feat: Add pay in advance logic into date service

app/services/subscriptions/dates/monthly_service.rb

@@ -4,13 +4,28 @@ module Subscriptions
   module Dates
     class MonthlyService < Subscriptions::DatesService
       def compute_from_date(date = base_date)
-        if terminated_pay_in_arrear?
+        if plan.pay_in_advance? || terminated_pay_in_arrear?
           return subscription.anniversary? ? previous_anniversary_day(billing_date) : billing_date.beginning_of_month
         end
 
         subscription.anniversary? ? previous_anniversary_day(date) : date.beginning_of_month
       end
 
+      def compute_charges_from_date
+        return from_date if plan.pay_in_arrear?
+        return base_date.beginning_of_month if calendar?
+
+        previous_anniversary_day(base_date)
+      end
+
+      def compute_charges_to_date
+        return to_date if plan.pay_in_arrear?
+
+        # NOTE: In pay in advance scenario, from_date will be the begining of the new period.
+        #       To get the end of the previous one, we just have to take the day before
+        from_date - 1.day # TODO: check with upgrade on subscription day
+      end
+
       private
 
       def compute_base_date
@@ -32,10 +47,6 @@ def compute_to_date
         build_date(year, month, day)
       end
 
-      def compute_charges_from_date
-        from_date
-      end
-
       def compute_next_end_of_period(date)
         return date.end_of_month if calendar?
 
@@ -56,6 +67,12 @@ def compute_next_end_of_period(date)
         build_date(year, month, day) - 1.day
       end
 
+      def compute_previous_beginning_of_period(date)
+        return date.beginning_of_month if calendar?
+
+        previous_anniversary_day(date)
+      end
+
       def previous_anniversary_day(date)
         year = nil
         month = nil
@@ -71,6 +88,13 @@ def previous_anniversary_day(date)
 
         build_date(year, month, day)
       end
+
+      def compute_duration(from_date:)
+        return Time.days_in_month(from_date.month, from_date.year) if calendar?
+
+        next_month_date = compute_to_date
+        (next_month_date.to_date + 1.day - from_date.to_date).to_i
+      end
     end
   end
 end

app/services/subscriptions/dates/weekly_service.rb

@@ -3,14 +3,16 @@
 module Subscriptions
   module Dates
     class WeeklyService < Subscriptions::DatesService
+      WEEK_DURATION = 7
+
       private
 
       def compute_base_date
         billing_date - 1.week
       end
 
       def compute_from_date
-        if terminated_pay_in_arrear?
+        if plan.pay_in_advance? || terminated_pay_in_arrear?
           return subscription.anniversary? ? previous_anniversary_day(billing_date) : billing_date.beginning_of_week
         end
 
@@ -24,7 +26,17 @@ def compute_to_date
       end
 
       def compute_charges_from_date
-        from_date
+        return from_date if plan.pay_in_arrear?
+
+        from_date - 1.week
+      end
+
+      def compute_charges_to_date
+        return to_date if plan.pay_in_arrear?
+
+        # NOTE: In pay in advance scenario, from_date will be the begining of the new period.
+        #       To get the end of the previous one, we just have to take the day before
+        from_date - 1.day
       end
 
       def compute_next_end_of_period(date)
@@ -35,13 +47,23 @@ def compute_next_end_of_period(date)
         date.next_occurring(subscription_day_name) - 1.day
       end
 
+      def compute_previous_beginning_of_period(date)
+        return date.beginning_of_week if calendar?
+
+        previous_anniversary_day(date)
+      end
+
       def previous_anniversary_day(date)
         date.prev_occurring(subscription_day_name)
       end
 
       def subscription_day_name
         @subscription_day_name ||= subscription_date.strftime('%A').downcase.to_sym
       end
+
+      def compute_duration(*)
+        WEEK_DURATION
+      end
     end
   end
 end

app/services/subscriptions/dates/yearly_service.rb

@@ -3,18 +3,24 @@
 module Subscriptions
   module Dates
     class YearlyService < Subscriptions::DatesService
+      def first_month_in_yearly_period?
+        return billing_date.month == 1 if calendar?
+
+        monthly_service.compute_from_date(billing_date - 1.month).month == subscription_date.month
+      end
+
       private
 
       def compute_base_date
         billing_date - 1.year
       end
 
       def monthly_service
-        @monthly_service ||= Subscriptions::Dates::MonthlyService.new(subscription, billing_date)
+        @monthly_service ||= Subscriptions::Dates::MonthlyService.new(subscription, billing_date, current_usage)
       end
 
       def compute_from_date
-        if terminated_pay_in_arrear?
+        if plan.pay_in_advance? || terminated_pay_in_arrear?
           return subscription.anniversary? ? previous_anniversary_day(billing_date) : billing_date.beginning_of_year
         end
 
