Extract methods showing voting style information

The idea is that different voting styles will display different
information messages.

app/models/budget/ballot.rb

@@ -17,10 +17,6 @@ class Budget
       investments.sum(:price).to_i
     end
 
-    def formatted_amount_spent(heading)
-      budget.formatted_amount(amount_spent(heading))
-    end
-
     def has_lines_in_group?(group)
       groups.include?(group)
     end
@@ -67,7 +63,9 @@ class Budget
     def voting_style
       @voting_style ||= voting_style_class.new(self)
     end
-    delegate :amount_available, :amount_spent, :enough_money?, :formatted_amount_available,
+    delegate :amount_available, :amount_available_info, :amount_spent, :amount_spent_info,
+             :amount_limit_info, :change_vote_info, :enough_money?, :formatted_amount_available,
+             :formatted_amount_limit, :formatted_amount_spent, :voted_info,
              to: :voting_style
 
     private

app/models/budget/voting_styles/base.rb

@@ -4,4 +4,43 @@ class Budget::VotingStyles::Base
   def initialize(ballot)
     @ballot = ballot
   end
+
+  def name
+    self.class.name.split("::").last.underscore
+  end
+
+  def change_vote_info(link:)
+    I18n.t("budgets.investments.index.sidebar.change_vote_info.#{name}", link: link)
+  end
+
+  def voted_info(heading)
+    I18n.t("budgets.investments.index.sidebar.voted_info.#{name}",
+      count: investments(heading).count,
+      amount_spent: ballot.budget.formatted_amount(investments_price(heading)))
+  end
+
+  def amount_available_info(heading)
+    I18n.t("budgets.ballots.show.amount_available.#{name}",
+           amount: formatted_amount_available(heading))
+  end
+
+  def amount_spent_info(heading)
+    I18n.t("budgets.ballots.show.amount_spent.#{name}",
+           amount: formatted_amount_spent(heading))
+  end
+
+  def amount_limit_info(heading)
+    I18n.t("budgets.ballots.show.amount_limit.#{name}",
+           amount: formatted_amount_limit(heading))
+  end
+
+  private
+
+    def investments(heading)
+      ballot.investments.by_heading(heading.id)
+    end
+
+    def investments_price(heading)
+      investments(heading).sum(:price).to_i
+    end
 end

app/models/budget/voting_styles/knapsack.rb

@@ -4,14 +4,30 @@ class Budget::VotingStyles::Knapsack < Budget::VotingStyles::Base
   end
 
   def amount_available(heading)
-    ballot.budget.heading_price(heading) - amount_spent(heading)
+    amount_limit(heading) - amount_spent(heading)
   end
 
   def amount_spent(heading)
-    ballot.investments.by_heading(heading.id).sum(:price).to_i
+    investments_price(heading)
+  end
+
+  def amount_limit(heading)
+    ballot.budget.heading_price(heading)
   end
 
   def formatted_amount_available(heading)
-    ballot.budget.formatted_amount(amount_available(heading))
+    format(amount_available(heading))
+  end
+
+  def formatted_amount_spent(heading)
+    format(amount_spent(heading))
+  end
+
+  def formatted_amount_limit(heading)
+    format(amount_limit(heading))
+  end
+
+  def format(amount)
+    ballot.budget.formatted_amount(amount)
   end
 end