/*
 * (C) Copyright 2005- ECMWF.
 *
 * This software is licensed under the terms of the Apache Licence Version 2.0
 * which can be obtained at http://www.apache.org/licenses/LICENSE-2.0.
 *
 * In applying this licence, ECMWF does not waive the privileges and immunities granted to it by
 * virtue of its status as an intergovernmental organisation nor does it submit to any jurisdiction.
 */

#include "grib_api_internal.h"

/*
   This is used by make_class.pl

   START_CLASS_DEF
   CLASS      = accessor
   SUPER      = grib_accessor_class_gen
   IMPLEMENTS = init
   IMPLEMENTS = unpack_double;unpack_double_element
   IMPLEMENTS = pack_double
   IMPLEMENTS = value_count
   IMPLEMENTS = dump;get_native_type
   MEMBERS=const char*  values
   MEMBERS=const char*  numberOfRows 
   MEMBERS=const char*  numberOfColumns
   MEMBERS=const char*  numberOfPoints
   MEMBERS=const char*  pl
   END_CLASS_DEF
 */

/* START_CLASS_IMP */

/*

Don't edit anything between START_CLASS_IMP and END_CLASS_IMP
Instead edit values between START_CLASS_DEF and END_CLASS_DEF
or edit "accessor.class" and rerun ./make_class.pl

*/

static int get_native_type(grib_accessor*);
static int pack_double(grib_accessor*, const double* val, size_t* len);
static int unpack_double(grib_accessor*, double* val, size_t* len);
static int value_count(grib_accessor*, long*);
static void dump(grib_accessor*, grib_dumper*);
static void init(grib_accessor*, const long, grib_arguments*);
static void init_class(grib_accessor_class*);
static int unpack_double_element(grib_accessor*, size_t i, double* val);

typedef struct grib_accessor_data_apply_boustrophedonic
{
    grib_accessor att;
    /* Members defined in gen */
    /* Members defined in data_apply_boustrophedonic */
    const char* values;
    const char* numberOfRows;
    const char* numberOfColumns;
    const char* numberOfPoints;
    const char* pl;
} grib_accessor_data_apply_boustrophedonic;

extern grib_accessor_class* grib_accessor_class_gen;

static grib_accessor_class _grib_accessor_class_data_apply_boustrophedonic = {
    &grib_accessor_class_gen,                         /* super                     */
    "data_apply_boustrophedonic",                     /* name                      */
    sizeof(grib_accessor_data_apply_boustrophedonic), /* size                      */
    0,                                                /* inited */
    &init_class,                                      /* init_class */
    &init,                                            /* init                      */
    0,                                                /* post_init                      */
    0,                                                /* free mem                       */
    &dump,                                            /* describes himself         */
    0,                                                /* get length of section     */
    0,                                                /* get length of string      */
    &value_count,                                     /* get number of values      */
    0,                                                /* get number of bytes      */
    0,                                                /* get offset to bytes           */
    &get_native_type,                                 /* get native type               */
    0,                                                /* get sub_section                */
    0,                                                /* grib_pack procedures long      */
    0,                                                /* grib_pack procedures long      */
    0,                                                /* grib_pack procedures long      */
    0,                                                /* grib_unpack procedures long    */
    &pack_double,                                     /* grib_pack procedures double    */
    &unpack_double,                                   /* grib_unpack procedures double  */
    0,                                                /* grib_pack procedures string    */
    0,                                                /* grib_unpack procedures string  */
    0,                                                /* grib_pack array procedures string    */
    0,                                                /* grib_unpack array procedures string  */
    0,                                                /* grib_pack procedures bytes     */
    0,                                                /* grib_unpack procedures bytes   */
    0,                                                /* pack_expression */
    0,                                                /* notify_change   */
    0,                                                /* update_size   */
    0,                                                /* preferred_size   */
    0,                                                /* resize   */
    0,                                                /* nearest_smaller_value */
    0,                                                /* next accessor    */
    0,                                                /* compare vs. another accessor   */
    &unpack_double_element,                           /* unpack only ith value          */
    0,                                                /* unpack a subarray         */
    0,                                                /* clear          */
    0,                                                /* clone accessor          */
};


grib_accessor_class* grib_accessor_class_data_apply_boustrophedonic = &_grib_accessor_class_data_apply_boustrophedonic;


