;;; org-clock.el --- The time clocking code for Org-mode

;; Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009
;;   Free Software Foundation, Inc.

;; Author: Carsten Dominik <carsten at orgmode dot org>
;; Keywords: outlines, hypermedia, calendar, wp
;; Homepage: http://orgmode.org
;; Version: 6.32
;;
;; 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 time clocking code for Org-mode

(require 'org)
(eval-when-compile
  (require 'cl)
  (require 'calendar))

(declare-function calendar-absolute-from-iso    "cal-iso"    (&optional date))
(defvar org-time-stamp-formats)

(defgroup org-clock nil
  "Options concerning clocking working time in Org-mode."
  :tag "Org Clock"
  :group 'org-progress)

(defcustom org-clock-into-drawer org-log-into-drawer
  "Should clocking info be wrapped into a drawer?
When t, clocking info will always be inserted into a :LOGBOOK: drawer.
If necessary, the drawer will be created.
When nil, the drawer will not be created, but used when present.
When an integer and the number of clocking entries in an item
reaches or exceeds this number, a drawer will be created.
When a string, it names the drawer to be used.

The default for this variable is the value of `org-log-into-drawer',
which see."
  :group 'org-todo
  :group 'org-clock
  :type '(choice
	  (const :tag "Always" t)
	  (const :tag "Only when drawer exists" nil)
	  (integer :tag "When at least N clock entries")
	  (const :tag "Into LOGBOOK drawer" "LOGBOOK")
	  (string :tag "Into Drawer named...")))

(defcustom org-clock-out-when-done t
  "When non-nil, clock will be stopped when the clocked entry is marked DONE.
A nil value means, clock will keep running until stopped explicitly with
`C-c C-x C-o', or until the clock is started in a different item."
  :group 'org-clock
  :type 'boolean)

(defcustom org-clock-out-remove-zero-time-clocks nil
  "Non-nil means, remove the clock line when the resulting time is zero."
  :group 'org-clock
  :type 'boolean)

(defcustom org-clock-in-switch-to-state nil
  "Set task to a special todo state while clocking it.
The value should be the state to which the entry should be
switched. If the value is a function, it must take one
parameter (the current TODO state of the item) and return the
state to switch it to."
  :group 'org-clock
  :group 'org-todo
  :type '(choice
	  (const :tag "Don't force a state" nil)
	  (string :tag "State")
	  (symbol :tag "Function")))

(defcustom org-clock-out-switch-to-state nil
  "Set task to a special todo state after clocking out.
The value should be the state to which the entry should be
switched. If the value is a function, it must take one
parameter (the current TODO state of the item) and return the
state to switch it to."
  :group 'org-clock
  :group 'org-todo
  :type '(choice
	  (const :tag "Don't force a state" nil)
	  (string :tag "State")
	  (symbol :tag "Function")))

(defcustom org-clock-history-length 5
  "Number of clock tasks to remember in history."
  :group 'org-clock
  :type 'integer)

(defcustom org-clock-goto-may-find-recent-task t
  "Non-nil means, `org-clock-goto' can go to recent task if no active clock."
  :group 'org-clock
  :type 'boolean)

(defcustom org-clock-heading-function nil
  "When non-nil, should be a function to create `org-clock-heading'.
This is the string shown in the mode line when a clock is running.
The function is called with point at the beginning of the headline."
  :group 'org-clock
  :type 'function)

(defcustom org-clock-string-limit 0
  "Maximum length of clock strings in the modeline. 0 means no limit."
  :group 'org-clock
  :type 'integer)

(defcustom org-clock-in-resume nil
  "If non-nil, resume clock when clocking into task with open clock.
When clocking into a task with a clock entry which has not been closed,
the clock can be resumed from that point."
  :group 'org-clock
  :type 'boolean)

(defcustom org-clock-persist nil
  "When non-nil, save the running clock when emacs is closed.
The clock is resumed when emacs restarts.
When this is t, both the running clock, and the entire clock
history are saved.  When this is the symbol `clock', only the
running clock is saved.

When Emacs restarts with saved clock information, the file containing the
running clock as well as all files mentioned in the clock history will
be visited.
All this depends on running `org-clock-persistence-insinuate' in .emacs"
  :group 'org-clock
  :type '(choice
	  (const :tag "Just the running clock" clock)
	  (const :tag "Just the history" history)
	  (const :tag "Clock and history" t)
	  (const :tag "No persistence" nil)))

(defcustom org-clock-persist-file (convert-standard-filename
				   "~/.emacs.d/org-clock-save.el")
  "File to save clock data to."
  :group 'org-clock
  :type 'string)

(defcustom org-clock-persist-query-save nil
  "When non-nil, ask before saving the current clock on exit."
  :group 'org-clock
  :type 'boolean)

(defcustom org-clock-persist-query-resume t
  "When non-nil, ask before resuming any stored clock during load."
  :group 'org-clock
  :type 'boolean)

(defcustom org-clock-sound nil
  "Sound that will used for notifications.
Possible values:

nil        no sound played.
t          standard Emacs beep
file name  play this sound file.  If not possible, fall back to beep"
  :group 'org-clock
  :type '(choice
	  (const :tag "No sound" nil)
	  (const :tag "Standard beep" t)
	  (file :tag "Play sound file")))

