// SPDX-FileCopyrightText: Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen
// SPDX-License-Identifier: BSD-3-Clause
#include "vtkGESignaReader.h"

#include "vtkByteSwap.h"
#include "vtkDataArray.h"
#include "vtkImageData.h"
#include "vtkMedicalImageProperties.h"
#include "vtkObjectFactory.h"
#include "vtkPointData.h"
#include <vtksys/SystemTools.hxx>

#include <cassert>
#include <vector>

VTK_ABI_NAMESPACE_BEGIN
vtkStandardNewMacro(vtkGESignaReader);

int vtkGESignaReader::CanReadFile(const char* fname)
{
  FILE* fp = vtksys::SystemTools::Fopen(fname, "rb");
  if (!fp)
  {
    return 0;
  }

  int magic;
  if (fread(&magic, 4, 1, fp) != 1)
  {
    fclose(fp);
    return 0;
  }
  vtkByteSwap::Swap4BE(&magic);

  if (magic != 0x494d4746) // "IMGF"
  {
    fclose(fp);
    return 0;
  }
  fclose(fp);
  return 3;
}

void vtkGESignaReader::ExecuteInformation()
{
  this->ComputeInternalFileName(this->DataExtent[4]);
  if (this->InternalFileName == nullptr)
  {
    return;
  }

  FILE* fp = vtksys::SystemTools::Fopen(this->InternalFileName, "rb");
  if (!fp)
  {
    vtkErrorMacro("Unable to open file " << this->InternalFileName);
    return;
  }

  int magic;
  if (fread(&magic, 4, 1, fp) != 1)
  {
    vtkErrorMacro("GESignaReader error reading file: " << this->FileName
                                                       << " Premature EOF while reading magic.");
    fclose(fp);
    return;
  }
  vtkByteSwap::Swap4BE(&magic);

  if (magic != 0x494d4746)
  {
    vtkErrorMacro(<< "Unknown file type! Not a GE ximg file!");
    fclose(fp);
    return;
  }

  // read in the pixel offset from the header
  int offset;
  if (fread(&offset, 4, 1, fp) != 1)
  {
    vtkErrorMacro("GESignaReader error reading file: "
      << this->FileName << " Premature EOF while reading pixel offset.");
    fclose(fp);
    return;
  }
  vtkByteSwap::Swap4BE(&offset);
  this->SetHeaderSize(offset);

  int width, height, depth;
  if (fread(&width, 4, 1, fp) != 1)
  {
    vtkErrorMacro("GESignaReader error reading file: " << this->FileName
                                                       << " Premature EOF while reading width.");
    fclose(fp);
    return;
  }
  vtkByteSwap::Swap4BE(&width);
  if (fread(&height, 4, 1, fp) != 1)
  {
    vtkErrorMacro("GESignaReader error reading file: " << this->FileName
                                                       << " Premature EOF while reading height.");
    fclose(fp);
    return;
  }
  vtkByteSwap::Swap4BE(&height);
  // depth in bits
  if (fread(&depth, 4, 1, fp) != 1)
  {
    vtkErrorMacro("GESignaReader error reading file: " << this->FileName
                                                       << " Premature EOF while reading depth.");
    fclose(fp);
    return;
  }
  vtkByteSwap::Swap4BE(&depth);

  int compression;
  if (fread(&compression, 4, 1, fp) != 1)
  {
    vtkErrorMacro("GESignaReader error reading file: "
      << this->FileName << " Premature EOF while reading compression.");
    fclose(fp);
    return;
  }
  vtkByteSwap::Swap4BE(&compression);

