/* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
 * vim:expandtab:shiftwidth=8:tabstop=8:
 */
/******************************************************************************\
*                                                                              *
*        Copyright (c) 2003, The Regents of the University of California       *
*      See the file COPYRIGHT for a complete copyright notice and license.     *
*                                                                              *
********************************************************************************
*
* Implement abstract I/O interface for Parallel NetCDF (NCMPI).
*
\******************************************************************************/

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <stdio.h>
#include <stdlib.h>
#include <sys/stat.h>
#include <pnetcdf.h>

#include "ior.h"
#include "iordef.h"
#include "aiori.h"
#include "utilities.h"

#define NUM_DIMS 3              /* number of dimensions to data set */

/*
 * NCMPI_CHECK will display a custom error message and then exit the program
 */
#define NCMPI_CHECK(NCMPI_RETURN, MSG) do {                              \
                                                                         \
    if (NCMPI_RETURN < 0) {                                              \
        fprintf(stdout, "** error **\n");                                \
        fprintf(stdout, "ERROR in %s (line %d): %s.\n",                  \
                __FILE__, __LINE__, MSG);                                \
        fprintf(stdout, "ERROR: %s.\n", ncmpi_strerror(NCMPI_RETURN));   \
        fprintf(stdout, "** exiting **\n");                              \
        exit(-1);                                                        \
    }                                                                    \
} while(0)

/**************************** P R O T O T Y P E S *****************************/

static int GetFileMode(IOR_param_t *);

static void *NCMPI_Create(char *, IOR_param_t *);
static void *NCMPI_Open(char *, IOR_param_t *);
static IOR_offset_t NCMPI_Xfer(int, void *, IOR_size_t *,
                               IOR_offset_t, IOR_param_t *);
static void NCMPI_Close(void *, IOR_param_t *);
static void NCMPI_Delete(char *, IOR_param_t *);
static char *NCMPI_GetVersion();
static void NCMPI_Fsync(void *, IOR_param_t *);
static IOR_offset_t NCMPI_GetFileSize(IOR_param_t *, MPI_Comm, char *);
static int NCMPI_Access(const char *, int, IOR_param_t *);

/************************** D E C L A R A T I O N S ***************************/

ior_aiori_t ncmpi_aiori = {
        .name = "NCMPI",
        .name_legacy = NULL,
        .create = NCMPI_Create,
        .open = NCMPI_Open,
        .xfer = NCMPI_Xfer,
        .close = NCMPI_Close,
        .delete = NCMPI_Delete,
        .get_version = NCMPI_GetVersion,
        .fsync = NCMPI_Fsync,
        .get_file_size = NCMPI_GetFileSize,
        .statfs = aiori_posix_statfs,
        .mkdir = aiori_posix_mkdir,
        .rmdir = aiori_posix_rmdir,
        .access = NCMPI_Access,
        .stat = aiori_posix_stat,
};

/***************************** F U N C T I O N S ******************************/

/*
 * Create and open a file through the NCMPI interface.
 */
static void *NCMPI_Create(char *testFileName, IOR_param_t * param)
{
        int *fd;
        int fd_mode;
        MPI_Info mpiHints = MPI_INFO_NULL;

        /* read and set MPI file hints from hintsFile */
        SetHints(&mpiHints, param->hintsFileName);
        if (rank == 0 && param->showHints) {
                fprintf(stdout, "\nhints passed to MPI_File_open() {\n");
                ShowHints(&mpiHints);
                fprintf(stdout, "}\n");
        }

        fd = (int *)malloc(sizeof(int));
        if (fd == NULL)
                ERR("malloc() failed");

        fd_mode = GetFileMode(param);
        NCMPI_CHECK(ncmpi_create(testComm, testFileName, fd_mode,
                                 mpiHints, fd), "cannot create file");

        /* free up the mpiHints object */
        if (mpiHints != MPI_INFO_NULL)
            MPI_CHECK(MPI_Info_free(&mpiHints), "cannot free file info");

#if defined(PNETCDF_VERSION_MAJOR) && (PNETCDF_VERSION_MAJOR > 1 || PNETCDF_VERSION_MINOR >= 2)
        /* ncmpi_get_file_info is first available in 1.2.0 */
        if (rank == 0 && param->showHints) {
            MPI_Info info_used;
            MPI_CHECK(ncmpi_get_file_info(*fd, &info_used),
                      "cannot inquire file info");
            /* print the MPI file hints currently used */
            fprintf(stdout, "\nhints returned from opened file {\n");
            ShowHints(&info_used);
            fprintf(stdout, "}\n");
            MPI_CHECK(MPI_Info_free(&info_used), "cannot free file info");
        }
#endif

        return (fd);
}

/*
 * Open a file through the NCMPI interface.
 */
static void *NCMPI_Open(char *testFileName, IOR_param_t * param)
{
        int *fd;
        int fd_mode;
        MPI_Info mpiHints = MPI_INFO_NULL;

