/*
 * Copyright 2005-2016 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_long
   IMPLEMENTS = unpack_long;pack_long
   IMPLEMENTS = init;dump;is_missing
   IMPLEMENTS = next_offset
   IMPLEMENTS = byte_count
   IMPLEMENTS = value_count
   IMPLEMENTS = byte_offset
   IMPLEMENTS = update_size; destroy
   MEMBERS    = long nbytes
   MEMBERS    = grib_arguments* arg
   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_long(grib_accessor*, const long* val,size_t *len);
static int unpack_long(grib_accessor*, long* val,size_t *len);
static long byte_count(grib_accessor*);
static long byte_offset(grib_accessor*);
static long next_offset(grib_accessor*);
static int value_count(grib_accessor*,long*);
static void destroy(grib_context*,grib_accessor*);
static void dump(grib_accessor*, grib_dumper*);
static void init(grib_accessor*,const long, grib_arguments* );
static void init_class(grib_accessor_class*);
static void update_size(grib_accessor*,size_t);

typedef struct grib_accessor_unsigned {
    grib_accessor          att;
/* Members defined in gen */
/* Members defined in long */
/* Members defined in unsigned */
	long nbytes;
	grib_arguments* arg;
} grib_accessor_unsigned;

extern grib_accessor_class* grib_accessor_class_long;

static grib_accessor_class _grib_accessor_class_unsigned = {
    &grib_accessor_class_long,                      /* super                     */
    "unsigned",                      /* name                      */
    sizeof(grib_accessor_unsigned),  /* size                      */
    0,                           /* inited */
    &init_class,                 /* init_class */
    &init,                       /* init                      */
    0,                  /* post_init                      */
    &destroy,                    /* free mem                       */
    &dump,                       /* describes himself         */
    &next_offset,                /* get length of section     */
    0,              /* get length of string      */
    &value_count,                /* get number of values      */
    &byte_count,                 /* get number of bytes      */
    &byte_offset,                /* 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      */
    &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 procedures bytes     */
    0,               /* grib_unpack procedures bytes   */
    0,            /* pack_expression */
    0,              /* notify_change   */
    &update_size,                /* 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_unsigned = &_grib_accessor_class_unsigned;


static void init_class(grib_accessor_class* c)
{
	c->string_length	=	(*(c->super))->string_length;
	c->get_native_type	=	(*(c->super))->get_native_type;
	c->sub_section	=	(*(c->super))->sub_section;
	c->pack_missing	=	(*(c->super))->pack_missing;
	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_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->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 len , grib_arguments* arg )
{
    grib_accessor_unsigned* self = (grib_accessor_unsigned*)a;
    self->arg = NULL;
    self->arg = arg;
    self->nbytes = len;

    if (a->flags & GRIB_ACCESSOR_FLAG_TRANSIENT) {
        a->length=0;
        if (!a->vvalue)
            a->vvalue=(grib_virtual_value*)grib_context_malloc_clear(a->parent->h->context,sizeof(grib_virtual_value));
        a->vvalue->type=GRIB_TYPE_LONG;
        a->vvalue->length=len;
    } else {
        long count=0;
        grib_value_count(a,&count);

        a->length = len*count;
        a->vvalue=NULL;
    }
}

static void dump(grib_accessor* a, grib_dumper* dumper)
{
    long rlen = 0;
    grib_value_count(a,&rlen);
    if(rlen == 1)
        grib_dump_long(dumper,a,NULL);
    else
        grib_dump_values(dumper,a);
}

static unsigned long ones[] = {
        0,
        0xff,
        0xffff,
        0xffffff,
        0xffffffff,
};

/* See GRIB-490 */
static const unsigned long all_ones = -1;
static int value_is_missing(long val)
{
    return (val == GRIB_MISSING_LONG || val == all_ones);
}

int pack_long_unsigned_helper(grib_accessor* a, const long* val, size_t *len, int check)
{
    grib_accessor_unsigned* self = (grib_accessor_unsigned*)a;
    int ret = 0;
    long off = 0;
    long rlen = 0;
    int err = 0;

    size_t buflen  = 0;
    unsigned char *buf = NULL;
    unsigned long i = 0;
    unsigned long missing = 0;

    err=grib_value_count(a,&rlen);
    if (err) return err;

    if(a->flags & GRIB_ACCESSOR_FLAG_CAN_BE_MISSING)
    {
        Assert(self->nbytes <= 4);
        missing = ones[self->nbytes];
    }

    if (a->flags & GRIB_ACCESSOR_FLAG_TRANSIENT) {
        a->vvalue->lval=val[0];

        if(missing && val[0] == GRIB_MISSING_LONG)
            a->vvalue->missing=1;
        else
            a->vvalue->missing=0;

        return GRIB_SUCCESS;
    }

    if(*len < 1)
    {
        grib_context_log(a->parent->h->context, GRIB_LOG_ERROR, "Wrong size for %s it contains %d values ", a->name , 1 );
        len[0] = 0;
        return GRIB_ARRAY_TOO_SMALL;
    }

    if (rlen == 1) {
        long v = val[0];

        if (missing)
            if(v == GRIB_MISSING_LONG)
                v = missing;

