Module: Lbank

Defined in:
lib/lbank.rb,
lib/lbank/version.rb

Defined Under Namespace

Classes: MemoryCache

Constant Summary collapse

RATE_TYPE = 
'LT'
TIMEZONE = 
'Europe/Vilnius'
URL = 
'http://www.lb.lt/webservices/FxRates/FxRates.asmx/getFxRates'
LTL = 
'LTL'
LTL_RATE = 
BigDecimal('3.45280')
VERSION = 
'1.0.0'

Class Method Summary collapse

Class Method Details

.cache ⇒ Object 



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# File 'lib/lbank.rb', line 17

def cache
  @cache ||= MemoryCache.new
end

.cache=(store) ⇒ Object 



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# File 'lib/lbank.rb', line 21

def cache=(store)
  @cache = store
end

.cache_key(date) ⇒ Object 



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# File 'lib/lbank.rb', line 52

def cache_key(date)
  "lbank-#{date}"
end

.connection ⇒ Object 



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# File 'lib/lbank.rb', line 56

def connection
  @connection ||= Faraday.new do |builder|
    builder.request :url_encoded
    builder.response :raise_error
    builder.response :xml, content_type: /\bxml$/
    builder.adapter Faraday.default_adapter
  end
end

.convert_currency(amount, from_currency, to_currency, date = nil) ⇒ Object 



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# File 'lib/lbank.rb', line 44

def convert_currency(amount, from_currency, to_currency, date = nil)
  rates = currency_rates(date)
  from_rate = rates[from_currency.to_s]
  to_rate = rates[to_currency.to_s]

  amount / from_rate * to_rate
end

.currency_rates(time = nil) ⇒ Object 



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# File 'lib/lbank.rb', line 25

def currency_rates(time = nil)
  time ||= Time.now
  bank_time = time.to_time.in_time_zone(TIMEZONE)
  date = bank_time.strftime('%Y-%m-%d')

  cache.fetch(cache_key(date)) do
    response = connection.post(URL, tp: RATE_TYPE, dt: date)
    fx_rates = response.body['FxRates']['FxRate']

    rates = { fx_rates[0]['CcyAmt'][0]['Ccy'] => 1 }
    rates[LTL] ||= LTL_RATE

    fx_rates.each_with_object(rates) do |rate, result|
      base, foreign = rate['CcyAmt']
      result[foreign['Ccy']] = BigDecimal(foreign['Amt']) / BigDecimal(base['Amt'])
    end
  end
end