  // seek to the exam series and image header offsets
  fseek(fp, 132, SEEK_SET);
  int examHdrOffset;
  if (fread(&examHdrOffset, 4, 1, fp) != 1)
  {
    vtkErrorMacro("GESignaReader error reading file: "
      << this->FileName << " Premature EOF while reading exam header offset.");
    fclose(fp);
    return;
  }
  vtkByteSwap::Swap4BE(&examHdrOffset);
  fseek(fp, 140, SEEK_SET);
  int seriesHdrOffset;
  if (fread(&seriesHdrOffset, 4, 1, fp) != 1)
  {
    vtkErrorMacro("GESignaReader error reading file: "
      << this->FileName << " Premature EOF while series header offset.");
    fclose(fp);
    return;
  }
  vtkByteSwap::Swap4BE(&seriesHdrOffset);
  fseek(fp, 148, SEEK_SET);
  int imgHdrOffset;
  if (fread(&imgHdrOffset, 4, 1, fp) != 1)
  {
    vtkErrorMacro("GESignaReader error reading file: "
      << this->FileName << " Premature EOF while image header offset.");
    fclose(fp);
    return;
  }
  vtkByteSwap::Swap4BE(&imgHdrOffset);

  // seek to the exam and read some info
  char tmpStr[1024];
  // suite ID
  fseek(fp, examHdrOffset + 0, SEEK_SET);
  if (fread(tmpStr, 4, 1, fp) != 1)
  {
    vtkErrorMacro(
      "GESignaReader error reading file: " << this->FileName << " Premature EOF while suite ID.");
    fclose(fp);
    return;
  }
  tmpStr[4] = 0;
  this->GetMedicalImageProperties()->SetStudyDescription(tmpStr); // StudyID would be more suited...
  // exam number
  fseek(fp, examHdrOffset + 8, SEEK_SET);
  unsigned short examnumber;
  if (fread(&examnumber, 2, 1, fp) != 1)
  {
    vtkErrorMacro("GESignaReader error reading file: " << this->FileName
                                                       << " Premature EOF while exam number.");
    fclose(fp);
    return;
  }
  vtkByteSwap::Swap2BE(&examnumber);
  snprintf(tmpStr, sizeof(tmpStr), "%d", examnumber);
  // this->SetStudyNumber(tmpStr);
  // Patient ID
  fseek(fp, examHdrOffset + 84, SEEK_SET);
  if (fread(tmpStr, 13, 1, fp) != 1)
  {
    vtkErrorMacro(
      "GESignaReader error reading file: " << this->FileName << " Premature EOF while patient ID.");
    fclose(fp);
    return;
  }
  tmpStr[13] = 0;
  this->SetPatientID(tmpStr);
  // Patient Name
  if (fread(tmpStr, 25, 1, fp) != 1)
  {
    vtkErrorMacro("GESignaReader error reading file: "
      << this->FileName << " Premature EOF while reading patient name.");
    fclose(fp);
    return;
  }
  tmpStr[25] = 0;
  this->SetPatientName(tmpStr);
  // Patient Age
  fseek(fp, examHdrOffset + 122, SEEK_SET);
  short patientage;
  if (fread(&patientage, 2, 1, fp) != 1)
  {
    vtkErrorMacro("GESignaReader error reading file: "
      << this->FileName << " Premature EOF while reading patient age.");
    fclose(fp);
    return;
  }
  vtkByteSwap::Swap2BE(&patientage);
  snprintf(tmpStr, sizeof(tmpStr), "%d", patientage);
  this->GetMedicalImageProperties()->SetPatientAge(tmpStr);
  // Patient Sex
  fseek(fp, examHdrOffset + 126, SEEK_SET);
  short patientsex;
  if (fread(&patientsex, 2, 1, fp) != 1)
  {
    vtkErrorMacro("GESignaReader error reading file: "
      << this->FileName << " Premature EOF while reading patient sex.");
    fclose(fp);
    return;
  }
  vtkByteSwap::Swap2BE(&patientsex);
  snprintf(tmpStr, sizeof(tmpStr), "%d", patientsex);
  this->GetMedicalImageProperties()->SetPatientSex(tmpStr);
  // Modality
  fseek(fp, examHdrOffset + 305, SEEK_SET);
  if (fread(tmpStr, 3, 1, fp) != 1)
  {
    vtkErrorMacro("GESignaReader error reading file: " << this->FileName
                                                       << " Premature EOF while reading modality.");
    fclose(fp);
    return;
  }
  tmpStr[3] = 0;
  this->SetModality(tmpStr);

