/*
 * (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.
 */

/**************************************
 * Enrico Fucile
 ************************************/

#include "grib_api_internal.h"


/*
   This is used by make_class.pl

   START_CLASS_DEF
   CLASS      = accessor
   SUPER      = grib_accessor_class_long
   IMPLEMENTS = unpack_long
   IMPLEMENTS = init
   MEMBERS = const char* ni
   MEMBERS = const char* nj
   MEMBERS = const char* plpresent
   MEMBERS = const char* pl
   MEMBERS = const char* order
   MEMBERS = const char* lat_first
   MEMBERS = const char* lon_first
   MEMBERS = const char* lat_last
   MEMBERS = const char* lon_last
   MEMBERS = const char* support_legacy
   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 unpack_long(grib_accessor*, long* val, size_t* len);
static void init(grib_accessor*, const long, grib_arguments*);
static void init_class(grib_accessor_class*);

typedef struct grib_accessor_number_of_points_gaussian
{
    grib_accessor att;
    /* Members defined in gen */
    /* Members defined in long */
    /* Members defined in number_of_points_gaussian */
    const char* ni;
    const char* nj;
    const char* plpresent;
    const char* pl;
    const char* order;
    const char* lat_first;
    const char* lon_first;
    const char* lat_last;
    const char* lon_last;
    const char* support_legacy;
} grib_accessor_number_of_points_gaussian;

extern grib_accessor_class* grib_accessor_class_long;

static grib_accessor_class _grib_accessor_class_number_of_points_gaussian = {
    &grib_accessor_class_long,                       /* super                     */
    "number_of_points_gaussian",                     /* name                      */
    sizeof(grib_accessor_number_of_points_gaussian), /* 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      */
    0,                                               /* 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      */
    &unpack_long,                                    /* grib_unpack procedures long    */
    0,                                               /* 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  */
    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   */
    0,                                               /* unpack only ith value          */
    0,                                               /* unpack a subarray         */
    0,                                               /* clear          */
    0,                                               /* clone accessor          */
};


grib_accessor_class* grib_accessor_class_number_of_points_gaussian = &_grib_accessor_class_number_of_points_gaussian;


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->value_count            = (*(c->super))->value_count;
    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->pack_double            = (*(c->super))->pack_double;
    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->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_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 */

#define EFDEBUG 0

static void init(grib_accessor* a, const long l, grib_arguments* c)
{
    int n                                         = 0;
    grib_handle* h                                = grib_handle_of_accessor(a);
    grib_accessor_number_of_points_gaussian* self = (grib_accessor_number_of_points_gaussian*)a;
    self->ni                                      = grib_arguments_get_name(h, c, n++);
    self->nj                                      = grib_arguments_get_name(h, c, n++);
    self->plpresent                               = grib_arguments_get_name(h, c, n++);
    self->pl                                      = grib_arguments_get_name(h, c, n++);
    self->order                                   = grib_arguments_get_name(h, c, n++);
    self->lat_first                               = grib_arguments_get_name(h, c, n++);
    self->lon_first                               = grib_arguments_get_name(h, c, n++);
    self->lat_last                                = grib_arguments_get_name(h, c, n++);
    self->lon_last                                = grib_arguments_get_name(h, c, n++);
    self->support_legacy                          = grib_arguments_get_name(h, c, n++);
    a->flags |= GRIB_ACCESSOR_FLAG_READ_ONLY;
    a->flags |= GRIB_ACCESSOR_FLAG_FUNCTION;
    a->length = 0;
}
#if 0
/*Legacy mode*/
static long num_points_reduced_gauss_old(grib_handle* h, long nj, long pl[],
                                         long max_pl, double lats[],
                                         double angular_precision,
                                         double lat_first, double lat_last,
                                         double lon_first, double lon_last)
{
    long result=0;
    int is_global=0;
    size_t plsize=0;
    long ilon_first=0,ilon_last=0;
    double lon_first_row=0,lon_last_row=0;
    float d = 0;
    is_global=is_gaussian_global(lat_first,lat_last,lon_first,lon_last,max_pl,lats,angular_precision);
    d=fabs(lats[0]-lats[1]);
    if ( !is_global ) {
        long j = 0;
        /*sub area*/
        (void)d;
#if EFDEBUG
        printf("-------- subarea fabs(lat_first-lats[0])=%g d=%g\n",fabs(lat_first-lats[0]),d);
        printf("-------- subarea fabs(lat_last+lats[0])=%g d=%g\n",fabs(lat_last+lats[0]),d);
        printf("-------- subarea lon_last=%g order=%ld 360.0-90.0/order=%g\n",
                lon_last,order,360.0-90.0/order);
        printf("-------- subarea lon_first=%g fabs(lon_last  -( 360.0-90.0/order))=%g 90.0/order=%g\n",
                lon_first,fabs(lon_last  - (360.0-90.0/order)),90.0/order);
#endif
        for (j=0;j<nj;j++) {
            long row_count=0;
#if EFDEBUG
            printf("--  %d ",j);
#endif
            grib_get_reduced_row(pl[j],lon_first,lon_last,&row_count,&ilon_first,&ilon_last);
            lon_first_row=((ilon_first)*360.0)/pl[j];
            lon_last_row=((ilon_last)*360.0)/pl[j];
            result += row_count;
            (void)lon_last_row;
            (void)lon_first_row;
#if EFDEBUG
            printf("        ilon_first=%ld lon_first=%.10e ilon_last=%ld lon_last=%.10e count=%ld row_count=%ld\n",
                    ilon_first,lon_first_row,ilon_last,lon_last_row,result,row_count);
#endif
        }
    } else {
        int i = 0;
        result=0;
        for (i=0;i<plsize;i++) result += pl[i];
    }
    return result;
}