@@ -32,9 +38,21 @@ def compute_to_date
       end
 
       def compute_charges_from_date
-        return from_date unless plan.bill_charges_monthly
+        return monthly_service.compute_charges_from_date if plan.bill_charges_monthly
+        return from_date if plan.pay_in_arrear?
+        return base_date.beginning_of_year if calendar?
+
+        previous_anniversary_day(base_date)
+      end
+
+      def compute_charges_to_date
+        return to_date if plan.pay_in_arrear?
+
+        # NOTE: In pay in advance scenario, from_date will be the begining of the new period.
+        #       To get the end of the previous one, we just have to take the day before
+        return from_date - 1.day unless plan.bill_charges_monthly
 
-        monthly_service.compute_from_date(billing_date - 1.month)
+        monthly_service.compute_charges_to_date
       end
 
       def compute_next_end_of_period(date)
@@ -51,13 +69,29 @@ def compute_next_end_of_period(date)
         build_date(year + 1, month, day) - 1.day
       end
 
+      def compute_previous_beginning_of_period(date)
+        return date.beginning_of_year if calendar?
+
+        previous_anniversary_day(date)
+      end
+
       def previous_anniversary_day(date)
         year = date.month < subscription_date.month ? date.year - 1 : date.year
         month = subscription_date.month
         day = subscription_date.day
 
         build_date(year, month, day)
       end
+
+      def compute_duration(from_date:)
+        return Time.days_in_year(from_date.year) if calendar?
+
+        year = from_date.year
+        # NOTE: if after February we must check if next year is a leap year
+        year += 1 if from_date.month > 2
+
+        Time.days_in_year(year)
+      end
     end
   end
 end

app/services/subscriptions/dates_service.rb

@@ -2,7 +2,7 @@
 
 module Subscriptions
   class DatesService
-    def self.new_instance(subscription, billing_date)
+    def self.new_instance(subscription, billing_date, current_usage: false)
       klass = case subscription.plan.interval&.to_sym
               when :weekly
                 Subscriptions::Dates::WeeklyService
@@ -14,15 +14,16 @@ def self.new_instance(subscription, billing_date)
                 raise NotImplementedError
       end
 
-      klass.new(subscription, billing_date)
+      klass.new(subscription, billing_date, current_usage)
     end
 
-    def initialize(subscription, billing_date)
+    def initialize(subscription, billing_date, current_usage)
       @subscription = subscription
 
       # NOTE: Billing date should usually be the end of the billing period + 1 day
       #       When subscription is terminated, it is the termination day
       @billing_date = billing_date.to_date
+      @current_usage = current_usage
     end
 
     def from_date
@@ -42,14 +43,8 @@ def to_date
       return @to_date if @to_date
 
       @to_date = compute_to_date
-
       @to_date = subscription.terminated_at.to_date if subscription.terminated? && @to_date > subscription.terminated_at
 
-      # NOTE: When price plan is configured as `pay_in_advance`, subscription creation will be
-      #       billed immediatly. An invoice must be generated for it with only the subscription fee.
-      #       The invoicing period will be only one day: the subscription day
-      @to_date = subscription.started_at.to_date if plan.pay_in_advance? && subscription.fees.subscription_kind.none?
-
       @to_date
     end
 
@@ -60,18 +55,38 @@ def charges_from_date
       date
     end
 
+    def charges_to_date
+      date = compute_charges_to_date
+      date = subscription.terminated_at.to_date if subscription.terminated? && date > subscription.terminated_at
+
+      date
+    end
+
     def next_end_of_period(date)
       compute_next_end_of_period(date)
     end
 
+    # NOTE: Retrieve the beginning of the previous period based on the billing date
+    def previous_beginning_of_period(current_period: false)
+      date = base_date
+      date = billing_date if current_period
+
+      compute_previous_beginning_of_period(date)
+    end
+
+    def single_day_price(optional_from_date: nil)
+      duration = compute_duration(from_date: optional_from_date || compute_from_date)
+      plan.amount_cents.fdiv(duration.to_i)
+    end
+
     private
 
-    attr_accessor :subscription, :billing_date
+    attr_accessor :subscription, :billing_date, :current_usage
 
     delegate :plan, :subscription_date, :calendar?, to: :subscription
 
     def base_date
-      @base_date ||= compute_base_date
+      @base_date ||= current_usage ? billing_date : compute_base_date
     end
 
     def terminated_pay_in_arrear?
@@ -88,6 +103,10 @@ def build_date(year, month, day)
       Date.new(year, month, day)
     end
 
+    def compute_base_date
+      raise NotImplementedError
+    end
+
     def compute_from_date
       raise NotImplementedError
     end
@@ -100,8 +119,20 @@ def compute_charges_from_date
       raise NotImplementedError
     end
 
+    def compute_charges_to_date
+      raise NotImplementedError
+    end
+
     def compute_next_end_of_period(date)
       raise NotImplementedError
     end
+
+    def first_month_in_yearly_period?
+      false
+    end
+
+    def compute_duration(from_date:)
+      raise NotImplementedError
+    end
   end
 end