# -*- mode: perl; -*-
use strict;
use warnings;
use Test::More tests => 14523;
###############################################################################
# Read and load configuration file and backend library.
use Config::Tiny ();
my $config_file = 'xt/author/lib.ini';
my $config = Config::Tiny -> read('xt/author/lib.ini')
  or die Config::Tiny -> errstr();
# Read the library to test.
our $LIB = $config->{_}->{lib};
die "No library defined in file '$config_file'"
  unless defined $LIB;
die "Invalid library name '$LIB' in file '$config_file'"
  unless $LIB =~ /^[A-Za-z]\w*(::\w+)*\z/;
# Read the reference type(s) the library uses.
our $REF = $config->{_}->{ref};
die "No reference type defined in file '$config_file'"
  unless defined $REF;
die "Invalid reference type '$REF' in file '$config_file'"
  unless $REF =~ /^[A-Za-z]\w*(::\w+)*\z/;
# Load the library.
eval "require $LIB";
die $@ if $@;
###############################################################################
my $scalar_util_ok = eval { require Scalar::Util; };
Scalar::Util -> import('refaddr') if $scalar_util_ok;
diag "Skipping some tests since Scalar::Util is not installed."
  unless $scalar_util_ok;
can_ok($LIB, '_modinv');
my @data;
# Add data in data file.
(my $datafile = $0) =~ s/\.t/.dat/;
open DATAFILE, $datafile or die "$datafile: can't open file for reading: $!";
while (<DATAFILE>) {
    s/\s+\z//;
    next if /^#/ || ! /\S/;
    push @data, [ split /:/ ];
}
close DATAFILE or die "$datafile: can't close file after reading: $!";
# List context.
for (my $i = 0 ; $i <= $#data ; ++ $i) {
    my ($in0, $in1, $out0, $out1, $out2, $out3) = @{ $data[$i] };
    my ($x, $m, @got);
    my $test = qq|\$x = $LIB->_new("$in0"); |
             . qq|\$m = $LIB->_new("$in1"); |
             . qq|\@got = $LIB->_modinv(\$x, \$m);|;
    diag("\n$test\n\n") if $ENV{AUTHOR_DEBUGGING};
    eval $test;
    is($@, "", "'$test' gives emtpy \$\@");
    subtest "_modinv() in list context: $test", sub {
        if ($out0 eq "undef") {
            plan tests => 1;
            # The output should ideally be nothing, but some backend libraries
            # return two undefs.
            subtest 'output when no inverse exists' => sub {
                plan tests => 1 + @got;
                ok(@got == 0 || @got == 2,
                   "'$test' gives zero or two output args");
                for my $got (@got) {
                    is($got, undef, "'$test' output arg is undef");
                }
            }
        } else {
            plan tests => 7;
            cmp_ok(scalar @got, "==", 2,
                   "'$test' gives two output args");
            is(ref($got[0]), $REF,
               "'$test' first output arg is a $REF");
            is($LIB->_check($got[0]), 0,
               "'$test' first output arg is valid");
          SKIP: {
                skip "Scalar::Util not available", 1 unless $scalar_util_ok;
                isnt(refaddr($got[0]), refaddr($m),
                     "'$test' first output arg is not the second input arg");
            }
            is(ref($got[1]), "",
               "'$test' second output arg is a scalar");
            like($got[1], qr/^[+-]\z/,
               "'$test' second output arg is valid");
            my $got  = $got[1] . $LIB->_str($got[0]);   # prepend sign to value
            my $alt0 = $out1 . $out0;
            my $alt1 = $out3 . $out2;
            ok($got eq $alt0 || $got eq $alt1,
               "'$test' output args have the right value");
        }
    };
}