A month ago I posted an earlier version of the game here, and got a great response, which was mainly about the structure of my code. I freed some time today and reworked the code from scratch.
Things I improved:
- Class separation
- No more god object
- Applied single responsibility principle for classes and methods
I would love to hear if the code can be improved even further (structure, logic, etc.), as this is I feel the maximum of my coding capability:
# players in the game
class Player
attr_reader :name, :symbol
def initialize(name, symbol)
@name = name
@symbol = symbol
end
end
# the game board
class Board
attr_accessor :board
def initialize
@board = (1..9).to_a
end
def display_board
puts "\e[H\e[2J" # ANSI clear
@board.each_slice(3).with_index do |row, idx|
print " #{row.join(' | ')}\n"
puts ' ---+---+---' unless idx == 2
end
puts
end
def welcome_msg
print "\nWelcome to Tic Tac Toe.\n\n"
puts 'Enter 1 to play against another player, 2 to play against an evil AI'\
', 3 to watch evil AI play against kind AI.'
puts 'Type EXIT anytime to quit.'
end
def cell_open?(position)
@board[position - 1].is_a?(Fixnum) ? true : false
end
def win_game?(symbol)
sequences = [[0, 1, 2], [3, 4, 5], [6, 7, 8],
[0, 3, 6], [1, 4, 7], [2, 5, 8],
[0, 4, 8], [2, 4, 6]]
sequences.each do |seq|
return true if seq.all? { |a| @board[a] == symbol }
end
false
end
def full?
@board.each do |cell|
return false if cell.is_a? Fixnum
end
true
end
def place_mark(position, symbol)
@board[position - 1] = symbol
end
end
# game logic
class Game
attr_accessor :board, :player1, :player2, :ai, :current_player
def initialize
@board = Board.new
@player1 = Player.new('Player 1', 'X')
@player2 = Player.new('Player 2', 'O')
@ai = AI.new('Evil AI', 'O')
@ai2 = AI.new('Kind AI', 'X')
@current_player = @player1
start_screen
end
def start_screen
@board.welcome_msg
choice = nil
until (1..3).include?(choice)
choice = gets.chomp
exit if choice.downcase == 'exit'
game_modes(choice.to_i)
end
end
def game_modes(choice)
case choice
when 1 then pvp_game
when 2 then pva_game
when 3 then ava_game
else puts 'You silly goose, try again.'
end
end
def pvp_game
@board.display_board
until game_over
player_place_n_check
swap_players
end
end
def pva_game
@board.display_board
until game_over
player_place_n_check
swap_pva
ai_place_n_check(@ai)
swap_pva
end
end
def ava_game
@board.display_board
until game_over
ai_place_n_check(@ai2)
swap_ava
ai_place_n_check(@ai)
swap_ava
end
end
def game_over
@board.win_game?(@current_player.symbol) || @board.full?
end
def player_place_n_check
position = player_input
@board.place_mark(position.to_i, @current_player.symbol)
@board.display_board
result?
end
def ai_place_n_check(player)
position = player.ai_turn(@board)
@board.place_mark(position.to_i, @current_player.symbol) unless position.nil?
@board.display_board
result?
end
def player_input
input = nil
until (1..9).include?(input) && @board.cell_open?(input)
puts "Choose a number (1-9) to place your mark #{@current_player.name}."
input = validate_input(gets.chomp)
end
input
end
def validate_input(input)
if input.to_i == 0
exit if input.downcase == 'exit'
puts 'You can\'t use a string, silly.'
else
position = validate_position(input.to_i)
end
position
end
def validate_position(position)
if !(1..9).include? position
puts 'This position does not exist, chief.'
puts 'Try again or type EXIT to, well, exit.'
elsif [email protected]_open? position
puts 'Nice try but this cell is already taken.'
puts 'Try again or type EXIT to, well, exit.'
end
position
end
def result?
if @board.win_game?(@current_player.symbol)
puts "Game Over, #{@current_player.name} has won."
exit
elsif @board.full?
puts 'Draw.'
exit
end
end
def swap_players
case @current_player
when @player1 then @current_player = @player2
else @current_player = @player1
end
end
def swap_pva
case @current_player
when @player1 then @current_player = @ai
else @current_player = @player1
end
end
def swap_ava
@current_player == @ai ? @current_player = @ai2 : @current_player = @ai
end
end
# AI player components
class AI
attr_accessor :board, :name, :symbol
def initialize(name, symbol)
@name = name
@symbol = symbol
end
def ai_turn(board)
loading_simulation
check_win(board)
return @finished if @finished
check_block(board)
return @finished if @finished
check_defaults(board)
return @finished if @finished
end
# first check if possible to win before human player.
def check_win(board)
@finished = false
1.upto(9) do |i|
origin = board.board[i - 1]
board.board[i - 1] = 'O' if origin.is_a? Fixnum
# put it there if AI can win that way.
return @finished = i if board.win_game?('O')
board.board[i - 1] = origin
end
end
# if impossible to win before player,
# check if possible to block player from winning.
def check_block(board)
@finished = false
1.upto(9) do |i|
origin = board.board[i - 1]
board.board[i - 1] = 'X' if origin.is_a? Fixnum
# put it there if player can win that way.
return @finished = i if board.win_game?('X')
board.board[i - 1] = origin
end
end
# if impossible to win nor block, default placement to center.
# if occupied, choose randomly between corners or sides.
def check_defaults(board)
@finished = false
if board.board[4].is_a? Fixnum
@finished = 5
else
rand < 0.51 ? possible_sides(board) : possible_corners(board)
end
end
def possible_sides(board)
[2, 4, 6, 8].each do |i|
return @finished = i if board.board[i - 1].is_a? Fixnum
end
end
def possible_corners(board)
[1, 3, 7, 9].each do |i|
return @finished = i if board.board[i - 1].is_a? Fixnum
end
end
def loading_simulation
str = "\r#{name} is scheming"
10.times do
print str += '.'
sleep(0.1)
end
end
end
Game.new
