numguess.rb

class NumGuess
	DEFAULT_NAME = "Player"
	MIN_LIMIT = 10

	@name = DEFAULT_NAME
	@limit = MIN_LIMIT
	@num = 0
	@tries = 0
	@max_tries = 0
	@correct = false

	def name=(name = DEFAULT_NAME)
		@name = name.empty? ? DEFAULT_NAME : name
	end

	def limit=(limit)
		@limit = limit < MIN_LIMIT ? MIN_LIMIT : limit
		@max_tries = Math.log(@limit, 2).floor + 1
	end

	def start_game
		@correct = false
		@tries = 0
		@num = rand(1..@limit)
	end

	def evaluate_guess(guess)
		return "That's just plain wrong." if guess.to_i.to_s != guess

		guess = guess.to_i
		return "Out of range." unless (1..@limit) === guess

		@tries += 1
		case guess <=> @num
			when -1
				return "Too low!"
			when 1
				return "Too high!"
			else
				@correct = true
				return ""
		end
	end

	def custom_message
		return "You're one lucky bastard!"              if @tries == 1
		return "You are the master of this game!"       if @tries < @max_tries
		return "You are a machine!"                     if @tries == @max_tries
		return "Very good result!"                      if @tries < @max_tries * 1.1
		return "I find your lack of skill disturbing!"  if @tries > @limit
		return "Try harder, you can do better!"
	end

	def run
		print "Welcome to NumGuess Ruby version!\n\n"
		print "Enter your name: "
		self.name = gets.chomp

		print "\nWelcome #{@name}, enter upper limit: "
		self.limit = gets.chomp.to_i

		begin
			print "\nGuess my number between 1 and #{@limit}!\n"
			start_game

			begin
				print "\nGuess: "
				print evaluate_guess(gets.chomp)
			end until @correct

			print "\nWell done #{@name}, you guessed my number from #{@tries} %s!\n" %
				(@tries == 1 ? "try" : "tries")

			print custom_message + "\n"
			print "Play again [y/N]? "
		end until gets.chomp.downcase != "y"

		print "\nOkay, bye."
	end
end

NumGuess.new.run