/* New MIR compatible way */
static long num_points_reduced_gauss_new(grib_handle* h, long nj, long pl[], double lon_first, double lon_last)
{
    long result = 0;
    long j;
    /* Always assume sub area */
    for (j=0;j<nj;j++) {
        long row_count=0;
        long ilon_first=0,ilon_last=0;
        grib_get_reduced_row2(pl[j], lon_first, lon_last, &row_count, &ilon_first, &ilon_last);
        result += row_count;
    }
    return result;
}
#endif

static int angleApproximatelyEqual(double A, double B, double angular_precision)
{
    return angular_precision > 0 ? (fabs(A - B) <= angular_precision) : (A == B);
}

static double longitude_normalise(double lon, double minimum)
{
    while (lon < minimum) {
        lon += 360;
    }
    while (lon >= minimum + 360) {
        lon -= 360;
    }
    return lon;
}

static void correctWestEast(long max_pl, double angular_precision, double* pWest, double* pEast)
{
    double w, e;
    const double inc = 360.0 / max_pl; /*smallest increment*/
    if (*pWest > *pEast)
        *pEast += 360;

    w = *pWest;
    e = *pEast;

    if (angleApproximatelyEqual(0, w, angular_precision)) {
        const int cond1 = angleApproximatelyEqual(360 - inc, e - w, angular_precision);
        const int cond2 = (360 - inc < e - w);
        const int cond3 = (e != w);
        const int cond4 = longitude_normalise(e, w) == w; /* e.normalise(w) == w */
        if (cond1 || cond2 || (cond3 && cond4)) {
            *pWest = 0;
            *pEast = 360 - inc;
        }
    }
}

static int get_number_of_data_values(grib_handle* h, size_t* numDataValues)
{
    int err  = 0;
    long bpv = 0, bitmapPresent = 0;
    size_t bitmapLength = 0;

    if ((err = grib_get_long(h, "bitsPerValue", &bpv)))
        return err;

    if (bpv != 0) {
        if (grib_get_size(h, "values", numDataValues) == GRIB_SUCCESS) {
            return GRIB_SUCCESS;
        }
    }
    else {
        /* Constant field (with or without bitmap) */
        if ((err = grib_get_long(h, "bitmapPresent", &bitmapPresent)))
            return err;
        if (bitmapPresent) {
            if ((err = grib_get_size(h, "bitmap", &bitmapLength)))
                return err;
            *numDataValues = bitmapLength;
            return GRIB_SUCCESS;
        }
        else {
            err = GRIB_NO_VALUES; /* Cannot determine number of values */
        }
    }

    return err;
}

static int unpack_long_with_legacy_support(grib_accessor* a, long* val, size_t* len);
static int unpack_long_new(grib_accessor* a, long* val, size_t* len);

static int unpack_long(grib_accessor* a, long* val, size_t* len)
{
    int ret                                       = GRIB_SUCCESS;
    long support_legacy                           = 1;
    grib_accessor_number_of_points_gaussian* self = (grib_accessor_number_of_points_gaussian*)a;
    grib_handle* h                                = grib_handle_of_accessor(a);

    if ((ret = grib_get_long_internal(h, self->support_legacy, &support_legacy)) != GRIB_SUCCESS)
        return ret;
    if (support_legacy == 1)
        return unpack_long_with_legacy_support(a, val, len);
    else
        return unpack_long_new(a, val, len);
}

