implemented logic for resigning and drawing, and for verifying messages as sensible

Author: TheGoatInTheBoat

src/capy_app/frontend/cogs/games/multiplayerchess_cog.py

@@ -37,10 +37,11 @@ async def multichess(self, interaction: discord.Interaction, opponent: discord.U
             ["♜", "♞", "♝", "♛", "♚", "♝", "♞", "♜"],
         ]
         players = [interaction.user, opponent]
-        symbols = ["♔", "♕", "♖", "♗", "♘", "♙", "♚", "♛", "♜", "♝", "♞", "♟"]
         turn = 0
+        draw_proposed = False
 
         # print out the board
+        # returns NONE
         def print_board(board):
             print("+---+---+---+---+---+---+---+---+")
             for i in range(len(board)):
@@ -51,15 +52,28 @@ def print_board(board):
                 print("+---+---+---+---+---+---+---+---+")
 
         # make the move specified by the user
+        # assumes the move given is valid
+        # returns NONE
         def make_move(board, piece, start, end):
-            return
+            board[start[0]][start[1]] = ""
+            board[end[0]][end[1]] = piece
 
         # parse the chess notation to obtain piece, start location, end location
+        # returns (False, False, False) if given string is NOT in valid notation form,
+        # otherwise returns piece, start location, end location
         def parse_notation(notation):
             return
 
+        # returns true if given king color is in check, false otherwise
+        def is_in_check(board, color):
+            # loop thru board looking for opponent's pieces, see what squares they attack
+            return
+
         # returns true if move legal, else false
-        def is_move_legal(piece, start, end):
+        def is_move_legal(board, piece, start, end):
+            # check to be sure piece, start, end are note false
+            if piece == False:
+                return False
             # check bounds
 
             # check if piece can move this way
@@ -69,13 +83,20 @@ def is_move_legal(piece, start, end):
             # check for being in check after move
             # should cover pins too
 
+            # castling rules
+            # castling out of check
+            # castling thru check
+            # has king or rook moved?
+
             return
 
         # check for checkmate
+        # returns true if checkmate has been played, false otherwise
         def check_win(board):
             return
 
         # check for stalemate or repetition
+        # returns true if stalemate or repetition found, false otherwise
         def check_draw(board):
             return
 
@@ -86,28 +107,53 @@ def check_draw(board):
 
         def check(msg: discord.Message):
             return (
-                msg.author == players[turn]
-                and msg.channel == interaction.channel
-                and msg.content.isdigit()
-                # check notation validity
-                and 1 <= int(msg.content) <= 9
-                and board[int(msg.content) - 1] == " "
+                # checking to make sure the message is valid
+                msg.author == players[turn]  # correct player sent the msg
+                and msg.channel == interaction.channel  # channel is correct
+                and (  # if notation, check notation validity
+                    msg.content == "draw?"
+                    or msg.content == "accept"
+                    or msg.content == "decline"
+                    or msg.content == "resign"
+                    or parse_notation(msg.content)[0] != False
+                )
+                and is_move_legal(board, parse_notation(msg.content))  # move must be legal
             )
 
         while True:
             try:
                 move_msg = await self.bot.wait_for("message", check=check, timeout=60.0)
-                move = int(move_msg.content) - 1
 
-                if check_win(board):
+                # check for draw offer
+                if move_msg.content == "draw?":
+                    draw_proposed = True
+                    await interaction.followup.send(
+                        f'{print_board()}\n{players[turn%2].mention} proposes a draw! Type "accept" to accept the draw or "decline" to decline it.'
+                    )
+                    return
+                # check for draw decline
+                if move_msg.content == "decline" and draw_proposed:
+                    draw_proposed = False
+                    await interaction.followup.send(
+                        f"{print_board()}\n{players[turn%2].mention} declines to draw."
+                    )
+                    return
+
+                # check for checkmates or resignations
+                if check_win(board) or move_msg.content == "resign":
                     await interaction.followup.send(
-                        f"{print_board()}\n✅ {players[turn].mention} wins! 🎉"
+                        f"{print_board()}\n✅ {players[turn%2].mention} wins! 🎉"
                     )
                     return
 
+                # check for draw
+                if check_draw(board) or (draw_proposed and move_msg.content == "accept"):
+                    await interaction.followup.send(f"{print_board()}\nIt's a draw!")
+                    return
+
                 turn += 1
                 await interaction.followup.send(
-                    f"{print_board()}\n{players[turn].mention}, it's your turn!"
+                    f"{print_board()}\n{players[turn%2].mention}, it's your turn!"
                 )
             except asyncio.TimeoutError:
                 await interaction.followup.send("⌛ Game timed out!")