/*
 *  Copyright 1996, University Corporation for Atmospheric Research
 *      See netcdf/COPYRIGHT file for copying and redistribution conditions.
 */
/* $Id: var.c,v 1.1 2010-01-06 16:34:07 kwleiter Exp $ */

#include "nc.h"
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include "ncx.h"
#include "rnd.h"

#if defined(_MSC_VER) && (_MSC_VER >= 1400)
#  pragma warning ( disable : 4130 ) /* logical operation on address of string constant */
#endif /* defined(_MSC_VER) && (_MSC_VER >= 1400) */

/*
 * Free var
 * Formerly
NC_free_var(var)
 */
void
free_NC_var(NC_var *varp)
{
  if(varp == NULL)
    return;
  free_NC_attrarrayV(&varp->attrs);
  free_NC_string(varp->name);
  free(varp);
}


/* 
 * Common code for new_NC_var() 
 * and ncx_get_NC_var()
 */
NC_var *
new_x_NC_var(
  NC_string *strp,
  size_t ndims)
{
  NC_var *varp;
  const size_t o1 = M_RNDUP(ndims * sizeof(int));
  const size_t o2 = M_RNDUP(ndims * sizeof(size_t));
  const size_t sz =  M_RNDUP(sizeof(NC_var)) +
     o1 + o2 + ndims * sizeof(size_t);

  varp = (NC_var *) malloc(sz);
  if(varp == NULL )
    return NULL;
  (void) memset(varp, 0, sz);

  varp->name = strp;
  varp->ndims = ndims;

  if(ndims != 0)
  {
    /*
     * NOTE: lint may complain about the next 3 lines:
     * "pointer cast may result in improper alignment".
     * We use the M_RNDUP() macro to get the proper alignment.
     */
    varp->dimids = (int *)((char *)varp + M_RNDUP(sizeof(NC_var)));
    varp->shape = (size_t *)((char *)varp->dimids + o1);
    varp->dsizes = (size_t *)((char *)varp->shape + o2);
  }

  varp->xsz = 0;
  varp->len = 0;
  varp->begin = 0;

  return varp;
}


/*
 * Formerly
NC_new_var()
 */
static NC_var *
new_NC_var(const char *name, nc_type type,
  size_t ndims, const int *dimids)
{
  NC_string *strp;
  NC_var *varp;

  strp = new_NC_string(strlen(name), name);
  if(strp == NULL)
    return NULL;

  varp = new_x_NC_var(strp, ndims);
  if(varp == NULL )
  {
    free_NC_string(strp);
    return NULL;
  }
  
  varp->type = type;

  if( ndims != 0 && dimids != NULL)
    (void) memcpy(varp->dimids, dimids, ndims * sizeof(int));

  return(varp);
}


static NC_var *
dup_NC_var(const NC_var *rvarp)
{
  NC_var *varp = new_NC_var(rvarp->name->cp, rvarp->type,
     rvarp->ndims, rvarp->dimids);
  if(varp == NULL)
    return NULL;

  
  if(dup_NC_attrarrayV(&varp->attrs, &rvarp->attrs) != NC_NOERR)
  {
    free_NC_var(varp);
    return NULL;
  }

  (void) memcpy(varp->shape, rvarp->shape,
       rvarp->ndims * sizeof(size_t));
  (void) memcpy(varp->dsizes, rvarp->dsizes,
       rvarp->ndims * sizeof(size_t));
  varp->xsz = rvarp->xsz;
  varp->len = rvarp->len;
  varp->begin = rvarp->begin;

  return varp;
}


/* vararray */


/*
 * Free the stuff "in" (referred to by) an NC_vararray.
 * Leaves the array itself allocated.
 */
void
free_NC_vararrayV0(NC_vararray *ncap)
{
  assert(ncap != NULL);

  if(ncap->nelems == 0)
    return;

  assert(ncap->value != NULL);

  {
    NC_var **vpp = ncap->value;
    NC_var *const *const end = &vpp[ncap->nelems];
    for( /*NADA*/; vpp < end; vpp++)
    {
      free_NC_var(*vpp);
      *vpp = NULL;
    }
  }
  ncap->nelems = 0;
}


