Class: ExchangeRates::Rate

Inherits:
ActiveRecord::Base
  • Object
show all
Defined in:
lib/exchange_rates/rate.rb

Constant Summary collapse

BASE_CURRENCY = 
'HKD'.freeze
CUSTOMS_VALUE_FALLBACK_CURRENCY = 
'USD'.freeze
NOT_SUPPORTED_CURRENCIES =

NB: to update the list of not supported currencies, run: Country.all.map(&:currency_code).uniq - Money::Currency.table.map{|c| c.to_s.upcase}

[nil, '', 'IMP', 'TVD'].freeze

Class Method Summary collapse

Class Method Details

.convert(amount, from_currency, to_currency = BASE_CURRENCY) ⇒ Object 



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# File 'lib/exchange_rates/rate.rb', line 14

def self.convert(amount, from_currency, to_currency = BASE_CURRENCY)
  case
  when amount == 0
    0
  when to_currency == from_currency
    amount
  when to_currency == BASE_CURRENCY
    amount * get_rate(from_currency)
  else
    amount * (get_rate(from_currency) / get_rate(to_currency))
  end
end

.get_rate(currency) ⇒ Object 



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# File 'lib/exchange_rates/rate.rb', line 27

def self.get_rate(currency)
  return 1 if currency == BASE_CURRENCY
  cached = Rails.cache.fetch("#{currency.downcase}_to_#{BASE_CURRENCY.downcase}", expired_at: Date.today.midnight + ENV['RESET_CACHED_CURRENCY_AT'].to_i.hours) do
    where(from_currency: currency).first.rate_to_base_currency
  end
  cached || where(from_currency: currency).first.rate_to_base_currency
end