+=item increment_next_bill
+
+Increment the next bill date (boolean, for calc_recur). Typically true except
+for particular situations.
+
+=item setup_fee
+
+This option is filled in by the method rather than controlling its operation.
+It indicates a deferred setup fee that is billed at calc_recur time (see price
+plan option prorate_defer_bill).
+
+=back
+
+Note: Don't calculate prices when not actually billing the package. For that,
+see the L</base_setup|base_setup> and L</base_recur|base_recur> methods.
+
+=cut
+
+#fatal fallbacks
+sub calc_setup { die 'no calc_setup for '. shift->plan. "\n"; }
+sub calc_recur { die 'no calc_recur for '. shift->plan. "\n"; }
+
+=item calc_remain CUST_PKG [ OPTION => VALUE ... ]
+
+Calculates and returns the remaining value to be credited upon package
+suspension, change, or cancellation, if enabled.
+
+Options are passed as a list of keys and values. Available options:
+
+=over 4
+
+=item time
+
+Override for the current time
+
+=item cust_credit_source_bill_pkg
+
+This option is filled in by the method rather than controlling its operation.
+It is an arrayref.
+L<FS::cust_credit_source_bill_pkg|FS::cust_credit_source_bill_pkg> records will
+be added to the arrayref indicating the specific line items and amounts which
+are the source of this remaining credit.
+
+=back
+
+Note: Don't calculate prices when not actually suspending or cancelling the
+package.
+
+=cut
+
+#fallback that returns 0 for old legacy packages with no plan
+sub calc_remain { 0; }
+
+=item calc_units CUST_PKG
+
+This returns the number of provisioned svc_phone records, or, of the package
+count_available_phones option is set, the number available to be provisoined
+in the package.
+
+=cut
+
+#fallback that returns 0 for old legacy packages with no plan
+sub calc_units { 0; }
+
+#fallback for everything not based on flat.pm
+sub recur_temporality { 'upcoming'; }
+
+=item calc_cancel START_DATE DETAILS_ARRAYREF OPTIONS_HASHREF
+
+Runs any necessary billing on cancellation: another recurring cycle for
+recur_temporailty 'preceding' pacakges with the bill_recur_on_cancel option
+set (calc_recur), or, any outstanding usage for pacakges with the
+bill_usage_on_cancel option set (calc_usage).
+
+=cut
+
+#fallback for everything not based on flat.pm, doesn't do this yet (which is
+#okay, nothing of ours not based on flat.pm does usage-on-cancel billing
+sub calc_cancel { 0; }
+
+#fallback for everything except bulk.pm
+sub hide_svc_detail { 0; }
+
+#fallback for packages that can't/won't summarize usage
+sub sum_usage { 0; }
+
+=item recur_cost_permonth CUST_PKG
+
+recur_cost divided by freq (only supported for monthly and longer frequencies)
+
+=cut
+
+sub recur_cost_permonth {
+ my($self, $cust_pkg) = @_;
+ return 0 unless $self->freq =~ /^\d+$/ && $self->freq > 0;
+ sprintf('%.2f', ($self->recur_cost || 0) / $self->freq );
+}
+
+=item cust_bill_pkg_recur CUST_PKG
+
+Actual recurring charge for the specified customer package from customer's most
+recent invoice
+
+=cut
+
+sub cust_bill_pkg_recur {
+ my($self, $cust_pkg) = @_;
+ my $cust_bill_pkg = qsearchs({
+ 'table' => 'cust_bill_pkg',
+ 'addl_from' => 'LEFT JOIN cust_bill USING ( invnum )',
+ 'hashref' => { 'pkgnum' => $cust_pkg->pkgnum,
+ 'recur' => { op=>'>', value=>'0' },
+ },
+ 'order_by' => 'ORDER BY cust_bill._date DESC,
+ cust_bill_pkg.sdate DESC
+ LIMIT 1
+ ',
+ }) or return 0; #die "use cust_bill_pkg_recur credits with once_perinv condition";
+ $cust_bill_pkg->recur;
+}
+
+=item unit_setup CUST_PKG
+
+Returns the setup fee for one unit of the package.
+
+=cut
+
+sub unit_setup {
+ my ($self, $cust_pkg) = @_;
+ $self->option('setup_fee') || 0;
+}
+
+=item setup_margin
+
+unit_setup minus setup_cost
+
+=cut
+
+sub setup_margin {