  // seek to the series and read some info
  // series number
  fseek(fp, seriesHdrOffset + 10, SEEK_SET);
  short series;
  if (fread(&series, 2, 1, fp) != 1)
  {
    vtkErrorMacro("GESignaReader error reading file: " << this->FileName
                                                       << " Premature EOF while reading series.");
    fclose(fp);
    return;
  }
  vtkByteSwap::Swap2BE(&series);
  snprintf(tmpStr, sizeof(tmpStr), "%d", series);
  this->SetSeries(tmpStr);
  // scan protocol name
  fseek(fp, seriesHdrOffset + 92, SEEK_SET);
  if (fread(tmpStr, 25, 1, fp) != 1)
  {
    vtkErrorMacro("GESignaReader error reading file: "
      << this->FileName << " Premature EOF while reading scan protocol.");
    fclose(fp);
    return;
  }
  tmpStr[25] = 0;
  this->SetStudy(tmpStr); // ??

  // now seek to the image header and read some values
  float tmpX, tmpY, tmpZ;
  float spacingX, spacingY, spacingZ;
  fseek(fp, imgHdrOffset + 50, SEEK_SET);
  if (fread(&spacingX, 4, 1, fp) != 1)
  {
    vtkErrorMacro("GESignaReader error reading file: "
      << this->FileName << " Premature EOF while reading spacing x.");
    fclose(fp);
    return;
  }
  vtkByteSwap::Swap4BE(&spacingX);
  if (fread(&spacingY, 4, 1, fp) != 1)
  {
    vtkErrorMacro("GESignaReader error reading file: "
      << this->FileName << " Premature EOF while reading spacing y.");
    fclose(fp);
    return;
  }
  vtkByteSwap::Swap4BE(&spacingY);
  fseek(fp, imgHdrOffset + 116, SEEK_SET);
  if (fread(&spacingZ, 4, 1, fp) != 1)
  {
    vtkErrorMacro("GESignaReader error reading file: "
      << this->FileName << " Premature EOF while reading spacing z.");
    fclose(fp);
    return;
  }
  vtkByteSwap::Swap4BE(&spacingZ);
  // Slice Thickness
  fseek(fp, imgHdrOffset + 26, SEEK_SET);
  if (fread(&tmpZ, 4, 1, fp) != 1)
  {
    vtkErrorMacro("GESignaReader error reading file: "
      << this->FileName << " Premature EOF while reading slice thickness.");
    fclose(fp);
    return;
  }
  vtkByteSwap::Swap4BE(&tmpZ);
  spacingZ = spacingZ + tmpZ;

  float origX, origY, origZ;
  fseek(fp, imgHdrOffset + 154, SEEK_SET);
  // read TLHC
  if (fread(&origX, 4, 1, fp) != 1)
  {
    vtkErrorMacro("GESignaReader error reading file: " << this->FileName
                                                       << " Premature EOF while reading origX.");
    fclose(fp);
    return;
  }
  vtkByteSwap::Swap4BE(&origX);
  if (fread(&origY, 4, 1, fp) != 1)
  {
    vtkErrorMacro("GESignaReader error reading file: " << this->FileName
                                                       << " Premature EOF while reading origY.");
    fclose(fp);
    return;
  }
  vtkByteSwap::Swap4BE(&origY);
  if (fread(&origZ, 4, 1, fp) != 1)
  {
    vtkErrorMacro("GESignaReader error reading file: " << this->FileName
                                                       << " Premature EOF while reading origZ.");
    fclose(fp);
    return;
  }
  vtkByteSwap::Swap4BE(&origZ);

