package DateTime::TimeZone::OffsetOnly;

use strict;
use warnings;
use namespace::autoclean;

our $VERSION = '2.16';

use parent 'DateTime::TimeZone';

use DateTime::TimeZone::UTC;
use Params::ValidationCompiler 0.13 qw( validation_for );
use Specio::Library::String;

{
    my $validator = validation_for(
        name             => '_check_new_params',
        name_is_optional => 1,
        params           => {
            offset => {
                type => t('NonEmptyStr'),
            },
        },
    );

    sub new {
        my $class = shift;
        my %p     = $validator->(@_);

        my $offset = DateTime::TimeZone::offset_as_seconds( $p{offset} );

        die "Invalid offset: $p{offset}\n" unless defined $offset;

        return DateTime::TimeZone::UTC->new unless $offset;

        my $self = {
            name   => DateTime::TimeZone::offset_as_string($offset),
            offset => $offset,
        };

        return bless $self, $class;
    }
}

sub is_dst_for_datetime {0}

sub offset_for_datetime       { $_[0]->{offset} }
sub offset_for_local_datetime { $_[0]->{offset} }

sub is_utc {0}

sub short_name_for_datetime { $_[0]->name }

sub category {undef}

sub STORABLE_freeze {
    my $self = shift;

    return $self->name;
}

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

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

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

    %$self = %$obj;

    return $self;
}

1;

# ABSTRACT: A DateTime::TimeZone object that just contains an offset

__END__

=pod

=encoding UTF-8

=head1 NAME

DateTime::TimeZone::OffsetOnly - A DateTime::TimeZone object that just contains an offset

=head1 VERSION

version 2.16

=head1 SYNOPSIS

  my $offset_tz = DateTime::TimeZone->new( name => '-0300' );

=head1 DESCRIPTION

This class is used to provide the DateTime::TimeZone API needed by
DateTime.pm, but with a fixed offset.  An object in this class always
returns the same offset as was given in its constructor, regardless of
the date.

=head1 USAGE

This class has the same methods as a real time zone object, but the
C<category()> method returns undef.

=head2 DateTime::TimeZone::OffsetOnly->new ( offset => $offset )

The value given to the offset parameter must be a string such as
"+0300".  Strings will be converted into numbers by the
C<DateTime::TimeZone::offset_as_seconds()> function.

=head2 $tz->offset_for_datetime( $datetime )

No matter what date is given, the offset provided to the constructor
is always used.

=head2 $tz->name()

=head2 $tz->short_name_for_datetime()

Both of these methods return the offset in string form.

=head1 SUPPORT

Bugs may be submitted at L<https://github.com/houseabsolute/DateTime-TimeZone/issues>.

I am also usually active on IRC as 'autarch' on C<irc://irc.perl.org>.

=head1 SOURCE

The source code repository for DateTime-TimeZone can be found at L<https://github.com/houseabsolute/DateTime-TimeZone>.

=head1 AUTHOR

Dave Rolsky <autarch@urth.org>

=head1 COPYRIGHT AND LICENSE

This software is copyright (c) 2018 by Dave Rolsky.

This is free software; you can redistribute it and/or modify it under
the same terms as the Perl 5 programming language system itself.

The full text of the license can be found in the
F<LICENSE> file included with this distribution.

=cut