;;; org-timer.el --- The relative timer code for Org-mode

;; Copyright (C) 2008-2012 Free Software Foundation, Inc.

;; Author: Carsten Dominik <carsten at orgmode dot org>
;; Keywords: outlines, hypermedia, calendar, wp
;; Homepage: http://orgmode.org
;;
;; This file is part of GNU Emacs.
;;
;; GNU Emacs 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.

;; GNU Emacs 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 GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;
;;; Commentary:

;; This file contains the relative timer code for Org-mode

;;; Code:

(require 'org)

(declare-function org-notify "org-clock" (notification &optional play-sound))
(declare-function org-agenda-error "org-agenda" ())

(defvar org-timer-start-time nil
  "t=0 for the running timer.")

(defvar org-timer-pause-time nil
  "Time when the timer was paused.")

(defconst org-timer-re "\\([-+]?[0-9]+\\):\\([0-9]\\{2\\}\\):\\([0-9]\\{2\\}\\)"
  "Regular expression used to match timer stamps.")

(defcustom org-timer-format "%s "
  "The format to insert the time of the timer.
This format must contain one instance of \"%s\" which will be replaced by
the value of the relative timer."
  :group 'org-time
  :type 'string)

(defcustom org-timer-default-timer 0
  "The default timer when a timer is set.
When 0, the user is prompted for a value."
  :group 'org-time
  :type 'number)

(defvar org-timer-start-hook nil
  "Hook run after relative timer is started.")

(defvar org-timer-stop-hook nil
  "Hook run before relative timer is stopped.")

(defvar org-timer-pause-hook nil
  "Hook run before relative timer is paused.")

(defvar org-timer-continue-hook nil
 "Hook run after relative timer is continued.")

(defvar org-timer-set-hook nil
  "Hook run after countdown timer is set.")

(defvar org-timer-done-hook nil
  "Hook run after countdown timer reaches zero.")

(defvar org-timer-cancel-hook nil
  "Hook run before countdown timer is canceled.")

;;;###autoload
(defun org-timer-start (&optional offset)
  "Set the starting time for the relative timer to now.
When called with prefix argument OFFSET, prompt the user for an offset time,
with the default taken from a timer stamp at point, if any.
If OFFSET is a string or an integer, it is directly taken to be the offset
without user interaction.
When called with a double prefix arg, all timer strings in the active
region will be shifted by a specific amount.  You will be prompted for
the amount, with the default to make the first timer string in
the region 0:00:00."
  (interactive "P")
  (if (equal offset '(16))
      (call-interactively 'org-timer-change-times-in-region)
    (let (delta def s)
      (if (not offset)
	  (setq org-timer-start-time (current-time))
	(cond
	 ((integerp offset) (setq delta offset))
	 ((stringp offset) (setq delta (org-timer-hms-to-secs offset)))
	 (t
	  (setq def (if (org-in-regexp org-timer-re)
			(match-string 0)
		      "0:00:00")
		s (read-string
		   (format "Restart timer with offset [%s]: " def)))
	  (unless (string-match "\\S-" s) (setq s def))
	  (setq delta (org-timer-hms-to-secs (org-timer-fix-incomplete s)))))
	(setq org-timer-start-time
	      (seconds-to-time
	       (- (org-float-time) delta))))
      (org-timer-set-mode-line 'on)
      (message "Timer start time set to %s, current value is %s"
	       (format-time-string "%T" org-timer-start-time)
	       (org-timer-secs-to-hms (or delta 0)))
      (run-hooks 'org-timer-start-hook))))

(defun org-timer-pause-or-continue (&optional stop)
  "Pause or continue the relative timer.
With prefix arg STOP, stop it entirely."
  (interactive "P")
  (cond
   (stop (org-timer-stop))
   ((not org-timer-start-time) (error "No timer is running"))
   (org-timer-pause-time
    ;; timer is paused, continue
    (setq org-timer-start-time
	  (seconds-to-time
	   (-
	    (org-float-time)
	    (- (org-float-time org-timer-pause-time)
	       (org-float-time org-timer-start-time))))
	  org-timer-pause-time nil)
    (org-timer-set-mode-line 'on)
    (run-hooks 'org-timer-continue-hook)
    (message "Timer continues at %s" (org-timer-value-string)))
   (t
    ;; pause timer
    (run-hooks 'org-timer-pause-hook)
    (setq org-timer-pause-time (current-time))
    (org-timer-set-mode-line 'pause)
    (message "Timer paused at %s" (org-timer-value-string)))))

(defun org-timer-stop ()
  "Stop the relative timer."
  (interactive)
  (run-hooks 'org-timer-stop-hook)
  (setq org-timer-start-time nil
	org-timer-pause-time nil)
  (org-timer-set-mode-line 'off))

;;;###autoload
(defun org-timer (&optional restart no-insert-p)
  "Insert a H:MM:SS string from the timer into the buffer.
The first time this command is used, the timer is started.  When used with
a \\[universal-argument] prefix, force restarting the timer.
When used with a double prefix argument \\[universal-argument], change all the timer string
in the region by a fixed amount.  This can be used to recalibrate a timer
that was not started at the correct moment.