  // read TRHC
  if (fread(&tmpX, 4, 1, fp) != 1)
  {
    vtkErrorMacro("GESignaReader error reading file: " << this->FileName
                                                       << " Premature EOF while reading TRHC x.");
    fclose(fp);
    return;
  }
  vtkByteSwap::Swap4BE(&tmpX);
  if (fread(&tmpY, 4, 1, fp) != 1)
  {
    vtkErrorMacro("GESignaReader error reading file: " << this->FileName
                                                       << " Premature EOF while reading TRCH y.");
    fclose(fp);
    return;
  }
  vtkByteSwap::Swap4BE(&tmpY);
  if (fread(&tmpZ, 4, 1, fp) != 1)
  {
    vtkErrorMacro("GESignaReader error reading file: " << this->FileName
                                                       << " Premature EOF while reading TRCH z.");
    fclose(fp);
    return;
  }
  vtkByteSwap::Swap4BE(&tmpZ);

  // compute BLHC = TLHC - TRHC + BRHC
  origX = origX - tmpX;
  origY = origY - tmpY;
  origZ = origZ - tmpZ;

  // read BRHC
  if (fread(&tmpX, 4, 1, fp) != 1)
  {
    vtkErrorMacro("GESignaReader error reading file: " << this->FileName
                                                       << " Premature EOF while reading BRHC x.");
    fclose(fp);
    return;
  }
  vtkByteSwap::Swap4BE(&tmpX);
  if (fread(&tmpY, 4, 1, fp) != 1)
  {
    vtkErrorMacro("GESignaReader error reading file: " << this->FileName
                                                       << " Premature EOF while reading BRHC y.");
    fclose(fp);
    return;
  }
  vtkByteSwap::Swap4BE(&tmpY);
  if (fread(&tmpZ, 4, 1, fp) != 1)
  {
    vtkErrorMacro("GESignaReader error reading file: " << this->FileName
                                                       << " Premature EOF while reading BRCH z.");
    fclose(fp);
    return;
  }
  vtkByteSwap::Swap4BE(&tmpZ);

  // compute BLHC = TLHC - TRHC + BRHC
  origX = origX + tmpX;
  origY = origY + tmpY;
  origZ = origZ + tmpZ;

  /*
  http://www.dclunie.com/medical-image-faq/html/part4.html#Signa5X
  image header - for MR (1022 bytes long):

  194 - int      - repetition time(usec)
  198 - int      - inversion time(usec)
  202 - int      - echo time(usec)
  210 - short    - number of echoes
  212 - short    - echo number
  218 - float    - NEX
  308 - char[33] - pulse sequence name
  362 - char[17] - coil name
  640 - short    - ETL for FSE
   */

  this->SetDataOrigin(origX, origY, origZ);

  this->DataExtent[0] = 0;
  this->DataExtent[1] = width - 1;
  this->DataExtent[2] = 0;
  this->DataExtent[3] = height - 1;

  this->SetDataScalarTypeToUnsignedShort();

  this->SetNumberOfScalarComponents(1);
  this->SetDataSpacing(spacingX, spacingY, spacingZ);
  this->vtkImageReader2::ExecuteInformation();

  // close the file
  fclose(fp);
}

static void vtkcopygenesisimage(FILE* infp, int width, int height, int compress, short* map_left,
  short* map_wide, unsigned short* output)
{
  unsigned short last_pixel = 0;
  for (int row = 0; row < height; ++row)
  {
    unsigned short start;
    unsigned short end;

    if (compress == 2 || compress == 4)
    { // packed/compacked
      assert(map_left);
      assert(map_wide);
      start = map_left[row];
      end = start + map_wide[row];
    }
    else
    {
      start = 0;
      end = width;
    }
    // Pad the first "empty" part of the line ...
    for (unsigned short k = 0; k < start; k++)
    {
      (*output) = 0;
      ++output;
    }

