Implement projected time

app/models/completion.rb

@@ -7,6 +7,7 @@
 #  display_relative_time   :string
 #  display_time_from_start :string
 #  missing_pieces          :integer
+#  projected_time          :integer
 #  remaining_pieces        :integer
 #  time_seconds            :integer
 #  created_at              :datetime         not null
@@ -36,11 +37,12 @@ class Completion < ApplicationRecord
   belongs_to :puzzle
   belongs_to :message, optional: true
 
-  before_save :add_time_seconds, if: -> { display_time_from_start.present? }
-  before_save :nullify_display_time
-  before_save :clean_pieces
+  has_one :offline, dependent: :destroy
 
-  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 }
+  before_save :clean_pieces
+  before_save :compute_projected_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/ }
   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 }
@@ -53,21 +55,18 @@ class Completion < ApplicationRecord
     end
   end
 
-  def nullify_display_time
-    if self.remaining_pieces
-      self.display_time_from_start = nil
-      self.display_relative_time = nil
-    end
-  end
-
   def add_time_seconds
-    arr = display_time_from_start.split(":")
-    if arr.size == 3
-      self.time_seconds = arr[0].to_i * 3600 + arr[1].to_i * 60 + arr[2].to_i
-    elsif arr.size == 2
-      self.time_seconds = arr[0].to_i * 60 + arr[1].to_i
-    elsif arr.size == 1
-      self.time_seconds = arr[0].to_i
+    if display_time_from_start.present?
+      arr = display_time_from_start.split(":")
+      if arr.size == 3
+        self.time_seconds = arr[0].to_i * 3600 + arr[1].to_i * 60 + arr[2].to_i
+      elsif arr.size == 2
+        self.time_seconds = arr[0].to_i * 60 + arr[1].to_i
+      elsif arr.size == 1
+        self.time_seconds = arr[0].to_i
+      end
+    else
+      self.time_seconds = 1
     end
   end
 
@@ -78,4 +77,16 @@ class Completion < ApplicationRecord
       self.missing_pieces = nil
     end
   end
+
+  def compute_projected_time
+    add_time_seconds
+    if self.completed
+      self.projected_time = self.time_seconds
+    elsif self.offline.present?
+      assembled_time = self.time_seconds
+      assembled_pieces = self.puzzle.pieces - self.remaining_pieces
+      pieces_per_second = assembled_pieces.to_f / assembled_time.to_f
+      self.projected_time = assembled_time + Integer(self.remaining_pieces.to_f / pieces_per_second)
+    end
+  end
 end