(defcustom org-clock-modeline-total 'auto
  "Default setting for the time included for the modeline clock.
This can be overruled locally using the CLOCK_MODELINE_TOTAL property.
Allowed values are:

current  Only the time in the current instance of the clock
today    All time clocked inot this task today
repeat   All time clocked into this task since last repeat
all      All time ever recorded for this task
auto     Automatically, either `all', or `repeat' for repeating tasks"
  :group 'org-clock
  :type '(choice
	  (const :tag "Current clock" current)
	  (const :tag "Today's task time" today)
	  (const :tag "Since last repeat" repeat)
	  (const :tag "All task time" all)
	  (const :tag "Automatically, `all' or since `repeat'" auto)))

(defcustom org-show-notification-handler nil
  "Function or program to send notification with.
The function or program will be called with the notification
string as argument."
  :group 'org-clock
  :type '(choice
	  (string :tag "Program")
	  (function :tag "Function")))

(defcustom org-clock-clocktable-default-properties '(:maxlevel 2 :scope file)
  "Default properties for new clocktables."
  :group 'org-clock
  :type 'plist)

(defcustom org-clock-idle-time nil
  "When non-nil, resolve open clocks if the user is idle more than X minutes."
  :group 'org-clock
  :type '(choice
	  (const :tag "Never" nil)
	  (integer :tag "After N minutes")))

(defcustom org-clock-auto-clock-resolution 'when-no-clock-is-running
  "When to automatically resolve open clocks found in Org buffers."
  :group 'org-clock
  :type '(choice
	  (const :tag "Never" nil)
	  (const :tag "Always" t)
	  (const :tag "When no clock is running" when-no-clock-is-running)))

(defvar org-clock-in-prepare-hook nil
  "Hook run when preparing the clock.
This hook is run before anything happens to the task that
you want to clock in.  For example, you can use this hook
to add an effort property.")
(defvar org-clock-in-hook nil
  "Hook run when starting the clock.")
(defvar org-clock-out-hook nil
  "Hook run when stopping the current clock.")

(defvar org-clock-cancel-hook nil
  "Hook run when cancelling the current clock.")
(defvar org-clock-goto-hook nil
  "Hook run when selecting the currently clocked-in entry.")
(defvar org-clock-has-been-used nil
  "Has the clock been used during the current Emacs session?")

;;; The clock for measuring work time.

(defvar org-mode-line-string "")
(put 'org-mode-line-string 'risky-local-variable t)

(defvar org-clock-mode-line-timer nil)
(defvar org-clock-idle-timer nil)
(defvar org-clock-heading "")
(defvar org-clock-heading-for-remember "")
(defvar org-clock-start-time "")

(defvar org-clock-left-over-time nil
  "If non-nil, user cancelled a clock; this is when leftover time started.")

(defvar org-clock-effort ""
  "Effort estimate of the currently clocking task")

(defvar org-clock-total-time nil
  "Holds total time, spent previously on currently clocked item.
This does not include the time in the currently running clock.")

(defvar org-clock-history nil
  "List of marker pointing to recent clocked tasks.")

(defvar org-clock-default-task (make-marker)
  "Marker pointing to the default task that should clock time.
The clock can be made to switch to this task after clocking out
of a different task.")

(defvar org-clock-interrupted-task (make-marker)
  "Marker pointing to the task that has been interrupted by the current clock.")

(defvar org-clock-mode-line-map (make-sparse-keymap))
(define-key org-clock-mode-line-map [mode-line mouse-2] 'org-clock-goto)
(define-key org-clock-mode-line-map [mode-line mouse-1] 'org-clock-menu)

(defun org-clock-menu ()
  (interactive)
  (popup-menu
   '("Clock"
     ["Clock out" org-clock-out t]
     ["Change effort estimate" org-clock-modify-effort-estimate t]
     ["Go to clock entry" org-clock-goto t]
     ["Switch task" (lambda () (interactive) (org-clock-in '(4))) :active t :keys "C-u C-c C-x C-i"])))

(defun org-clock-history-push (&optional pos buffer)
  "Push a marker to the clock history."
  (setq org-clock-history-length (max 1 (min 35 org-clock-history-length)))
  (let ((m (move-marker (make-marker) (or pos (point)) buffer)) n l)
    (while (setq n (member m org-clock-history))
      (move-marker (car n) nil))
    (setq org-clock-history
	  (delq nil
		(mapcar (lambda (x) (if (marker-buffer x) x nil))
			org-clock-history)))
    (when (>= (setq l (length org-clock-history)) org-clock-history-length)
      (setq org-clock-history
	    (nreverse
	     (nthcdr (- l org-clock-history-length -1)
		     (nreverse org-clock-history)))))
    (push m org-clock-history)))

(defun org-clock-save-markers-for-cut-and-paste (beg end)
  "Save relative positions of markers in region."
  (org-check-and-save-marker org-clock-marker beg end)
  (org-check-and-save-marker org-clock-hd-marker beg end)
  (org-check-and-save-marker org-clock-default-task beg end)
  (org-check-and-save-marker org-clock-interrupted-task beg end)
  (mapc (lambda (m) (org-check-and-save-marker m beg end))
	org-clock-history))

