bots: Create Chess Bot.

Chess Bot is a bot that allows you to play chess against either another
user or the computer. Use `start with other user` or
`start as <color> with computer` to start a game.

In order to play against a computer, `chess.conf` must be set with the
key `stockfish_location` set to the location of the Stockfish program on
this computer.

Use `bot_handler.storage` to preserve game state across messages.

(@showell also did minor work here to have the test use verify_dialog()
and have the bot respond to empty messages)
This commit is contained in:
Marco Burstein 2017-12-04 20:34:52 -08:00 committed by Steve Howell
parent 2fa677a3e0
commit 700ce6a673
7 changed files with 914 additions and 1 deletions

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@ -58,6 +58,8 @@ force_include = [
"zulip_bots/zulip_bots/bots/define/test_define.py",
"zulip_bots/zulip_bots/bots/encrypt/encrypt.py",
"zulip_bots/zulip_bots/bots/encrypt/test_encrypt.py",
"zulip_bots/zulip_bots/bots/chess/chess.py",
"zulip_bots/zulip_bots/bots/chess/test_chess.py",
]
parser = argparse.ArgumentParser(description="Run mypy on files tracked by git.")

View file

@ -52,7 +52,8 @@ setuptools_info = dict(
'html2text', # for bots/define
'BeautifulSoup4', # for bots/googlesearch
'lxml', # for bots/googlesearch
'requests' # for bots/link_shortener
'requests', # for bots/link_shortener
'python-chess[engine,gaviota]' # for bots/chess
],
)

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@ -0,0 +1,2 @@
[chess]
stockfish_location = <the location of Stockfish on this machine>

