#include "SDDS.h"
#include "mdb.h"
#include "scan.h"
 
#define SET_COLLECTIVE_IO 0
#define N_OPTIONS 1
char *option[N_OPTIONS]={"collectiveIO"};

#define INITIAL_BIG_BUFFER_SIZE SDDS_MAXLINE

static char *USAGE="read <filename> [-collectiveIO]";

int main(int argc, char *argv[]) {
  char *filename=NULL; 
  SDDS_DATASET SDDS_dataset; 
  MPI_DATASET *MPI_dataset; 
  int  mpi_code, n_processors, myid;
  int32_t rows=0, collective_io=0, i_arg;
  double startTime;
  MPI_Comm comm;
  SCANNED_ARG *s_arg;

  MPI_Init(&argc,&argv);
  argc = scanargs(&s_arg, argc, argv); 
  if (argc<2)
    bomb(NULL, USAGE);
  for (i_arg=1; i_arg<argc; i_arg++) {
    if (s_arg[i_arg].arg_type==OPTION) {
      switch (match_string(s_arg[i_arg].list[0], option, N_OPTIONS, 0)) {
      case SET_COLLECTIVE_IO:
        collective_io = 1;
        break;
      default:
        break;
      }
    } else if (!filename)
      filename = s_arg[i_arg].list[0];
    else 
      SDDS_Bomb("Too many files gvien.");
  }
  SDDS_SetDefaultBufferSize(4000000);
  /* 1. set the communicator for MPI IO */
  comm = MPI_COMM_WORLD; 
  if (MPI_SUCCESS != (mpi_code=MPI_Comm_rank(comm, &myid)))
    SDDS_MPI_GOTO_ERROR(stderr,  "MPI_Comm_rank failed", mpi_code, 1);
  
  if (MPI_SUCCESS != (mpi_code=MPI_Comm_size(comm, &n_processors)))
    SDDS_MPI_GOTO_ERROR(stderr, "MPI_Comm_size failed", mpi_code, 1); 
  SDDS_MPI_Setup(&SDDS_dataset, 1, n_processors, myid, comm, 1);
  MPI_dataset = SDDS_dataset.MPI_dataset;
  if (MPI_dataset->myid==0)
    fprintf(stderr,"filename=%s\n", filename);
  startTime = MPI_Wtime();
  SDDS_SetDefaultBufferSize(4000000);
  /* 2. open file (all processors) */
  if (!SDDS_MPI_InitializeInput(&SDDS_dataset, filename)) 
    SDDS_PrintErrors(stderr, SDDS_VERBOSE_PrintErrors|SDDS_EXIT_PrintErrors);
  MPI_dataset->collective_io = collective_io;
  
  rows =  0;
  while (1) {
    rows=SDDS_ReadPage(&SDDS_dataset);
    fprintf(stderr, "read page=%d\n", rows);
    if (rows==0) {
      SDDS_PrintErrors(stderr, SDDS_VERBOSE_PrintErrors|SDDS_EXIT_PrintErrors);
    } else if (rows==-1)
      break;
    else {
      rows =  SDDS_CountRowsOfInterest(&SDDS_dataset);
      fprintf(stderr, "rank=%d, rows=%d\n", MPI_dataset->myid, rows);
      fprintf(stderr, "total rows %d\n", MPI_dataset->total_rows);
    }
  }
  if (!SDDS_Terminate(&SDDS_dataset) )
    SDDS_PrintErrors(stderr, SDDS_VERBOSE_PrintErrors|SDDS_EXIT_PrintErrors);

  if (MPI_dataset->myid==0)
    fprintf(stderr,"rank=%d, time spent=%f\n", MPI_dataset->myid, MPI_Wtime()-startTime);
  MPI_Finalize();
  return 0;
}