Files
tavolo/server/src/scopa/ws.py
T

307 lines
11 KiB
Python

"""WebSocket endpoint for live play.
Clients connect to ``/ws/games/{game_id}`` using their session cookie (the
OIDC login stores the user in the session, which the session mixin loads
onto the websocket). Only seated players are accepted.
Protocol
--------
Server -> client messages are JSON objects with a ``type``:
* ``state`` — the personalized game view (own hand visible, others hidden).
* ``game_over`` — sent once when the match ends, with the final scores.
* ``error`` — a rejected action or malformed message.
Client -> server messages are JSON objects::
{"action": "play", "card": "07D", "capture": ["02D", "05C"]}
{"action": "play", "card": "07D"}
{"action": "ack"}
{"action": "state"}
``capture`` lists the table cards to take and must be a legal capture when
one exists (see :func:`scopa.game.engine.legal_captures`); it is omitted
when the played card cannot capture. ``ack`` acknowledges the hand-end
scoring summary; the next hand is dealt when all four players have
acknowledged or the timeout fires.
Mutations run under the per-game lock; after a successful move the new
state is saved to Redis and a change signal is published. Every connected
websocket is subscribed to that signal and re-renders the state, so all
players see the move immediately (and consistently across workers).
If a player does not move before the per-game ``turn_timeout``, the server
plays a random card (with a random legal capture when one is required) for
them, so a disconnected or idle player cannot stall the match. The timer is
re-armed by every client connection and state broadcast, and fires
immediately when a reconnect finds the deadline already past.
"""
from __future__ import annotations
import asyncio
import json
from contextlib import suppress
from datetime import datetime, timezone
from typing import Any, Awaitable, Callable, Dict, Optional
from kaya.core import WebSocket
from . import auth
from .app import app, game_store
from .game import engine
from .game.errors import GameError
from .game.state import PHASE_FINISHED, PHASE_HAND_END, PHASE_PLAYING, GameState
from .stats import save_match_result
Send = Callable[[Dict[str, Any]], Awaitable[None]]
def _error(message: str, code: str = "invalid") -> Dict[str, Any]:
return {"type": "error", "code": code, "message": message}
def _state_message(state: GameState, sub: str) -> Dict[str, Any]:
return {"type": "state", "game": engine.state_for_player(state, sub)}
@app.websocket("/ws/games/${game_id}")
async def game_socket(ws: WebSocket, game_id: str) -> None:
user = auth.get_ws_user(ws)
if user is None:
await ws.close(4401)
return
state = await game_store.load(game_id)
if state is None:
await ws.close(4404)
return
if not state.seated(user.sub):
await ws.close(4403)
return
await ws.accept()
send_lock = asyncio.Lock()
async def send(payload: Dict[str, Any]) -> None:
async with send_lock:
await ws.send_text(json.dumps(payload))
await send(_state_message(state, user.sub))
schedule_turn_timer(game_id, state)
async with game_store.subscribe(game_id) as events:
forward = asyncio.create_task(
_forward(events, game_id, user.sub, send)
)
try:
async for message in ws:
if message.kind == "close":
break
if message.kind != "text" or not isinstance(message.data, str):
await send(_error("expected a text frame with a JSON object"))
continue
await _handle_message(send, game_id, user.sub, message.data)
finally:
forward.cancel()
with suppress(asyncio.CancelledError):
await forward
async def _forward(
events,
game_id: str,
sub: str,
send: Send,
) -> None:
async for _ in events:
state = await game_store.load(game_id)
if state is None:
return
schedule_turn_timer(game_id, state)
await send(_state_message(state, sub))
if state.phase == PHASE_FINISHED:
await send(
{
"type": "game_over",
"scores": {"A": state.scores[0], "B": state.scores[1]},
"winner": "A" if state.winner == 0 else "B",
}
)
return
async def _handle_message(send: Send, game_id: str, sub: str, raw: str) -> None:
try:
data = json.loads(raw)
except (ValueError, TypeError):
await send(_error("invalid JSON"))
return
if not isinstance(data, dict):
await send(_error("message must be a JSON object"))
return
action = data.get("action")
if action == "play":
await _handle_play(send, game_id, sub, data)
elif action == "ack":
await _handle_ack(send, game_id, sub)
elif action in ("state", "sync"):
state = await game_store.load(game_id)
if state is not None:
await send(_state_message(state, sub))
else:
await send(_error(f"unknown action: {action!r}"))