(defun org-clock-select-task (&optional prompt)
  "Select a task that recently was associated with clocking."
  (interactive)
  (let (sel-list rpl (i 0) s)
    (save-window-excursion
      (org-switch-to-buffer-other-window
       (get-buffer-create "*Clock Task Select*"))
      (erase-buffer)
      (when (marker-buffer org-clock-default-task)
	(insert (org-add-props "Default Task\n" nil 'face 'bold))
	(setq s (org-clock-insert-selection-line ?d org-clock-default-task))
	(push s sel-list))
      (when (marker-buffer org-clock-interrupted-task)
	(insert (org-add-props "The task interrupted by starting the last one\n" nil 'face 'bold))
	(setq s (org-clock-insert-selection-line ?i org-clock-interrupted-task))
	(push s sel-list))
      (when (marker-buffer org-clock-marker)
	(insert (org-add-props "Current Clocking Task\n" nil 'face 'bold))
	(setq s (org-clock-insert-selection-line ?c org-clock-marker))
	(push s sel-list))
      (insert (org-add-props "Recent Tasks\n" nil 'face 'bold))
      (mapc
       (lambda (m)
	 (when (marker-buffer m)
	   (setq i (1+ i)
		 s (org-clock-insert-selection-line
		    (if (< i 10)
			(+ i ?0)
		      (+ i (- ?A 10))) m))
	   (push s sel-list)))
       org-clock-history)
      (org-fit-window-to-buffer)
      (message (or prompt "Select task for clocking:"))
      (setq rpl (read-char-exclusive))
      (cond
       ((eq rpl ?q) nil)
       ((eq rpl ?x) nil)
       ((assoc rpl sel-list) (cdr (assoc rpl sel-list)))
       (t (error "Invalid task choice %c" rpl))))))

(defun org-clock-insert-selection-line (i marker)
  "Insert a line for the clock selection menu.
And return a cons cell with the selection character integer and the marker
pointing to it."
  (when (marker-buffer marker)
    (let (file cat task heading prefix)
      (with-current-buffer (org-base-buffer (marker-buffer marker))
	(save-excursion
	  (save-restriction
	    (widen)
	    (goto-char marker)
	    (setq file (buffer-file-name (marker-buffer marker))
		  cat (or (org-get-category)
			  (progn (org-refresh-category-properties)
				 (org-get-category)))
		  heading (org-get-heading 'notags)
		  prefix (save-excursion
			   (org-back-to-heading t)
			   (looking-at "\\*+ ")
			   (match-string 0))
		  task (substring
			(org-fontify-like-in-org-mode
			 (concat prefix heading)
			 org-odd-levels-only)
			(length prefix))))))
      (when (and cat task)
	(insert (format "[%c] %-15s %s\n" i cat task))
	(cons i marker)))))

(defun org-clock-get-clock-string ()
  "Form a clock-string, that will be show in the mode line.
If an effort estimate was defined for current item, use
01:30/01:50 format (clocked/estimated).
If not, show simply the clocked time like 01:50."
  (let* ((clocked-time (org-clock-get-clocked-time))
	 (h (floor clocked-time 60))
	 (m (- clocked-time (* 60 h))))
    (if (and org-clock-effort)
	(let* ((effort-in-minutes (org-hh:mm-string-to-minutes org-clock-effort))
	       (effort-h (floor effort-in-minutes 60))
	       (effort-m (- effort-in-minutes (* effort-h 60))))
	  (format (concat "-[" org-time-clocksum-format "/" org-time-clocksum-format " (%s)]")
		  h m effort-h effort-m  org-clock-heading))
      (format (concat "-[" org-time-clocksum-format " (%s)]")
	      h m org-clock-heading))))

(defun org-clock-update-mode-line ()
  (setq org-mode-line-string
	(org-propertize
	 (let ((clock-string (org-clock-get-clock-string))
	       (help-text "Org-mode clock is running.\nmouse-1 shows a menu\nmouse-2 will jump to task"))
	   (if (and (> org-clock-string-limit 0)
		    (> (length clock-string) org-clock-string-limit))
	       (org-propertize (substring clock-string 0 org-clock-string-limit)
			       'help-echo (concat help-text ": " org-clock-heading))
	     (org-propertize clock-string 'help-echo help-text)))
	 'local-map org-clock-mode-line-map
	 'mouse-face (if (featurep 'xemacs) 'highlight 'mode-line-highlight)
	 'face 'org-mode-line-clock))
  (if org-clock-effort (org-clock-notify-once-if-expired))
  (force-mode-line-update))

(defun org-clock-get-clocked-time ()
  "Get the clocked time for the current item in minutes.
The time returned includes the time spent on this task in
previous clocking intervals."
  (let ((currently-clocked-time
	 (floor (- (org-float-time)
		   (org-float-time org-clock-start-time)) 60)))
    (+ currently-clocked-time (or org-clock-total-time 0))))