static void init_class(grib_accessor_class* c)
{
    c->next_offset            = (*(c->super))->next_offset;
    c->string_length          = (*(c->super))->string_length;
    c->byte_count             = (*(c->super))->byte_count;
    c->byte_offset            = (*(c->super))->byte_offset;
    c->sub_section            = (*(c->super))->sub_section;
    c->pack_missing           = (*(c->super))->pack_missing;
    c->is_missing             = (*(c->super))->is_missing;
    c->pack_long              = (*(c->super))->pack_long;
    c->unpack_long            = (*(c->super))->unpack_long;
    c->pack_string            = (*(c->super))->pack_string;
    c->unpack_string          = (*(c->super))->unpack_string;
    c->pack_string_array      = (*(c->super))->pack_string_array;
    c->unpack_string_array    = (*(c->super))->unpack_string_array;
    c->pack_bytes             = (*(c->super))->pack_bytes;
    c->unpack_bytes           = (*(c->super))->unpack_bytes;
    c->pack_expression        = (*(c->super))->pack_expression;
    c->notify_change          = (*(c->super))->notify_change;
    c->update_size            = (*(c->super))->update_size;
    c->preferred_size         = (*(c->super))->preferred_size;
    c->resize                 = (*(c->super))->resize;
    c->nearest_smaller_value  = (*(c->super))->nearest_smaller_value;
    c->next                   = (*(c->super))->next;
    c->compare                = (*(c->super))->compare;
    c->unpack_double_subarray = (*(c->super))->unpack_double_subarray;
    c->clear                  = (*(c->super))->clear;
    c->make_clone             = (*(c->super))->make_clone;
}

/* END_CLASS_IMP */

static void init(grib_accessor* a, const long v, grib_arguments* args)
{
    int n                                          = 0;
    grib_accessor_data_apply_boustrophedonic* self = (grib_accessor_data_apply_boustrophedonic*)a;

    self->values          = grib_arguments_get_name(grib_handle_of_accessor(a), args, n++);
    self->numberOfRows    = grib_arguments_get_name(grib_handle_of_accessor(a), args, n++);
    self->numberOfColumns = grib_arguments_get_name(grib_handle_of_accessor(a), args, n++);
    self->numberOfPoints  = grib_arguments_get_name(grib_handle_of_accessor(a), args, n++);
    self->pl              = grib_arguments_get_name(grib_handle_of_accessor(a), args, n++);

    a->length = 0;
}
static void dump(grib_accessor* a, grib_dumper* dumper)
{
    grib_dump_values(dumper, a);
}

static int value_count(grib_accessor* a, long* numberOfPoints)
{
    grib_accessor_data_apply_boustrophedonic* self = (grib_accessor_data_apply_boustrophedonic*)a;
    int ret                                        = 0;

    *numberOfPoints = 0;
    ret             = grib_get_long_internal(grib_handle_of_accessor(a), self->numberOfPoints, numberOfPoints);

    return ret;
}

static int unpack_double(grib_accessor* a, double* val, size_t* len)
{
    grib_accessor_data_apply_boustrophedonic* self = (grib_accessor_data_apply_boustrophedonic*)a;
    size_t plSize                                  = 0;
    long* pl                                       = 0;
    double* values                                 = 0;
    double* pvalues                                = 0;
    double* pval                                   = 0;
    size_t valuesSize                              = 0;
    long i, j;
    int ret;
    long numberOfPoints, numberOfRows, numberOfColumns;

    ret = grib_get_long_internal(grib_handle_of_accessor(a), self->numberOfPoints, &numberOfPoints);
    if (ret)
        return ret;

    if (*len < numberOfPoints) {
        *len = numberOfPoints;
        return GRIB_ARRAY_TOO_SMALL;
    }

    ret = grib_get_size(grib_handle_of_accessor(a), self->values, &valuesSize);
    if (ret)
        return ret;

    /* constant field */
    if (valuesSize == 0)
        return 0;

    if (valuesSize != numberOfPoints) {
        grib_context_log(a->context, GRIB_LOG_ERROR, "boustrophedonic ordering error: ( %s=%ld ) != (sizeOf(%s)=%ld)",
                         self->numberOfPoints, numberOfPoints, self->values, (long)valuesSize);
        return GRIB_DECODING_ERROR;
    }

    values = (double*)grib_context_malloc_clear(a->context, sizeof(double) * numberOfPoints);
    ret    = grib_get_double_array_internal(grib_handle_of_accessor(a), self->values, values, &valuesSize);
    if (ret)
        return ret;

    pvalues = values;
    pval    = val;

    ret = grib_get_long_internal(grib_handle_of_accessor(a), self->numberOfRows, &numberOfRows);
    if (ret)
        return ret;

    ret = grib_get_long_internal(grib_handle_of_accessor(a), self->numberOfColumns, &numberOfColumns);
    if (ret)
        return ret;

    if (grib_get_size(grib_handle_of_accessor(a), self->pl, &plSize) == GRIB_SUCCESS) {
        Assert(plSize == numberOfRows);
        pl  = (long*)grib_context_malloc_clear(a->context, sizeof(long) * plSize);
        ret = grib_get_long_array_internal(grib_handle_of_accessor(a), self->pl, pl, &plSize);
        if (ret)
            return ret;

