card-game.el/cg-net.el
Corwin Brust b5410e1830 Add 16 games and known-games research; bump to 1.0.60
Console UNICODE games on the cg-core EIEIO engine, all ERT-tested (88/88):
- Tableau solitaire (cg-solitaire.el): Klondike, FreeCell, Spider, Yukon,
  Canfield, Forty Thieves, Scorpion.
- Pile solitaire (cg-patience.el): Golf, TriPeaks, Pyramid.
- Trick-taking (cg-trick.el): Hearts, Spades, Whist, Oh Hell.
- Shedding/climbing: Crazy Eights (cg-eights.el), President (cg-president.el).

Wire all into the card-game chooser, Makefile, and README; add
known-games.org research collation; bump every file to 1.0.60.
2026-06-25 01:58:24 -05:00

226 lines
8.8 KiB
EmacsLisp

;;; cg-net.el --- Networked multiplayer for card games -*- lexical-binding: t; -*-
;; Copyright (C) 2026 Corwin Brust
;; Author: Corwin Brust <corwin@bru.st>
;; Maintainer: Corwin Brust <corwin@bru.st>
;; Version: 1.0.60
;; Package-Requires: ((emacs "26.1"))
;; Keywords: games
;; URL: https://code.bru.st/corwin/card-game.el
;; This program is free software; you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation, either version 3 of the License, or
;; (at your option) any later version.
;; This program is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
;; GNU General Public License for more details.
;; You should have received a copy of the GNU General Public License
;; along with this program. If not, see <https://www.gnu.org/licenses/>.
;;; Commentary:
;; Host-authoritative networking for the card games. One Emacs is the
;; HOST: it owns the canonical game and listens for players. Other
;; Emacsen CONNECT as clients, send move "intents", and receive the new
;; game state to redraw. Because the games are turn-based there is
;; nothing to merge, so this is a simple authoritative server rather
;; than a CRDT; crdt.el is kept in reserve for any future free-form
;; shared state.
;;
;; Transport is line-delimited s-expressions over `make-network-process'
;; (plain TCP), so it works wherever Emacs has TCP -- including an
;; Android client joining a desktop host. A message is a plist with a
;; `:type' key:
;;
;; client -> host: (:type hello :name NAME)
;; (:type move :move MOVE)
;; host -> client: (:type welcome :seat N)
;; (:type state :state SEXP)
;;
;; A game plugs in by defining methods on `cg-net-apply-move' (host
;; side) and, if its state is not just the env plist, on
;; `cg-net-game-state' / `cg-net-set-game-state'. Clients add a
;; redraw function to `cg-net-state-functions'.
;;; Code:
(require 'cg-core)
(defgroup cg-net nil
"Networked play for card games."
:group 'card-games
:prefix "cg-net-")
(defcustom cg-net-port 7500
"Default TCP port used to host or join a game."
:type 'integer :group 'cg-net)
(defvar cg-net-state-functions nil
"Abnormal hook run on a client after the game state is updated.
Each function is called with the client's game object.")
(defvar cg-net-connect-functions nil
"Abnormal hook run on the host when a client connects.
Each function is called with (HOST SEAT): the `cg-net-host' struct and
the seat number just assigned to the new connection.")
;;;; Game integration points
(cl-defgeneric cg-net-apply-move (game seat move)
"Apply MOVE made by SEAT to GAME on the host.
Return non-nil when the move was accepted (and state should broadcast).")
(cl-defgeneric cg-net-game-state (game &optional seat)
"Return a `read'able representation of GAME's shared state for SEAT.
SEAT is the recipient's seat number, letting a game hide other players'
private information; nil requests the full host view.")
(cl-defmethod cg-net-game-state ((game cg-game) &optional _seat)
"Default: return GAME's env plist (no per-seat filtering)."
(oref game env))
(cl-defgeneric cg-net-set-game-state (game state)
"Replace GAME's shared state with STATE on a client.")
(cl-defmethod cg-net-set-game-state ((game cg-game) state)
"Default: install STATE as GAME's env plist."
(oset game env state))
;;;; Wire protocol
(defun cg-net--send (proc msg)
"Send MSG (a sexp) to PROC as one newline-terminated line."
(when (process-live-p proc)
(let ((print-length nil) (print-level nil))
(process-send-string proc (concat (prin1-to-string msg) "\n")))))
(defun cg-net--filter (handler)
"Return a process filter dispatching each complete line to HANDLER.
HANDLER is called with (PROC MSG)."
(lambda (proc string)
(let ((buf (concat (or (process-get proc 'cg-net-buf) "") string))
