mad-raz/EGP-Rates

# frozen_string_literal: true
Add an empty line after magic comments.
module EGPRates
  # Class Representing the bank to get the data from
  class Bank
    attr_reader :sym
 
    # Abstract method
    # Subclasses banks define the logic to get the exchange rates hash
    # it should return [Hash] sell: { SYM: rate, ... } , buy: { SYM: rate, ... }
    #   for the available currencies (represented by :SYM) on the bank pages
    def exchange_rates
      raise NotImplementedError
    end
 
    private
 
    # Make a call to the @uri to get the raw_response
    # @return [Net::HTTPSuccess] of the raw response
    # @raises [ResponseError] if response is not 200 OK
    def response
      response = Net::HTTP.get_response(@uri)
      if response.is_a? Net::HTTPRedirection
        response = Net::HTTP.get_response(URI.parse(response['location']))
      end
      fail ResponseError, response.code unless response.is_a? Net::HTTPSuccess
      response
    end
 
    # Convert currency string to ISO symbol
    # @param currency [String] "US Dollar"
    # @return [Symbol] :USD ISO currency name
    # rubocop:disable Metrics/CyclomaticComplexity
    # rubocop:disable Metrics/MethodLength
    def currency_symbol(currency)
      case currency
      when /UAE|EMIRATES|Dirham|AED/i then :AED
      when /Australian/i              then :AUD
      when /Bahrain|BHD/i             then :BHD
      when /Canadian|CANAD\. Dollar/i then :CAD
      when /Swiss|CHF/i               then :CHF
      when /Chinese/                  then :CNY
      when /Danish/i                  then :DKK
      when /Euro|EUR/i                then :EUR
      when /British|Sterl.|GBP/i      then :GBP
      when /Jordanian/i               then :JOD
      when /Japanese|JPY|YEN/i        then :JPY
      when /Kuwait/i                  then :KWD
      when /Norwegian|NORWEG\./i      then :NOK
      when /Omani/i                   then :OMR
      when /Qatar/i                   then :QAR
      when /SAR|Saudi/i               then :SAR
      when /Swidish|Swedish/i         then :SEK
      when /U(\.)?S(\.)? Dollar|USD/i then :USD
      else fail ResponseError, "Unknown currency #{currency}"
      end
    end
    # rubocop:enable Metrics/CyclomaticComplexity
    # rubocop:enable Metrics/MethodLength
 
    # Parse the #raw_exchange_rates returned in response
    # @param [Array] of the raw_data scraped
    #   [
    #     [ 'Currency_1', 'BuyRate', 'SellRate', ... ],
    #     [ 'Currency_2', 'BuyRate', 'SellRate', ... ],
    #     [ 'Currency_3', 'BuyRate', 'SellRate', ... ],
    #     ...
    #   ]
    #
    # @return [Hash] of exchange rates for selling and buying
    #   {
    #     { sell: { SYM: rate }, { SYM: rate }, ... },
    #     { buy:  { SYM: rate }, { SYM: rate }, ... }
    #   }
    def parse(raw_data)
      raw_data.each_with_object(sell: {}, buy: {}) do |row, result|
        sell_rate = row[2].to_f
        buy_rate  = row[1].to_f
        currency  = currency_symbol(row[0])
 
        result[:sell][currency] = sell_rate
        result[:buy][currency]  = buy_rate
      end
    end
  end
end