# -*- encoding: utf-8 -*-
# -*- frozen_string_literal: true -*-
# -*- warn_indent: true -*-

module UnitMeasurements
  # The +UnitMeasurements::Comparison+ mixin module is included in measurement
  # classes to enable comparison operations (e.g., less than, equal to, greater
  # than, etc.) between two measurements of the same unit group.
  #
  # This module is included in the +Measurement+ class to allow comparison of two
  # measurements.
  #
  # @see Measurement
  # @author {Harshal V. Ladhe}[https://shivam091.github.io/]
  # @since 1.3.0
  module Comparison
    include Comparable

    # This method is used to compare the quantity of two measurements. It
    # implements the comparison logic based on the +<=>+ method defined in the
    # +Comparable+ module.
    #
    # @example
    #   UnitMeasurements::Length.new(1, "km") == UnitMeasurements::Length.new(1, :km)
    #   => true
    #
    #   UnitMeasurements::Length.parse("1 km") == UnitMeasurements::Length.parse("1000 m")
    #   => true
    #
    #   UnitMeasurements::Length.parse("1 km") != UnitMeasurements::Length.parse("1 m")
    #   => true
    #
    #   UnitMeasurements::Length.parse("1 km") < UnitMeasurements::Length.parse("0.5 km")
    #   => false
    #
    #   UnitMeasurements::Length.parse("1 km") > UnitMeasurements::Length.parse("0.5 km")
    #   => true
    #
    #   UnitMeasurements::Length.parse("1 km") <= UnitMeasurements::Length.parse("0.5 km")
    #   => false
    #
    #   UnitMeasurements::Length.parse("1 km") >= UnitMeasurements::Length.parse("0.5 km")
    #   => true
    #
    #   UnitMeasurements::Length.new(1, "ft").between?(UnitMeasurements::Length.new(12, "in"), UnitMeasurements::Length.new(24, "in"))
    #   => true
    #
    # @param [Measurement] object The measurement instance to compare with.
    #
    # @return
    #   +nil+ if the comparison is not possible (e.g., if the +object+ is not of
    #   the same unit group). A negative integer if +self+ is less than +object+.
    #   +Zero+ if self is equal to +object+. A positive integer if +self+ is
    #   greater than +object+.
    #
    # @author {Harshal V. Ladhe}[https://shivam091.github.io/]
    # @since 1.3.0
    def <=>(object)
      return nil unless object.is_a?(self.class)

      quantity <=> object.convert_to(unit.name).quantity
    end
  end
end