package MetaCPAN::Model::Archive;

use v5.10;
use Moose;
use MooseX::StrictConstructor;
use MetaCPAN::Types::TypeTiny qw( AbsPath ArrayRef Bool InstanceOf Str );

use Archive::Any ();
use Carp         qw( croak );
use Digest::file qw( digest_file_hex );
use Path::Tiny   qw( path );

=head1 NAME

MetaCPAN::Model::Archive - Inspect and extract archive files

=head1 SYNOPSIS

    use MetaCPAN::Model::Archive;

    my $archive = MetaCPAN::Model::Archive->new( file => $some_file );
    my $files = $archive->files;
    my $extraction_dir = $archive->extract;

=head1 DESCRIPTION

This class manages getting information about and extraction of archive
files (tarballs, zipfiles, etc...) and their extraction directories.

The object is read-only and will only extract once.  If you alter the
extraction directory and want a fresh one, make a new object.

The Archive will clean up its extraction directory upon destruction.

=head1 ATTRIBUTES

=head3 archive

I<Required>

The file to be extracted.  It will be returned as a Path::Tiny
object.

=cut

has file => (
    is       => 'ro',
    isa      => AbsPath,
    coerce   => 1,
    required => 1,
);

has _extractor => (
    is      => 'ro',
    isa     => InstanceOf ['Archive::Any'],
    handles => [ qw(
        is_impolite
        is_naughty
    ) ],
    init_arg => undef,
    lazy     => 1,
    default  => sub {
        my $self = shift;
        croak $self->file . ' does not exist' unless -e $self->file;
        return Archive::Any->new( $self->file );
    },
);

# MD5 digest for the archive file
has file_digest_md5 => (
    is      => 'ro',
    isa     => Str,
    lazy    => 1,
    default => sub {
        my $self = shift;
        digest_file_hex( $self->file, 'MD5' );
    },
);

# SHA256 digest for the archive file
has file_digest_sha256 => (
    is      => 'ro',
    isa     => Str,
    lazy    => 1,
    default => sub {
        my $self = shift;
        digest_file_hex( $self->file, 'SHA-256' );
    },
);

# Holding the File::Temp::Dir object here is necessary to keep it
# alive until the object is destroyed.
has _tempdir => (
    is       => 'ro',
    isa      => AbsPath,
    init_arg => undef,
    lazy     => 1,
    default  => sub {

        my $scratch_disk = '/mnt/scratch_disk';
        return -d $scratch_disk
            ? Path::Tiny->tempdir('/mnt/scratch_disk/tempXXXXX')
            : Path::Tiny->tempdir;
    },
);

has extract_dir => (
    is      => 'ro',
    isa     => AbsPath,
    lazy    => 1,
    coerce  => 1,
    default => sub {
        my $self = shift;
        return path( $self->_tempdir );
    },
);

has _has_extracted => (
    is       => 'ro',
    isa      => Bool,
    init_arg => undef,
    default  => 0,
    writer   => '_set_has_extracted',
);

=head1 METHODS

=head3 files

    my $files = $archive->files;

A list of the files in the archive as an array ref.

=cut

# A cheap way to cache the result.
has files => (
    is       => 'ro',
    isa      => ArrayRef,
    init_arg => undef,
    lazy     => 1,
    default  => sub {
        my $self = shift;
        return [ $self->_extractor->files ];
    },
);

=head3 extract

    my $extract_dir = $archive->extract;

Extract the archive into a temp directory.  The directory will be a
L<Path::Tiny> object.

Only the first call to extract will perform the extraction.  After
that it will just return the extraction directory.  If you want to
re-extract the archive, create a new object.

The extraction directory will be cleaned up when the object is destroyed.

=cut

sub extract {
    my $self = shift;

    return $self->extract_dir if $self->_has_extracted;

    $self->_extractor->extract( $self->extract_dir );
    $self->_set_has_extracted(1);

    return $self->extract_dir;
}

1;