fix crashes; add counts to initial import

app/admin/issuances.rb

@@ -16,6 +16,21 @@
   #   permitted
   # end
 
+  filter :creator
+  filter :issuer
+  filter :gift_card_type
+  filter :status
+  filter :card_amount
+  filter :quantitiy
+  filter :begin_use_date
+  filter :end_use_date
+  filter :expiration_date
+  filter :allocated_certificates
+  filter :numbering
+  filter :issued_at
+  filter :created_at
+  filter :updated_at
+
   index do
     id_column
     tag_column :status
@@ -31,6 +46,11 @@
     column :max_certificate do |issuance|
       issuance.allocated_certificates.split(Issuance::CERTIFICATE_DISPLAY_SEPARATOR).last
     end
+    column :used do |issuance|
+      used = issuance.gift_cards.where(registrations_available: 0).count
+      total = issuance.gift_cards.count
+      raw("#{number_with_delimiter(used)}/#{number_with_delimiter(issuance.gift_cards.count)}<br/>(#{(used / total.to_f * 100).round(1)}%)")
+    end
     column :begin_use_date
     column :end_use_date
     column :expiration_date

app/models/issuance.rb

@@ -40,7 +40,7 @@ class Issuance < ApplicationRecord
   end
 
   def to_s
-    if preview?
+    if previewing?
       "Gift Card Issuance (Preview)"
     elsif issued?
       "Issuance by #{issuer.full_name} #{created_at}"

import.rb

@@ -136,3 +136,7 @@
 end
 
 GiftCard.import(batch)
+
+Issuance.where(quantity: [nil, 0]).each do |i|
+  i.update(quantity: i.gift_cards.count)
+end