(defun org-clock-modify-effort-estimate (&optional value)
 "Add to or set the effort estimate of the item currently being clocked.
VALUE can be a number of minutes, or a string with forat hh:mm or mm.
WHen the strig starts with a + or a - sign, the current value of the effort
property will be changed by that amount.
This will update the \"Effort\" property of currently clocked item, and
the mode line."
 (interactive)
 (when (org-clock-is-active)
   (let ((current org-clock-effort) sign)
     (unless value
       ;; Prompt user for a value or a change
       (setq value
	     (read-string
	      (format "Set effort (hh:mm or mm%s): "
		      (if current
			  (format ", prefix + to add to %s" org-clock-effort)
			"")))))
     (when (stringp value)
       ;; A string.  See if it is a delta
       (setq sign (string-to-char value))
       (if (member sign '(?- ?+))
	   (setq current (org-hh:mm-string-to-minutes (substring current 1)))
	 (setq current 0))
       (setq value (org-hh:mm-string-to-minutes value))
       (if (equal ?- sign)
	   (setq value (- current value))
	 (if (equal ?+ sign) (setq value (+ current value)))))
     (setq value (max 0 value)
	   org-clock-effort (org-minutes-to-hh:mm-string value))
     (org-entry-put org-clock-marker "Effort" org-clock-effort)
     (org-clock-update-mode-line)
     (message "Effort is now %s" org-clock-effort))))

(defvar org-clock-notification-was-shown nil
  "Shows if we have shown notification already.")

(defun org-clock-notify-once-if-expired ()
  "Show notification if we spent more time than we estimated before.
Notification is shown only once."
  (when (marker-buffer org-clock-marker)
    (let ((effort-in-minutes (org-hh:mm-string-to-minutes org-clock-effort))
	  (clocked-time (org-clock-get-clocked-time)))
      (if (>= clocked-time effort-in-minutes)
	  (unless org-clock-notification-was-shown
	    (setq org-clock-notification-was-shown t)
	    (org-notify
	     (format "Task '%s' should be finished by now. (%s)"
		     org-clock-heading org-clock-effort) t))
	(setq org-clock-notification-was-shown nil)))))

(defun org-notify (notification &optional play-sound)
  "Send a NOTIFICATION and maybe PLAY-SOUND."
  (org-show-notification notification)
  (if play-sound (org-clock-play-sound)))

(defun org-show-notification (notification)
  "Show notification.
Use `org-show-notification-handler' if defined,
use libnotify if available, or fall back on a message."
  (cond ((functionp org-show-notification-handler)
	 (funcall org-show-notification-handler notification))
	((stringp org-show-notification-handler)
	 (start-process "emacs-timer-notification" nil
			org-show-notification-handler notification))
	((org-program-exists "notify-send")
	 (start-process "emacs-timer-notification" nil
			"notify-send" notification))
	;; Maybe the handler will send a message, so only use message as
	;; a fall back option
	(t (message notification))))

(defun org-clock-play-sound ()
  "Play sound as configured by `org-clock-sound'.
Use alsa's aplay tool if available."
  (cond
   ((not org-clock-sound))
   ((eq org-clock-sound t) (beep t) (beep t))
   ((stringp org-clock-sound)
    (if (file-exists-p org-clock-sound)
	(if (org-program-exists "aplay")
	    (start-process "org-clock-play-notification" nil
			   "aplay" org-clock-sound)
	  (condition-case nil
	      (play-sound-file org-clock-sound)
	    (error (beep t) (beep t))))))))

(defun org-program-exists (program-name)
  "Checks whenever we can locate program and launch it."
  (if (eq system-type 'gnu/linux)
      (= 0 (call-process "which" nil nil nil program-name))))

(defvar org-clock-mode-line-entry nil
  "Information for the modeline about the running clock.")

(defun org-find-open-clocks (file)
  "Search through the given file and find all open clocks."
  (let ((buf (or (get-file-buffer file)
		 (find-file-noselect file)))
	clocks)
    (with-current-buffer buf
      (save-excursion
	(goto-char (point-min))
	(while (re-search-forward "CLOCK: \\(\\[.*?\\]\\)$" nil t)
	  (push (cons (copy-marker (1- (match-end 1)) t)
		      (org-time-string-to-time (match-string 1))) clocks))))
    clocks))

(defsubst org-is-active-clock (clock)
  "Return t if CLOCK is the currently active clock."
  (and (org-clock-is-active)
       (= org-clock-marker (car clock))))

(defmacro org-with-clock-position (clock &rest forms)
  "Evaluate FORMS with CLOCK as the current active clock."
  `(with-current-buffer (marker-buffer (car ,clock))
     (save-excursion
       (save-restriction
	 (widen)
	 (goto-char (car ,clock))
	 (beginning-of-line)
	 ,@forms))))

(put 'org-with-clock-position 'lisp-indent-function 1)

(defmacro org-with-clock (clock &rest forms)
  "Evaluate FORMS with CLOCK as the current active clock.
This macro also protects the current active clock from being altered."
  `(org-with-clock-position ,clock
     (let ((org-clock-start-time (cdr ,clock))
	   (org-clock-total-time)
	   (org-clock-history)
	   (org-clock-effort)
	   (org-clock-marker (car ,clock))
	   (org-clock-hd-marker (save-excursion
				  (outline-back-to-heading t)
				  (point-marker))))
       ,@forms)))