(start 0) nl)
(while (setq nl (string-search "\n" buf start))
(let ((line (substring buf start nl)))
(setq start (1+ nl))
(unless (string-empty-p line)
(condition-case err
(funcall handler proc (car (read-from-string line)))
(error (message "cg-net: bad message: %S" err)))))
)
(process-put proc 'cg-net-buf (substring buf start)))))
;;;; Host
(cl-defstruct (cg-net-host (:constructor cg-net--host-make))
server game (clients nil) (next-seat 0))
(defvar cg-net--host nil
"The running `cg-net-host', or nil when not hosting.")
(defun cg-net-hosting-p ()
"Return non-nil when this Emacs is hosting a game."
(and cg-net--host (process-live-p (cg-net-host-server cg-net--host))))
(defun cg-net-host-start (game &optional port)
"Begin hosting GAME on PORT (default `cg-net-port'). Return the server process."
(let* ((port (or port cg-net-port))
(server (make-network-process
:name "cg-host" :server t :service port
:host "0.0.0.0" :family 'ipv4 :coding 'utf-8
:log #'cg-net--host-accept)))
(setq cg-net--host (cg-net--host-make :server server :game game))
server))
(defun cg-net-host-stop ()
"Stop hosting and close all client connections."
(when cg-net--host
(dolist (c (cg-net-host-clients cg-net--host))
(when (process-live-p c) (delete-process c)))
(when (process-live-p (cg-net-host-server cg-net--host))
(delete-process (cg-net-host-server cg-net--host)))
(setq cg-net--host nil)))
(defun cg-net--host-accept (_server connection _message)
"Set up an accepted CONNECTION: assign a seat and send the current state."
(let ((seat (cg-net-host-next-seat cg-net--host)))
(setf (cg-net-host-next-seat cg-net--host) (1+ seat))
(push connection (cg-net-host-clients cg-net--host))
(process-put connection 'cg-net-seat seat)
(set-process-coding-system connection 'utf-8 'utf-8)
(set-process-filter connection (cg-net--filter #'cg-net--host-handle))
(cg-net--send connection (list :type 'welcome :seat seat))
(cg-net--send connection
(list :type 'state
:state (cg-net-game-state (cg-net-host-game cg-net--host) seat)))
(run-hook-with-args 'cg-net-connect-functions cg-net--host seat)))
(defun cg-net--host-handle (proc msg)
"Handle one message MSG from a client PROC on the host."
(pcase (plist-get msg :type)
('hello (process-put proc 'cg-net-name (plist-get msg :name)))
('move
(let ((seat (process-get proc 'cg-net-seat))
(game (cg-net-host-game cg-net--host)))
(when (cg-net-apply-move game seat (plist-get msg :move))
(cg-net-host-broadcast))))))
(defun cg-net-host-broadcast ()
"Send each connected client the game state filtered for its seat."
(when cg-net--host
(let ((game (cg-net-host-game cg-net--host)))
(dolist (c (cg-net-host-clients cg-net--host))
(cg-net--send c (list :type 'state
:state (cg-net-game-state
game (process-get c 'cg-net-seat))))))))
;;;; Client
(cl-defstruct (cg-net-client (:constructor cg-net--client-make))
proc game (seat nil))
(defvar cg-net--client nil
"The active `cg-net-client', or nil when not connected.")
(defun cg-net-connected-p ()
"Return non-nil when connected to a host as a client."
(and cg-net--client (process-live-p (cg-net-client-proc cg-net--client))))
(defun cg-net-connect (host port name game)
"Connect to HOST on PORT as NAME, syncing into the local GAME.
Return the new `cg-net-client'."
(let ((proc (make-network-process
:name "cg-client" :host host :service port
:family 'ipv4 :coding 'utf-8)))
(setq cg-net--client (cg-net--client-make :proc proc :game game))
(set-process-coding-system proc 'utf-8 'utf-8)
(set-process-filter proc (cg-net--filter #'cg-net--client-handle))
(cg-net--send proc (list :type 'hello :name name))
cg-net--client))
(defun cg-net-disconnect ()
"Disconnect from the host."
(when (and cg-net--client (process-live-p (cg-net-client-proc cg-net--client)))
(delete-process (cg-net-client-proc cg-net--client)))
(setq cg-net--client nil))
(defun cg-net--client-handle (_proc msg)
"Handle one message MSG from the host on a client."
(pcase (plist-get msg :type)
('welcome (setf (cg-net-client-seat cg-net--client) (plist-get msg :seat)))
('state
(let ((game (cg-net-client-game cg-net--client)))
(cg-net-set-game-state game (plist-get msg :state))
(run-hook-with-args 'cg-net-state-functions game)))))
(defun cg-net-send-move (move)
"Send MOVE to the host from this client."
(cg-net--send (cg-net-client-proc cg-net--client) (list :type 'move :move move)))
(provide 'cg-net)
;;; cg-net.el ends here