;;; chess-announce.el --- Scheme to verbally announce chess moves  -*- lexical-binding: t; -*-

;; Copyright (C) 2002-2020  Free Software Foundation, Inc.

;; Author: John Wiegley <johnw@gnu.org>
;; Maintainer: Mario Lang <mlang@delysid.org>
;; Keywords: games

;; 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 <http://www.gnu.org/licenses/>.

;;; Code:

(require 'chess-game)
(require 'chess-message)

(chess-message-catalog 'english
  '((queen	  . "queen")
    (king	  . "king")
    (bishop	  . "bishop")
    (knight	  . "knight")
    (rook	  . "rook")
    (pawn	  . "pawn")
    (short-castle . "short castle")
    (long-castle  . "long castle")
    (check	  . "check")
    (checkmate	  . "checkmate")
    (stalemate	  . "stalemate")
    (en-passant	  . "on possont")
    (promote	  . "promote to %s")
    (piece-moves  . "%s to %s")
    (piece-takes  . "%s takes %s at %s")))

(defvar chess-announce-names
  '((?q . queen)
    (?k . king)
    (?b . bishop)
    (?n . knight)
    (?r . rook)
    (?p . pawn)))

(autoload 'festival-start-process "festival")
(autoload 'festival-kill-process "festival")

(defvar chess-announce-functions
  (if (and (executable-find "festival")
	   (not (featurep 'emacspeak)))
      (if (fboundp 'festival-say-string)
	  '(festival-start-process festival-say-string festival-kill-process)
	'(ignore chess-announce-festival ignore))
    '(ignore message ignore))
  "These three functions are used to for announcing moves.
The first is called one start of the announcer.  The second is called
with the string to announce each time.  The third is called to
shutdown the announcer process, if necessary.")

(defsubst chess-piece-name (char)
  (chess-string (cdr (assq (downcase char)
			   chess-announce-names))))

(defun chess-announce-handler (game event &rest args)
  (cond
   ((eq event 'initialize)
    (funcall (nth 0 chess-announce-functions))
    t)

   ((eq event 'destroy)
    (funcall (nth 2 chess-announce-functions)))

   ((eq event 'move)
    (let* ((ply (chess-game-ply game (1- (chess-game-index game))))
	   (pos (chess-ply-pos ply)))
      (unless (eq (chess-game-data game 'my-color)
		  (chess-pos-side-to-move pos))
	(let* ((source (chess-ply-source ply))
	       (target (chess-ply-target ply))
	       (s-piece (and source (chess-pos-piece pos source)))
	       (t-piece (and target (chess-pos-piece pos target)))
	       (which (chess-ply-keyword ply :which))
	       text)
	  (if which
	      (setq which (char-to-string which)))
	  (cond
	   ((chess-ply-keyword ply :castle)
	    (setq text (chess-string 'short-castle)))
	   ((chess-ply-keyword ply :long-castle)
	    (setq text (chess-string 'long-castle)))
	   ((and s-piece t-piece (= t-piece ? ) target)
	    (setq text
		  (concat which
			  (chess-string 'piece-moves
					(chess-piece-name s-piece)
					(chess-index-to-coord target)))))
	   ((and s-piece t-piece target)
	    (setq text
		  (concat which
			  (chess-string 'piece-takes
					(chess-piece-name s-piece)
					(chess-piece-name t-piece)
					(chess-index-to-coord target))))))

	  (let ((promotion (chess-ply-keyword ply :promote)))
	    (if promotion
		(setq text
		      (concat text ", "
			      (chess-string 'promote
					    (chess-piece-name promotion))))))
	  (if (chess-ply-keyword ply :en-passant)
	      (setq text (concat text ", " (chess-string 'en-passant))))
	  (if (chess-ply-keyword ply :check)
	      (setq text (concat text ", " (chess-string 'check))))
	  (if (chess-ply-keyword ply :checkmate)
	      (setq text (concat text ", " (chess-string 'checkmate))))
	  (if (chess-ply-keyword ply :stalemate)
	      (setq text (concat text ", " (chess-string 'stalemate))))

	  (funcall (nth 1 chess-announce-functions) text)))))
   ((eq event 'kibitz)
    (funcall (nth 1 chess-announce-functions) (car args)))))

(defun chess-announce-festival (text)
  "Announce the given text using festival.
This is less efficient than festival.el, which should be installed if
possible.  Debian installs it automatically when you apt-get install
festival."
  (let ((proc (start-process "announce" nil "/usr/bin/festival" "--tts")))
    (when (and proc (eq (process-status proc) 'run))
      (process-send-string proc (concat text "\n"))
      (process-send-eof proc))))

(provide 'chess-announce)

;;; chess-announce.el ends here