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@ -0,0 +1,746 @@
import chess
import chess.uci
import re
import copy
from typing import Any, Optional
from zulip_bots.lib import ExternalBotHandler
START_REGEX = re.compile('start with other user$')
START_COMPUTER_REGEX = re.compile(
'start as (?P<user_color>white|black) with computer'
)
MOVE_REGEX = re.compile('do (?P<move_san>.+)$')
RESIGN_REGEX = re.compile('resign$')
class ChessHandler(object):
def usage(self) -> str:
return (
'Chess Bot is a bot that allows you to play chess against either '
'another user or the computer. Use `start with other user` or '
'`start as <color> with computer` to start a game.\n\n'
'In order to play against a computer, `chess.conf` must be set '
'with the key `stockfish_location` set to the location of the '
'Stockfish program on this computer.'
)
def initialize(self, bot_handler: ExternalBotHandler) -> None:
self.config_info = bot_handler.get_config_info('chess')
try:
self.engine = chess.uci.popen_engine(
self.config_info['stockfish_location']
)
self.engine.uci()
except FileNotFoundError:
# It is helpful to allow for fake Stockfish locations if the bot
# runner is testing or knows they won't be using an engine.
print('That Stockfish doesn\'t exist. Continuing.')
def handle_message(
self,
message: dict,
bot_handler: ExternalBotHandler
) -> None:
content = message['content']
if content == '':
bot_handler.send_reply(message, self.usage())
return
start_regex_match = START_REGEX.match(content)
start_computer_regex_match = START_COMPUTER_REGEX.match(content)
move_regex_match = MOVE_REGEX.match(content)
resign_regex_match = RESIGN_REGEX.match(content)
is_with_computer = False
last_fen = chess.Board().fen()
if bot_handler.storage.contains('is_with_computer'):
is_with_computer = (
# `bot_handler`'s `storage` only accepts `str` values.
bot_handler.storage.get('is_with_computer') == str(True)
)
if bot_handler.storage.contains('last_fen'):
last_fen = bot_handler.storage.get('last_fen')
if start_regex_match:
self.start(message, bot_handler)
elif start_computer_regex_match:
self.start_computer(
message,
bot_handler,
start_computer_regex_match.group('user_color') == 'white'
)
elif move_regex_match:
if is_with_computer:
self.move_computer(
message,
bot_handler,
last_fen,
move_regex_match.group('move_san')
)
else:
self.move(
message,
bot_handler,
last_fen,
move_regex_match.group('move_san')
)
elif resign_regex_match:
self.resign(
message,
bot_handler,
last_fen
)
def start(self, message: dict, bot_handler: ExternalBotHandler) -> None:
"""Starts a game with another user, with the current user as white.
Replies to the bot handler.
Parameters:
- message: The Zulip Bots message object.
- bot_handler: The Zulip Bots bot handler object.
"""
new_board = chess.Board()
bot_handler.send_reply(
message,
make_start_reponse(new_board)
)
# `bot_handler`'s `storage` only accepts `str` values.
bot_handler.storage.put('is_with_computer', str(False))
bot_handler.storage.put('last_fen', new_board.fen())
def start_computer(
self,
message: dict,
bot_handler: ExternalBotHandler,
is_white_user: bool
) -> None:
"""Starts a game with the computer. Replies to the bot handler.
Parameters:
- message: The Zulip Bots message object.
- bot_handler: The Zulip Bots bot handler object.
- is_white_user: Whether or not the player wants to be
white. If false, the user is black. If the
user is white, they will get to make the
first move; if they are black the computer
will make the first move.
"""
new_board = chess.Board()
if is_white_user:
bot_handler.send_reply(
message,
make_start_computer_reponse(new_board)
)
# `bot_handler`'s `storage` only accepts `str` values.
bot_handler.storage.put('is_with_computer', str(True))
bot_handler.storage.put('last_fen', new_board.fen())
else:
self.move_computer_first(
message,
bot_handler,
new_board.fen(),
)
def validate_board(
self,
message: dict,
bot_handler: ExternalBotHandler,
fen: str
) -> Optional[chess.Board]:
"""Validates a board based on its FEN string. Replies to the bot
handler if there is an error with the board.
Parameters:
- message: The Zulip Bots message object.
- bot_handler: The Zulip Bots bot handler object.
- fen: The FEN string of the board.
Returns: `False` if the board didn't pass, or the board object itself
if it did.
"""
try:
last_board = chess.Board(fen)
except ValueError:
bot_handler.send_reply(
message,
make_copied_wrong_response()
)
return False
return last_board
def validate_move(
self,
message: dict,
bot_handler: ExternalBotHandler,
last_board: chess.Board,
move_san: str,
is_computer: object
) -> Optional[chess.Move]:
