;;; emms-playing-time.el --- Display emms playing time on mode line

;; Copyright (C) 2005, 2006 Free Software Foundation, Inc.

;; Author: William Xu <william.xwl@gmail.com>

;; 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 2, 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, write to the Free Software
;; Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
;; 02110-1301 USA

;;; Commentary:

;; Display playing time on mode line, it looks like: 01:32/04:09.

;; Put this file into your load-path and the following into your
;; ~/.emacs:
;;              (require 'emms-playing-time)
;;
;; Then either `M-x emms-playing-time-enable' or add
;; (emms-playing-time 1) in your .emacs to enable.

;;; Code:

(defvar emms-playing-time-version "0.1 $Revision: 1.7 $"
  "EMMS playing time version string.")
;; $Id: emms-playing-time.el,v 1.7 2005/09/08 16:07:20 xwl Exp $

(eval-when-compile (require 'cl))
(require 'emms-info)
(require 'emms-info-mp3info)
(require 'emms-player-simple)

;;; Customizations

(defgroup emms-playing-time nil
  "Playing-time module for EMMS."
  :group 'emms)

(defcustom emms-playing-time-display-short-p nil
  "If non-nil, only display elapsed time, don't display total
playing time. e.g., display 02:37 instead of 02:37/05:49. You
should enable `emms-playing-time-display-p' first, though."
  :type 'boolean
  :group 'emms-playing-time)

(defcustom emms-playing-time-display-format " %s "
  "Format used for displaying playing time."
  :type 'string
  :group 'emms-playing-time)

;;; Emms playing time

(defvar emms-playing-time-display-p nil
  "Whether emms playing time is enabled or not")

(defvar emms-playing-time 0
  "How long has EMMS run up to now.")

(defvar emms-playing-time-string "")

(defvar emms-playing-time-display-timer nil)

(defun emms-playing-time-start ()
  "Get ready for display playing time."
  (setq emms-playing-time 0)
  (unless emms-playing-time-display-timer
    (setq emms-playing-time-display-timer
	  (run-at-time nil 1 'emms-playing-time-display))))

(defun emms-playing-time-stop ()
  "Remove playing time on the mode line."
  (if (or (not emms-player-paused-p)
	  emms-player-stopped-p)
      (progn
	(setq emms-playing-time-string "")
	(force-mode-line-update)))
  (emms-cancel-timer emms-playing-time-display-timer)
  (setq emms-playing-time-display-timer nil))

(defun emms-playing-time-pause ()
  "Pause playing time."
  (if emms-player-paused-p
      (emms-playing-time-stop)
    (unless emms-playing-time-display-timer
      (setq emms-playing-time-display-timer
	    (run-at-time nil 1 'emms-playing-time-display)))))

(defun emms-playing-time-seek (sec)
  "Seek forward or backward SEC playing time."
  (setq emms-playing-time (+ emms-playing-time sec))
  (when (< emms-playing-time 0)		; back to start point
    (setq emms-playing-time 0)))

(defun emms-playing-time (arg)
  "Turn on emms playing time if ARG is positive, off otherwise."
  (interactive "p")
  (if (and arg (> arg 0))
      (progn
	(setq emms-playing-time-display-p t)
	(emms-playing-time-mode-line)
	(add-hook 'emms-player-started-hook     'emms-playing-time-start)
	(add-hook 'emms-player-stopped-hook     'emms-playing-time-stop)
	(add-hook 'emms-player-finished-hook    'emms-playing-time-stop)
	(add-hook 'emms-player-paused-hook      'emms-playing-time-pause)
	(add-hook 'emms-player-seeked-functions 'emms-playing-time-seek))
    (setq emms-playing-time-display-p nil)
    (emms-playing-time-stop)
    (emms-playing-time-restore-mode-line)
    (remove-hook 'emms-player-started-hook     'emms-playing-time-start)
    (remove-hook 'emms-player-stopped-hook     'emms-playing-time-stop)
    (remove-hook 'emms-player-finished-hook    'emms-playing-time-stop)
    (remove-hook 'emms-player-paused-hook      'emms-playing-time-pause)
    (remove-hook 'emms-player-seeked-functions 'emms-playing-time-seek)))

;;;###autoload
(defun emms-playing-time-enable ()
  "Enable displaying emms playing time on mode line."
  (interactive)
  (emms-playing-time 1)
  (message "emms playing time enabled"))

;;;###autoload
(defun emms-playing-time-disable ()
  "Disable displaying emms playing time on mode line."
  (interactive)
  (emms-playing-time -1)
  (message "emms playing time disabled"))

;;;###autoload
(defun emms-playing-time-toggle ()
  "Toggle displaying emms playing time on mode line."
  (interactive)
  (if emms-playing-time-display-p
      (emms-playing-time-disable)
    (emms-playing-time-enable)))

(defun emms-playing-time-display ()
  "Display playing time on the mode line."
  (setq emms-playing-time (1+ emms-playing-time))
  (let* ((min (/ emms-playing-time 60))
	 (sec (% emms-playing-time 60))
	 (total-playing-time
	  (or (emms-track-get
	       (emms-playlist-current-selected-track)
	       'info-playing-time)
	      0))
	 (total-min-only (/ total-playing-time 60))
	 (total-sec-only (% total-playing-time 60)))
    (setq emms-playing-time-string
	  (format
	   emms-playing-time-display-format
	   (emms-replace-regexp-in-string
	    " " "0"
	    (if (or emms-playing-time-display-short-p
		    ;; unable to get total playing-time
		    (eq total-playing-time 0))
		(format "%2d:%2d" min sec)
	      (format "%2d:%2d/%2s:%2s"
		      min sec total-min-only total-sec-only)))))
    (force-mode-line-update)))

(defun emms-playing-time-mode-line ()
  "Add playing time to the mode line."
  (or global-mode-string (setq global-mode-string '("")))
  (unless (member 'emms-playing-time-string
		  global-mode-string)
    (setq global-mode-string
	  (append global-mode-string
		  '(emms-playing-time-string)))))

(defun emms-playing-time-restore-mode-line ()
  "Restore the mode line."
  (setq global-mode-string
	(remove 'emms-playing-time-string global-mode-string))
  (force-mode-line-update))

(provide 'emms-playing-time)

;;; emms-playing-time.el ends here