        /* Check if value fits into number of bits */
        if (check) {
            const long nbits = self->nbytes*8;
            /* See GRIB-23 and GRIB-262 */
            if (! value_is_missing(v) ) {
                if (v < 0) {
                    grib_context_log(a->parent->h->context, GRIB_LOG_ERROR,
                            "Key \"%s\": Trying to encode a negative value of %ld for key of type unsigned\n", a->name, v);
                    return GRIB_ENCODING_ERROR;
                }
                if (nbits < 32) {
                    unsigned long maxval = (1 << nbits)-1;
                    if (v > maxval) {
                        grib_context_log(a->parent->h->context, GRIB_LOG_ERROR,
                                "Key \"%s\": Trying to encode value of %ld but the maximum allowable value is %ld (number of bits=%ld)\n",
                                a->name, v, maxval, nbits);
                        return GRIB_ENCODING_ERROR;
                    }
                }
            }
        }

        off = a->offset*8;
        ret = grib_encode_unsigned_long(a->parent->h->buffer->data, v, &off, self->nbytes*8);
        if (ret == GRIB_SUCCESS) len[0] = 1;
        if (*len > 1)  grib_context_log(a->parent->h->context, GRIB_LOG_WARNING, "grib_accessor_unsigned : Trying to pack %d values in a scalar %s, packing first value",  *len, a->name  );
        len[0] = 1;
        return ret;
    }

    /* TODO: We assume that there are no missing values if there are more that 1 value */
    buflen = *len*self->nbytes;

    buf = (unsigned char*)grib_context_malloc(a->parent->h->context,buflen);

    for(i=0; i < *len;i++)
        grib_encode_unsigned_long(buf, val[i] ,  &off,  self->nbytes*8);

    ret = grib_set_long_internal(a->parent->h,grib_arguments_get_name(a->parent->h,self->arg,0),*len);

    if(ret == GRIB_SUCCESS)
        grib_buffer_replace(a, buf, buflen,1,1);
    else
        *len = 0;

    grib_context_free(a->parent->h->context,buf);
    return ret;
}

static int unpack_long(grib_accessor* a, long* val, size_t *len)
{
    grib_accessor_unsigned* self = (grib_accessor_unsigned*)a;
    long rlen = 0;
    unsigned long i = 0;
    unsigned long missing = 0;
    long count=0;
    int err = 0;
    long pos = a->offset*8;

    err=grib_value_count(a,&count);
    if (err) return err;
    rlen=count;

    if(*len < rlen)
    {
        grib_context_log(a->parent->h->context, GRIB_LOG_ERROR, " wrong size (%ld) for %s it contains %d values ",*len, a->name , rlen);
        *len = 0;
        return GRIB_ARRAY_TOO_SMALL;
    }

    if (a->flags & GRIB_ACCESSOR_FLAG_TRANSIENT) {
        *val=a->vvalue->lval;
        *len=1;
        return GRIB_SUCCESS;
    }

    if(a->flags & GRIB_ACCESSOR_FLAG_CAN_BE_MISSING)
    {
        Assert(self->nbytes <= 4);
        missing = ones[self->nbytes];
    }

    for(i=0; i< rlen;i++){
        val[i] = (long)grib_decode_unsigned_long(a->parent->h->buffer->data , &pos, self->nbytes*8);
        if(missing)
            if(val[i] == missing)
                val[i] = GRIB_MISSING_LONG;
    }

    *len = rlen;
    return GRIB_SUCCESS;
}

static int pack_long(grib_accessor* a, const long* val, size_t *len)
{
    /* See GRIB-262 as example of why we do the checks */
    return pack_long_unsigned_helper(a,val,len, /*check=*/1);
}

static long byte_count(grib_accessor* a)
{
    return a->length;
}

static int value_count(grib_accessor* a,long* len)
{
    grib_accessor_unsigned* self = (grib_accessor_unsigned*)a;
    if(!self->arg) {*len=1;return 0;}
    return grib_get_long_internal(a->parent->h,grib_arguments_get_name(a->parent->h,self->arg,0),len);
}

static long byte_offset(grib_accessor* a)
{
    return a->offset;
}

static void update_size(grib_accessor* a,size_t s)
{
    a->length = s;
}

static long next_offset(grib_accessor* a)
{
    return grib_byte_offset(a)+grib_byte_count(a);
}

static int is_missing(grib_accessor* a)
{
    int i=0;
    unsigned char ff=0xff;
    unsigned long offset=a->offset;

    if (a->length==0) {
        Assert(a->vvalue!=NULL);
        return a->vvalue->missing;
    }

    for (i=0;i<a->length;i++) {
        if (a->parent->h->buffer->data[offset] != ff) {
            return 0;
        }
        offset++;
    }
    return 1;
}

static void destroy(grib_context* context,grib_accessor* a)
{
    if (a->vvalue != NULL)
        grib_context_free(context, a->vvalue);

    a->vvalue=NULL;
}
