Vehicle view (#1117)

app/models/vehicle.rb

@@ -1,3 +1,22 @@
 class Vehicle < ApplicationRecord
   include Accountable
+
+  attribute :mileage_unit, :string, default: "mi"
+
+  def mileage
+    Measurement.new(mileage_value, mileage_unit) if mileage_value.present?
+  end
+
+  def purchase_price
+    first_valuation_amount
+  end
+
+  def trend
+    TimeSeries::Trend.new(current: account.balance_money, previous: first_valuation_amount)
+  end
+
+  private
+    def first_valuation_amount
+      account.entries.account_valuations.order(:date).first&.amount_money || account.balance_money
+    end
 end