A ruby command line version of tic tac toe

tic_tac_toe.rb

class Board 
	attr_reader :spaces, :name, :board_example, :num_to_words
	attr_accessor :view
	
	def initialize
		@spaces = {
			:one => EMPTY, 
			:two => EMPTY, 
			:three => EMPTY,
			:four => EMPTY, 
			:five => EMPTY, 
			:six => EMPTY, 
			:seven => EMPTY,
			:eight => EMPTY,
			:nine => EMPTY,
		}
		@view = ""+spaces[:one]+"|"+spaces[:two]+"|"+spaces[:three]+"\n-----\n"+spaces[:four]+"|"+spaces[:five]+"|"+spaces[:six]+"\n-----\n"+spaces[:seven]+"|"+spaces[:eight]+"|"+spaces[:nine]
		@board_example = "1|2|3\n-----\n4|5|6\n-----\n7|8|9"
		@num_to_words = { 1 => 'one', 2 => 'two', 3 => 'three', 4 => 'four', 5 => 'five', 6 => 'six', 7 => 'seven', 8 => 'eight', 9 => 'nine'}
	end 
	
	EMPTY = ' '
	
	def check_if_win_possible(letter)
		if (spaces[:one] == letter && spaces[:two] == letter || spaces[:six] == letter && spaces[:nine] == letter || spaces[:seven] == letter && spaces[:five] == letter) && spaces[:three] == EMPTY
			return 3
		elsif (spaces[:one] == letter && spaces[:three] == letter || spaces[:five] == letter && spaces[:eight] == letter)&& spaces[:two] == EMPTY 
			return 2 
		elsif (spaces[:one] == letter && spaces[:five] == letter || spaces[:three] == letter && spaces[:six] == letter || spaces[:seven] == letter && spaces[:eight] == letter) && spaces[:nine] == EMPTY
			return 9 
		elsif (spaces[:one] == letter && spaces[:four] == letter || spaces[:three] == letter && spaces[:five] == letter || spaces[:nine] == letter && spaces[:eight] == letter) && spaces[:seven] == EMPTY 
			return 7
		elsif (spaces[:one] == letter && spaces[:seven] == letter || spaces[:six] == letter && spaces[:five] == letter) && spaces[:four] == EMPTY
			return 4
		elsif (spaces[:two] == letter && spaces[:three] == letter || spaces[:four] == letter && spaces[:seven] == letter || spaces[:nine] == letter && spaces[:five] == letter) && spaces[:one] == EMPTY
			return 1
		elsif (spaces[:two] == letter && spaces[:five] == letter || spaces[:seven] == letter && spaces[:nine] == letter) && spaces[:eight] == EMPTY
			return 8 
		elsif (spaces[:two] == letter && spaces[:eight] == letter || spaces[:four] == letter && spaces[:six] == letter || spaces[:three] == letter && spaces[:seven] == letter) && spaces[:five] == EMPTY
			return 5
		elsif (spaces[:three] == letter && spaces[:nine] == letter || spaces[:four] == letter && spaces[:five] == letter) && spaces[:six] == EMPTY
			return 6
		else 
			return false
		end 
	end 
	
	def check_if_winner(letter)
		# check all possible winning lines
		if spaces[:one] == letter && spaces[:two] == letter && spaces[:three] == letter
			return true
		elsif  spaces[:four] == letter && spaces[:five] == letter && spaces[:six] == letter
			return true
		elsif spaces[:seven] == letter && spaces[:eight] == letter && spaces[:nine] == letter
			return true
		elsif spaces[:one] == letter && spaces[:four] == letter && spaces[:seven] == letter
			return true
		elsif spaces[:two] == letter && spaces[:five] == letter && spaces[:eight] == letter
			return true
		elsif spaces[:three] == letter && spaces[:six] == letter && spaces[:nine] == letter
			return true
		elsif spaces[:one] == letter && spaces[:five] == letter && spaces[:nine] == letter
			return true
		elsif spaces[:three] == letter && spaces[:five] == letter && spaces[:seven] == letter
			return true
		else
			return false
		end 
	end 