(put 'org-with-clock 'lisp-indent-function 1)

(defsubst org-clock-clock-in (clock &optional resume)
  "Clock in to the clock located by CLOCK.
If necessary, clock-out of the currently active clock."
  (org-with-clock-position clock
    (let ((org-clock-in-resume (or resume org-clock-in-resume)))
      (org-clock-in))))

(defsubst org-clock-clock-out (clock &optional fail-quietly at-time)
  "Clock out of the clock located by CLOCK."
  (let ((temp (copy-marker (car clock)
			   (marker-insertion-type (car clock)))))
    (if (org-is-active-clock clock)
	(org-clock-out fail-quietly at-time)
      (org-with-clock clock
	(org-clock-out fail-quietly at-time)))
    (setcar clock temp)))

(defsubst org-clock-clock-cancel (clock)
  "Cancel the clock located by CLOCK."
  (let ((temp (copy-marker (car clock)
			   (marker-insertion-type (car clock)))))
    (if (org-is-active-clock clock)
	(org-clock-cancel)
      (org-with-clock clock
	(org-clock-cancel)))
    (setcar clock temp)))

(defvar org-clock-clocking-in nil)
(defvar org-clock-resolving-clocks nil)
(defvar org-clock-resolving-clocks-due-to-idleness nil)

(defun org-clock-resolve-clock (clock resolve-to &optional close-p
				      restart-p fail-quietly)
  "Resolve `CLOCK' given the time `RESOLVE-TO', and the present.
`CLOCK' is a cons cell of the form (MARKER START-TIME).
This routine can do one of many things:

  if `RESOLVE-TO' is nil
    if `CLOSE-P' is non-nil, give an error
    if this clock is the active clock, cancel it
    else delete the clock line (as if it never happened)
    if `RESTART-P' is non-nil, start a new clock

  else if `RESOLVE-TO' is the symbol `now'
    if `RESTART-P' is non-nil, give an error
    if `CLOSE-P' is non-nil, clock out the entry and
       if this clock is the active clock, stop it
    else if this clock is the active clock, do nothing
    else if there is no active clock, resume this clock
    else ask to cancel the active clock, and if so,
         resume this clock after cancelling it

  else if `RESOLVE-TO' is some date in the future
    give an error about `RESOLVE-TO' being invalid

  else if `RESOLVE-TO' is some date in the past
    if `RESTART-P' is non-nil, give an error
    if `CLOSE-P' is non-nil, enter a closing time and
       if this clock is the active clock, stop it
    else if this clock is the active clock, enter a
       closing time, stop the current clock, then
       start a new clock for the same item
    else just enter a closing time for this clock
       and then start a new clock for the same item"
  (let ((org-clock-resolving-clocks t))
    (cond
     ((null resolve-to)
      (org-clock-clock-cancel clock)
      (if (and restart-p (not org-clock-clocking-in))
	  (org-clock-clock-in clock)))

     ((eq resolve-to 'now)
      (if restart-p
	  (error "RESTART-P is not valid here"))
      (if (or close-p org-clock-clocking-in)
	  (org-clock-clock-out clock fail-quietly)
	(unless (org-is-active-clock clock)
	  (org-clock-clock-in clock t))))

     ((not (time-less-p resolve-to (current-time)))
      (error "RESOLVE-TO must refer to a time in the past"))

     (t
      (if restart-p
	  (error "RESTART-P is not valid here"))
      (org-clock-clock-out clock fail-quietly resolve-to)
      (unless org-clock-clocking-in
	(if close-p
	    (setq org-clock-left-over-time resolve-to)
	  (org-clock-clock-in clock)))))))

(defun org-clock-resolve (clock &optional prompt-fn last-valid fail-quietly)
  "Resolve an open org-mode clock.
An open clock was found, with `dangling' possibly being non-nil.
If this function was invoked with a prefix argument, non-dangling
open clocks are ignored.  The given clock requires some sort of
user intervention to resolve it, either because a clock was left
dangling or due to an idle timeout.  The clock resolution can
either be:

  (a) deleted, the user doesn't care about the clock
  (b) restarted from the current time (if no other clock is open)
  (c) closed, giving the clock X minutes
  (d) closed and then restarted
  (e) resumed, as if the user had never left