        /* read and set MPI file hints from hintsFile */
        SetHints(&mpiHints, param->hintsFileName);
        if (rank == 0 && param->showHints) {
                fprintf(stdout, "\nhints passed to MPI_File_open() {\n");
                ShowHints(&mpiHints);
                fprintf(stdout, "}\n");
        }

        fd = (int *)malloc(sizeof(int));
        if (fd == NULL)
                ERR("malloc() failed");

        fd_mode = GetFileMode(param);
        NCMPI_CHECK(ncmpi_open(testComm, testFileName, fd_mode,
                               mpiHints, fd), "cannot open file");

        /* free up the mpiHints object */
        if (mpiHints != MPI_INFO_NULL)
            MPI_CHECK(MPI_Info_free(&mpiHints), "cannot free file info");

#if defined(PNETCDF_VERSION_MAJOR) && (PNETCDF_VERSION_MAJOR > 1 || PNETCDF_VERSION_MINOR >= 2)
        /* ncmpi_get_file_info is first available in 1.2.0 */
        if (rank == 0 && param->showHints) {
            MPI_Info info_used;
            MPI_CHECK(ncmpi_get_file_info(*fd, &info_used),
                      "cannot inquire file info");
            /* print the MPI file hints currently used */
            fprintf(stdout, "\nhints returned from opened file {\n");
            ShowHints(&info_used);
            fprintf(stdout, "}\n");
            MPI_CHECK(MPI_Info_free(&info_used), "cannot free file info");
        }
#endif

        return (fd);
}

/*
 * Write or read access to file using the NCMPI interface.
 */
static IOR_offset_t NCMPI_Xfer(int access, void *fd, IOR_size_t * buffer,
                               IOR_offset_t length, IOR_param_t * param)
{
        signed char *bufferPtr = (signed char *)buffer;
        static int firstReadCheck = FALSE, startDataSet;
        int var_id, dim_id[NUM_DIMS];
        MPI_Offset bufSize[NUM_DIMS], offset[NUM_DIMS];
        IOR_offset_t segmentPosition;
        int segmentNum, transferNum;

        /* determine by offset if need to start data set */
        if (param->filePerProc == TRUE) {
                segmentPosition = (IOR_offset_t) 0;
        } else {
                segmentPosition =
                    (IOR_offset_t) ((rank + rankOffset) % param->numTasks)
                    * param->blockSize;
        }
        if ((int)(param->offset - segmentPosition) == 0) {
                startDataSet = TRUE;
                /*
                 * this toggle is for the read check operation, which passes through
                 * this function twice; note that this function will open a data set
                 * only on the first read check and close only on the second
                 */
                if (access == READCHECK) {
                        if (firstReadCheck == TRUE) {
                                firstReadCheck = FALSE;
                        } else {
                                firstReadCheck = TRUE;
                        }
                }
        }

        if (startDataSet == TRUE &&
            (access != READCHECK || firstReadCheck == TRUE)) {
                if (access == WRITE) {
                        int numTransfers =
                            param->blockSize / param->transferSize;

                        /* reshape 1D array to 3D array:
                           [segmentCount*numTasks][numTransfers][transferSize]
                           Requirement: none of these dimensions should be > 4G,
                         */
                        NCMPI_CHECK(ncmpi_def_dim
                                    (*(int *)fd, "segments_times_np",
                                     NC_UNLIMITED, &dim_id[0]),
                                    "cannot define data set dimensions");
                        NCMPI_CHECK(ncmpi_def_dim
                                    (*(int *)fd, "number_of_transfers",
                                     numTransfers, &dim_id[1]),
                                    "cannot define data set dimensions");
                        NCMPI_CHECK(ncmpi_def_dim
                                    (*(int *)fd, "transfer_size",
                                     param->transferSize, &dim_id[2]),
                                    "cannot define data set dimensions");
                        NCMPI_CHECK(ncmpi_def_var
                                    (*(int *)fd, "data_var", NC_BYTE, NUM_DIMS,
                                     dim_id, &var_id),
                                    "cannot define data set variables");
                        NCMPI_CHECK(ncmpi_enddef(*(int *)fd),
                                    "cannot close data set define mode");

