#!perl 
use strict;
use warnings;
use Sereal::Decoder;
use File::Spec;
use lib File::Spec->catdir(qw(t lib));
BEGIN {
    lib->import('lib')
        if !-d 't';
}

use Sereal::TestSet qw(:all);
use Test::More tests => 3;

# Regression test for issue 15 on github:
# https://github.com/Sereal/Sereal/issues/15

# Snappy compression was broken by assuming remaining document length
# is the same as compressed-data-length.

SKIP: {
    my $have_enc = have_encoder_and_decoder();
    if (not $have_enc) {
        skip "Need encoder for Snappy regression tests", 3;
    }
    else {
        require Sereal::Encoder;

        my $encoder = Sereal::Encoder->new( { snappy_incr => 1, snappy_threshold => 1 } );
        my $decoder = Sereal::Decoder->new();

        # establish base behaviour
        ok( $decoder->decode($encoder->encode("foo")), 'normal decode' );

        # build test string with data after first document
        my $str;
        foreach my $i (0..1) {
            $str .= $encoder->encode("foo");
        }

        ok( _decode_with_offset($str, $decoder), 'decode with offset' );
    }
} # end SKIP block

sub _decode_with_offset {
    my ($value, $decoder) = @_;

    my @decoded_values;
    my $pos = 0;
    #my $first = index($value, "=srl", 1);
    #$value = substr($value, 0, $first);
    my $ok = eval {
        while ($pos < length($value)) {
            push @decoded_values, $decoder->decode_with_offset($value, $pos);
            last if $decoder->bytes_consumed == 0;
            $pos += $decoder->bytes_consumed;
        }
        1;
    };
    my $err = $@;
    ok($ok, "decoding did not die")
        or diag("Exception: $err"), return;

    return \@decoded_values;
}