Offline participation form: ask for missing/remaining pieces

app/models/completion.rb

@@ -34,16 +34,17 @@ class Completion < ApplicationRecord
   belongs_to :puzzle
   belongs_to :message, optional: true
 
-  before_save :add_time_seconds
+  before_save :add_time_seconds, if: -> { display_time_from_start.present? }
   before_save :nullify_display_time
 
   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 :contestant_id, uniqueness: { scope: :puzzle }, if: -> { contest.puzzles.size == 1 }
   validates :puzzle_id, uniqueness: { scope: :contestant }, if: -> { contest.puzzles.size > 1 }
-  validate :remaining_pieces_is_correct
+  validates :remaining_pieces, numericality: { only_integer: true }, if: -> { remaining_pieces.present? }
+  validate :remaining_pieces_is_correct, if: -> { remaining_pieces.present? }
 
   def remaining_pieces_is_correct
-    if self.remaining_pieces && self.remaining_pieces > self.puzzle.pieces
+    if self.remaining_pieces > self.puzzle.pieces
       errors.add(:remaining_pieces, "Cannot be greater than the number of pieces for this puzzle")
     end
   end