/*
 * (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_data_simple_packing
   IMPLEMENTS = init
   IMPLEMENTS = pack_double
   IMPLEMENTS = pack_bytes 
   IMPLEMENTS = value_count
   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 pack_bytes(grib_accessor*, const unsigned char*, size_t* len);
static int pack_double(grib_accessor*, const double* val, size_t* len);
static int value_count(grib_accessor*, long*);
static void init(grib_accessor*, const long, grib_arguments*);
static void init_class(grib_accessor_class*);

typedef struct grib_accessor_data_g2simple_packing
{
    grib_accessor att;
    /* Members defined in gen */
    /* Members defined in values */
    int carg;
    const char* seclen;
    const char* offsetdata;
    const char* offsetsection;
    int dirty;
    /* Members defined in data_simple_packing */
    int edition;
    const char* units_factor;
    const char* units_bias;
    const char* changing_precision;
    const char* number_of_values;
    const char* bits_per_value;
    const char* reference_value;
    const char* binary_scale_factor;
    const char* decimal_scale_factor;
    const char* optimize_scaling_factor;
    /* Members defined in data_g2simple_packing */
} grib_accessor_data_g2simple_packing;

extern grib_accessor_class* grib_accessor_class_data_simple_packing;

static grib_accessor_class _grib_accessor_class_data_g2simple_packing = {
    &grib_accessor_class_data_simple_packing,    /* super                     */
    "data_g2simple_packing",                     /* name                      */
    sizeof(grib_accessor_data_g2simple_packing), /* size                      */
    0,                                           /* inited */
    &init_class,                                 /* init_class */
    &init,                                       /* init                      */
    0,                                           /* post_init                      */
    0,                                           /* free mem                       */
    0,                                           /* 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           */
    0,                                           /* 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    */
    0,                                           /* 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  */
    &pack_bytes,                                 /* 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   */
    0,                                           /* unpack only ith value          */
    0,                                           /* unpack a subarray         */
    0,                                           /* clear          */
    0,                                           /* clone accessor          */
};


grib_accessor_class* grib_accessor_class_data_g2simple_packing = &_grib_accessor_class_data_g2simple_packing;


static void init_class(grib_accessor_class* c)
{
    c->dump                   = (*(c->super))->dump;
    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->get_native_type        = (*(c->super))->get_native_type;
    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->unpack_double          = (*(c->super))->unpack_double;
    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->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_element  = (*(c->super))->unpack_double_element;
    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)
{
    grib_accessor_data_g2simple_packing* self = (grib_accessor_data_g2simple_packing*)a;
    a->flags |= GRIB_ACCESSOR_FLAG_DATA;
    self->edition = 2;
}

static int value_count(grib_accessor* a, long* n_vals)
{
    grib_accessor_data_g2simple_packing* self = (grib_accessor_data_g2simple_packing*)a;
    *n_vals                                   = 0;
    return grib_get_long_internal(grib_handle_of_accessor(a), self->number_of_values, n_vals);
}

static int pack_double(grib_accessor* a, const double* cval, size_t* len)
{
    grib_accessor_data_g2simple_packing* self = (grib_accessor_data_g2simple_packing*)a;
    grib_accessor_class* super                = *(a->cclass->super);
    size_t n_vals                             = *len;
    double reference_value                    = 0;
    long binary_scale_factor                  = 0;
    long bits_per_value                       = 0;
    long decimal_scale_factor                 = 0;
    double decimal                            = 1;
    size_t buflen                             = 0;
    unsigned char* buf                        = NULL;
    unsigned char* encoded                    = NULL;
    double divisor                            = 1;
    long off                                  = 0;
    int ret                                   = 0;
    double units_factor                       = 1.0;
    double units_bias                         = 0.0;
    double* val                               = (double*)cval;
    int i;

    if (*len == 0) {
        grib_buffer_replace(a, NULL, 0, 1, 1);
        return GRIB_SUCCESS;
    }

    if (ret == GRIB_SUCCESS)
        ret = grib_set_long_internal(grib_handle_of_accessor(a), self->number_of_values, *len);

    if (ret != GRIB_SUCCESS)
        return ret;

    if (self->units_factor &&
        (grib_get_double_internal(grib_handle_of_accessor(a), self->units_factor, &units_factor) == GRIB_SUCCESS)) {
        grib_set_double_internal(grib_handle_of_accessor(a), self->units_factor, 1.0);
    }

    if (self->units_bias &&
        (grib_get_double_internal(grib_handle_of_accessor(a), self->units_bias, &units_bias) == GRIB_SUCCESS)) {
        grib_set_double_internal(grib_handle_of_accessor(a), self->units_bias, 0.0);
    }

    if (units_factor != 1.0) {
        if (units_bias != 0.0)
            for (i = 0; i < n_vals; i++)
                val[i] = val[i] * units_factor + units_bias;
        else
            for (i = 0; i < n_vals; i++)
                val[i] *= units_factor;
    }
    else if (units_bias != 0.0)
        for (i = 0; i < n_vals; i++)
            val[i] += units_bias;

    if (super != grib_accessor_class_data_g2simple_packing) {
        /* Normal case: parent not same as me! */
        ret = super->pack_double(a, val, len);
    }
    else {
        /* GRIB-364: simple packing with logarithm pre-processing */
        grib_accessor_class* super2 = NULL;
        Assert(super->super);
        super2 = *(super->super);
        ret    = super2->pack_double(a, val, len);
    }
    switch (ret) {
        case GRIB_CONSTANT_FIELD:
            grib_buffer_replace(a, NULL, 0, 1, 1);
            return GRIB_SUCCESS;
        case GRIB_SUCCESS:
            break;
        default:
            grib_context_log(a->context, GRIB_LOG_ERROR, "GRIB2 simple packing: unable to set values (%s)", grib_get_error_message(ret));
            return ret;
    }

    if ((ret = grib_get_double_internal(grib_handle_of_accessor(a), self->reference_value, &reference_value)) != GRIB_SUCCESS)
        return ret;

    if ((ret = grib_get_long_internal(grib_handle_of_accessor(a), self->binary_scale_factor, &binary_scale_factor)) != GRIB_SUCCESS)
        return ret;

    if ((ret = grib_get_long_internal(grib_handle_of_accessor(a), self->bits_per_value, &bits_per_value)) !=
        GRIB_SUCCESS)
        return ret;

    if ((ret = grib_get_long_internal(grib_handle_of_accessor(a), self->decimal_scale_factor, &decimal_scale_factor)) != GRIB_SUCCESS)
        return ret;

    decimal = grib_power(decimal_scale_factor, 10);
    divisor = grib_power(-binary_scale_factor, 2);

    buflen  = (((bits_per_value * n_vals) + 7) / 8) * sizeof(unsigned char);
    buf     = (unsigned char*)grib_context_buffer_malloc_clear(a->context, buflen);
    encoded = buf;

    grib_encode_double_array(n_vals, val, bits_per_value, reference_value, decimal, divisor, encoded, &off);

    grib_context_log(a->context, GRIB_LOG_DEBUG,
                     "grib_accessor_data_g2simple_packing : pack_double : packing %s, %d values", a->name, n_vals);

    grib_buffer_replace(a, buf, buflen, 1, 1);

    grib_context_buffer_free(a->context, buf);

    return ret;
}

static int pack_bytes(grib_accessor* a, const unsigned char* val, size_t* len)
{
    size_t length = *len;
    grib_buffer_replace(a, val, length, 1, 1);
    return GRIB_SUCCESS;
}