	def check_if_corner_open
		if spaces[:one] == EMPTY
			return 1
		elsif spaces[:three] == EMPTY
			return 3
		elsif spaces[:seven] == EMPTY 
			return 7
		elsif spaces[:nine] == EMPTY
			return 9
		else 
			return false 
		end 
	end 
	
	def update_view
		@view = ""+spaces[:one]+"|"+spaces[:two]+"|"+spaces[:three]+"\n-----\n"+spaces[:four]+"|"+spaces[:five]+"|"+spaces[:six]+"\n-----\n"+spaces[:seven]+"|"+spaces[:eight]+"|"+spaces[:nine]
	end 

	def check_if_center_open
		if spaces[:five] == EMPTY
			return true
		else 
			return false
		end 
	end 

	def make_move(square_num, letter)
		square = num_to_words[square_num.to_i]
		if @spaces[square.to_sym] == EMPTY
			new_space = { square.to_sym => letter }
			@spaces.merge!(new_space) 
			update_view
		else
			puts 'Oops! Invalid move, try again'
			square = gets.chomp
			make_move(square, letter)
		end	
	end 

	def check_if_tie
		space_values = @spaces.values
		i = 0 
		while i < space_values.length-1 do 
			i += 1
			if space_values[i] == EMPTY
				return false 
			end 
		end 
		return true		
	end 

	def find_empty_space
		space_values = @spaces.values
		i = 0 
		while i < space_values.length-1 do 
			i += 1
			if space_values[i] == EMPTY
				return i+1
			end
		end
	end 
	
	def computer_move 
		if check_if_tie
			puts @view
			puts "Tie Game!"
			play_again?
		elsif check_if_win_possible('O') != false
			make_move(check_if_win_possible('O'), 'O')
		elsif check_if_win_possible('X') != false
			make_move(check_if_win_possible('X'), 'O')
		elsif check_if_center_open
			make_move(5, 'O')
		elsif check_if_corner_open != false
			make_move(check_if_corner_open, 'O')
		else
			make_move(find_empty_space, 'O')
		end
	end 
	
	def reset_board
		reset_spaces = {
			:one => EMPTY, 
			:two => EMPTY, 
			:three => EMPTY,
			:four => EMPTY, 
			:five => EMPTY, 
			:six => EMPTY, 
			:seven => EMPTY,
			:eight => EMPTY,
			:nine => EMPTY,
		}
		@spaces.merge!(reset_spaces) 
		update_view
	end 
end 

def start_game
	@board = Board.new
	puts "Okay. Let's go over how to play. Each square on the board is numbered from 1 to 9. Like this: "
	puts @board.board_example
	puts 'So, to make a move, simply type the number of the square you\'d like to place your letter on. Got it? [\'yes\' or \'y\']'
	answer = gets.chomp.to_s
	puts answer
	if answer == 'yes' || answer == 'y'
		game_loop
	end 	
end 

def game_loop
	puts @board.view
	puts "Whats your move?"
	square = gets.chomp
	make_move(square)
	if @board.check_if_winner('X')
		puts @board.view 
		puts 'You win!'
		play_again?
	elsif @board.check_if_winner('O')
		puts @board.view
		puts 'Computer Wins!'
		play_again?
	elsif @board.check_if_tie
		puts @board.view
		puts "Tie Game!"
		play_again?
	else 
		game_loop
	end 
end 

def make_move(square)
	if square.length == 1 && square.to_i > 0 && square.to_i < 10
		@board.make_move(square, 'X')
		@board.computer_move
	else
		puts 'Oops! Try putting just the number value (Like 1 or 7)'
		square = gets.chomp
		make_move(square)
	end
end

def play_again?
	puts 'Do you want to play again?'
	answer = gets.chomp.to_s
	if answer == 'yes' || answer == 'y'
		@board.reset_board
		game_loop
	else
		puts "Okay, Bye!"
	end
end

start_game