtkMetaDataSet") == 0)
        {
            frames.push_back (eNested);
        }
        else if(strcmp(eNested->GetName(), "MetaData") == 0)
        {
            flags.push_back (eNested);
        }
        else if(strcmp(eNested->GetName(), "DataSet") == 0)
        {
            data = eNested;
        }
    }

    if (!frames.size())
    {
        switch(type)
        {
            case vtkMetaDataSet::VTK_META_VOLUME_MESH: metadataset = vtkMetaVolumeMesh::New(); break;
            case vtkMetaDataSet::VTK_META_SURFACE_MESH: metadataset = vtkMetaSurfaceMesh::New(); break;
            default:
                vtkWarningMacro (<<"dataset type not handled"<<endl); break;
        }
    }
    else
    {
        metadataset = vtkMetaDataSetSequence::New();
    }

    name = element->GetAttribute("name");
    if (name)
        metadataset->SetName (name);
    if (element->GetScalarAttribute("time", time))
        metadataset->SetTime (time);
    tag = element->GetAttribute("tag");
    if (tag)
        metadataset->SetTag (tag);

    for (unsigned int j=0; j<flags.size(); j++)
    {
        const char *key = flags[j]->GetAttribute("key");
        if (!key)
            continue;
        double val;
        flags[j]->GetScalarAttribute("value", val);
        metadataset->SetMetaData<double>(key, val);
    }

    if (!frames.size())
    {
        // Construct the name of the internal file.
        std::string fileName;
        const char *file = data->GetAttribute("file");
        if(!(file[0] == '/' || file[1] == ':'))
        {
            fileName = filePath;
            if(fileName.length())
            {
                fileName += "/";
            }
        }
        fileName += file;

        // Get the file extension.
        std::string ext;
        std::string::size_type pos2 = fileName.rfind('.');
        if(pos2 != fileName.npos)
        {
            ext = fileName.substr(pos2+1);
        }

        // Search for the reader matching this extension.
        const char *rname = 0;
        for(const vtkDataManagerReaderEntry *r =
                this->Internal->ReaderList;
            !rname && r->extension; ++r)
        {
            if(ext == r->extension)
            {
                rname = r->name;
            }
        }
        vtkDataSet *output = this->FileToDataSet(rname, fileName);
        if (!output)
        {
            vtkErrorMacro("Output is not a dataset for  " << rname);
            return nullptr;
        }

        metadataset->SetDataSet (output);
    }
    else
    {
        vtkMetaDataSetSequence *sequence = vtkMetaDataSetSequence::SafeDownCast (metadataset);
        for (unsigned int i=0; i<frames.size(); i++)
        {
            vtkMetaDataSet *frame = this->CreateMetaDataSetFromXMLElement (frames[i]);
            if (frame)
                sequence->AddMetaDataSet (frame);

            frame->Delete();
        }
    }

    return metadataset;
}

//----------------------------------------------------------------------------
void vtkDataManagerReader::ReadXMLData()
{
    // vtkExecutive* exec = this->GetExecutive();
    // vtkInformation* info = exec->GetOutputInformation(0);

    //unsigned int updatePiece = static_cast<unsigned int>(
    //  info->Get(vtkStreamingDemandDrivenPipeline::UPDATE_PIECE_NUMBER()));
    //unsigned int updateNumPieces =  static_cast<unsigned int>(
    //  info->Get(vtkStreamingDemandDrivenPipeline::UPDATE_NUMBER_OF_PIECES()));

    // Find the path to this file in case the internal files are
    // specified as relative paths.
    std::string filePath = this->FileName;
    std::string::size_type pos = filePath.find_last_of("/\\");
    if(pos != filePath.npos)
    {
        filePath = filePath.substr(0, pos);
    }
    else
    {
        filePath = "";
    }

    std::vector<vtkXMLDataElement*>::iterator d;

    for(d=this->Internal->MetaDataSets.begin();
        d != this->Internal->MetaDataSets.end(); ++d)
    {
        vtkMetaDataSet *metadataset = this->CreateMetaDataSetFromXMLElement (*d);
        if (metadataset)
        {
            this->GetOutput()->AddMetaDataSet (metadataset);
            metadataset->Delete();
        }
    }
}

//----------------------------------------------------------------------------
int vtkDataManagerReader::RequestInformation(
    vtkInformation *request,
    vtkInformationVector * *inputVector,
    vtkInformationVector *outputVector)
{
    this->Superclass::RequestInformation(request, inputVector, outputVector);
    vtkInformation *info = outputVector->GetInformationObject(0);
    info->Set(
        vtkStreamingDemandDrivenPipeline::UPDATE_NUMBER_OF_PIECES(), -1);

    return 1;
}

// //----------------------------------------------------------------------------
// void vtkDataManagerReader::HandleDataSet(vtkXMLDataElement*,
//                                                int group, int dsId,
//                                                vtkMultiGroupDataSet* output,
//                                                vtkDataSet* data)
// {
//   output->SetDataSet(group, dsId, data);
// }

//----------------------------------------------------------------------------
const vtkDataManagerReaderEntry
vtkDataManagerReaderInternals::ReaderList[] =
{
    {"vtp", "vtkXMLPolyDataReader"},
    {"vtu", "vtkXMLUnstructuredGridReader"},
    {"vti", "vtkXMLImageDataReader"},
    {"vtr", "vtkXMLRectilinearGridReader"},
    {"vts", "vtkXMLStructuredGridReader"},
    {"vtk", "vtkDataSetReader"},
    {0, 0}
};


//----------------------------------------------------------------------------
vtkMetaDataSet*vtkDataManagerReader::CreateMetaDataSetFromDataSet (vtkDataSet *dataset, const char *name)
{
    vtkMetaDataSet *metadataset = 0;

    switch (dataset->GetDataObjectType())
    {
        case VTK_UNSTRUCTURED_GRID:
            metadataset = vtkMetaVolumeMesh::New();
            break;
        case VTK_POLY_DATA:
            metadataset = vtkMetaSurfaceMesh::New();
            break;
        default:
            vtkWarningMacro (<<"dataset type not handled"<<endl);
            break;
    }

    metadataset->SetDataSet (dataset);
    metadataset->SetName (name);
    return metadataset;
}

//----------------------------------------------------------------------------
void vtkDataManagerReader::RestoreMetaDataSetInformation (vtkXMLDataElement *element)
{
    int NumberOfMetaDataSets = element->GetNumberOfNestedElements();
    int i;
    for(i=0; i < NumberOfMetaDataSets; ++i)
    {
        vtkMetaDataSet *metadataset = this->GetOutput()->GetMetaDataSet (i);
        if (!metadataset)
            continue;

        vtkXMLDataElement *metadatasetelement = element->GetNestedElement(i);
        const char *name = metadatasetelement->GetAttribute("name");
        const char *tag = metadatasetelement->GetAttribute("tag");
        int type = 0;
        double time;
        metadatasetelement->GetScalarAttribute("type", type);
        metadatasetelement->GetScalarAttribute("time", time);

        metadataset->SetName (name);
        metadataset->SetTime (time);
        metadataset->SetTag (tag);
        int NumberOfFlags = metadatasetelement->GetNumberOfNestedElements();
        for (int j=0; j<NumberOfFlags; j++)
        {
            vtkXMLDataElement *flagelement = metadatasetelement->GetNestedElement(j);
            const char *key = flagelement->GetAttribute("key");
            double val;
            flagelement->GetScalarAttribute("value", val);
            metadataset->SetMetaData<double>(key, val);
        }
    }
}