"""Validates a move based on its SAN string and the current board.
Replies to the bot handler if there is an error with the move.
Parameters:
- message: The Zulip Bots message object.
- bot_handler: The Zulip Bots bot handler object.
- last_board: The board object before the move.
- move_san: The SAN of the move.
- is_computer: Whether or not the user is playing against a
computer (used in the response if the move is not
legal).
Returns: `False` if the move didn't pass, or the move object itself if
it did.
"""
try:
move = last_board.parse_san(move_san)
except ValueError:
bot_handler.send_reply(
message,
make_not_legal_response(
last_board,
move_san
)
)
return None
if move not in last_board.legal_moves:
bot_handler.send_reply(
message,
make_not_legal_response(last_board, move_san)
)
return None
return move
def check_game_over(
self,
message: dict,
bot_handler: ExternalBotHandler,
new_board: chess.Board
) -> bool:
"""Checks if a game is over due to
- checkmate,
- stalemate,
- insufficient material,
- 50 moves without a capture or pawn move, or
- 3-fold repetition.
Replies to the bot handler if it is game over.
Parameters:
- message: The Zulip Bots message object.
- bot_handler: The Zulip Bots bot handler object.
- new_board: The board object.
Returns: True if it is game over, false if it's not.
"""
# This assumes that the players will claim a draw after 3-fold
# repetition or 50 moves go by without a capture or pawn move.
# According to the official rules, the game is only guaranteed to
# be over if it's *5*-fold or *75* moves, but if either player
# wants the game to be a draw, after 3 or 75 it a draw. For now,
# just assume that the players would want the draw.
if new_board.is_game_over(True):
game_over_output = ''
if new_board.is_checkmate():
game_over_output = make_loss_response(
new_board,
'was checkmated'
)
elif new_board.is_stalemate():
game_over_output = make_draw_response('stalemate')
elif new_board.is_insufficient_material():
game_over_output = make_draw_response(
'insufficient material'
)
elif new_board.can_claim_fifty_moves():
game_over_output = make_draw_response(
'50 moves without a capture or pawn move'
)
elif new_board.can_claim_threefold_repetition():
game_over_output = make_draw_response('3-fold repetition')
bot_handler.send_reply(
message,
game_over_output
)
return True
return False
def move(
self,
message: dict,
bot_handler: ExternalBotHandler,
last_fen: str,
move_san: str
) -> None:
"""Makes a move for a user in a game with another user. Replies to
the bot handler.
Parameters:
- message: The Zulip Bots message object.
- bot_handler: The Zulip Bots bot handler object.
- last_fen: The FEN string of the board before the move.
- move_san: The SAN of the move to make.
"""
last_board = self.validate_board(message, bot_handler, last_fen)
if not last_board:
return
move = self.validate_move(
message,
bot_handler,
last_board,
move_san,
False
)
if not move:
return
new_board = copy.copy(last_board)
new_board.push(move)
if self.check_game_over(message, bot_handler, new_board):
return
bot_handler.send_reply(
message,
make_move_reponse(last_board, new_board, move)
)
bot_handler.storage.put('last_fen', new_board.fen())
def move_computer(
self,
message: dict,
bot_handler: ExternalBotHandler,
last_fen: str,
move_san: str
) -> None:
"""Preforms a move for a user in a game with the computer and then
makes the computer's move. Replies to the bot handler. Unlike `move`,
replies only once to the bot handler every two moves (only after the
computer moves) instead of after every move. Doesn't require a call in
order to make the computer move. To make the computer move without the
user going first, use `move_computer_first`.
Parameters:
- message: The Zulip Bots message object.
- bot_handler: The Zulip Bots bot handler object.
- last_fen: The FEN string of the board before the user's move.
- move_san: The SAN of the user's move to make.
"""
last_board = self.validate_board(message, bot_handler, last_fen)
if not last_board:
return
move = self.validate_move(
message,
bot_handler,
last_board,
move_san,
True
)
if not move:
return
new_board = copy.copy(last_board)
new_board.push(move)
if self.check_game_over(message, bot_handler, new_board):
return
computer_move = calculate_computer_move(
new_board,
self.engine
)
new_board_after_computer_move = copy.copy(new_board)
new_board_after_computer_move.push(computer_move)
if self.check_game_over(
message,
bot_handler,
new_board_after_computer_move
):
return
bot_handler.send_reply(
message,
make_move_reponse(
new_board,
new_board_after_computer_move,
computer_move
)
)
bot_handler.storage.put(
'last_fen',
new_board_after_computer_move.fen()
)