/*
 * Free NC_vararray values.
 * formerly
NC_free_array()
 */
void
free_NC_vararrayV(NC_vararray *ncap)
{
  assert(ncap != NULL);
  
  if(ncap->nalloc == 0)
    return;

  assert(ncap->value != NULL);

  free_NC_vararrayV0(ncap);

  free(ncap->value);
  ncap->value = NULL;
  ncap->nalloc = 0;
}


int
dup_NC_vararrayV(NC_vararray *ncap, const NC_vararray *ref)
{
  int status = NC_NOERR;

  assert(ref != NULL);
  assert(ncap != NULL);

  if(ref->nelems != 0)
  {
    const size_t sz = ref->nelems * sizeof(NC_var *);
    ncap->value = (NC_var **) malloc(sz);
    if(ncap->value == NULL)
      return NC_ENOMEM;
    (void) memset(ncap->value, 0, sz);
    ncap->nalloc = ref->nelems;
  }

  ncap->nelems = 0;
  {
    NC_var **vpp = ncap->value;
    const NC_var **drpp = (const NC_var **)ref->value;
    NC_var *const *const end = &vpp[ref->nelems];
    for( /*NADA*/; vpp < end; drpp++, vpp++, ncap->nelems++)
    {
      *vpp = dup_NC_var(*drpp);
      if(*vpp == NULL)
      {
        status = NC_ENOMEM;
        break;
      }
    }
  }

  if(status != NC_NOERR)
  {
    free_NC_vararrayV(ncap);
    return status;
  }

  assert(ncap->nelems == ref->nelems);

  return NC_NOERR;
}


/*
 * Add a new handle on the end of an array of handles
 * Formerly
NC_incr_array(array, tail)
 */
static int
incr_NC_vararray(NC_vararray *ncap, NC_var *newelemp)
{
  NC_var **vp;

  assert(ncap != NULL);

  if(ncap->nalloc == 0)
  {
    assert(ncap->nelems == 0);
    vp = (NC_var **) malloc(NC_ARRAY_GROWBY * sizeof(NC_var *));
    if(vp == NULL)
      return NC_ENOMEM;
    ncap->value = vp;
    ncap->nalloc = NC_ARRAY_GROWBY;
  }
  else if(ncap->nelems +1 > ncap->nalloc)
  {
    vp = (NC_var **) realloc(ncap->value,
      (ncap->nalloc + NC_ARRAY_GROWBY) * sizeof(NC_var *));
    if(vp == NULL)
      return NC_ENOMEM;
    ncap->value = vp;
    ncap->nalloc += NC_ARRAY_GROWBY;
  }

  if(newelemp != NULL)
  {
    ncap->value[ncap->nelems] = newelemp;
    ncap->nelems++;
  }
  return NC_NOERR;
}


static NC_var *
elem_NC_vararray(const NC_vararray *ncap, size_t elem)
{
  assert(ncap != NULL);
    /* cast needed for braindead systems with signed size_t */
  if(ncap->nelems == 0 || (unsigned long)elem >= ncap->nelems)
    return NULL;

  assert(ncap->value != NULL);

  return ncap->value[elem];
}


/* End vararray per se */


/*
 * Step thru NC_VARIABLE array, seeking match on name.
 * Return varid or -1 on not found.
 * *varpp is set to the appropriate NC_var.
 * Formerly (sort of)
NC_hvarid
 */
int
NC_findvar(const NC_vararray *ncap, const char *name, NC_var **varpp)
{
  NC_var **loc;
  size_t slen;
  int varid;

  assert(ncap != NULL);

  if(ncap->nelems == 0)
    return -1;

  loc = (NC_var **) ncap->value;

  slen = strlen(name);

  for(varid = 0; (size_t) varid < ncap->nelems; varid++, loc++)
  {
    /* NOTE: The [slen-1] check is a specific optimization for
     * exodusII files with many blocks and variables. Because
     * names usually end with a different suffix, check that
     * before comparing entire string.
     */
    if(strlen((*loc)->name->cp) == slen &&
       name[slen-1]==(*loc)->name->cp[slen-1] &&
       strncmp((*loc)->name->cp, name, slen) == 0)
    {
      if(varpp != NULL)
        *varpp = *loc;
      return(varid); /* Normal return */
    }
  }
  return(-1); /* not found */
}

