Implement missing & remaining pieces propagation + cleaner forms

app/models/completion.rb

@@ -3,8 +3,10 @@
 # Table name: completions
 #
 #  id                      :integer          not null, primary key
+#  completed               :boolean
 #  display_relative_time   :string
 #  display_time_from_start :string
+#  missing_pieces          :integer
 #  remaining_pieces        :integer
 #  time_seconds            :integer
 #  created_at              :datetime         not null
@@ -36,8 +38,10 @@ class Completion < ApplicationRecord
 
   before_save :add_time_seconds, if: -> { display_time_from_start.present? }
   before_save :nullify_display_time
+  before_save :clean_pieces
 
-  validates :display_time_from_start, presence: true, format: { with: /\A(((\d\d|\d):\d\d|\d\d|\d):\d\d|\d\d|\d)\z/ }, if: -> { remaining_pieces == nil }
+  validates :display_time_from_start, presence: true, format: { with: /\A(((\d\d|\d):\d\d|\d\d|\d):\d\d|\d\d|\d)\z/ }, if: -> { completed }
+  validates :remaining_pieces, presence: true, if: -> { !completed }
   validates :contestant_id, uniqueness: { scope: :puzzle }, if: -> { contest.puzzles.size == 1 }
   validates :puzzle_id, uniqueness: { scope: :contestant }, if: -> { contest.puzzles.size > 1 }
   validates :remaining_pieces, numericality: { only_integer: true }, if: -> { remaining_pieces.present? }
@@ -66,4 +70,12 @@ class Completion < ApplicationRecord
       self.time_seconds = arr[0].to_i
     end
   end
+
+  def clean_pieces
+    if self.completed
+      self.remaining_pieces = nil
+    else
+      self.missing_pieces = nil
+    end
+  end
 end