Auto-play a random legal card when the turn timeout expires

server/src/scopa/game/engine.py

@@ -64,6 +64,11 @@ PLAYERS = 4
 # the HAND_ACK_TIMEOUT_SECONDS environment variable).
 DEFAULT_HAND_ACK_TIMEOUT_SECONDS = 30
 
+# Default seconds a player has to play before the server plays a random
+# legal card for them. Games carry their own copy in
+# ``GameState.turn_timeout`` (configurable via TURN_TIMEOUT_SECONDS).
+DEFAULT_TURN_TIMEOUT_SECONDS = 30
+
 # Primiera card values: sevens are best, then sixes, then aces, then the
 # remaining ranks in descending order. All of 8/9/10 are worth 10.
 PRIMIERA_VALUES: Dict[int, int] = {
@@ -124,6 +129,7 @@ def create_game(
     creator_name: str,
     target_score: int = DEFAULT_TARGET_SCORE,
     hand_ack_timeout: int = DEFAULT_HAND_ACK_TIMEOUT_SECONDS,
+    turn_timeout: int = DEFAULT_TURN_TIMEOUT_SECONDS,
 ) -> GameState:
     """Create a lobby game with the creator seated first."""
     if target_score < 1 or target_score > 100:
@@ -136,6 +142,7 @@ def create_game(
         phase=PHASE_LOBBY,
         players=[PlayerState(sub=creator_sub, name=creator_name, seat=0)],
         hand_ack_timeout=hand_ack_timeout,
+        turn_timeout=turn_timeout,
         created_at=datetime.now(timezone.utc).isoformat(),
     )
 
@@ -162,6 +169,12 @@ def start_game(state: GameState) -> None:
     _deal_hand(state)
 
 
+def _set_turn_deadline(state: GameState) -> None:
+    """Arm the auto-play deadline for whoever is on turn."""
+    deadline = datetime.now(timezone.utc) + timedelta(seconds=state.turn_timeout)
+    state.turn_deadline = deadline.isoformat()
+
+
 def _deal_hand(state: GameState) -> None:
     deck = shuffled_deck()
     for player in state.players:
@@ -173,6 +186,7 @@ def _deal_hand(state: GameState) -> None:
     # Dealer rotates each hand; the first card is played by the player to
     # the dealer's left.
     state.turn = (state.dealer + 1) % PLAYERS
+    _set_turn_deadline(state)
     for offset in range(HAND_SIZE):
         for seat in range(PLAYERS):
             player = _player_at(state, (state.dealer + 1 + seat) % PLAYERS)
@@ -254,6 +268,7 @@ def play(
         _end_hand(state)
     else:
         state.turn = (state.turn + 1) % PLAYERS
+        _set_turn_deadline(state)
 
 
 def _match_option(
@@ -269,6 +284,32 @@ def _match_option(
     return None
 
 
+def auto_play(state: GameState, rng: Optional[random.Random] = None) -> None:
+    """Play a random legal move for the player currently on turn.
+
+    A card is drawn at random from that player's hand; if it can capture,
+    one of the legal captures is chosen at random (the rules require a
+    capture when one exists). Delegates to :func:`play`, so the move is
+    fully validated and can end the hand or the match. Pass ``rng`` for
+    deterministic tests.
+    """
+    if state.phase != PHASE_PLAYING:
+        raise GameNotStarted("the game has not started yet")
+    player = _player_at(state, state.turn)
+    if not player.hand:
+        raise IllegalMove("the player on turn has no cards")
+    chooser = rng or _rng
+    card = chooser.choice(player.hand)
+    options = legal_captures(state.table, card)
+    capture = chooser.choice(options) if options else None
+    play(
+        state,
+        player.sub,
+        card.code,
+        [c.code for c in capture] if capture else None,
+    )
+
+
 def _end_hand(state: GameState) -> None:
     """Sweep the table and score the hand.
 
@@ -278,6 +319,7 @@ def _end_hand(state: GameState) -> None:
     the hand-end timeout in the websocket layer). If the match is over the
     game goes to ``finished`` immediately.
     """
+    state.turn_deadline = None
     if state.table and state.last_taker is not None:
         taker = _player_at(state, state.last_taker)
         taker.captured.extend(state.table)
@@ -444,6 +486,7 @@ def state_for_player(state: GameState, sub: str) -> Dict[str, object]:
         "last_move": state.last_move.to_json() if state.last_move else None,
         "acknowledged": list(state.acked),
         "hand_end_deadline": state.hand_end_deadline,
+        "turn_deadline": state.turn_deadline,
     }
     if viewer is not None and state.phase == PHASE_PLAYING and viewer.seat == state.turn:
         payload["your_turn"] = True