/************************************************************

  This example shows how to read and write enumerated
  datatypes to an attribute.  The program first writes
  enumerated values to an attribute with a dataspace of
  DIM0xDIM1, then closes the file.  Next, it reopens the
  file, reads back the data, and outputs it to the screen.

  This file is intended for use with HDF5 Library version 1.6

 ************************************************************/

#include "hdf5.h"
#include <stdio.h>
#include <stdlib.h>

#define FILE          "h5ex_t_enumatt.h5"
#define DATASET       "DS1"
#define ATTRIBUTE     "A1"
#define DIM0          4
#define DIM1          7
#define F_BASET       H5T_STD_I16BE  /* File base type */
#define M_BASET       H5T_NATIVE_INT /* Memory base type */
#define NAME_BUF_SIZE 16

typedef enum { SOLID, LIQUID, GAS, PLASMA } phase_t; /* Enumerated type */

int
main(void)
{
    hid_t file, filetype, memtype, space, dset, attr;
    /* Handles */
    herr_t  status;
    hsize_t dims[2] = {DIM0, DIM1};
    phase_t wdata[DIM0][DIM1], /* Write buffer */
        **rdata,               /* Read buffer */
        val;
    char *names[4] = {"SOLID", "LIQUID", "GAS", "PLASMA"}, name[NAME_BUF_SIZE];
    int   ndims, i, j;

    /*
     * Initialize data.
     */
    for (i = 0; i < DIM0; i++)
        for (j = 0; j < DIM1; j++)
            wdata[i][j] = (phase_t)((i + 1) * j - j) % (int)(PLASMA + 1);

    /*
     * Create a new file using the default properties.
     */
    file = H5Fcreate(FILE, H5F_ACC_TRUNC, H5P_DEFAULT, H5P_DEFAULT);

    /*
     * Create the enumerated datatypes for file and memory.  This
     * process is simplified if native types are used for the file,
     * as only one type must be defined.
     */
    filetype = H5Tenum_create(F_BASET);
    memtype  = H5Tenum_create(M_BASET);

    for (i = (int)SOLID; i <= (int)PLASMA; i++) {
        /*
         * Insert enumerated value for memtype.
         */
        val    = (phase_t)i;
        status = H5Tenum_insert(memtype, names[i], &val);
        /*
         * Insert enumerated value for filetype.  We must first convert
         * the numerical value val to the base type of the destination.
         */
        status = H5Tconvert(M_BASET, F_BASET, 1, &val, NULL, H5P_DEFAULT);
        status = H5Tenum_insert(filetype, names[i], &val);
    }

    /*
     * Create dataset with a scalar dataspace.
     */
    space  = H5Screate(H5S_SCALAR);
    dset   = H5Dcreate(file, DATASET, H5T_STD_I32LE, space, H5P_DEFAULT);
    status = H5Sclose(space);

    /*
     * Create dataspace.  Setting maximum size to NULL sets the maximum
     * size to be the current size.
     */
    space = H5Screate_simple(2, dims, NULL);

    /*
     * Create the attribute and write the enumerated data to it.
     */
    attr   = H5Acreate(dset, ATTRIBUTE, filetype, space, H5P_DEFAULT);
    status = H5Awrite(attr, memtype, wdata[0]);

    /*
     * Close and release resources.
     */
    status = H5Aclose(attr);
    status = H5Dclose(dset);
    status = H5Sclose(space);
    status = H5Tclose(filetype);
    status = H5Fclose(file);

    /*
     * Now we begin the read section of this example.  Here we assume
     * the attribute has the same name and rank, but can have any size.
     * Therefore we must allocate a new array to read in data using
     * malloc().  For simplicity, we do not rebuild memtype.
     */

    /*
     * Open file, dataset, and attribute.
     */
    file = H5Fopen(FILE, H5F_ACC_RDONLY, H5P_DEFAULT);
    dset = H5Dopen(file, DATASET);
    attr = H5Aopen_name(dset, ATTRIBUTE);

    /*
     * Get dataspace and allocate memory for read buffer.  This is a
     * two dimensional attribute so the dynamic allocation must be done
     * in steps.
     */
    space = H5Aget_space(attr);
    ndims = H5Sget_simple_extent_dims(space, dims, NULL);

    /*
     * Allocate array of pointers to rows.
     */
    rdata = (phase_t **)malloc(dims[0] * sizeof(phase_t *));

    /*
     * Allocate space for enumerated data.
     */
    rdata[0] = (phase_t *)malloc(dims[0] * dims[1] * sizeof(phase_t));

    /*
     * Set the rest of the pointers to rows to the correct addresses.
     */
    for (i = 1; i < dims[0]; i++)
        rdata[i] = rdata[0] + i * dims[1];

    /*
     * Read the data.
     */
    status = H5Aread(attr, memtype, rdata[0]);

    /*
     * Output the data to the screen.
     */
    printf("%s:\n", ATTRIBUTE);
    for (i = 0; i < dims[0]; i++) {
        printf(" [");
        for (j = 0; j < dims[1]; j++) {

            /*
             * Get the name of the enumeration member.
             */
            status = H5Tenum_nameof(memtype, &rdata[i][j], name, NAME_BUF_SIZE);
            printf(" %-6s", name);
        }
        printf("]\n");
    }

    /*
     * Close and release resources.
     */
    free(rdata[0]);
    free(rdata);
    status = H5Aclose(attr);
    status = H5Dclose(dset);
    status = H5Sclose(space);
    status = H5Tclose(memtype);
    status = H5Fclose(file);

    return 0;
}