If NO-INSERT-P is non-nil, return the string instead of inserting
it in the buffer."
  (interactive "P")
  (when (or (equal restart '(4)) (not org-timer-start-time))
    (org-timer-start))
  (if no-insert-p
      (org-timer-value-string)
    (insert (org-timer-value-string))))

(defun org-timer-value-string ()
  (format org-timer-format (org-timer-secs-to-hms (floor (org-timer-seconds)))))

(defvar org-timer-timer-is-countdown nil)
(defun org-timer-seconds ()
  (if org-timer-timer-is-countdown
      (- (org-float-time org-timer-start-time)
	 (org-float-time (current-time)))
    (- (org-float-time (or org-timer-pause-time (current-time)))
       (org-float-time org-timer-start-time))))

;;;###autoload
(defun org-timer-change-times-in-region (beg end delta)
  "Change all h:mm:ss time in region by a DELTA."
  (interactive
   "r\nsEnter time difference like \"-1:08:26\". Default is first time to zero: ")
  (let ((re "[-+]?[0-9]+:[0-9]\\{2\\}:[0-9]\\{2\\}") p)
    (unless (string-match "\\S-" delta)
      (save-excursion
	(goto-char beg)
	(when (re-search-forward re end t)
	  (setq delta (match-string 0))
	  (if (equal (string-to-char delta) ?-)
	      (setq delta (substring delta 1))
	    (setq delta (concat "-" delta))))))
    (setq delta (org-timer-hms-to-secs (org-timer-fix-incomplete delta)))
    (when (= delta 0) (error "No change"))
    (save-excursion
      (goto-char end)
      (while (re-search-backward re beg t)
	(setq p (point))
	(replace-match
	 (save-match-data
	   (org-timer-secs-to-hms (+ (org-timer-hms-to-secs (match-string 0)) delta)))
	 t t)
	(goto-char p)))))

;;;###autoload
(defun org-timer-item (&optional arg)
  "Insert a description-type item with the current timer value."
  (interactive "P")
  (let ((itemp (org-in-item-p)) (pos (point)))
    (cond
     ;; In a timer list, insert with `org-list-insert-item',
     ;; then fix the list.
     ((and itemp (goto-char itemp) (org-at-item-timer-p))
      (let* ((struct (org-list-struct))
	     (prevs (org-list-prevs-alist struct))
	     (s (concat (org-timer (when arg '(4)) t) ":: ")))
	(setq struct (org-list-insert-item pos struct prevs nil s))
	(org-list-write-struct struct (org-list-parents-alist struct))
	(looking-at org-list-full-item-re)
	(goto-char (match-end 0))))
     ;; In a list of another type, don't break anything: throw an error.
     (itemp (goto-char pos) (error "This is not a timer list"))
     ;; Else, start a new list.
     (t
      (beginning-of-line)
      (org-indent-line-function)
      (insert  "- ")
      (org-timer (when arg '(4)))
      (insert ":: ")))))

(defun org-timer-fix-incomplete (hms)
  "If hms is a H:MM:SS string with missing hour or hour and minute, fix it."
  (if (string-match "\\(?:\\([0-9]+:\\)?\\([0-9]+:\\)\\)?\\([0-9]+\\)" hms)
      (replace-match
       (format "%d:%02d:%02d"
	       (if (match-end 1) (string-to-number (match-string 1 hms)) 0)
	       (if (match-end 2) (string-to-number (match-string 2 hms)) 0)
	       (string-to-number (match-string 3 hms)))
       t t hms)
    (error "Cannot parse HMS string \"%s\"" hms)))

(defun org-timer-hms-to-secs (hms)
  "Convert h:mm:ss string to an integer time.
If the string starts with a minus sign, the integer will be negative."
  (if (not (string-match
	    "\\([-+]?[0-9]+\\):\\([0-9]\\{2\\}\\):\\([0-9]\\{2\\}\\)"
	    hms))
      0
    (let* ((h (string-to-number (match-string 1 hms)))
	   (m (string-to-number (match-string 2 hms)))
	   (s (string-to-number (match-string 3 hms)))
	   (sign (equal (substring (match-string 1 hms) 0 1) "-")))
      (setq h (abs h))
      (* (if sign -1 1) (+ s (* 60 (+ m (* 60 h))))))))

(defun org-timer-secs-to-hms (s)
  "Convert integer S into h:mm:ss.
If the integer is negative, the string will start with \"-\"."
  (let (sign m h)
    (setq sign (if (< s 0) "-" "")
	  s (abs s)
	  m (/ s 60) s (- s (* 60 m))
	  h (/ m 60) m (- m (* 60 h)))
    (format "%s%d:%02d:%02d" sign h m s)))

(defvar org-timer-mode-line-timer nil)
(defvar org-timer-mode-line-string nil)

