From a620ce3b904e9a9ba1da9c990f63f7a94acb785c Mon Sep 17 00:00:00 2001
From: Mark Wells <mark@freeside.biz>
Date: Sat, 9 Aug 2014 17:40:49 -0700
Subject: [PATCH] two-sided printing of invoice batches, #29927

---
 FS/FS/Conf.pm       | 7 +++++++
 FS/FS/bill_batch.pm | 9 +++++++++
 FS/FS/cust_bill.pm  | 2 ++
 3 files changed, 18 insertions(+)

diff --git a/FS/FS/Conf.pm b/FS/FS/Conf.pm
index 8f4d05b3c..616a06c90 100644
--- a/FS/FS/Conf.pm
+++ b/FS/FS/Conf.pm
@@ -1527,6 +1527,13 @@ and customer address. Include units.',
     'type'        => 'checkbox',
   },
 
+  {
+    'key'         => 'invoice_print_pdf-duplex',
+    'section'     => 'invoicing',
+    'description' => 'Insert blank pages so that spooled invoices are each an even number of pages.  Use this for double-sided printing.',
+    'type'        => 'checkbox',
+  },
+
   { 
     'key'         => 'invoice_default_terms',
     'section'     => 'invoicing',
diff --git a/FS/FS/bill_batch.pm b/FS/FS/bill_batch.pm
index fb41e0e6b..d4f2aec29 100644
--- a/FS/FS/bill_batch.pm
+++ b/FS/FS/bill_batch.pm
@@ -61,6 +61,8 @@ sub print_pdf {
   my @invoices = sort { $a->invnum <=> $b->invnum } $self->cust_bill_batch;
   return "No invoices in batch ".$self->batchnum.'.' if !@invoices;
 
+  my $duplex = FS::Conf->exists('invoice_print_pdf-duplex');
+
   my $pdf_out;
   my $num = 0;
   foreach my $invoice (@invoices) {
@@ -73,6 +75,13 @@ sub print_pdf {
     else {
       $pdf_out = CAM::PDF->new($part);
     }
+    if ( $duplex ) {
+      my $n = $pdf_out->numPages;
+      if ( $n % 2 == 1 ) {
+        # then insert a blank page so we end on an even number
+        $pdf_out->duplicatePage($n, 1);
+      }
+    }
     if($job) {
       # update progressbar
       $num++;
diff --git a/FS/FS/cust_bill.pm b/FS/FS/cust_bill.pm
index 676f218c7..1b9b34792 100644
--- a/FS/FS/cust_bill.pm
+++ b/FS/FS/cust_bill.pm
@@ -1507,6 +1507,8 @@ sub fax_invoice {
 Place this invoice into the open batch (see C<FS::bill_batch>).  If there 
 isn't an open batch, one will be created.
 
+HASHREF may contain any options to be passed to C<print_pdf>.
+
 =cut
 
 sub batch_invoice {
-- 
2.11.0