                } else {
                        NCMPI_CHECK(ncmpi_inq_varid
                                    (*(int *)fd, "data_var", &var_id),
                                    "cannot retrieve data set variable");
                }

                if (param->collective == FALSE) {
                        NCMPI_CHECK(ncmpi_begin_indep_data(*(int *)fd),
                                    "cannot enable independent data mode");
                }

                param->var_id = var_id;
                startDataSet = FALSE;
        }

        var_id = param->var_id;

        /* calculate the segment number */
        segmentNum = param->offset / (param->numTasks * param->blockSize);

        /* calculate the transfer number in each block */
        transferNum = param->offset % param->blockSize / param->transferSize;

        /* read/write the 3rd dim of the dataset, each is of
           amount param->transferSize */
        bufSize[0] = 1;
        bufSize[1] = 1;
        bufSize[2] = param->transferSize;

        offset[0] = segmentNum * param->numTasks + rank;
        offset[1] = transferNum;
        offset[2] = 0;

        /* access the file */
        if (access == WRITE) {  /* WRITE */
                if (param->collective) {
                        NCMPI_CHECK(ncmpi_put_vara_schar_all
                                    (*(int *)fd, var_id, offset, bufSize,
                                     bufferPtr),
                                    "cannot write to data set");
                } else {
                        NCMPI_CHECK(ncmpi_put_vara_schar
                                    (*(int *)fd, var_id, offset, bufSize,
                                     bufferPtr),
                                    "cannot write to data set");
                }
        } else {                /* READ or CHECK */
                if (param->collective == TRUE) {
                        NCMPI_CHECK(ncmpi_get_vara_schar_all
                                    (*(int *)fd, var_id, offset, bufSize,
                                     bufferPtr),
                                    "cannot read from data set");
                } else {
                        NCMPI_CHECK(ncmpi_get_vara_schar
                                    (*(int *)fd, var_id, offset, bufSize,
                                     bufferPtr),
                                    "cannot read from data set");
                }
        }

        return (length);
}

/*
 * Perform fsync().
 */
static void NCMPI_Fsync(void *fd, IOR_param_t * param)
{
        ;
}

/*
 * Close a file through the NCMPI interface.
 */
static void NCMPI_Close(void *fd, IOR_param_t * param)
{
        if (param->collective == FALSE) {
                NCMPI_CHECK(ncmpi_end_indep_data(*(int *)fd),
                            "cannot disable independent data mode");
        }
        NCMPI_CHECK(ncmpi_close(*(int *)fd), "cannot close file");
        free(fd);
}

/*
 * Delete a file through the NCMPI interface.
 */
static void NCMPI_Delete(char *testFileName, IOR_param_t * param)
{
        return(MPIIO_Delete(testFileName, param));
}

/*
 * Determine api version.
 */
static char* NCMPI_GetVersion()
{
  return (char *)ncmpi_inq_libvers();
}

/*
 * Return the correct file mode for NCMPI.
 */
static int GetFileMode(IOR_param_t * param)
{
        int fd_mode = 0;

        /* set IOR file flags to NCMPI flags */
        /* -- file open flags -- */
        if (param->openFlags & IOR_RDONLY) {
                fd_mode |= NC_NOWRITE;
        }
        if (param->openFlags & IOR_WRONLY) {
                fprintf(stdout, "File write only not implemented in NCMPI\n");
        }
        if (param->openFlags & IOR_RDWR) {
                fd_mode |= NC_WRITE;
        }
        if (param->openFlags & IOR_APPEND) {
                fprintf(stdout, "File append not implemented in NCMPI\n");
        }
        if (param->openFlags & IOR_CREAT) {
                fd_mode |= NC_CLOBBER;
        }
        if (param->openFlags & IOR_EXCL) {
                fprintf(stdout, "Exclusive access not implemented in NCMPI\n");
        }
        if (param->openFlags & IOR_TRUNC) {
                fprintf(stdout, "File truncation not implemented in NCMPI\n");
        }
        if (param->openFlags & IOR_DIRECT) {
                fprintf(stdout, "O_DIRECT not implemented in NCMPI\n");
        }

        /* to enable > 4GB file size */
        fd_mode |= NC_64BIT_OFFSET;

        return (fd_mode);
}

/*
 * Use MPIIO call to get file size.
 */
static IOR_offset_t NCMPI_GetFileSize(IOR_param_t * test, MPI_Comm testComm,
                                      char *testFileName)
{
        return(MPIIO_GetFileSize(test, testComm, testFileName));
}

/*
 * Use MPIIO call to check for access.
 */
static int NCMPI_Access(const char *path, int mode, IOR_param_t *param)
{
        return(MPIIO_Access(path, mode, param));
}