def move_computer_first(
self,
message: dict,
bot_handler: ExternalBotHandler,
last_fen: str
) -> None:
"""Preforms a move for the computer without having the user go first in
a game with the computer. Replies to the bot handler. Like
`move_computer`, but doesn't have the user move first. This is usually
only useful at the beginning of a game.
Parameters:
- message: The Zulip Bots message object.
- bot_handler: The Zulip Bots bot handler object.
- last_fen: The FEN string of the board before the computer's
move.
"""
last_board = self.validate_board(message, bot_handler, last_fen)
computer_move = calculate_computer_move(
last_board,
self.engine
)
new_board_after_computer_move = copy.copy(last_board)
new_board_after_computer_move.push(computer_move)
if self.check_game_over(
message,
bot_handler,
new_board_after_computer_move
):
return
bot_handler.send_reply(
message,
make_move_reponse(
last_board,
new_board_after_computer_move,
computer_move
)
)
bot_handler.storage.put(
'last_fen',
new_board_after_computer_move.fen()
)
# `bot_handler`'s `storage` only accepts `str` values.
bot_handler.storage.put('is_with_computer', str(True))
def resign(
self,
message: dict,
bot_handler: ExternalBotHandler,
last_fen: str
) -> None:
"""Resigns the game for the current player.
Parameters:
- message: The Zulip Bots message object.
- bot_handler: The Zulip Bots bot handler object.
- last_fen: The FEN string of the board.
"""
last_board = self.validate_board(message, bot_handler, last_fen)
if not last_board:
return
bot_handler.send_reply(
message,
make_loss_response(last_board, 'resigned')
)
handler_class = ChessHandler
def calculate_computer_move(board: chess.Board, engine: Any) -> chess.Move:
"""Calculates the computer's move.
Parameters:
- board: The board object before the move.
- engine: The UCI engine object.
Returns: The computer's move object.
"""
engine.position(board)
best_move_and_ponder_move = engine.go(movetime=(3000))
return best_move_and_ponder_move[0]
def make_draw_response(reason: str) -> str:
"""Makes a response string for a draw.
Parameters:
- reason: The reason for the draw, in the form of a noun, e.g.,
'stalemate' or 'insufficient material'.
Returns: The draw response string.
"""
return 'It\'s a draw because of {}!'.format(reason)
def make_loss_response(board: chess.Board, reason: str) -> str:
"""Makes a response string for a loss (or win).
Parameters:
- board: The board object at the end of the game.
- reason: The reason for the loss, in the form of a predicate, e.g.,
'was checkmated'.
Returns: The loss response string.
"""
return (
'*{}* {}. **{}** wins!\n\n'
'{}'
).format(
'White' if board.turn else 'Black',
reason,
'Black' if board.turn else 'White',
make_str(board, board.turn)
)
def make_not_legal_response(board: chess.Board, move_san: str) -> str:
"""Makes a response string for a not-legal move.
Parameters:
- board: The board object before the move.
- move_san: The SAN of the not-legal move.
Returns: The not-legal-move response string.
"""
return (
'Sorry, the move *{}* isn\'t legal.\n\n'
'{}'
'\n\n\n'
'{}'
).format(
move_san,
make_str(board, board.turn),
make_footer()
)
def make_copied_wrong_response() -> str:
"""Makes a response string for a FEN string that was copied wrong.
Returns: The copied-wrong response string.
"""
return (
'Sorry, it seems like you copied down the response wrong.\n\n'
'Please try to copy the response again from the last message!'
)
def make_start_reponse(board: chess.Board) -> str:
"""Makes a response string for the first response of a game with another
user.
Parameters:
- board: The board object to start the game with (which most-likely
should be general opening chess position).
Returns: The starting response string.
"""
return (
'New game! The board looks like this:\n\n'
'{}'
'\n\n\n'
'Now it\'s **{}**\'s turn.'
'\n\n\n'
'{}'
).format(
make_str(board, True),
'white' if board.turn else 'black',
make_footer()
)
def make_start_computer_reponse(board: chess.Board) -> str:
"""Makes a response string for the first response of a game with a
computer, when the user is playing as white. If the user is playing as
black, use `ChessHandler.move_computer_first`.
Parameters:
- board: The board object to start the game with (which most-likely
should be general opening chess position).
Returns: The starting response string.
"""
return (
'New game with computer! The board looks like this:\n\n'
'{}'
'\n\n\n'
'Now it\'s **{}**\'s turn.'
'\n\n\n'
'{}'
).format(
make_str(board, True),
'white' if board.turn else 'black',
make_footer()
)
def make_move_reponse(
last_board: chess.Board,
new_board: chess.Board,
move: chess.Move
) -> str:
