lib/ec2spec/price_calculator.rb in ec2spec-0.1.2 vs lib/ec2spec/price_calculator.rb in ec2spec-0.1.3

@@ -1,9 +1,57 @@
+require 'singleton'
+require 'ec2spec/calculator/api_price_calculator'
+require 'ec2spec/calculator/manual_price_calculator'
+
 module Ec2spec
+  class UndefinedCalcError < StandardError; end
+  class ApiKeyError < StandardError; end
+
   class PriceCalculator
-    def initialize(instance_type)
-      @instance_type = instance_type
+    include Singleton
+
+    attr_accessor :currency_unit, :dollar_exchange_rate
+
+    PRICE_CALCULATORS = {
+      manual: Calculator::ManualPriceCalculator,
+      api:    Calculator::ApiPriceCalculator,
+    }
+
+    def initialize
+      @currency_unit = nil
+      @dollar_exchange_rate = nil
+      @app_id = nil
     end
 
-    def price_per_unit; end
+    def prepare(unit, rate, calc_type = :manual, app_id = nil)
+      @currency_unit = unit
+      @dollar_exchange_rate = rate
+      @app_id = app_id
+      @calc_type = calc_type
+
+      extend_calc
+
+      Money.infinite_precision = true
+      raise ApiKeyError if calc_type_sym == :api && app_id.nil?
+      prepare_exchange_api(app_id) if calc_type_sym == :api
+      self
+    end
+
+    def currency_values?
+      !@currency_unit.nil?
+    end
+
+    private
+
+    def extend_calc
+      raise UndefinedCalcError unless PRICE_CALCULATORS.key?(calc_type_sym)
+      extend PRICE_CALCULATORS[calc_type_sym]
+      Ec2spec.logger.debug("Calculate price: #{@calc_type}")
+    end
+
+    def calc_type_sym
+      @calc_type.to_sym
+    rescue NoMethodError
+      raise UndefinedCalcError
+    end
   end
 end