The format of clock is (CONS MARKER START-TIME), where MARKER
identifies the buffer and position the clock is open at (and
thus, the heading it's under), and START-TIME is when the clock
was started."
  (assert clock)
  (let* ((ch
	  (save-window-excursion
	    (save-excursion
	      (unless org-clock-resolving-clocks-due-to-idleness
		(org-with-clock clock
		  (org-clock-goto))
		(with-current-buffer (marker-buffer (car clock))
		  (goto-char (car clock))
		  (if org-clock-into-drawer
		      (ignore-errors
			(outline-flag-region (save-excursion
					       (outline-back-to-heading t)
					       (search-forward ":LOGBOOK:")
					       (goto-char (match-beginning 0)))
					     (save-excursion
					       (outline-back-to-heading t)
					       (search-forward ":LOGBOOK:")
					       (search-forward ":END:")
					       (goto-char (match-end 0)))
					     nil)))))
	      (let (char-pressed)
		(while (null char-pressed)
		  (setq char-pressed
			(read-char (concat (funcall prompt-fn clock)
					   " [(kK)eep (sS)ubtract (C)ancel]? ")
				   nil 45)))
		char-pressed))))
	 (default (floor (/ (org-float-time
			     (time-subtract (current-time) last-valid)) 60)))
	 (keep (and (memq ch '(?k ?K))
		    (read-number "Keep how many minutes? " default)))
	 (subtractp (memq ch '(?s ?S)))
	 (barely-started-p (< (- (org-float-time last-valid)
				 (org-float-time (cdr clock))) 45))
	 (start-over (and subtractp barely-started-p)))
    (if (or (null ch)
	    (not (memq ch '(?k ?K ?s ?S ?C))))
	(message "")
      (org-clock-resolve-clock
       clock (cond
	      ((or (eq ch ?C)
		   ;; If the time on the clock was less than a minute before
		   ;; the user went away, and they've ask to subtract all the
		   ;; time...
		   start-over)
	       nil)
	      (subtractp
	       last-valid)
	      ((= keep default)
	       'now)
	      (t
	       (time-add last-valid (seconds-to-time (* 60 keep)))))
       (memq ch '(?K ?S))
       (and start-over
	    (not (memq ch '(?K ?S ?C))))
       fail-quietly))))

(defun org-resolve-clocks (&optional also-non-dangling-p prompt-fn last-valid)
  "Resolve all currently open org-mode clocks.
If `also-non-dangling-p' is non-nil, also ask to resolve
non-dangling (i.e., currently open and valid) clocks."
  (interactive "P")
  (unless org-clock-resolving-clocks
    (let ((org-clock-resolving-clocks t))
      (dolist (file (org-agenda-files))
	(let ((clocks (org-find-open-clocks file)))
	  (dolist (clock clocks)
	    (let ((dangling (or (not (org-clock-is-active))
				(/= (car clock) org-clock-marker))))
	      (unless (and (not dangling) (not also-non-dangling-p))
		(org-clock-resolve
		 clock
		 (or prompt-fn
		     (function
		      (lambda (clock)
			(format
			 "Dangling clock started %d mins ago"
			 (floor
			  (/ (- (org-float-time (current-time))
				(org-float-time (cdr clock))) 60))))))
		 (or last-valid
		     (cdr clock)))))))))))

(defun org-emacs-idle-seconds ()
  "Return the current Emacs idle time in seconds, or nil if not idle."
  (let ((idle-time (current-idle-time)))
    (if idle-time
	(org-float-time idle-time)
      0)))

(defun org-mac-idle-seconds ()
  "Return the current Mac idle time in seconds"
  (string-to-number (shell-command-to-string "ioreg -c IOHIDSystem | perl -ane 'if (/Idle/) {$idle=(pop @F)/1000000000; print $idle; last}'")))

(defun org-x11-idle-seconds ()
  "Return the current X11 idle time in seconds"
  (/ (string-to-number (shell-command-to-string "x11idle")) 1000))

(defun org-user-idle-seconds ()
  "Return the number of seconds the user has been idle for.
This routine returns a floating point number."
  (if (or (eq system-type 'darwin) (eq window-system 'x))
      (let ((emacs-idle (org-emacs-idle-seconds)))
	;; If Emacs has been idle for longer than the user's
	;; `org-clock-idle-time' value, check whether the whole system has
	;; really been idle for that long.
	(if (> emacs-idle (* 60 org-clock-idle-time))
	    (min emacs-idle (if (eq system-type 'darwin)
				(org-mac-idle-seconds)
			      (org-x11-idle-seconds)))
	  emacs-idle))
    (org-emacs-idle-seconds)))

(defvar org-clock-user-idle-seconds)

(defun org-resolve-clocks-if-idle ()
  "Resolve all currently open org-mode clocks.
This is performed after `org-clock-idle-time' minutes, to check
if the user really wants to stay clocked in after being idle for
so long."
  (when (and org-clock-idle-time (not org-clock-resolving-clocks)
	     org-clock-marker)
    (let ((org-clock-user-idle-seconds (org-user-idle-seconds))
	  (org-clock-resolving-clocks-due-to-idleness t))
      (if (> org-clock-user-idle-seconds (* 60 org-clock-idle-time))
	  (org-clock-resolve
	   (cons org-clock-marker
		 org-clock-start-time)
	   (function
	    (lambda (clock)
	      (format "Clocked in & idle for %d mins"
		      (/ org-clock-user-idle-seconds 60))))
	   (time-subtract (current-time)
			  (seconds-to-time org-clock-user-idle-seconds)))))))