(defun org-timer-set-mode-line (value)
  "Set the mode-line display of the relative timer.
VALUE can be `on', `off', or `pause'."
  (or global-mode-string (setq global-mode-string '("")))
  (or (memq 'org-timer-mode-line-string global-mode-string)
      (setq global-mode-string
	    (append global-mode-string '(org-timer-mode-line-string))))
  (cond
   ((equal value 'off)
    (when org-timer-mode-line-timer
      (cancel-timer org-timer-mode-line-timer)
      (setq org-timer-mode-line-timer nil))
    (setq global-mode-string
	  (delq 'org-timer-mode-line-string global-mode-string))
    (force-mode-line-update))
   ((equal value 'pause)
    (when org-timer-mode-line-timer
      (cancel-timer org-timer-mode-line-timer)
      (setq org-timer-mode-line-timer nil)))
   ((equal value 'on)
    (or global-mode-string (setq global-mode-string '("")))
    (or (memq 'org-timer-mode-line-string global-mode-string)
	(setq global-mode-string
	      (append global-mode-string '(org-timer-mode-line-string))))
    (org-timer-update-mode-line)
    (when org-timer-mode-line-timer
      (cancel-timer org-timer-mode-line-timer))
    (setq org-timer-mode-line-timer
	  (run-with-timer 1 1 'org-timer-update-mode-line)))))

(defun org-timer-update-mode-line ()
  "Update the timer time in the mode line."
  (if org-timer-pause-time
      nil
    (setq org-timer-mode-line-string
	  (concat " <" (substring (org-timer-value-string) 0 -1) ">"))
    (force-mode-line-update)))

(defvar org-timer-current-timer nil)
(defun org-timer-cancel-timer ()
  "Cancel the current timer."
  (interactive)
  (when (eval org-timer-current-timer)
    (run-hooks 'org-timer-cancel-hook)
    (cancel-timer org-timer-current-timer)
    (setq org-timer-current-timer nil)
    (setq org-timer-timer-is-countdown nil)
    (org-timer-set-mode-line 'off))
  (message "Last timer canceled"))

(defun org-timer-show-remaining-time ()
  "Display the remaining time before the timer ends."
  (interactive)
  (require 'time)
  (if (not org-timer-current-timer)
      (message "No timer set")
    (let* ((rtime (decode-time
		   (time-subtract (timer--time org-timer-current-timer)
				  (current-time))))
	   (rsecs (nth 0 rtime))
	   (rmins (nth 1 rtime)))
      (message "%d minute(s) %d seconds left before next time out"
	       rmins rsecs))))

;;;###autoload
(defun org-timer-set-timer (&optional opt)
  "Prompt for a duration and set a timer.

If `org-timer-default-timer' is not zero, suggest this value as
the default duration for the timer.  If a timer is already set,
prompt the user if she wants to replace it.

Called with a numeric prefix argument, use this numeric value as
the duration of the timer.

Called with a `C-u' prefix arguments, use `org-timer-default-timer'
without prompting the user for a duration.

With two `C-u' prefix arguments, use `org-timer-default-timer'
without prompting the user for a duration and automatically
replace any running timer."
  (interactive "P")
  (let ((minutes (or (and (numberp opt) (number-to-string opt))
		     (and (listp opt) (not (null opt))
			  (number-to-string org-timer-default-timer))
		     (read-from-minibuffer
		      "How many minutes left? "
		      (if (not (eq org-timer-default-timer 0))
			  (number-to-string org-timer-default-timer))))))
    (if (not (string-match "[0-9]+" minutes))
	(org-timer-show-remaining-time)
    (let* ((mins (string-to-number (match-string 0 minutes)))
	   (secs (* mins 60))
	   (hl (cond
		((string-match "Org Agenda" (buffer-name))
		 (let* ((marker (or (get-text-property (point) 'org-marker)
				    (org-agenda-error)))
			(hdmarker (or (get-text-property (point) 'org-hd-marker)
				      marker))
			(pos (marker-position marker)))
		   (with-current-buffer (marker-buffer marker)
		     (widen)
		     (goto-char pos)
		     (org-show-entry)
		     (or (ignore-errors (org-get-heading))
			 (concat "File:" (file-name-nondirectory (buffer-file-name)))))))
		((eq major-mode 'org-mode)
		 (or (ignore-errors (org-get-heading))
		     (concat "File:" (file-name-nondirectory (buffer-file-name)))))
		(t (error "Not in an Org buffer"))))
	   timer-set)
      (if (or (and org-timer-current-timer
		   (or (equal opt '(16))
		       (y-or-n-p "Replace current timer? ")))
	      (not org-timer-current-timer))
	  (progn
	    (require 'org-clock)
	    (when org-timer-current-timer
	      (cancel-timer org-timer-current-timer))
	    (setq org-timer-current-timer
		  (run-with-timer
		   secs nil `(lambda ()
			       (setq org-timer-current-timer nil)
			       (org-notify ,(format "%s: time out" hl) t)
			       (setq org-timer-timer-is-countdown nil)
			       (org-timer-set-mode-line 'off)
			       (run-hooks 'org-timer-done-hook))))
	    (run-hooks 'org-timer-set-hook)
	    (setq org-timer-timer-is-countdown t
		  org-timer-start-time
		  (time-add (current-time) (seconds-to-time (* mins 60))))
	    (org-timer-set-mode-line 'on))
	(message "No timer set"))))))

(provide 'org-timer)

;;; org-timer.el ends here