    if (compress == 3 || compress == 4)
    { // compressed/compacked
      while (start < end)
      {
        unsigned char byte;
        if (!fread(&byte, 1, 1, infp))
        {
          return;
        }
        if (byte & 0x80)
        {
          unsigned char byte2;
          if (!fread(&byte2, 1, 1, infp))
          {
            return;
          }
          if (byte & 0x40)
          { // next word
            if (!fread(&byte, 1, 1, infp))
            {
              return;
            }
            last_pixel = (((unsigned short)byte2 << 8) + byte);
          }
          else
          { // 14 bit delta
            if (byte & 0x20)
            {
              byte |= 0xe0;
            }
            else
            {
              byte &= 0x1f;
            }
            last_pixel += (((short)byte << 8) + byte2);
          }
        }
        else
        { // 7 bit delta
          if (byte & 0x40)
          {
            byte |= 0xc0;
          }
          last_pixel += (signed char)byte;
        }
        (*output) = last_pixel;
        ++output;
        ++start;
      }
    }
    else
    {
      while (start < end)
      {
        unsigned short u;
        if (!fread(&u, 2, 1, infp))
        {
          return;
        }
        vtkByteSwap::Swap2BE(&u);
        (*output) = u;
        ++output;
        ++start;
      }
    }

    // Pad the last "empty" part of the line ...
    for (int j = end; j < width; j++)
    {
      (*output) = 0;
      ++output;
    }
  }
}

static void vtkGESignaReaderUpdate2(
  vtkGESignaReader* self, unsigned short* outPtr, int* outExt, vtkIdType*)
{
  FILE* fp = vtksys::SystemTools::Fopen(self->GetInternalFileName(), "rb");
  if (!fp)
  {
    return;
  }

  int magic;
  if (fread(&magic, 4, 1, fp) != 1)
  {
    vtkGenericWarningMacro("GESignaReader error reading file: "
      << self->GetInternalFileName() << " Premature EOF while reading magic.");
    fclose(fp);
    return;
  }
  vtkByteSwap::Swap4BE(&magic);

  if (magic != 0x494d4746)
  {
    vtkGenericWarningMacro(<< "Unknown file type! Not a GE ximg file!");
    fclose(fp);
    return;
  }

  // read in the pixel offset from the header
  int offset;
  if (fread(&offset, 4, 1, fp) != 1)
  {
    vtkGenericWarningMacro("GESignaReader error reading file: "
      << self->GetInternalFileName() << " Premature EOF while reading origY.");
    fclose(fp);
    return;
  }
  vtkByteSwap::Swap4BE(&offset);

  int width, height, depth;
  if (fread(&width, 4, 1, fp) != 1)
  {
    vtkGenericWarningMacro("GESignaReader error reading file: "
      << self->GetInternalFileName() << " Premature EOF while reading width.");
    fclose(fp);
    return;
  }
  vtkByteSwap::Swap4BE(&width);
  if (fread(&height, 4, 1, fp) != 1)
  {
    vtkGenericWarningMacro("GESignaReader error reading file: "
      << self->GetInternalFileName() << " Premature EOF while reading height.");
    fclose(fp);
    return;
  }
  vtkByteSwap::Swap4BE(&height);
  // depth in bits
  if (fread(&depth, 4, 1, fp) != 1)
  {
    vtkGenericWarningMacro("GESignaReader error reading file: "
      << self->GetInternalFileName() << " Premature EOF while reading depth.");
    fclose(fp);
    return;
  }
  vtkByteSwap::Swap4BE(&depth);

  int compression;
  if (fread(&compression, 4, 1, fp) != 1)
  {
    vtkGenericWarningMacro("GESignaReader error reading file: "
      << self->GetInternalFileName() << " Premature EOF while reading compression.");
    fclose(fp);
    return;
  }
  vtkByteSwap::Swap4BE(&compression);

