// Gmsh - Copyright (C) 1997-2025 C. Geuzaine, J.-F. Remacle
//
// See the LICENSE.txt file in the Gmsh root directory for license information.
// Please report all issues on https://gitlab.onelab.info/gmsh/gmsh/issues.

#include "GmshConfig.h"
#include "GmshMessage.h"
#include "PView.h"
#include "PViewData.h"
#include "PViewOptions.h"
#include "PViewDataList.h"
#include "PViewDataGModel.h"
#include "VertexArray.h"
#include "StringUtils.h"
#include "Context.h"
#include "OS.h"
#include "adaptiveData.h"

bool PView::readPOS(const std::string &fileName, int fileIndex)
{
  FILE *fp = Fopen(fileName.c_str(), "rb");
  if(!fp) {
    Msg::Error("Unable to open file '%s'", fileName.c_str());
    return false;
  }

  char str[256] = "XXX";
  double version = -1.;
  int format = -1, size = -1, index = -1;

  while(1) {
    while(str[0] != '$') {
      if(!fgets(str, sizeof(str), fp) || feof(fp)) break;
    }

    if(feof(fp)) break;

    if(!strncmp(&str[1], "PostFormat", 10)) {
      if(!fscanf(fp, "%lf %d %d\n", &version, &format, &size)) {
        Msg::Error("Read error");
        fclose(fp);
        return false;
      }
      if(version < 1.0) {
        Msg::Error("Post-processing file too old (ver. %g < 1.0)", version);
        fclose(fp);
        return false;
      }
      if(size == sizeof(double))
        Msg::Debug("Data is in double precision format (size==%d)", size);
      else {
        Msg::Error("Unknown data size (%d) in post-processing file", size);
        fclose(fp);
        return false;
      }
    }
    else if(!strncmp(&str[1], "View", 4)) {
      index++;
      if(fileIndex < 0 || fileIndex == index) {
        PViewDataList *d = new PViewDataList();
        if(!d->readPOS(fp, version, format ? true : false)) {
          Msg::Error("Could not read data in list format");
          delete d;
          fclose(fp);
          return false;
        }
        else {
          d->setFileName(fileName);
          d->setFileIndex(index);
          new PView(d);
        }
      }
    }

    do {
      if(!fgets(str, sizeof(str), fp) || feof(fp)) break;
    } while(str[0] != '$');
  }

  fclose(fp);
  return true;
}

bool PView::readMSHInterpolationScheme(FILE *fp)
{
  char str[256] = "XXX";
  std::string name;
  if(!fgets(str, sizeof(str), fp)) {
    return false;
  }
  name = ExtractDoubleQuotedString(str, sizeof(str));
  Msg::Debug("Reading interpolation scheme '%s'", name.c_str());
  PViewData::removeInterpolationScheme(name);
  int numTypes;
  if(fscanf(fp, "%d", &numTypes) != 1) {
    return false;
  }
  for(int i = 0; i < numTypes; i++) {
    int type, numMatrices;
    if(fscanf(fp, "%d %d", &type, &numMatrices) != 2) {
      return false;
    }
    for(int j = 0; j < numMatrices; j++) {
      int m, n;
      if(fscanf(fp, "%d %d", &m, &n) != 2) {
        return false;
      }
      fullMatrix<double> mat(m, n);
      for(int k = 0; k < m; k++) {
        for(int l = 0; l < n; l++) {
          double d;
          if(fscanf(fp, "%lf", &d) != 1) {
            return false;
          }
          mat.set(k, l, d);
        }
      }
      PViewData::addMatrixToInterpolationScheme(name, type, mat);
    }
  }
  return true;
}

bool PView::readMSHViewData(const std::string &fileName, FILE *fp,
                            bool binary, bool swap, const char *dataType,
                            int partitionToRead)
{
  PViewDataGModel::DataType type;
  if(!strncmp(dataType, "NodeData", 8))
    type = PViewDataGModel::NodeData;
  else if(!strncmp(dataType, "ElementData", 11))
    type = PViewDataGModel::ElementData;
  else
    type = PViewDataGModel::ElementNodeData;

