Pythagorean Triplet

triplet.rb

class Triplet
  attr_reader :a, :b, :c
  
  def initialize(a, b, c)
    @a = a
    @b = b
    @c = c
  end
  
  def sum
    [a, b, c].inject(:+)
  end
  
  def product
    [a, b, c].inject(:*)
  end
  
  def pythagorean?
    [a**2, b**2].inject(:+) == c**2
  end
  
  def self.where(values)
    TestTriplets.new(values).get_triplets
  end
end
  
class TestTriplets
  attr_reader :min_max, :sum
  
  def initialize(values)
    min_factor = values.fetch(:min_factor, 1)
    max_factor = values.fetch(:max_factor)
    @min_max = (min_factor..max_factor).to_a
    @sum = values.fetch(:sum, nil)
  end

  def get_triplets
    triplets = []
    min_max.combination(3).each do |a, b, c|
      triplet_class = Triplet.new(a, b, c)
      triplets.push(triplet_class) if valid_triplet?(triplet_class)
    end
    triplets
  end

  def valid_triplet?(triplet_class)
    if sum.nil?
      triplet_class.pythagorean?
    else
      triplet_class.pythagorean? && triplet_class.sum == sum
    end
  end
end