(TicTacToe): Created `AI` class for Tic Tac Toe against computer playing.

1 files changed, 47 insertions, 0 deletions

diff --git a/bot/exts/evergreen/tic_tac_toe.py b/bot/exts/evergreen/tic_tac_toe.py
index a9971ad2..b306e803 100644
--- a/bot/exts/evergreen/tic_tac_toe.py
+++ b/bot/exts/evergreen/tic_tac_toe.py
@@ -1,4 +1,5 @@
 import asyncio
+import random
 import typing as t
 
 import discord
@@ -44,6 +45,52 @@ class Player:
             return False, list(Emojis.number_emojis.keys())[list(Emojis.number_emojis.values()).index(react.emoji)]
 
 
+class AI:
+    """Tic Tac Toe AI class for against computer gaming."""
+
+    def __init__(self, symbol: str):
+        self.symbol = symbol
+
+    async def check_win(self, board: t.Dict[int, str]) -> bool:
+        """Check does this move will result game end."""
+        if (
+            # Horizontal
+            board[1] == board[2] == board[3]
+            or board[4] == board[5] == board[6]
+            or board[7] == board[8] == board[9]
+            # Vertical
+            or board[1] == board[4] == board[7]
+            or board[2] == board[5] == board[8]
+            or board[3] == board[6] == board[9]
+            # Diagonal
+            or board[1] == board[5] == board[9]
+            or board[3] == board[5] == board[7]
+        ):
+            return True
+        return False
+
+    async def get_move(self, board: t.Dict[int, str], _: discord.Message) -> t.Tuple[bool, int]:
+        """Get move from AI. AI use Minimax strategy."""
+        possible_moves = [i for i, emoji in board.items() if emoji in Emojis.number_emojis]
+
+        for symbol in (Emojis.x, Emojis.o):
+            for move in possible_moves:
+                board_copy = board.copy()
+                board_copy[move] = symbol
+                if self.check_win(board_copy):
+                    return False, move
+
+        open_corners = [i for i in possible_moves if i in (1, 3, 7, 9)]
+        if len(open_corners) > 0:
+            return False, random.choice(open_corners)
+
+        if 5 in possible_moves:
+            return False, 5
+
+        open_edges = [i for i in possible_moves if i in (2, 4, 6, 8)]
+        return False, random.choice(open_edges)
+
+
 class Game:
     """Class that contains information and functions about Tic Tac Toe game."""