  char str[256] = "XXX";

  int numTags;
  // string tags
  std::string viewName, interpolationScheme;
  if(!fgets(str, sizeof(str), fp)) {
    return false;
  }
  if(sscanf(str, "%d", &numTags) != 1) {
    return false;
  }
  for(int i = 0; i < numTags; i++) {
    if(!fgets(str, sizeof(str), fp)) {
      return false;
    }
    if(i == 0)
      viewName = ExtractDoubleQuotedString(str, sizeof(str));
    else if(i == 1)
      interpolationScheme = ExtractDoubleQuotedString(str, sizeof(str));
  }
  // double tags
  double time = 0.;
  if(!fgets(str, sizeof(str), fp)) {
    return false;
  }
  if(sscanf(str, "%d", &numTags) != 1) {
    return false;
  }
  for(int i = 0; i < numTags; i++) {
    if(!fgets(str, sizeof(str), fp)) {
      return false;
    }
    if(i == 0) {
      if(sscanf(str, "%lf", &time) != 1) {
        return false;
      }
    }
  }
  // integer tags
  int timeStep = 0, numComp = 0, numEnt = 0, partition = 0;
  long int blocksize = 0;
  if(!fgets(str, sizeof(str), fp)) {
    return false;
  }
  if(sscanf(str, "%d", &numTags) != 1) {
    return false;
  }
  for(int i = 0; i < numTags; i++) {
    if(!fgets(str, sizeof(str), fp)) {
      return false;
    }
    if(i == 0) {
      if(sscanf(str, "%d", &timeStep) != 1) {
        return false;
      }
    }
    else if(i == 1) {
      if(sscanf(str, "%d", &numComp) != 1) {
        return false;
      }
    }
    else if(i == 2) {
      if(sscanf(str, "%d", &numEnt) != 1) {
        return false;
      }
    }
    else if(i == 3) {
      if(sscanf(str, "%d", &partition) != 1) {
        return false;
      }
    }
    else if(i == 4) {
      if(sscanf(str, "%ld", &blocksize) != 1) {
        return false;
      }
    }
  }
  if(partitionToRead == -1 || partitionToRead == partition) {
    // if default (no particular partition requested from MergeFile -> -1) or
    // if current partition corresponds to the requested partition, read the
    // data
    if(numEnt > 0) {
      // either get existing viewData, or create new one
      PView *p = getViewByName(viewName, timeStep, partition);
      PViewDataGModel *d = nullptr;
      if(p) d = dynamic_cast<PViewDataGModel *>(p->getData());
      bool create = d ? false : true;
      if(create) d = new PViewDataGModel(type);
      // currently unused indices:
      int fileIndex = -1, index = 1;
      if(!d->readMSH(viewName, fileName, fileIndex, fp, binary, swap,
                     timeStep, time, partition, numComp, numEnt,
                     interpolationScheme)) {
        Msg::Error("Could not read data in file '%s'", fileName.c_str());
        if(create) delete d;
        return false;
      }
      else {
        d->setName(viewName);
        d->setFileName(fileName);
        d->setFileIndex(index);
        if(create) new PView(d);
      }
    }
  }
  else if(blocksize > 0 && partitionToRead != partition) {
    // if current partition does not correspond to the requested partition
    // and if its blocksise has been read (5th integer in the header),
    // jump over it
    fseek(fp, blocksize, SEEK_CUR);
  }
  return true;
}

