joeyates/m9t

require "m9t/base"

module M9t
  # Represents a temperature
  # Using degrees (celcius), not kelvin, as default unit
  class Temperature
    DEFAULT_OPTIONS = {
      units: :degrees, abbreviated: false, precision: 5
    }
    CONVERSIONS  = {
      degrees:   1.0,
      kelvin:    nil,
      fahrenheit: nil
    }

    # Conversions
    ABSOLUTE_ZERO = -273.15

    include M9t::Base

    class << self
      # Accepts a value in kelvin and returns the equivalent M9t::Temperature
      def kelvin(kelvin)
        new(kelvin.to_f + ABSOLUTE_ZERO)
      end

      def fahrenheit(fahrenheit)
        new(fahrenheit_to_degrees(fahrenheit))
      end

      # Converts degrees to kelvin
      def to_kelvin(degrees)
        degrees.to_f - ABSOLUTE_ZERO
      end

      # Converts degrees to Fahrenheit
      def to_fahrenheit(degrees)
        degrees.to_f * 9.0 / 5.0 + 32
      end

      # Converts kelvin to degrees
      def kelvin_to_degrees(kelvin)
        kelvin.to_f + ABSOLUTE_ZERO
      end

      # Converts Fahrenheit to degrees
      def fahrenheit_to_degrees(fahrenheit)
        (fahrenheit.to_f - 32) * 5.0 / 9.0
      end
    end

    alias :to_degrees :value

    # Returns the value converted to kilometers
    def to_kelvin
      self.class.to_kelvin(@value)
    end

    def to_fahrenheit
      self.class.to_fahrenheit(@value)
    end
  end
end