/* 
 * For a netcdf type
 *  return the size of one element in the external representation.
 * Note that arrays get rounded up to X_ALIGN boundaries.
 * Formerly
NC_xtypelen
 * See also ncx_len()
 */
size_t
ncx_szof(nc_type type)
{
  switch(type){
  case NC_BYTE:
  case NC_CHAR:
    return(1);
  case NC_SHORT :
    return(2);
  case NC_INT:
    return X_SIZEOF_INT;
  case NC_FLOAT:
    return X_SIZEOF_FLOAT;
  case NC_DOUBLE : 
    return X_SIZEOF_DOUBLE;
  case NC_NAT:
    break; /* Some compilers complain if enums are missing from a switch */
  }
  /* default */
  assert("ncx_szof invalid type" == 0);
  return 0;
}


/*
 * 'compile' the shape and len of a variable
 *  Formerly
NC_var_shape(var, dims)
 */
int
NC_var_shape(NC_var *varp, const NC_dimarray *dims)
{
  size_t *shp, *dsp, *op;
  int *ip;
  const NC_dim *dimp;
  size_t product = 1;
  
  varp->xsz = ncx_szof(varp->type);

  if(varp->ndims == 0)
  {
    goto out;
  }

  /*
   * use the user supplied dimension indices
   * to determine the shape
   */
  for(ip = varp->dimids, op = varp->shape
    ; ip < &varp->dimids[varp->ndims]; ip++, op++)
  {
    if(*ip < 0 || (size_t) (*ip) >= ((dims != NULL) ? dims->nelems : 1) )
      return NC_EBADDIM;
    
    dimp = elem_NC_dimarray(dims, (size_t)*ip);
    *op = dimp->size;
    if(*op == NC_UNLIMITED && ip != varp->dimids)
      return NC_EUNLIMPOS;
  }

  /* 
   * Compute the dsizes
   */
        /* ndims is > 0 here */
  for(shp = varp->shape + varp->ndims -1,
        dsp = varp->dsizes + varp->ndims -1;
      shp >= varp->shape;
      shp--, dsp--)
  {
    if(!(shp == varp->shape && IS_RECVAR(varp)))
      product *= *shp;
    *dsp = product;
  }


out :
    if( varp->xsz <= X_UINT_MAX / product ) /* if integer multiply will not overflow */
  {
          varp->len = product * varp->xsz;
        } else
  { /* OK for last var to be "too big", indicated by this special len */
          varp->len = X_UINT_MAX;
        }
  switch(varp->type) {
  case NC_BYTE :
  case NC_CHAR :
  case NC_SHORT :
    if( varp->len%4 != 0 )
    {
      varp->len += 4 - varp->len%4; /* round up */
  /*    *dsp += 4 - *dsp%4; */
    }
    break;
  default:
    /* already aligned */
    break;
  }
#if 0
  arrayp("\tshape", varp->ndims, varp->shape);
  arrayp("\tdsizes", varp->ndims, varp->dsizes);
#endif
  return NC_NOERR;
}

/*
 * Check whether variable size is less than or equal to vlen_max,
 * without overflowing in arithmetic calculations.  If OK, return 1,
 * else, return 0.  For CDF1 format or for CDF2 format on non-LFS
 * platforms, vlen_max should be 2^31 - 4, but for CDF2 format on
 * systems with LFS it should be 2^32 - 4.
 */
int
NC_check_vlen(NC_var *varp, size_t vlen_max) {
  size_t prod=varp->xsz;  /* product of xsz and dimensions so far */

  int ii;

  for(ii = IS_RECVAR(varp) ? 1 : 0; ii < (int)varp->ndims; ii++) {
    if (varp->shape[ii] > vlen_max / prod) {
      return 0;   /* size in bytes won't fit in a 32-bit int */
    }
    prod *= varp->shape[ii];
  }
  return 1;     /* OK */
}


