/*
 * (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      = expression
   IMPLEMENTS = destroy
   IMPLEMENTS = native_type
   IMPLEMENTS = get_name
   IMPLEMENTS = evaluate_long
   IMPLEMENTS = evaluate_double
   IMPLEMENTS = evaluate_string
   IMPLEMENTS = print
   IMPLEMENTS = add_dependency
   MEMBERS    = char *name
   MEMBERS    = size_t start
   MEMBERS    = size_t length
   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 "expression.class" and rerun ./make_class.pl

*/

typedef const char* string; /* to keep make_class.pl happy */


static void init_class              (grib_expression_class*);

static void        destroy(grib_context*,grib_expression* e);

static void        print(grib_context*,grib_expression*,grib_handle*);
static void        add_dependency(grib_expression* e, grib_accessor* observer);
static string get_name(grib_expression* e);

static int        native_type(grib_expression*,grib_handle*);

static int        evaluate_long(grib_expression*,grib_handle*,long*);
static int      evaluate_double(grib_expression*,grib_handle*,double*);
static string evaluate_string(grib_expression*,grib_handle*,char*,size_t*,int*);

typedef struct grib_expression_is_integer{
  grib_expression base;
    /* Members defined in is_integer */
    char *name;
    size_t start;
    size_t length;
} grib_expression_is_integer;


static grib_expression_class _grib_expression_class_is_integer = {
    0,                    /* super                     */
    "is_integer",                    /* name                      */
    sizeof(grib_expression_is_integer),/* size of instance        */
    0,                           /* inited */
    &init_class,                 /* init_class */
    0,                     /* constructor               */
    &destroy,                  /* destructor                */
    &print,
    &add_dependency,
    &native_type,
    &get_name,
    &evaluate_long,
    &evaluate_double,
    &evaluate_string,
};

grib_expression_class* grib_expression_class_is_integer = &_grib_expression_class_is_integer;


static void init_class(grib_expression_class* c)
{
}
/* END_CLASS_IMP */

static const char* get_name(grib_expression* g)
{
    grib_expression_is_integer* e = (grib_expression_is_integer*)g;
    return e->name;
}

static int evaluate_long(grib_expression* g, grib_handle* h, long* result)
{
    grib_expression_is_integer* e = (grib_expression_is_integer*)g;
    int err                       = 0;
    char mybuf[1024]              = {0,};
    size_t size = 1024;
    char* p     = 0;
    long val    = 0;
    char* start = 0;

    if ((err = grib_get_string_internal(h, e->name, mybuf, &size)) != GRIB_SUCCESS)
        return err;

    start = mybuf + e->start;

    if (e->length > 0)
        start[e->length] = 0;

    val = strtol(start, &p, 10);

    if (*p != 0)
        *result = 0;
    else
        *result = 1;

    (void)val;
    return err;
}

static int evaluate_double(grib_expression* g, grib_handle* h, double* result)
{
    int err      = 0;
    long lresult = 0;

    err     = evaluate_long(g, h, &lresult);
    *result = lresult;
    return err;
}

static string evaluate_string(grib_expression* g, grib_handle* h, char* buf, size_t* size, int* err)
{
    long lresult   = 0;
    double dresult = 0.0;

    switch (grib_expression_native_type(h, g)) {
        case GRIB_TYPE_LONG:
            *err = evaluate_long(g, h, &lresult);
            snprintf(buf, 32, "%ld", lresult);
            break;
        case GRIB_TYPE_DOUBLE:
            *err = evaluate_double(g, h, &dresult);
            snprintf(buf, 32, "%g", dresult);
            break;
    }
    return buf;
}

static void print(grib_context* c, grib_expression* g, grib_handle* f)
{
    // grib_expression_is_integer* e = (grib_expression_is_integer*)g;
    // printf("access('%s", e->name);
    // if (f) {
    //     long s = 0;
    //     grib_get_long(f, e->name, &s);
    //     printf("=%ld", s);
    // }
    // printf("')");
}

static void destroy(grib_context* c, grib_expression* g)
{
    grib_expression_is_integer* e = (grib_expression_is_integer*)g;
    grib_context_free_persistent(c, e->name);
}


static void add_dependency(grib_expression* g, grib_accessor* observer)
{
    grib_expression_is_integer* e = (grib_expression_is_integer*)g;
    grib_accessor* observed       = grib_find_accessor(grib_handle_of_accessor(observer), e->name);

    if (!observed) {
        /* grib_context_log(observer->context, GRIB_LOG_ERROR, */
        /* "Error in accessor_add_dependency: cannot find [%s]", e->name); */
        /* Assert(observed); */
        return;
    }

    grib_dependency_add(observer, observed);
}

grib_expression* new_is_integer_expression(grib_context* c, const char* name, int start, int length)
{
    grib_expression_is_integer* e = (grib_expression_is_integer*)grib_context_malloc_clear_persistent(c, sizeof(grib_expression_is_integer));
    e->base.cclass                = grib_expression_class_is_integer;
    e->name                       = grib_context_strdup_persistent(c, name);
    e->start                      = start;
    e->length                     = length;
    return (grib_expression*)e;
}

static int native_type(grib_expression* g, grib_handle* h)
{
    return GRIB_TYPE_LONG;
}