"""Makes a response string for after a move is made.
Parameters:
- last_board: The board object before the move.
- new_board: The board object after the move.
- move: The move object.
Returns: The move response string.
"""
return (
'The board was like this:\n\n'
'{}'
'\n\n\n'
'Then *{}* moved *{}*:\n\n'
'{}'
'\n\n\n'
'Now it\'s **{}**\'s turn.'
'\n\n\n'
'{}'
).format(
make_str(last_board, new_board.turn),
'white' if last_board.turn else 'black',
last_board.san(move),
make_str(new_board, new_board.turn),
'white' if new_board.turn else 'black',
make_footer()
)
def make_footer() -> str:
"""Makes a footer to be appended to the bottom of other, actionable
responses.
"""
return (
'To make your next move, respond to Chess Bot with\n\n'
'```do <your move>```\n\n'
'*Remember to @-mention Chess Bot at the beginning of your '
'response.*'
)
def make_str(board: chess.Board, is_white_on_bottom: bool) -> str:
"""Converts a board object into a string to be used in Markdown. Backticks
are added around the string to preserve formatting.
Parameters:
- board: The board object.
- is_white_on_bottom: Whether or not white should be on the bottom
side in the string. If false, black will be on
the bottom.
Returns: The string made from the board.
"""
default_str = board.__str__()
replaced_str = replace_with_unicode(default_str)
replaced_and_guided_str = guide_with_numbers(replaced_str)
properly_flipped_str = (
replaced_and_guided_str if is_white_on_bottom
else replaced_and_guided_str[::-1]
)
trimmed_str = trim_whitespace_before_newline(properly_flipped_str)
monospaced_str = '```\n{}\n```'.format(trimmed_str)
return monospaced_str
def guide_with_numbers(board_str: str) -> str:
"""Adds numbers and letters on the side of a string without them made out
of a board.
Parameters:
- board_str: The string from the board object.
Returns: The string with the numbers and letters.
"""
# Spaces and newlines would mess up the loop because they add extra indexes
# between pieces. Newlines are added later by the loop and spaces are added
# back in at the end.
board_without_whitespace_str = board_str.replace(' ', '').replace('\n', '')
# The first number, 8, needs to be added first because it comes before a
# newline. From then on, numbers are inserted at newlines.
row_list = list('8' + board_without_whitespace_str)
for i, char in enumerate(row_list):
# `(i + 1) % 10 == 0` if it is the end of a row, i.e., the 10th column
# since lists are 0-indexed.
if (i + 1) % 10 == 0:
# Since `i + 1` is always a multiple of 10 (because index 0, 10,
# 20, etc. is the other row letter and 1-8, 11-18, 21-28, etc. are
# the squares), `(i + 1) // 10` is the inverted row number (1 when
# it should be 8, 2 when it should be 7, etc.), so therefore
# `9 - (i + 1) // 10` is the actual row number.
row_num = 9 - (i + 1) // 10
# The 3 separate components are split into only 2 elements so that
# the newline isn't counted by the loop. If they were split into 3,
# or combined into just 1 string, the counter would become off
# because it would be counting what is really 2 rows as 3 or 1.
row_list[i:i] = [str(row_num) + '\n', str(row_num - 1)]
# 1 is appended to the end because it isn't created in the loop, and lines
# that begin with spaces have their spaces removed for aesthetics.
row_str = (' '.join(row_list) + ' 1').replace('\n ', '\n')
# a, b, c, d, e, f, g, and h are easy to add in.
row_and_col_str = (
' a b c d e f g h \n' + row_str + '\n a b c d e f g h '
)
return row_and_col_str
def replace_with_unicode(board_str: str) -> str:
"""Replaces the default characters in a board object's string output with
Unicode chess characters, e.g., '' instead of 'R.'
Parameters:
- board_str: The string from the board object.
Returns: The string with the replaced characters.
"""
replaced_str = board_str
replaced_str = replaced_str.replace('P', '')
replaced_str = replaced_str.replace('N', '')
replaced_str = replaced_str.replace('B', '')
replaced_str = replaced_str.replace('R', '')
replaced_str = replaced_str.replace('Q', '')
replaced_str = replaced_str.replace('K', '')
replaced_str = replaced_str.replace('p', '')
replaced_str = replaced_str.replace('n', '')
replaced_str = replaced_str.replace('b', '')
replaced_str = replaced_str.replace('r', '')
replaced_str = replaced_str.replace('q', '')
replaced_str = replaced_str.replace('k', '')
replaced_str = replaced_str.replace('.', '·')
return replaced_str
def trim_whitespace_before_newline(str_to_trim: str) -> str:
"""Removes any spaces before a newline in a string.
Parameters:
- str_to_trim: The string to trim.
Returns: The trimmed string.
"""
return re.sub('\s+$', '', str_to_trim, flags=re.M)

