module Spread2RDF
  class Coord < Struct.new(:column, :row)
    def initialize(*args)
      case args.length
        when 2 then super
        when 1
          case args = args.first
            when Hash
              super(args[:column], args[:row])
            when Symbol, String
              coord = args.to_s
              raise "Invalid cell coordinates #{coord}" unless coord =~ /(\w+)(\d+)/
              super(Regexp.last_match[1], Regexp.last_match[2].to_i)
            else raise ArgumentError, "can't handle argument #{args}"
          end
        else raise ArgumentError, "too many arguments: #{args}"
      end
    end

    def column_as_number
      Roo::Base.letter_to_number(column)
    end

    def column_as_index
      column_as_number - 1
    end

    def increment_column(count = 1)
      self.class.increment_column(self.column, count)
    end

    def to_s
      "#{column}#{row}"
    end

    def to_sym
      to_s.to_sym
    end

    class << self
      alias [] new

      def increment_column(column, count=1)
        Roo::Base.number_to_letter(Roo::Base.letter_to_number(column) + count)
      end
    end

  end
end