/*
 * (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 = evaluate_long
   IMPLEMENTS = evaluate_double
   IMPLEMENTS = print
   IMPLEMENTS = add_dependency
   MEMBERS    = grib_expression *left
   MEMBERS = grib_expression *right
   MEMBERS = grib_binop_long_proc    long_func
   MEMBERS = grib_binop_double_proc  double_func
   MEMBERS = grib_binop_string_proc  string_func
   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 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*);

typedef struct grib_expression_binop
{
    grib_expression base;
    /* Members defined in binop */
    grib_expression* left;
    grib_expression* right;
    grib_binop_long_proc long_func;
    grib_binop_double_proc double_func;
    grib_binop_string_proc string_func;
} grib_expression_binop;


static grib_expression_class _grib_expression_class_binop = {
    0,                             /* super                     */
    "binop",                       /* name                      */
    sizeof(grib_expression_binop), /* size of instance          */
    0,                             /* inited */
    &init_class,                   /* init_class */
    0,                             /* constructor               */
    &destroy,                      /* destructor                */
    &print,
    &add_dependency,

    &native_type,
    0,

    &evaluate_long,
    &evaluate_double,
    0,
};

grib_expression_class* grib_expression_class_binop = &_grib_expression_class_binop;


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

static int evaluate_long(grib_expression* g, grib_handle* h, long* lres)
{
    long v1 = 0;
    long v2 = 0;
    int ret;
    grib_expression_binop* e = (grib_expression_binop*)g;

#if 0 /* DEBUGGING */
    {
        int typeLeft, typeRight;
        const char* nameLeft;
        const char* nameRight;
        typeLeft = grib_expression_native_type(h, e->left);
        typeRight = grib_expression_native_type(h, e->right);
        nameLeft = grib_expression_get_name(e->left);
        nameRight= grib_expression_get_name(e->right);
        printf("eval_long nameLeft=%s (type=%d), nameRight=%s (type=%d)\n",nameLeft,typeLeft, nameRight,typeRight);
        grib_expression_print(h->context, g, h);
        printf("\n");
    }
#endif

    ret = grib_expression_evaluate_long(h, e->left, &v1);
    if (ret != GRIB_SUCCESS)
        return ret;

    ret = grib_expression_evaluate_long(h, e->right, &v2);
    if (ret != GRIB_SUCCESS)
        return ret;

    *lres = e->long_func(v1, v2);
    return GRIB_SUCCESS;
}

static int evaluate_double(grib_expression* g, grib_handle* h, double* dres)
{
    double v1 = 0.0;
    double v2 = 0.0;
    int ret;

    grib_expression_binop* e = (grib_expression_binop*)g;

#if 0 /* DEBUGGING */
    {
        int typeLeft, typeRight;
        const char* nameLeft;
        const char* nameRight;
        typeLeft = grib_expression_native_type(h, e->left);
        typeRight = grib_expression_native_type(h, e->right);
        nameLeft = grib_expression_get_name(e->left);
        nameRight= grib_expression_get_name(e->right);
        printf("eval_dbl nameLeft=%s (type=%d), nameRight=%s (type=%d)\n",nameLeft,typeLeft, nameRight,typeRight);
        grib_expression_print(h->context, g, h);
        printf("\n");
    }
#endif

    ret = grib_expression_evaluate_double(h, e->left, &v1);
    if (ret != GRIB_SUCCESS)
        return ret;

    ret = grib_expression_evaluate_double(h, e->right, &v2);
    if (ret != GRIB_SUCCESS)
        return ret;

    *dres = e->double_func ? e->double_func(v1, v2) : e->long_func(v1, v2);

    return GRIB_SUCCESS;
}

static void print(grib_context* c, grib_expression* g, grib_handle* f)
{
    grib_expression_binop* e = (grib_expression_binop*)g;
    printf("binop(");
    grib_expression_print(c, e->left, f);
    printf(",");
    grib_expression_print(c, e->right, f);
    printf(")");
}

static void destroy(grib_context* c, grib_expression* g)
{
    grib_expression_binop* e = (grib_expression_binop*)g;
    grib_expression_free(c, e->left);
    grib_expression_free(c, e->right);
}

static void add_dependency(grib_expression* g, grib_accessor* observer)
{
    grib_expression_binop* e = (grib_expression_binop*)g;
    grib_dependency_observe_expression(observer, e->left);
    grib_dependency_observe_expression(observer, e->right);
}

grib_expression* new_binop_expression(grib_context* c,
                                      grib_binop_long_proc long_func,
                                      grib_binop_double_proc double_func,
                                      grib_expression* left, grib_expression* right)
{
    grib_expression_binop* e = (grib_expression_binop*)grib_context_malloc_clear_persistent(c, sizeof(grib_expression_binop));
    e->base.cclass           = grib_expression_class_binop;
    e->left                  = left;
    e->right                 = right;
    e->long_func             = long_func;
    e->double_func           = double_func;
    return (grib_expression*)e;
}

static int native_type(grib_expression* g, grib_handle* h)
{
    grib_expression_binop* e = (grib_expression_binop*)g;
    /* See GRIB-394 : The type of this binary expression will be double if any of its operands are double */
    if (grib_expression_native_type(h, e->left) == GRIB_TYPE_DOUBLE ||
        grib_expression_native_type(h, e->right) == GRIB_TYPE_DOUBLE) {
        return GRIB_TYPE_DOUBLE;
    }
    return e->long_func ? GRIB_TYPE_LONG : GRIB_TYPE_DOUBLE;
}