  std::vector<short> leftMap;
  std::vector<short> widthMap;

  if (compression == 2 || compression == 4)
  { // packed/compacked

    leftMap.resize(height);
    widthMap.resize(height);

    fseek(fp, 64, SEEK_SET);
    int packHdrOffset;
    if (fread(&packHdrOffset, 4, 1, fp) != 1)
    {
      vtkGenericWarningMacro("GESignaReader error reading file: "
        << self->GetInternalFileName() << " Premature EOF while reading packHdrOffset.");
      fclose(fp);
      return;
    }
    vtkByteSwap::Swap4BE(&packHdrOffset);

    // now seek to the pack header and read some values
    fseek(fp, packHdrOffset, SEEK_SET);
    // read in the maps
    int i;
    for (i = 0; i < height; i++)
    {
      if (fread(leftMap.data() + i, 2, 1, fp) != 1)
      {
        vtkGenericWarningMacro("GESignaReader error reading file: "
          << self->GetInternalFileName() << " Premature EOF while reading maps.");
        fclose(fp);
        return;
      }
      vtkByteSwap::Swap2BE(leftMap.data() + i);
      if (fread(widthMap.data(), 2, 1, fp) != 1)
      {
        vtkGenericWarningMacro("GESignaReader error reading file: "
          << self->GetInternalFileName() << " Premature EOF while reading maps.");
        fclose(fp);
        return;
      }
      vtkByteSwap::Swap2BE(widthMap.data() + i);
    }
  }

  // seek to pixel data
  fseek(fp, offset, SEEK_SET);

  // read in the pixels
  std::vector<unsigned short> tmp(width * height);
  int* dext = self->GetDataExtent();
  vtkcopygenesisimage(
    fp, dext[1] + 1, dext[3] + 1, compression, leftMap.data(), widthMap.data(), tmp.data());

  // now copy into desired extent
  int yp;
  for (yp = outExt[2]; yp <= outExt[3]; ++yp)
  {
    int ymod = height - yp - 1;
    memcpy(outPtr, tmp.data() + ymod * width + outExt[0], 2 * width);
    outPtr = outPtr + width;
  }

  fclose(fp);
}

//------------------------------------------------------------------------------
// This function reads in one data of data.
// templated to handle different data types.
static void vtkGESignaReaderUpdate(
  vtkGESignaReader* self, vtkImageData* data, unsigned short* outPtr)
{
  vtkIdType outIncr[3];
  int outExtent[6];
  unsigned short* outPtr2;

  data->GetExtent(outExtent);
  data->GetIncrements(outIncr);

  outPtr2 = outPtr;
  int idx2;
  for (idx2 = outExtent[4]; idx2 <= outExtent[5]; ++idx2)
  {
    self->ComputeInternalFileName(idx2);
    // read in a PNG file
    vtkGESignaReaderUpdate2(self, outPtr2, outExtent, outIncr);
    self->UpdateProgress((idx2 - outExtent[4]) / (outExtent[5] - outExtent[4] + 1.0));
    outPtr2 += outIncr[2];
  }
}

//------------------------------------------------------------------------------
// This function reads a data from a file.  The datas extent/axes
// are assumed to be the same as the file extent/order.
void vtkGESignaReader::ExecuteDataWithInformation(vtkDataObject* output, vtkInformation* outInfo)
{
  vtkImageData* data = this->AllocateOutputData(output, outInfo);

  if (this->InternalFileName == nullptr)
  {
    vtkErrorMacro(<< "Either a FileName or FilePrefix must be specified.");
    return;
  }

  data->GetPointData()->GetScalars()->SetName("GESignalImage");

  this->ComputeDataIncrements();

  // Call the correct templated function for the output
  void* outPtr;

  // Call the correct templated function for the input
  outPtr = data->GetScalarPointer();
  vtkGESignaReaderUpdate(this, data, (unsigned short*)(outPtr));
}

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