/*
 * Given valid ncp and varid, return var
 *  else NULL on error
 * Formerly
NC_hlookupvar()
 */
NC_var *
NC_lookupvar(NC *ncp, int varid)
{
  NC_var *varp;

  if(varid == NC_GLOBAL)
  {
    /* Global is error in this context */
    return(NULL);
  }

  varp = elem_NC_vararray(&ncp->vars, (size_t)varid);
  if(varp == NULL)
  {
    return NULL;
  }

  assert(varp != NULL);

  return(varp);
}


/* Public */

int
nc_def_var( int ncid, const char *name, nc_type type,
   int ndims, const int *dimids, int *varidp)
{
  int status;
  NC *ncp;
  int varid;
  NC_var *varp;

  status = NC_check_id(ncid, &ncp); 
  if(status != NC_NOERR)
    return status;

  if(!NC_indef(ncp))
  {
    return NC_ENOTINDEFINE;
  }

  status = NC_check_name(name);
  if(status != NC_NOERR)
    return status;

  status = nc_cktype(type);
  if(status != NC_NOERR)
    return status;

    /* cast needed for braindead systems with signed size_t */
  if((unsigned long) ndims > X_INT_MAX) /* Backward compat */
  {
    return NC_EINVAL;
  } 

  if(ncp->vars.nelems >= NC_MAX_VARS)
  {
    return NC_EMAXVARS;
  }

  varid = NC_findvar(&ncp->vars, name, &varp);
  if(varid != -1)
  {
    return NC_ENAMEINUSE;
  }
  
  varp = new_NC_var(name, type, ndims, dimids);
  if(varp == NULL)
    return NC_ENOMEM;

  status = NC_var_shape(varp, &ncp->dims);
  if(status != NC_NOERR)
  {
    free_NC_var(varp);
    return status;
  }

  status = incr_NC_vararray(&ncp->vars, varp);
  if(status != NC_NOERR)
  {
    free_NC_var(varp);
    return status;
  }

  if(varidp != NULL)
    *varidp = (int)ncp->vars.nelems -1; /* varid */
  return NC_NOERR;
}


int
nc_inq_varid(int ncid, const char *name, int *varid_ptr)
{
  int status;
  NC *ncp;
  NC_var *varp;
  int varid;

  status = NC_check_id(ncid, &ncp); 
  if(status != NC_NOERR)
    return status;

  varid = NC_findvar(&ncp->vars, name, &varp);
  if(varid == -1)
  {
    return NC_ENOTVAR;
  }

  *varid_ptr = varid;
  return NC_NOERR;
}


int
nc_inq_var(int ncid,
  int varid,
  char *name,
  nc_type *typep,
  int *ndimsp,
  int *dimids,
  int *nattsp)
{
  int status;
  NC *ncp;
  NC_var *varp;
  size_t ii;

  status = NC_check_id(ncid, &ncp); 
  if(status != NC_NOERR)
    return status;

  varp = elem_NC_vararray(&ncp->vars, (size_t)varid);
  if(varp == NULL)
    return NC_ENOTVAR;

  if(name != NULL)
  {
    (void) strncpy(name, varp->name->cp, varp->name->nchars);
    name[varp->name->nchars] = 0;
  }

  if(typep != 0)
    *typep = varp->type;
  if(ndimsp != 0)
  {
    *ndimsp = (int) varp->ndims;
  }
  if(dimids != 0)
  {
    for(ii = 0; ii < varp->ndims; ii++)
    {
      dimids[ii] = varp->dimids[ii];
    }
  }
  if(nattsp != 0)
  {
    *nattsp = (int) varp->attrs.nelems;
  }

  return NC_NOERR;
}


int 
nc_inq_varname(int ncid, int varid, char *name)
{
  int status;
  NC *ncp;
  NC_var *varp;

  status = NC_check_id(ncid, &ncp); 
  if(status != NC_NOERR)
    return status;