/* New algorithm */
static int unpack_long_new(grib_accessor* a, long* val, size_t* len)
{
    int ret       = GRIB_SUCCESS;
    int is_global = 0;
    long ni = 0, nj = 0, plpresent = 0, order = 0;
    size_t plsize = 0;
    double lat_first, lat_last, lon_first, lon_last;
    long* pl     = NULL;
    long* plsave = NULL;
    long row_count;
    long ilon_first = 0, ilon_last = 0;
    double angular_precision = 1.0 / 1000000.0;
    long editionNumber       = 0;
    grib_handle* h           = grib_handle_of_accessor(a);

    grib_accessor_number_of_points_gaussian* self = (grib_accessor_number_of_points_gaussian*)a;
    grib_context* c                               = a->context;

    if ((ret = grib_get_long_internal(h, self->ni, &ni)) != GRIB_SUCCESS)
        return ret;

    if ((ret = grib_get_long_internal(h, self->nj, &nj)) != GRIB_SUCCESS)
        return ret;

    if ((ret = grib_get_long_internal(h, self->plpresent, &plpresent)) != GRIB_SUCCESS)
        return ret;

    if (nj == 0)
        return GRIB_GEOCALCULUS_PROBLEM;

    if (grib_get_long(h, "editionNumber", &editionNumber) == GRIB_SUCCESS) {
        if (editionNumber == 1)
            angular_precision = 1.0 / 1000;
    }

    if (plpresent) {
        long max_pl          = 0;
        int j                = 0;
        double lon_first_row = 0, lon_last_row = 0;

        /*reduced*/
        if ((ret = grib_get_long_internal(h, self->order, &order)) != GRIB_SUCCESS)
            return ret;
        if ((ret = grib_get_double_internal(h, self->lat_first, &lat_first)) != GRIB_SUCCESS)
            return ret;
        if ((ret = grib_get_double_internal(h, self->lon_first, &lon_first)) != GRIB_SUCCESS)
            return ret;
        if ((ret = grib_get_double_internal(h, self->lat_last, &lat_last)) != GRIB_SUCCESS)
            return ret;
        if ((ret = grib_get_double_internal(h, self->lon_last, &lon_last)) != GRIB_SUCCESS)
            return ret;

        if ((ret = grib_get_size(h, self->pl, &plsize)) != GRIB_SUCCESS)
            return ret;

        pl     = (long*)grib_context_malloc_clear(c, sizeof(long) * plsize);
        plsave = pl;
        grib_get_long_array_internal(h, self->pl, pl, &plsize);

        if (lon_last < 0)
            lon_last += 360;
        if (lon_first < 0)
            lon_first += 360;

        /* Find the maximum element of "pl" array, do not assume it's 4*N! */
        /* This could be an Octahedral Gaussian Grid */
        max_pl = pl[0];
        for (j = 1; j < plsize; j++) {
            if (pl[j] > max_pl)
                max_pl = pl[j];
        }

        is_global = 0; /* ECC-445 */

        correctWestEast(max_pl, angular_precision, &lon_first, &lon_last);

        if (!is_global) {
            /*sub area*/
            *val = 0;
            for (j = 0; j < nj; j++) {
                row_count = 0;
                grib_get_reduced_row_wrapper(h, pl[j], lon_first, lon_last, &row_count, &ilon_first, &ilon_last);
                lon_first_row = ((ilon_first)*360.0) / pl[j];
                lon_last_row  = ((ilon_last)*360.0) / pl[j];
                *val += row_count;
                (void)lon_last_row;
                (void)lon_first_row;
            }
        }
        else {
            int i = 0;
            *val  = 0;
            for (i = 0; i < plsize; i++)
                *val += pl[i];
        }
    }
    else {
        /*regular*/
        *val = ni * nj;
    }
    if (plsave)
        grib_context_free(c, plsave);

    return ret;
}

/* With Legacy support */
static int unpack_long_with_legacy_support(grib_accessor* a, long* val, size_t* len)
{
    int ret       = GRIB_SUCCESS;
    int is_global = 0;
    long ni = 0, nj = 0, plpresent = 0, order = 0;
    size_t plsize = 0;
    double lat_first, lat_last, lon_first, lon_last;
    long* pl     = NULL;
    long* plsave = NULL;
    long row_count;
    long ilon_first = 0, ilon_last = 0;
    double angular_precision = 1.0 / 1000000.0;
    long editionNumber       = 0;
    grib_handle* h           = grib_handle_of_accessor(a);
    size_t numDataValues     = 0;

    grib_accessor_number_of_points_gaussian* self = (grib_accessor_number_of_points_gaussian*)a;
    grib_context* c                               = a->context;

    if ((ret = grib_get_long_internal(h, self->ni, &ni)) != GRIB_SUCCESS)
        return ret;

    if ((ret = grib_get_long_internal(h, self->nj, &nj)) != GRIB_SUCCESS)
        return ret;

    if ((ret = grib_get_long_internal(h, self->plpresent, &plpresent)) != GRIB_SUCCESS)
        return ret;

    if (nj == 0)
        return GRIB_GEOCALCULUS_PROBLEM;

    if (grib_get_long(h, "editionNumber", &editionNumber) == GRIB_SUCCESS) {
        if (editionNumber == 1)
            angular_precision = 1.0 / 1000;
    }

    if (plpresent) {
        long max_pl = 0;
        int j                = 0;
        double lon_first_row = 0, lon_last_row = 0;

