Refactor user redirect after submission

app/models/submission.rb

@@ -18,6 +18,8 @@ class Submission < ActiveRecord::Base
   validates :cause, inclusion: {in: CAUSES}
   validates :exercise_id, presence: true
 
+  MAX_COMMENTS_ON_RECOMMENDED_RFC = 5
+
   def build_files_hash(files, attribute)
     files.map(&attribute.to_proc).zip(files).to_h
   end
@@ -53,4 +55,16 @@ class Submission < ActiveRecord::Base
   def to_s
     Submission.model_name.human
   end
+
+  def redirect_to_feedback?
+    ((user_id + exercise.created_at.to_i) % 10 == 1) && exercise.needs_more_feedback
+  end
+
+  def own_unsolved_rfc
+    RequestForComment.unsolved.where(exercise_id: exercise, user_id: user_id).first
+  end
+
+  def unsolved_rfc
+    RequestForComment.unsolved.where(exercise_id: exercise).where.not(question: nil).order("RANDOM()").find { | rfc_element |(rfc_element.comments_count < MAX_COMMENTS_ON_RECOMMENDED_RFC) }
+  end
 end