/*
 * Copyright 2005-2015 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_double
   IMPLEMENTS = unpack_double;pack_double;is_missing
   IMPLEMENTS = pack_long
   IMPLEMENTS = init
   MEMBERS=const char*    value
   MEMBERS=const char*    multiplier
   MEMBERS=const char*    divisor
   MEMBERS=const char*    truncating
   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 is_missing(grib_accessor*);
static int pack_double(grib_accessor*, const double* val,size_t *len);
static int pack_long(grib_accessor*, const long* val,size_t *len);
static int unpack_double(grib_accessor*, double* val,size_t *len);
static void init(grib_accessor*,const long, grib_arguments* );
static void init_class(grib_accessor_class*);

typedef struct grib_accessor_scale {
    grib_accessor          att;
/* Members defined in gen */
/* Members defined in double */
/* Members defined in scale */
	const char*    value;
	const char*    multiplier;
	const char*    divisor;
	const char*    truncating;
} grib_accessor_scale;

extern grib_accessor_class* grib_accessor_class_double;

static grib_accessor_class _grib_accessor_class_scale = {
    &grib_accessor_class_double,                      /* super                     */
    "scale",                      /* name                      */
    sizeof(grib_accessor_scale),  /* 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      */
    &is_missing,               /* grib_pack procedures long      */
    &pack_long,                  /* 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 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          */
};


grib_accessor_class* grib_accessor_class_scale = &_grib_accessor_class_scale;


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->unpack_long	=	(*(c->super))->unpack_long;
	c->pack_string	=	(*(c->super))->pack_string;
	c->unpack_string	=	(*(c->super))->unpack_string;
	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;
}

/* END_CLASS_IMP */

static void init(grib_accessor* a,const long l, grib_arguments* c)
{
  grib_accessor_scale* self = (grib_accessor_scale*)a;
  int n = 0;

  self->value = grib_arguments_get_name(a->parent->h,c,n++);
  self->multiplier    = grib_arguments_get_name(a->parent->h,c,n++);
  self->divisor    = grib_arguments_get_name(a->parent->h,c,n++);
  self->truncating    = grib_arguments_get_name(a->parent->h,c,n++);

}

static int    unpack_double   (grib_accessor* a, double* val, size_t *len)
{
  grib_accessor_scale* self = (grib_accessor_scale*)a;
  int ret = 0;
  long value = 0;
  long multiplier = 0;
  long divisor = 0;

  if(*len < 1){
    ret = GRIB_ARRAY_TOO_SMALL;
    grib_context_log(a->parent->h->context, GRIB_LOG_ERROR,
      "Accessor %s cannot gather value for %s and/or %s error %d",
      a->name,self->multiplier, self->divisor, ret);
    return ret;
  }

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

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

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

  if (value == GRIB_MISSING_LONG) *val=GRIB_MISSING_DOUBLE;
  else *val = ((double)(value*multiplier))/divisor;
  /*printf("unpack_double: divisor=%ld multiplier=%ld long_value=%ld scaled_value=%.30f\n",(double)divisor,(double)multiplier,value,*val);*/

  if (ret == GRIB_SUCCESS) *len = 1;

  return ret;
}


static int pack_long(grib_accessor* a, const long* val, size_t *len)
{
  const double dval=(double)*val ;
  return pack_double(a, &dval,len);
}

static int pack_double(grib_accessor* a, const double* val, size_t *len)
{
  grib_accessor_scale* self = (grib_accessor_scale*)a;
  int ret = 0;

  long value = 0;
  long divisor = 0;
  long multiplier = 0;
  long truncating=0;
  double x;

  ret = grib_get_long_internal(a->parent->h, self->divisor,&divisor);
  if(ret != GRIB_SUCCESS) {
    grib_context_log(a->parent->h->context, GRIB_LOG_ERROR, "Accessor %s cannont gather value for %s error %d \n", a->name, self->divisor, ret);
    return ret;
  }
  ret = grib_get_long_internal(a->parent->h, self->multiplier,&multiplier);
  if(ret != GRIB_SUCCESS){
    grib_context_log(a->parent->h->context, GRIB_LOG_ERROR, "Accessor %s cannont gather value for %s error %d \n", a->name, self->divisor, ret);
    return ret;
  }
  if (self->truncating) {
    ret = grib_get_long_internal(a->parent->h, self->truncating,&truncating);
    if(ret != GRIB_SUCCESS){
      grib_context_log(a->parent->h->context, GRIB_LOG_ERROR, "Accessor %s cannont gather value for %s error %d \n", a->name, self->truncating, ret);
      return ret;
    }
  }

  if (multiplier == 0) {
    grib_context_log(a->parent->h->context, GRIB_LOG_ERROR, "Accessor %s cannont divide by a zero multiplier %s error %d  \n", a->name, self->multiplier, ret);
    return GRIB_ENCODING_ERROR;
  }

  x=*val * (double)divisor / (double)multiplier;
  if (*val == GRIB_MISSING_DOUBLE) value = GRIB_MISSING_LONG;
  else if (truncating) {
  	value = (long)x;
  } else {
	value = x > 0 ? (long)(x+0.5) : (long)(x-0.5) ;
  }

  ret = grib_set_long_internal(a->parent->h, self->value,value);
  if(ret )
    grib_context_log(a->parent->h->context, GRIB_LOG_ERROR, "Accessor %s cannont pack value for %s error %d \n", a->name, self->value, ret);

  if (ret == GRIB_SUCCESS) *len = 1;

  return ret;
}

static int is_missing(grib_accessor* a){
  grib_accessor_scale* self = (grib_accessor_scale*)a;
  grib_accessor* av=grib_find_accessor(a->parent->h,self->value);

  if (!av) return GRIB_NOT_FOUND;
  return grib_is_missing_internal(av);
#if 0
  int ret=0;
  long value=0;

  if((ret = grib_get_long_internal(a->parent->h,self->value,
     &value) )   != GRIB_SUCCESS){
    grib_context_log(a->parent->h->context, GRIB_LOG_ERROR,
      "Accessor %s cannont gather value for %s error %d \n", a->name,
       self->value, ret);
    return 0;
  }

  return (value == GRIB_MISSING_LONG);
#endif

   
}

