rpsls-oop.rb

class Hand
  WEAPONS = [:rock, :paper, :scissors, :lizard, :spock]

  attr_reader :weapon

  def initialize(weapon)
    @weapon = weapon.to_sym
  end

  def valid?
    WEAPONS.include?(weapon)
  end
end

class RPSLS
  RESULTS = {
    rock: {
      lizard: 'crushes',
      scissors: 'crushes'
    },
    paper: {
      rock: 'covers',
      spock: 'disproves'
    },
    scissors: {
      paper: 'cuts',
      lizard: 'decapitate'
    },
    lizard: {
      paper: 'eats',
      spock: 'poisons'
    },
    spock: {
      scissors: 'smashes',
      vaporizes: 'rock'
    }
  }

  attr_reader :winner, :loser

  def initialize(first, second)
    first, second = first.to_sym, second.to_sym

    if RESULTS[first].keys.include?(second)
      @winner, @loser = Hand.new(first), Hand.new(second)
    else
      @winner, @loser = Hand.new(second), Hand.new(first)
    end

    raise unless winner.valid? && loser.valid?
  end

  def result
    "#{winner.weapon.capitalize} #{RESULTS[winner.weapon][loser.weapon]} #{loser.weapon.capitalize}"
  end
end