--- /dev/null
+package DBIx::Class::DeploymentHandler::VersionHandler::ExplicitVersions;
+use Moose;
+use Method::Signatures::Simple;
+use Carp 'croak';
+
+with 'DBIx::Class::DeploymentHandler::HandlesVersioning';
+
+has ordered_versions => (
+ is => 'ro',
+ isa => 'ArrayRef',
+ required => 1,
+ trigger => sub {
+ my $to_version = $_[0]->to_version;
+ my $db_version = $_[0]->db_version;
+
+ croak 'to_version not in ordered_versions'
+ unless grep { $to_version eq $_ } @{ $_[1] };
+
+ for (@{ $_[1] }) {
+ return if $_ eq $db_version;
+ croak 'to_version is before database version in ordered_versions'
+ if $_ eq $to_version;
+ }
+ },
+);
+
+has _version_idx => (
+ is => 'rw',
+ isa => 'Int',
+ lazy_build => 1,
+);
+
+method _inc_version_idx { $self->_version_idx($self->_version_idx + 1 ) }
+
+method _build__version_idx {
+ my $start = $self->version_rs->db_version;
+ my $idx = 0;
+ for (@{$self->ordered_versions}) {
+ return $idx
+ if $_ eq $self->db_version;
+ $idx++;
+ }
+ croak 'database version not found in ordered_versions!';
+}
+
+sub next_version_set { # sub instead of method because of when roles get composed
+ my $self = shift;
+ return undef
+ if $self->ordered_versions->[$self->_version_idx] eq $self->to_version;
+ my $next_idx = $self->_inc_version_idx;
+ if ( $next_idx <= $#{ $self->ordered_versions }) {
+ return [
+ $self->ordered_versions->[$next_idx - 1],
+ $self->ordered_versions->[$next_idx ],
+ ]
+ } else {
+ return undef
+ }
+}
+
+__PACKAGE__->meta->make_immutable;
+
+1;
+
+__END__
+
+vim: ts=2 sw=2 expandtab