# --- hand-end acknowledgement ------------------------------------------------
# Running auto-continue timers, keyed by (game_id, hand_number), so a hand's
# timeout is scheduled only once even when several clients are connected.
_hand_end_timers: Dict[tuple, asyncio.Task] = {}
async def _handle_ack(send: Send, game_id: str, sub: str) -> None:
async with game_store.lock(game_id):
state = await game_store.load(game_id)
if state is None:
await send(_error("game not found", code="not_found"))
return
try:
engine.acknowledge_hand(state, sub)
except GameError as exc:
await send(_error(str(exc), code="illegal_move"))
return
await game_store.save(state)
await game_store.publish(game_id)
def schedule_hand_end_timer(game_id: str, hand_number: int, timeout: int) -> None:
"""Deal the next hand after the acknowledgement timeout, even if not
everyone has clicked. Fizzles if the hand already advanced."""
key = (game_id, hand_number)
if key in _hand_end_timers:
return
async def _auto_advance() -> None:
try:
await asyncio.sleep(timeout)
async with game_store.lock(game_id):
state = await game_store.load(game_id)
if (
state is None
or state.phase != engine.PHASE_HAND_END
or state.hand_number != hand_number
):
return
for player in state.players:
engine.acknowledge_hand(state, player.sub)
await game_store.save(state)
await game_store.publish(game_id)
finally:
_hand_end_timers.pop(key, None)
_hand_end_timers[key] = asyncio.create_task(_auto_advance())
# --- auto-play on turn timeout ------------------------------------------------
# Running turn timers, keyed by (game_id, hand_number, turn, deadline), so a
# turn's timeout is scheduled only once even when several clients are
# connected. Including the deadline means a re-arm after a reconnect cannot
# duplicate a timer for a turn that was already auto-played.
_turn_timers: Dict[tuple, asyncio.Task] = {}
def schedule_turn_timer(game_id: str, state: GameState) -> None:
"""Auto-play a random legal card if the player on turn misses the
deadline. Fizzles if the turn already advanced."""
if state.phase != PHASE_PLAYING or not state.turn_deadline:
return
key = (game_id, state.hand_number, state.turn, state.turn_deadline)
if key in _turn_timers:
return
hand_number = state.hand_number
turn = state.turn
deadline_raw = state.turn_deadline
try:
deadline = datetime.fromisoformat(deadline_raw)
except ValueError:
return
async def _auto_play() -> None:
try:
delay = (deadline - datetime.now(timezone.utc)).total_seconds()
await asyncio.sleep(max(delay, 0))
async with game_store.lock(game_id):
state = await game_store.load(game_id)
if (
state is None
or state.phase != PHASE_PLAYING
or state.hand_number != hand_number
or state.turn != turn
or state.turn_deadline != deadline_raw
):
# The turn moved on (or the game ended) without this
# timer firing: make sure the current turn is armed.
if state is not None:
schedule_turn_timer(game_id, state)
return
try:
engine.auto_play(state)
except GameError:
return
await _after_play(state, game_id)
finally:
_turn_timers.pop(key, None)
_turn_timers[key] = asyncio.create_task(_auto_play())
async def _after_play(state: GameState, game_id: str) -> None:
"""Persist a successful move and notify every connected player.
Callers must hold the per-game lock. Handles the two terminal
transitions: the match result is written to Postgres once, and a
hand-end summary schedules the auto-continue timeout.
"""
if state.phase == PHASE_FINISHED:
await save_match_result(state)
elif state.phase == PHASE_HAND_END:
schedule_hand_end_timer(game_id, state.hand_number, state.hand_ack_timeout)
await game_store.save(state)
await game_store.publish(game_id)
async def _handle_play(
send: Send, game_id: str, sub: str, data: Dict[str, Any]
) -> None:
card = data.get("card")
capture = data.get("capture")
if not isinstance(card, str):
await send(_error("'card' must be a card code string"))
return
if capture is not None and (
not isinstance(capture, list)
or any(not isinstance(item, str) for item in capture)
):
await send(_error("'capture' must be a list of card codes"))
return
async with game_store.lock(game_id):
state = await game_store.load(game_id)
if state is None:
await send(_error("game not found", code="not_found"))
return
try:
engine.play(state, sub, card, capture)
except GameError as exc:
await send(_error(str(exc), code="illegal_move"))
return
except ValueError:
await send(_error("invalid card code", code="illegal_move"))
return
await _after_play(state, game_id)