use strict;
use warnings;

package Ox::Lock;
use vars '$VERSION';
$VERSION = '0.05';


use Fcntl ':flock';

sub new {
    my $proto = shift;

    return undef
        unless defined $proto;

    my $class = ref($proto) || $proto;
    my $self = bless {}, $class;

    $self->init(@_) if @_;
    $self->directory('/') unless defined $self->directory;

    return ($self);
}

sub DESTROY {
    shift->unlock;
}

sub directory {
    my $self = shift;
    return ($self->value_('directory', @_));
}

sub handle {
    my $self = shift;
    return $self->directory().".lock";
}

sub load {
    my $self = shift;

    $self->unload();

    unless(-e $self->handle) {
        my $fh;
        if(open my $fh, ">", $self->handle) {
            $self->{-lock} = $fh;
            return (1);
        }
    }

    return (0);
}

sub unload {
    my $self = shift;
    if(defined $self->{-lock}) {
        close $self->{-lock};
        unlink $self->handle;
        $self->{-lock} = undef;
    }
}

sub lock {
    my $self = shift;

    if($self->load) {
        return (flock $self->{-lock}, LOCK_EX);
    } else {
        return (0);
    }
}

sub trylock {
    my $self = shift;

    if($self->load) {
        return (flock $self->{-lock}, LOCK_EX | LOCK_NB);
    } else {
        return (0);
    }
}

sub unlock {
    shift->unload;
}

sub init(\%) {
    my ($self, %args) = @_;

    exists $args{$_} && ($self->value_($_, delete $args{$_}))
        foreach (qw/directory/);
}

sub value_ {
    my ($self, $field, $value) = @_;

    return (undef)
        unless defined $field;

    if(defined $value) {
        $self->{'OWML_'.lc($field)} = $value;
    }

    return ($self->{'OWML_'.lc($field)});
}

1;