module HttpEventLogger
  module Event

    class Headers

      def initialize(headers)
        @headers = headers.is_a?(Hash) ? headers : to_hash_if_possible(headers)
      end

      def [](name)
        @headers.is_a?(Hash) ? header_value_for(name) : nil
      end

      def to_s
        @headers.is_a?(Hash) ? @headers.map { |key, value| "#{key}: #{value}" }.join(", ") : @headers
      end

      private

      def to_hash_if_possible(headers)
        if headers.respond_to?(:reduce)
          headers.reduce({}) do |hash, header|
            hash[header[0]] = header[1]
            hash
          end
        else
          headers
        end
      end

      def header_value_for(name)
        header = @headers.find { |key, value| key.downcase == name.downcase }
        header ? header[1] : nil
      end

    end

  end
end