        /*reduced*/
        if ((ret = grib_get_long_internal(h, self->order, &order)) != GRIB_SUCCESS)
            return ret;
        if ((ret = grib_get_double_internal(h, self->lat_first, &lat_first)) != GRIB_SUCCESS)
            return ret;
        if ((ret = grib_get_double_internal(h, self->lon_first, &lon_first)) != GRIB_SUCCESS)
            return ret;
        if ((ret = grib_get_double_internal(h, self->lat_last, &lat_last)) != GRIB_SUCCESS)
            return ret;
        if ((ret = grib_get_double_internal(h, self->lon_last, &lon_last)) != GRIB_SUCCESS)
            return ret;

        if ((ret = grib_get_size(h, self->pl, &plsize)) != GRIB_SUCCESS)
            return ret;

        pl     = (long*)grib_context_malloc_clear(c, sizeof(long) * plsize);
        plsave = pl;
        grib_get_long_array_internal(h, self->pl, pl, &plsize);

        if (lon_last < 0)
            lon_last += 360;
        if (lon_first < 0)
            lon_first += 360;

        /* Find the maximum element of "pl" array, do not assume it's 4*N! */
        /* This could be an Octahedral Gaussian Grid */
        max_pl = pl[0];
        for (j = 1; j < plsize; j++) {
            if (pl[j] > max_pl)
                max_pl = pl[j];
        }

        /*is_global=is_gaussian_global(lat_first,lat_last,lon_first,lon_last,max_pl,lats,angular_precision);*/
        is_global = 0; /* ECC-445 */

        correctWestEast(max_pl, angular_precision, &lon_first, &lon_last);

        if (!is_global) {
            /*sub area*/
#if EFDEBUG
            printf("-------- subarea fabs(lat_first-lats[0])=%g d=%g\n", fabs(lat_first - lats[0]), d);
            printf("-------- subarea fabs(lat_last+lats[0])=%g d=%g\n", fabs(lat_last + lats[0]), d);
            printf("-------- subarea lon_last=%g order=%ld 360.0-90.0/order=%g\n",
                   lon_last, order, 360.0 - 90.0 / order);
            printf("-------- subarea lon_first=%g fabs(lon_last  -( 360.0-90.0/order))=%g 90.0/order=%g\n",
                   lon_first, fabs(lon_last - (360.0 - 90.0 / order)), 90.0 / order);
#endif
            *val = 0;
            for (j = 0; j < nj; j++) {
                row_count = 0;
#if EFDEBUG
                printf("--  %d ", j);
#endif
                grib_get_reduced_row_wrapper(h, pl[j], lon_first, lon_last, &row_count, &ilon_first, &ilon_last);
#if 0
                if ( row_count != pl[j] ) {
                    printf("oops...... rc=%ld but pl[%d]=%ld\n", row_count, j,pl[j]);
                }
#endif
                lon_first_row = ((ilon_first)*360.0) / pl[j];
                lon_last_row  = ((ilon_last)*360.0) / pl[j];
                *val += row_count;
                (void)lon_last_row;
                (void)lon_first_row;
#if EFDEBUG
                printf("        ilon_first=%ld lon_first=%.10e ilon_last=%ld lon_last=%.10e count=%ld row_count=%ld\n",
                       ilon_first, lon_first_row, ilon_last, lon_last_row, *val, row_count);
#endif
            }
        }
        else {
            int i = 0;
            *val  = 0;
            for (i = 0; i < plsize; i++)
                *val += pl[i];
        }
    }
    else {
        /*regular*/
        *val = ni * nj;
    }
#if EFDEBUG
    printf("DEBUG:     number_of_points_gaussian=%ld plpresent=%ld plsize=%d\n", *val, plpresent, plsize);
    for (i = 0; i < plsize; i++)
        printf(" DEBUG: pl[%d]=%ld\n", i, pl[i]);
#endif

    if (plsave)
        grib_context_free(c, plsave);

    /* ECC-756: Now decide whether this is legacy GRIB1 message. */
    /* Query data values to see if there is a mismatch */
    if (get_number_of_data_values(h, &numDataValues) == GRIB_SUCCESS) {
        if (*val != numDataValues) {
            if (h->context->debug)
                fprintf(stderr,
                        "ECCODES DEBUG number_of_points_gaussian: LEGACY MODE activated. "
                        "Count(=%ld) changed to num values(=%ld)\n",
                        *val, (long)numDataValues);
            *val = numDataValues;
        }
    }

    return ret;
}