        for (j = 0; j < numberOfRows; j++) {
            if (j % 2) {
                pval += pl[j];
                for (i = 0; i < pl[j]; i++)
                    *(pval--) = *(pvalues++);
                pval += pl[j];
            }
            else {
                for (i = 0; i < pl[j]; i++)
                    *(pval++) = *(pvalues++);
            }
        }

        grib_context_free(a->context, pl);
    }
    else {
        for (j = 0; j < numberOfRows; j++) {
            if (j % 2) {
                pval += numberOfColumns - 1;
                for (i = 0; i < numberOfColumns; i++)
                    *(pval--) = *(pvalues++);
                pval += numberOfColumns + 1;
            }
            else {
                for (i = 0; i < numberOfColumns; i++)
                    *(pval++) = *(pvalues++);
            }
        }
    }

    grib_context_free(a->context, values);

    return GRIB_SUCCESS;
}

static int unpack_double_element(grib_accessor* a, size_t idx, double* val)
{
    size_t size;
    double* values;
    int err = 0;

    /* GRIB-564: The index idx relates to codedValues NOT values! */

    err = grib_get_size(a->parent->h, "codedValues", &size);
    if (err)
        return err;
    if (idx > size)
        return GRIB_INVALID_NEAREST;

    values = (double*)grib_context_malloc_clear(a->parent->h->context, size * sizeof(double));
    err    = grib_get_double_array(a->parent->h, "codedValues", values, &size);
    if (err) {
        grib_context_free(a->parent->h->context, values);
        return err;
    }
    *val = values[idx];
    grib_context_free(a->parent->h->context, values);
    return GRIB_SUCCESS;
}

static int pack_double(grib_accessor* a, const double* val, size_t* len)
{
    grib_accessor_data_apply_boustrophedonic* self = (grib_accessor_data_apply_boustrophedonic*)a;
    size_t plSize                                  = 0;
    long* pl                                       = 0;
    double* values                                 = 0;
    double* pvalues                                = 0;
    double* pval                                   = 0;
    size_t valuesSize                              = 0;
    long i, j;
    int ret;
    long numberOfPoints, numberOfRows, numberOfColumns;

    ret = grib_get_long_internal(grib_handle_of_accessor(a), self->numberOfPoints, &numberOfPoints);
    if (ret)
        return ret;

    if (*len < numberOfPoints) {
        *len = numberOfPoints;
        return GRIB_ARRAY_TOO_SMALL;
    }

    valuesSize = numberOfPoints;

    values = (double*)grib_context_malloc_clear(a->context, sizeof(double) * numberOfPoints);

    pvalues = values;
    pval    = (double*)val;

    ret = grib_get_long_internal(grib_handle_of_accessor(a), self->numberOfRows, &numberOfRows);
    if (ret)
        return ret;

    ret = grib_get_long_internal(grib_handle_of_accessor(a), self->numberOfColumns, &numberOfColumns);
    if (ret)
        return ret;

    if (grib_get_size(grib_handle_of_accessor(a), self->pl, &plSize) == GRIB_SUCCESS) {
        Assert(plSize == numberOfRows);
        pl  = (long*)grib_context_malloc_clear(a->context, sizeof(long) * plSize);
        ret = grib_get_long_array_internal(grib_handle_of_accessor(a), self->pl, pl, &plSize);
        if (ret)
            return ret;

        for (j = 0; j < numberOfRows; j++) {
            if (j % 2) {
                pvalues += pl[j];
                for (i = 0; i < pl[j]; i++) {
                    *(--pvalues) = *(pval++);
                }
                pvalues += pl[j];
            }
            else {
                for (i = 0; i < pl[j]; i++)
                    *(pvalues++) = *(pval++);
            }
        }

        grib_context_free(a->context, pl);
    }
    else {
        for (j = 0; j < numberOfRows; j++) {
            if (j % 2) {
                pvalues += numberOfColumns;
                for (i = 0; i < numberOfColumns; i++)
                    *(--pvalues) = *(pval++);
                pvalues += numberOfColumns;
            }
            else {
                for (i = 0; i < numberOfColumns; i++)
                    *(pvalues++) = *(pval++);
            }
        }
    }
    ret = grib_set_double_array_internal(grib_handle_of_accessor(a), self->values, values, valuesSize);
    if (ret)
        return ret;

    grib_context_free(a->context, values);

    return GRIB_SUCCESS;
}

static int get_native_type(grib_accessor* a)
{
    return GRIB_TYPE_DOUBLE;
}
