//#include "genFuncs.hpp"

#include <assert.h>
#include <fstream>
#include <iostream>
#include <map>
#include <sstream>
#include <string>
#include <vector>

#include <petscdmda.h>
#include <petscts.h>
#include <petscviewer.h>

using namespace std;

PetscErrorCode loadValueFromCheckpoint(const string outputDir, const string filename, PetscScalar &value) {
  PetscErrorCode ierr = 0;
  #if VERBOSE > 1
  ierr = PetscPrinf(PETSC_COMM_WORLD, "Starting loadValueFromCheckpoint in genFuncs.cpp.\n"); CHKERRQ(ierr);
  ierr = PetscPrintf(PETSC_COMM_WORLD, "Attempting to load %s%s\n", outputDir.c_str(), filename.c_str()); CHKERRQ(ierr);
  #endif

  string checkpointFile = outputDir + filename;
  bool fileExists = doesFileExist(checkpointFile);
  if (fileExists) {
    PetscPrintf(PETSC_COMM_WORLD, "Loading %s\n", filename.c_str());
    PetscViewer viewer;
    int fd;
    PetscViewerBinaryOpen(PETSC_COMM_WORLD, checkpointFile.c_str(), FILE_MODE_READ, &viewer);
    PetscViewerBinaryGetDescriptor(viewer, &fd);
    PetscBinaryRead(fd, &value, 1, PETSC_SCALAR);
    PetscViewerDestroy(&viewer);
  }
  else {
    PetscPrintf(PETSC_COMM_WORLD, "Warning: %s not found.\n", checkpointFile.c_str());
  }

  #if VERBOSE > 1
  ierr = PetscPrintf(PETSC_COMM_WORLD, "Ending loadValueFromCheckpoint in %s.\n", filename.c_str()); CHKERRQ(ierr);
  #endif

  return ierr;
}


int main(int argc, char **args) {
  PetscErrorCode ierr = 0;

  ierr = PetscInitialize(&argc, &args, NULL, NULL); CHKERRQ(ierr);

  // directory and filename
  const string outputDir = "/home/yyy910805/";
  const string filename = "_test";
  PetscScalar value = 0;

  loadValueFromCheckpoint(outputDir, filename, value);
  ierr = PetscPrintf(PETSC_COMM_WORLD, " %f\n", value); CHKERRQ(ierr);

  ierr = PetscFinalize(); CHKERRQ(ierr);
  
  return 0;
}