  varp = elem_NC_vararray(&ncp->vars, (size_t)varid);
  if(varp == NULL)
    return NC_ENOTVAR;

  if(name != NULL)
  {
    (void) strncpy(name, varp->name->cp, varp->name->nchars);
    name[varp->name->nchars] = 0;
  }

  return NC_NOERR;
}

int 
nc_inq_vartype(int ncid, int varid, nc_type *typep)
{
  int status;
  NC *ncp;
  NC_var *varp;

  status = NC_check_id(ncid, &ncp); 
  if(status != NC_NOERR)
    return status;

  varp = elem_NC_vararray(&ncp->vars, (size_t)varid);
  if(varp == NULL)
    return NC_ENOTVAR;

  if(typep != 0)
    *typep = varp->type;

  return NC_NOERR;
}

int 
nc_inq_varndims(int ncid, int varid, int *ndimsp)
{
  int status;
  NC *ncp;
  NC_var *varp;

  status = NC_check_id(ncid, &ncp); 
  if(status != NC_NOERR)
    return status;

  varp = elem_NC_vararray(&ncp->vars, (size_t)varid);
  if(varp == NULL)
    return NC_ENOTVAR; /* TODO: is this the right error code? */

  if(ndimsp != 0)
  {
    *ndimsp = (int) varp->ndims;
  }

  return NC_NOERR;
}


int 
nc_inq_vardimid(int ncid, int varid, int *dimids)
{
  int status;
  NC *ncp;
  NC_var *varp;
  size_t ii;

  status = NC_check_id(ncid, &ncp); 
  if(status != NC_NOERR)
    return status;

  varp = elem_NC_vararray(&ncp->vars, (size_t)varid);
  if(varp == NULL)
    return NC_ENOTVAR; /* TODO: is this the right error code? */

  if(dimids != 0)
  {
    for(ii = 0; ii < varp->ndims; ii++)
    {
      dimids[ii] = varp->dimids[ii];
    }
  }

  return NC_NOERR;
}


int 
nc_inq_varnatts(int ncid, int varid, int *nattsp)
{
  int status;
  NC *ncp;
  NC_var *varp;

  if(varid == NC_GLOBAL)
    return  nc_inq_natts(ncid, nattsp);

  status = NC_check_id(ncid, &ncp); 
  if(status != NC_NOERR)
    return status;

  varp = elem_NC_vararray(&ncp->vars, (size_t)varid);
  if(varp == NULL)
    return NC_ENOTVAR; /* TODO: is this the right error code? */

  if(nattsp != 0)
  {
    *nattsp = (int) varp->attrs.nelems;
  }

  return NC_NOERR;
}

int
nc_rename_var(int ncid, int varid, const char *newname)
{
  int status;
  NC *ncp;
  NC_var *varp;
  NC_string *old, *newStr;
  int other;

  status = NC_check_id(ncid, &ncp); 
  if(status != NC_NOERR)
    return status;

  if(NC_readonly(ncp))
  {
    return NC_EPERM;
  }

  status = NC_check_name(newname);
  if(status != NC_NOERR)
    return status;

  /* check for name in use */
  other = NC_findvar(&ncp->vars, newname, &varp);
  if(other != -1)
  {
    return NC_ENAMEINUSE;
  }
  
  varp = NC_lookupvar(ncp, varid);
  if(varp == NULL)
  {
    /* invalid varid */
    return NC_ENOTVAR; /* TODO: is this the right error code? */
  }

  old = varp->name;
  if(NC_indef(ncp))
  {
    newStr = new_NC_string(strlen(newname),newname);
    if(newStr == NULL)
      return(-1);
    varp->name = newStr;
    free_NC_string(old);
    return NC_NOERR;
  }

  /* else, not in define mode */
  status = set_NC_string(varp->name, newname);
  if(status != NC_NOERR)
    return status;

  set_NC_hdirty(ncp);

  if(NC_doHsync(ncp))
  {
    status = NC_sync(ncp);
    if(status != NC_NOERR)
      return status;
  }

  return NC_NOERR;
}