(defun org-clock-in (&optional select)
  "Start the clock on the current item.
If necessary, clock-out of the currently active clock.
With prefix arg SELECT, offer a list of recently clocked tasks to
clock into.  When SELECT is `C-u C-u', clock into the current task and mark
is as the default task, a special task that will always be offered in
the clocking selection, associated with the letter `d'."
  (interactive "P")
  (setq org-clock-notification-was-shown nil)
  (catch 'abort
    (let ((interrupting (and (not org-clock-resolving-clocks-due-to-idleness)
			     (marker-buffer org-clock-marker)))
	  ts selected-task target-pos (msg-extra "")
	  (left-over (and (not org-clock-resolving-clocks)
			  org-clock-left-over-time)))
      (when (and org-clock-auto-clock-resolution
		 (or (not interrupting)
		     (eq t org-clock-auto-clock-resolution))
		 (not org-clock-clocking-in)
		 (not org-clock-resolving-clocks))
	(setq org-clock-left-over-time nil)
	(let ((org-clock-clocking-in t))
	  (org-resolve-clocks)))	; check if any clocks are dangling
      (when (equal select '(4))
	(setq selected-task (org-clock-select-task "Clock-in on task: "))
	(if selected-task
	    (setq selected-task (copy-marker selected-task))
	  (error "Abort")))
      (when interrupting
	;; We are interrupting the clocking of a different task.
	;; Save a marker to this task, so that we can go back.
	(move-marker org-clock-interrupted-task
		     (marker-position org-clock-marker)
		     (marker-buffer org-clock-marker))
	(org-clock-out t))
      
      (when (equal select '(16))
	;; Mark as default clocking task
	(org-clock-mark-default-task))
      
      ;; Clock in at which position?
      (setq target-pos
	    (if (and (eobp) (not (org-on-heading-p)))
		(point-at-bol 0)
	      (point)))
      (run-hooks 'org-clock-in-prepare-hook)
      (save-excursion
	(when (and selected-task (marker-buffer selected-task))
	  ;; There is a selected task, move to the correct buffer
	  ;; and set the new target position.
	  (set-buffer (org-base-buffer (marker-buffer selected-task)))
	  (setq target-pos (marker-position selected-task))
	  (move-marker selected-task nil))
	(save-excursion
	  (save-restriction
	    (widen)
	    (goto-char target-pos)
	    (org-back-to-heading t)
	    (or interrupting (move-marker org-clock-interrupted-task nil))
	    (org-clock-history-push)
	    (cond ((functionp org-clock-in-switch-to-state)
		   (looking-at org-complex-heading-regexp)
		   (let ((newstate (funcall org-clock-in-switch-to-state
					    (match-string 2))))
		     (if newstate (org-todo newstate))))
		  ((and org-clock-in-switch-to-state
			(not (looking-at (concat outline-regexp "[ \t]*"
						 org-clock-in-switch-to-state
						 "\\>"))))
		   (org-todo org-clock-in-switch-to-state)))
	    (setq org-clock-heading-for-remember
		  (and (looking-at org-complex-heading-regexp)
		       (match-end 4)
		       (org-trim (buffer-substring (match-end 1)
						   (match-end 4)))))
	    (setq org-clock-heading
		  (cond ((and org-clock-heading-function
			      (functionp org-clock-heading-function))
			 (funcall org-clock-heading-function))
			((looking-at org-complex-heading-regexp)
			 (match-string 4))
			(t "???")))
	    (setq org-clock-heading (org-propertize org-clock-heading
						    'face nil))
	    (org-clock-find-position org-clock-in-resume)
	    (cond
	     ((and org-clock-in-resume
		   (looking-at
		    (concat "^[ \t]* " org-clock-string
			    " \\[\\([0-9]\\{4\\}-[0-9]\\{2\\}-[0-9]\\{2\\}"
			    " +\\sw+\.? +[012][0-9]:[0-5][0-9]\\)\\][ \t]*$")))
	      (message "Matched %s" (match-string 1))
	      (setq ts (concat "[" (match-string 1) "]"))
	      (goto-char (match-end 1))
	      (setq org-clock-start-time
		    (apply 'encode-time
			   (org-parse-time-string (match-string 1))))
	      (setq org-clock-effort (org-get-effort))
	      (setq org-clock-total-time (org-clock-sum-current-item
					  (org-clock-get-sum-start))))
	     ((eq org-clock-in-resume 'auto-restart)
	      ;; called from org-clock-load during startup,
	      ;; do not interrupt, but warn!
	      (message "Cannot restart clock because task does not contain unfinished clock")
	      (ding)
	      (sit-for 2)
	      (throw 'abort nil))
	     (t
	      (insert-before-markers "\n")
	      (backward-char 1)
	      (org-indent-line-function)
	      (when (and (save-excursion
			   (end-of-line 0)
			   (org-in-item-p)))
		(beginning-of-line 1)
		(org-indent-line-to (- (org-get-indentation) 2)))
	      (insert org-clock-string " ")
	      (setq org-clock-effort (org-get-effort))
	      (setq org-clock-total-time (org-clock-sum-current-item
					  (org-clock-get-sum-start)))
	      (setq org-clock-start-time
		    (or (and left-over
			     (y-or-n-p
			      (format
			       "You stopped another clock %d mins ago; start this one from then? "
			       (/ (- (org-float-time (current-time))
				     (org-float-time left-over)) 60)))
			     left-over)
			(current-time)))
	      (setq ts (org-insert-time-stamp org-clock-start-time
					      'with-hm 'inactive))))
	    (move-marker org-clock-marker (point) (buffer-base-buffer))
	    (move-marker org-clock-hd-marker
			 (save-excursion (org-back-to-heading t) (point))
			 (buffer-base-buffer))
	    (setq org-clock-has-been-used t)
	    (or global-mode-string (setq global-mode-string '("")))
	    (or (memq 'org-mode-line-string global-mode-string)
		(setq global-mode-string
		      (append global-mode-string '(org-mode-line-string))))
	    (org-clock-update-mode-line)
	    (when org-clock-mode-line-timer
	      (cancel-timer org-clock-mode-line-timer)
	      (setq org-clock-mode-line-timer nil))
	    (setq org-clock-mode-line-timer
		  (run-with-timer 60 60 'org-clock-update-mode-line))
	    (when org-clock-idle-timer
	      (cancel-timer org-clock-idle-timer)
	      (setq org-clock-idle-timer nil))
	    (setq org-clock-idle-timer
		  (run-with-timer 60 60 'org-resolve-clocks-if-idle))
	    (message "Clock starts at %s - %s" ts msg-extra)
	    (run-hooks 'org-clock-in-hook)))))))

