Contents

require 'danconia/stores/in_memory'

module Danconia
  class Exchange
    attr_reader :store

    def initialize store: Stores::InMemory.new
      @store = store
    end

    def rate from, to
      if from == 'USD' and direct_rate = @store.direct_rate(from, to)
        direct_rate
      elsif to == 'USD' and inverse_rate = @store.direct_rate(to, from)
        (1.0 / inverse_rate).round 6
      elsif from != 'USD' and to != 'USD' and from_in_usd = rate(from, 'USD') and to_per_usd = rate('USD', to)
        (from_in_usd * to_per_usd).round 6
      else
        raise Errors::ExchangeRateNotFound.new(from, to)
      end
    end

    def rates
      @store.rates
    end

    # Currently is only needed for money formatting
    def available_currencies
      []
    end
  end
end

Version data entries

1 entries across 1 versions & 1 rubygems

Version	Path
danconia-0.2.1	lib/danconia/exchange.rb