use strict;
use warnings;

use Test::More;

use Inline C => Config =>
	BUILD_NOISY => 1,
	clean_after_build => 0,
	warnings => 10,
;
use Inline C => <<'EOC';
#include <stdio.h>

/************************************************************/

/* Monkeypatch by LeoNerd to set an arrayref into a scalarref
   As posted on https://kiwiirc.com/nextclient/#irc://irc.perl.org/#perl
   at 10:50 23/07/2021
   A BIG THANK YOU LeoNerd
*/

#define HAVE_PERL_VERSION(R, V, S) \
    (PERL_REVISION > (R) || (PERL_REVISION == (R) && (PERL_VERSION > (V) || (PERL_VERSION == (V) && (PERL_SUBVERSION >= (S))))))

#define sv_setrv(s, r)  S_sv_setrv(aTHX_ s, r)
static void S_sv_setrv(pTHX_ SV *sv, SV *rv)
{
  sv_setiv(sv, (IV)rv);
#if !HAVE_PERL_VERSION(5, 24, 0)
  SvIOK_off(sv);
#endif
  SvROK_on(sv);
}
/************************************************************/
int is_array_ref(
	SV *array,
	size_t *array_sz
){
	if( ! SvROK(array) ){ fprintf(stderr, "is_array_ref() : warning, input '%p' is not a reference.\n", array); return 0; }
	if( SvTYPE(SvRV(array)) != SVt_PVAV ){ fprintf(stderr, "is_array_ref() : warning, input ref '%p' is not an ARRAY reference.\n", array); return 0; }
	// it's an array, cast it to AV to get its len via av_len();
	// yes, av_len needs to be bumped up
	int asz = 1+av_len((AV *)SvRV(array));
	if( asz < 0 ){ fprintf(stderr, "is_array_ref() : error, input array ref '%p' has negative size!\n", array); return 0; }
	*array_sz = (size_t )asz;
	return 1; // success, it is an array and size returned by ref, above
}

int func(
	SV *inp,
	SV *out
){
	AV *av, *av2;
	size_t i, j, asz;
	if( is_array_ref(out, &asz) ){
		printf("Case1: @out\n");
		// we have an \@R, e.g. func(\@R)
		 av = (AV *)SvRV(out);
		// but first clear any contents
		if( asz > 0 ) av_clear(av);
	} else if( SvROK(out) ){
		printf("Case3: \\$out\n");
		// we have a scalar ref, e.g. func(\$x)
		av = newAV();
		sv_setrv(SvRV(out), (SV *)av);
	} else {
		printf("Case2: $out\n");
		// we have a scalar e.g func($x);
		av = newAV();
		sv_setrv(out, (SV *)av);
	}

	for(i=0;i<5;i++){
		av2 = newAV();
		av_extend(av2, 3);
		//av_push(av, (SV *)av2);
		// LeoNerd suggestion:
		av_push(av, newRV_noinc((SV *)av2));
		for(j=0;j<3;j++){
			av_store(av2, j, newSViv(42));
		}
	}
	return 0; // success
}
EOC

my @inp = (1..5);
my @out;
my $T = 'Case1';
is(func(\@inp, \@out),0, "$T: called success.");
is(scalar(@out), 5, "$T: rows are 5");
for(my $i=0;$i<5;$i++){
	ok(ref($out[$i])eq'ARRAY', "$T : item $i is ARRAYref.");
	is(scalar(@{$out[$i]}), 3, "$T : it has 3 elements: ".scalar(@{$out[$i]}));
        for(my $j=0;$j<3;$j++){
          is($out[$i]->[$j], 42, "$T : it's value is 42.");
        }
}

$T = 'Case2';
my $out;
is(func(\@inp, $out),0, "$T: called success.");
ok(ref($out)eq'ARRAY', "$T: it is now an ARRAYref.");
@out = @$out;
is(scalar(@out), 5, "$T: rows are 5");
for(my $i=0;$i<5;$i++){
	ok(ref($out[$i])eq'ARRAY', "$T : item $i is ARRAYref.");
	is(scalar(@{$out[$i]}), 3, "$T : it has 3 elements.");
        for(my $j=0;$j<3;$j++){
          is($out[$i]->[$j], 42, "$T : it's value is 42.");
        }
}

$T = 'Case3';
$out = undef;
is(func(\@inp, \$out),0, "$T: called success.");
ok(ref($out)eq'ARRAY', "$T: it is now an ARRAYref: ".ref($out));
@out = @$out;
is(scalar(@out), 5, "$T: rows are 5");
for(my $i=0;$i<5;$i++){
	ok(ref($out[$i])eq'ARRAY', "$T : item $i is ARRAYref.");
	is(scalar(@{$out[$i]}), 3, "$T : it has 3 elements.");
        for(my $j=0;$j<3;$j++){
          is($out[$i]->[$j], 42, "$T : it's value is 42.");
        }
}

done_testing();