sub name      { $_[0]->{name} }
sub category  { (split /\//, $_[0]->{name}, 2)[0] }

sub is_valid_name
{
    my $tz;
    {
        local $@;
        $tz = eval { $_[0]->new( name => $_[1] ) };
    }

    return $tz && $tz->isa('DateTime::TimeZone') ? 1 : 0
}

sub STORABLE_freeze
{
    my $self = shift;

    return $self->name;
}

sub STORABLE_thaw
{
    my $self = shift;
    my $cloning = shift;
    my $serialized = shift;

    my $class = ref $self || $self;

    my $obj;
    if ( $class->isa(__PACKAGE__) )
    {
        $obj = __PACKAGE__->new( name => $serialized );
    }
    else
    {
        $obj = $class->new( name => $serialized );
    }

    %$self = %$obj;

    return $self;
}

#
# Functions
#
sub offset_as_seconds
{
    {
        local $@;
        shift if eval { $_[0]->isa('DateTime::TimeZone') };
    }

    my $offset = shift;

    return undef unless defined $offset;

    return 0 if $offset eq '0';

    my ( $sign, $hours, $minutes, $seconds );
    if ( $offset =~ /^([\+\-])?(\d\d?):(\d\d)(?::(\d\d))?$/ )
    {
        ( $sign, $hours, $minutes, $seconds ) = ( $1, $2, $3, $4 );
    }
    elsif ( $offset =~ /^([\+\-])?(\d\d)(\d\d)(\d\d)?$/ )
    {
        ( $sign, $hours, $minutes, $seconds ) = ( $1, $2, $3, $4 );
    }
    else
    {
        return undef;
    }

    $sign = '+' unless defined $sign;
    return undef unless $hours >= 0 && $hours <= 99;
    return undef unless $minutes >= 0 && $minutes <= 59;
    return undef unless ! defined( $seconds ) || ( $seconds >= 0 && $seconds <= 59 );

    my $total =  $hours * 3600 + $minutes * 60;
    $total += $seconds if $seconds;
    $total *= -1 if $sign eq '-';

    return $total;
}

sub offset_as_string
{
    {
        local $@;
        shift if eval { $_[0]->isa('DateTime::TimeZone') };
    }

    my $offset = shift;

    return undef unless defined $offset;
    return undef unless $offset >= -359999 && $offset <= 359999;

    my $sign = $offset < 0 ? '-' : '+';