module Eancom
  module Parser
    class Segment

      attr_accessor :tag, :string, :components, :segment_class

      def initialize(string)
        @string = string
        @components = []
        @tag = una? ? 'UNA' : string.split(data_delimiter)[0]
        @segment_class = find_segment_class
      end

      def parse
        parse_component
        klass = find_segment_class
        structure = find_structure
        klass.initialize_by_components(structure, @components)
      end

      private

      def parse_component
        if una?
          parse_una
        else
          string.split(data_delimiter).each do |data|
            components << parse_data(data)
          end
        end
      end

      def parse_data(data)
        component = []
        data.split(component_delimiter).each do |c|
          component << c
        end
        component
      end

      def parse_una
        components << [string[0..2]]
        components << [string[3]]
        components << [string[4]]
        components << [string[5]]
        components << [string[6]]
        components << [string[7]]
        components << [DELIMITERS[:segment]]
      end

      def find_segment_class
        Eancom.find_segment(tag: tag)
      end

      def find_structure
        Eancom.find_structure(tag: tag)
      end

      def data_delimiter
        DELIMITERS[:data]
      end

      def component_delimiter
        DELIMITERS[:component]
      end

      def una?
        string =~ /^UNA/
      end
    end
  end
end