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@ -0,0 +1,39 @@
## Starting a Game
You can start a game with another user by typing
```
start with other user
```
or you can start a game with a computer with
```
start as <white or black> with computer
```
## Playing
After starting the game, you can make your move by typing
```
do <your move>
```
using [Standard Algebraic Chess Notation](https://goo.gl/rehi8n). For example,
`do e4` to move a pawn to *e4* or `do Nf3` to move a night to *f3* or `do O-O`
to castle.
## Ending the game
The bot will detect if a game is over. You can end one early by resigning
with the
```
resign
```
command.
(Or you could just stop responding.)

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@ -0,0 +1,123 @@
#!/usr/bin/env python
from zulip_bots.test_lib import StubBotTestCase
class TestChessBot(StubBotTestCase):
bot_name = "chess"
START_RESPONSE = '''New game! The board looks like this:
```
a b c d e f g h
8 8
7 7
6 · · · · · · · · 6
5 · · · · · · · · 5
4 · · · · · · · · 4
3 · · · · · · · · 3
2 2
1 1
a b c d e f g h
```
Now it's **white**'s turn.
To make your next move, respond to Chess Bot with
```do <your move>```
*Remember to @-mention Chess Bot at the beginning of your response.*'''
DO_E4_RESPONSE = '''The board was like this:
```
h g f e d c b a
1 1
2 2
3 · · · · · · · · 3
4 · · · · · · · · 4
5 · · · · · · · · 5
6 · · · · · · · · 6
7 7
8 8
h g f e d c b a
```
Then *white* moved *e4*:
```
h g f e d c b a
1 1
2 · 2
3 · · · · · · · · 3
4 · · · · · · · 4
5 · · · · · · · · 5
6 · · · · · · · · 6
7 7
8 8
h g f e d c b a
```
Now it's **black**'s turn.
To make your next move, respond to Chess Bot with
```do <your move>```
*Remember to @-mention Chess Bot at the beginning of your response.*'''
DO_KE4_RESPONSE = '''Sorry, the move *Ke4* isn't legal.
```
h g f e d c b a
1 1
2 · 2
3 · · · · · · · · 3
4 · · · · · · · 4
5 · · · · · · · · 5
6 · · · · · · · · 6
7 7
8 8
h g f e d c b a
```
To make your next move, respond to Chess Bot with
```do <your move>```
*Remember to @-mention Chess Bot at the beginning of your response.*'''
RESIGN_RESPONSE = '''*Black* resigned. **White** wins!
```
h g f e d c b a
1 1
2 · 2
3 · · · · · · · · 3
4 · · · · · · · 4
5 · · · · · · · · 5
6 · · · · · · · · 6
7 7
8 8
h g f e d c b a
```'''
def test_bot_responds_to_empty_message(self) -> None:
with self.mock_config_info({'stockfish_location': '/foo/bar'}):
response = self.get_response(dict(content=''))
self.assertIn('play chess', response['content'])
def test_main(self) -> None:
with self.mock_config_info({'stockfish_location': '/foo/bar'}):
self.verify_dialog([
('start with other user', self.START_RESPONSE),
('do e4', self.DO_E4_RESPONSE),
('do Ke4', self.DO_KE4_RESPONSE),
('resign', self.RESIGN_RESPONSE),
])