Consider nil in price expire time as effective

#522

app/models/billing/price.rb

@@ -12,6 +12,7 @@ module Billing
     validates :operation_category, inclusion: { in: Proc.new { |price| price.class.operation_categories } }
     validates :duration, inclusion: { in: Proc.new { |price| price.class.durations } }
 
+    alias_attribute :effect_time, :valid_from
     alias_attribute :expire_time, :valid_to
     monetize :price_cents, allow_nil: true, numericality: { greater_than_or_equal_to: 0 }
     after_initialize :init_values
@@ -22,22 +23,37 @@ module Billing
 
     def self.durations
       [
-        '3 mons',
-        '6 mons',
-        '9 mons',
-        '1 year',
-        '2 years',
-        '3 years',
-        '4 years',
-        '5 years',
-        '6 years',
-        '7 years',
-        '8 years',
-        '9 years',
-        '10 years',
+          '3 mons',
+          '6 mons',
+          '9 mons',
+          '1 year',
+          '2 years',
+          '3 years',
+          '4 years',
+          '5 years',
+          '6 years',
+          '7 years',
+          '8 years',
+          '9 years',
+          '10 years',
       ]
     end
 
+    def self.statuses
+      %w[pending effective expired]
+    end
+
+    def self.pending
+      where("#{attribute_alias(:effect_time)} > ?", Time.zone.now)
+    end
+
+    def self.effective
+      condition = "#{attribute_alias(:effect_time)} <= :now " \
+      " AND (#{attribute_alias(:expire_time)} >= :now" \
+      " OR #{attribute_alias(:expire_time)} IS NULL)"
+      where(condition, now: Time.zone.now)
+    end
+
     def self.valid
       where('valid_from <= ? AND (valid_to >= ? OR valid_to IS NULL)', Time.zone.now.end_of_day,
             Time.zone.now.beginning_of_day)

app/models/concerns/billing/price/expirable.rb

@@ -2,10 +2,6 @@ module Concerns::Billing::Price::Expirable
   extend ActiveSupport::Concern
 
   class_methods do
-    def unexpired
-      where("#{attribute_alias(:expire_time)} >= ?", Time.zone.now)
-    end
-
     def expired
       where("#{attribute_alias(:expire_time)} < ?", Time.zone.now)
     end