#ifdef __cplusplus
extern "C" {
#endif
#include "EXTERN.h"
#include "perl.h"
#include "XSUB.h"
#include "ppport.h"
#include "Av_CharPtrPtr.h"  /* XS_*_charPtrPtr() */
#ifdef __cplusplus
}
#endif


/* Used by the INPUT typemap for char**.
 * Will convert a Perl AV* (containing strings) to a C char**.
 */
char **
XS_unpack_charPtrPtr( rv )
     SV *rv;
{
  AV *av;
  SV **ssv;
  char **s;
  int avlen;
  int x;
  
  if( SvROK( rv ) && (SvTYPE(SvRV(rv)) == SVt_PVAV) )
    av = (AV*)SvRV(rv);
  else {
    return( (char**)NULL );
  }
  
  /* is it empty? */
  avlen = av_len(av);
  if( avlen < 0 ){
    /*warn("XS_unpack_charPtrPtr: array was empty");*/
    return( (char**)NULL );
  }
  
  /* av_len+2 == number of strings, plus 1 for an end-of-array sentinel.
   */
  s = (char **)safemalloc( sizeof(char*) * (avlen + 2) );
  if( s == NULL ){
    warn("XS_unpack_charPtrPtr: unable to malloc char**");
    return( (char**)NULL );
  }
  for( x = 0; x <= avlen; ++x ){
    ssv = av_fetch( av, x, 0 );
    if( ssv != NULL ){
      if( SvPOK( *ssv ) ){
	s[x] = (char *)safemalloc( SvCUR(*ssv) + 1 );
	if( s[x] == NULL )
	  warn("XS_unpack_charPtrPtr: unable to malloc char*");
	else
	  strcpy( s[x], SvPV( *ssv, PL_na ) );
      }
/*      else
        warn("XS_unpack_charPtrPtr: array elem %d was not a string.", x );*/
    }
    else
      s[x] = (char*)NULL;
  }
  s[x] = (char*)NULL; /* sentinel */
  return( s );
}

/* Used by the OUTPUT typemap for char**.
 * Will convert a C char** to a Perl AV*.
 */
void
XS_pack_charPtrPtr( st, s )
SV *st;
char **s;
{
	AV *av = newAV();
	SV *sv;
	char **c;

	for( c = s; *c != NULL; ++c ){
		sv = newSVpv( *c, 0 );
		av_push( av, sv );
	}
	sv = newSVrv( st, NULL );	/* upgrade stack SV to an RV */
	SvREFCNT_dec( sv );	/* discard */
	SvRV( st ) = (SV*)av;	/* make stack RV point at our AV */
}


/* cleanup the temporary char** from XS_unpack_charPtrPtr */
void
XS_release_charPtrPtr(s)
char **s;
{
	char **c;
	for( c = s; *c != NULL; ++c )
		safefree( *c );
	safefree( s );
}