require "bigdecimal"

module Eddy
  module Models
    module Element
      # Decimal Numeric (decimal points must be transmitted if used).
      class R < Base

        # @param min [Integer]
        # @param max [Integer]
        # @param req [String] (nil)
        # @param ref [String] (nil)
        # @param val [Numeric] (nil)
        # @return [void]
        def initialize(
          min:,
          max:,
          req: nil,
          ref: nil,
          val: nil
        )
          @type = "R"
          @min = min
          @max = max
          self.req = req
          self.ref = ref
          self.value = val
        end

        # @param arg [Numeric]
        # @raise [ArgumentError] Unless passed a Numeric value.
        # @return [void]
        def value=(arg)
          if arg == :skip
            @val = :skip
            return
          end
          if arg.nil?()
            @val = arg
            return
          end
          raise Eddy::Errors::TypeValidationError.new(element: self, arg: arg) unless arg.is_a?(Numeric)
          @val = arg
        end

        # @return [String]
        def value()
          return super()
        end

        # @return [String]
        def process_value()
          return self.class.process_value(@val, self.max)
        end

        # Stringify a numeric value and trim it to `max`.
        #
        # TODO: Use `sprintf` here?
        #
        # See:
        #
        # - [Ruby class types and case statements (Stack Overflow)](https://stackoverflow.com/questions/3908380/ruby-class-types-and-case-statements)
        # - [Numbers and Class Hierarchy in Ruby (Medium)](https://medium.com/rubyinside/numbers-and-class-hierarchy-in-ruby-8c93c4749316)
        #
        # @param val [Numeric]
        # @param max [Integer]
        # @return [String]
        def self.process_value(val, max)
          case val
          when Integer
            return val.to_s.slice(0..max)
          when Float
            # FIXME: This isn't correct.
            return val.to_s.slice(0..(max + 1))
          when Complex
            # TODO: Handle case
            raise NotImplementedError, "eddy: support for Complex types in R data elements has not been implemented."
          when Rational
            # TODO: Handle case
            raise NotImplementedError, "eddy: support for Rational types in R data elements has not been implemented."
          when BigDecimal
            # TODO: Handle case
            raise NotImplementedError, "eddy: support for BigDecimal types in R data elements has not been implemented."
            # return val.to_f.to_s.slice(0..(max + 1))
          end
        end

      end
    end
  end
end