class JustExchangeRates

# File lib/justexchangerates.rb, line 19
def initialize(base: 'USD', cache_refresh: '1 week', cache_path: '.', \
               debug: false, app_id: nil)

  @base, @debug, @app_id, @cache_refresh = base, debug, app_id, cache_refresh
  
  filename = 'justexchangerates_' + base.downcase + '.json'    
  @cache_filepath = File.join(cache_path, filename)
    
  h = if cache_refresh then      
          
    if File.exists? @cache_filepath then
      
      JSON.parse(File.read(@cache_filepath), {:symbolize_names => true})
      
    else
      {base: @base, date: Time.now, rates: {}}
    end        
          
  end
  
  puts 'h: ' + h.inspect if debug
  
  @base, @date, @rates = h[:base], h[:date], h[:rates]    

end

# File lib/justexchangerates.rb, line 45
def rate(currency)
  
  if @rates.has_key? currency.upcase.to_sym then
    
    seconds = ChronicDuration.parse(@cache_refresh) 
    puts 'seconds: ' + seconds.inspect if @debug
    t = (Time.parse(rates[currency.upcase.to_sym].last) \
        + seconds)
    puts 't: ' + t.inspect if @debug
    if t > Time.now then
      rates[currency.upcase.to_sym].first
    else
      fetch_rate currency
    end
    
  else
    fetch_rate currency
  end
  
end

# File lib/justexchangerates.rb, line 69
def fetch_rate(currency)
  
  puts 'inside fetch_rate' if @debug
  puts '@app_id: ' + @app_id.inspect if @debug
  
  rate = OpenExchangeRates::Rates.new(app_id: @app_id)\
      .exchange_rate(from: @base, to: currency)
  
  puts "currency: %s rate: %s" % [currency, rate] if @debug
  
  @rates[currency.upcase.to_sym] = [rate, Time.now.to_s]
  File.write @cache_filepath, \
      {base: @base, date: @date, rates: @rates}.to_json
  rate
  
end