#if defined(HAVE_MED)

extern std::vector<std::string> medGetFieldNames(const std::string &fileName);

bool PView::readMED(const std::string &fileName, int fileIndex)
{
  std::vector<std::string> fieldNames = medGetFieldNames(fileName);

  for(std::size_t index = 0; index < fieldNames.size(); index++) {
    if(fileIndex < 0 || (int)index == fileIndex) {
      PViewDataGModel *d = nullptr;
      // we use the filename as a kind of "partition" indicator, allowing to
      // complete datasets provided in separate files (e.g. coming from DDM)
      PView *p = getViewByName(fieldNames[index], -1, -1, fileName);
      if(p) d = dynamic_cast<PViewDataGModel *>(p->getData());
      bool create = d ? false : true;
      if(create) d = new PViewDataGModel();
      if(!d->readMED(fileName, index)) {
        Msg::Error("Could not read data in MED file");
        if(create) delete d;
        return false;
      }
      else {
        if(create) new PView(d);
      }
    }
  }

  return true;
}

#else

bool PView::readMED(const std::string &fileName, int fileIndex)
{
  Msg::Error("Gmsh must be compiled with MED support to read '%s'",
             fileName.c_str());
  return false;
}

#endif

bool PView::readPCH(const std::string &fileName, int fileIndex)
{
  PViewDataGModel::DataType type = PViewDataGModel::NodeData;
  // PViewDataGModel::ElementData;
  // PViewDataGModel::ElementNodeData;
  PViewDataGModel *d = new PViewDataGModel(type);
  d->setFileName(fileName);
  d->readPCH(fileName, fileIndex);
  new PView(d);
  return true;
}

bool PView::write(const std::string &fileName, int format, bool append)
{
  Msg::StatusBar(true, "Writing '%s'...", fileName.c_str());

  bool ret;
  switch(format) {
  case 0: ret = _data->writePOS(fileName, false, false, append); break; // ASCII
  case 1: ret = _data->writePOS(fileName, true, false, append); break; // binary
  case 2: ret = _data->writePOS(fileName, false, true, append); break; // parsed
  case 3: ret = _data->writeSTL(fileName); break;
  case 4: ret = _data->writeTXT(fileName); break;
  case 5:
    ret = _data->writeMSH(fileName, CTX::instance()->mesh.mshFileVersion,
                          CTX::instance()->mesh.binary,
                          CTX::instance()->post.saveMesh, append, 0,
                          CTX::instance()->post.saveInterpolationMatrices,
                          CTX::instance()->post.forceNodeData,
                          CTX::instance()->post.forceElementData);
    break;
  case 6: ret = _data->writeMED(fileName); break;
  case 7: ret = writeX3D(fileName); break;
  case 10: {
    std::string ext = SplitFileName(fileName)[2];
    if(ext == ".pos")
      ret = _data->writePOS(fileName, CTX::instance()->post.binary,
                            !CTX::instance()->post.binary, append);
    else if(ext == ".stl")
      ret = _data->writeSTL(fileName);
    else if(ext == ".msh")
      ret = _data->writeMSH(fileName, CTX::instance()->mesh.mshFileVersion,
                            CTX::instance()->mesh.binary,
                            CTX::instance()->post.saveMesh, append, 0,
                            CTX::instance()->post.saveInterpolationMatrices,
                            CTX::instance()->post.forceNodeData,
                            CTX::instance()->post.forceElementData);
    else if(ext == ".med")
      ret = _data->writeMED(fileName);
    else if(ext == ".x3d")
      ret = writeX3D(fileName);
    else
      ret = _data->writeTXT(fileName);
    break;
  }
  default:
    ret = false;
    Msg::Error("Unknown view format %d", format);
    break;
  }

  if(ret) Msg::StatusBar(true, "Done writing '%s'", fileName.c_str());
  return ret;
}

// Routines for export of adapted views to pvtu file format for parallel
// visualization with paraview.
bool PView::writeAdapt(const std::string &guifileName, int useDefaultName,
                       bool isBinary, int adaptLev, double adaptErr, int npart,
                       bool append)
{
  Msg::StatusBar(true, "Writing '%s'...", guifileName.c_str());
  _data->saveAdaptedViewForVTK(guifileName, useDefaultName, _options->timeStep,
                               adaptLev, adaptErr, npart, isBinary);
  return true;
}

void PView::sendToServer(const std::string &name)
{
  Msg::Info("Sending View[%d] to ONELAB as parameter '%s'", _index,
            name.c_str());
  _data->sendToServer(name);
}
