Add Processor

This class looks up all actionable subscriptions and installments,
groups them by user and schedules them to be reprocessed.

1 files changed, 90 insertions, 0 deletions

diff --git a/lib/solidus_subscriptions/processor.rb b/lib/solidus_subscriptions/processor.rb
new file mode 100644
index 0000000..97b39df
--- /dev/null
+++ b/lib/solidus_subscriptions/processor.rb
@@ -0,0 +1,90 @@
+# This class is responsible for finding subscriptions and installments
+# which need to be processed. It will group them together by user and attempts
+# to process them together.
+#
+# This class passes the reponsibility of actually creating the order off onto
+# the consolidated installment class.
+#
+# This class generates `ProcessInstallmentsJob`s
+module SolidusSubscriptions
+  class Processor
+    class << self
+      # Find all actionable subscriptions and intallments, group them together
+      # by user, and schedule a processing job for the group as a batch
+      def run
+        batched_users_to_be_processed.each { |batch| new(batch).build_jobs }
+      end
+
+      private
+
+      def batched_users_to_be_processed
+        subscriptions = Subscription.arel_table
+        installments = Installment.arel_table
+
+        Spree::User.
+          joins(:subscriptions).
+          joins(
+            subscriptions.
+              join(installments, Arel::Nodes::OuterJoin).
+              on(subscriptions[:id].eq(installments[:subscription_id])).
+              join_sources
+          ).
+          where(
+            Subscription.actionable.arel.constraints.reduce(:and).
+              or(Installment.actionable.arel.constraints.reduce(:and))
+          ).
+          distinct.
+          find_in_batches
+      end
+    end
+
+    # @return [Array<Spree.user_class>]
+    attr_reader :users
+
+    # Get a new instance of the SolidusSubscriptions::Processor
+    #
+    # @param users [Array<Spree.user_class>] A list of users with actionable
+    #   subscriptions or installments
+    #
+    # @return [SolidusSubscriptions::Processor]
+    def initialize(users)
+      @users = users
+      @installments = {}
+    end
+
+    # Create `ProcessInstallmentsJob`s for the users used to initalize the
+    # instance
+    def build_jobs
+      users.map { |user| ProcessInstallmentsJob.perform_later installments(user) }
+    end
+
+    private
+
+    def subscriptions_by_id
+      @subscriptions_by_id ||= Subscription.
+        actionable.
+        where(user_id: user_ids).
+        group_by(&:user_id)
+    end
+
+    def retry_installments
+      @failed_installments ||= Installment.
+        actionable.
+        includes(:subscription).
+        where(solidus_subscriptions_subscriptions: { user_id: user_ids }).
+        group_by { |i| i.subscription.user_id }
+    end
+
+    def installments(user)
+      @installments[user.id] ||= retry_installments.fetch(user.id, []) + new_installments(user)
+    end
+
+    def new_installments(user)
+      subscriptions_by_id.fetch(user.id, []).map { |sub| sub.installments.create! }
+    end
+
+    def user_ids
+      @user_ids ||= users.map(&:id)
+    end
+  end
+end