(defun org-clock-mark-default-task ()
  "Mark current task as default task."
  (interactive)
  (save-excursion
    (org-back-to-heading t)
    (move-marker org-clock-default-task (point))))

(defvar msg-extra)
(defun org-clock-get-sum-start ()
  "Return the time from which clock times should be counted.
This is for the currently running clock as it is displayed
in the mode line.  This function looks at the properties
LAST_REPEAT and in particular CLOCK_MODELINE_TOTAL and the
corresponding variable `org-clock-modeline-total' and then
decides which time to use."
  (let ((cmt (or (org-entry-get nil "CLOCK_MODELINE_TOTAL")
		 (symbol-name org-clock-modeline-total)))
	(lr (org-entry-get nil "LAST_REPEAT")))
    (cond
     ((equal cmt "current")
      (setq msg-extra "showing time in current clock instance")
      (current-time))
     ((equal cmt "today")
      (setq msg-extra "showing today's task time.")
      (let* ((dt (decode-time (current-time))))
	(setq dt (append (list 0 0 0) (nthcdr 3 dt)))
	(if org-extend-today-until
	    (setf (nth 2 dt) org-extend-today-until))
	(apply 'encode-time dt)))
     ((or (equal cmt "all")
	  (and (or (not cmt) (equal cmt "auto"))
	       (not lr)))
      (setq msg-extra "showing entire task time.")
      nil)
     ((or (equal cmt "repeat")
	  (and (or (not cmt) (equal cmt "auto"))
	       lr))
      (setq msg-extra "showing task time since last repeat.")
      (if (not lr)
	  nil
	(org-time-string-to-time lr)))
     (t nil))))

(defun org-clock-find-position (find-unclosed)
  "Find the location where the next clock line should be inserted.
When FIND-UNCLOSED is non-nil, first check if there is an unclosed clock
line and position cursor in that line."
  (org-back-to-heading t)
  (catch 'exit
    (let ((beg (save-excursion
		 (beginning-of-line 2)
		 (or (bolp) (newline))
		 (point)))
	  (end (progn (outline-next-heading) (point)))
	  (re (concat "^[ \t]*" org-clock-string))
	  (cnt 0)
	  (drawer (if (stringp org-clock-into-drawer)
		      org-clock-into-drawer "LOGBOOK"))
	  first last ind-last)
      (goto-char beg)
      (when (and find-unclosed
		 (re-search-forward
		  (concat "^[ \t]* " org-clock-string
			  " \\[\\([0-9]\\{4\\}-[0-9]\\{2\\}-[0-9]\\{2\\}"
			  " +\\sw+ +[012][0-9]:[0-5][0-9]\\)\\][ \t]*$")
		  end t))
	(beginning-of-line 1)
	(throw 'exit t))
      (when (eobp) (newline) (setq end (max (point) end)))
      (when (re-search-forward (concat "^[ \t]*:" drawer ":") end t)
	;; we seem to have a CLOCK drawer, so go there.
	(beginning-of-line 2)
	(or org-log-states-order-reversed
	    (and (re-search-forward org-property-end-re nil t)
		 (goto-char (match-beginning 0))))
	(throw 'exit t))
      ;; Lets count the CLOCK lines
      (goto-char beg)
      (while (re-search-forward re end t)
	(setq first (or first (match-beginning 0))
	      last (match-beginning 0)
	      cnt (1+ cnt)))
      (when (and (integerp org-clock-into-drawer)
		 last
		 (>= (1+ cnt) org-clock-into-drawer))
	;; Wrap current entries into a new drawer
	(goto-char last)
	(setq ind-last (org-get-indentation))
	(beginning-of-line 2)
	(if (and (>= (org-get-indentation) ind-last)
		 (org-at-item-p))
	    (org-end-of-item))
	(insert ":END:\n")
	(beginning-of-line 0)
	(org-indent-line-to ind-last)
	(goto-char first)
	(insert ":" drawer ":\n")
	(beginning-of-line 0)
	(org-indent-line-function)
	(org-flag-drawer t)
	(beginning-of-line 2)
	(or org-log-states-order-reversed
	    (and (re-search-forward org-property-end-re nil t)
		 (goto-char (match-beginning 0))))
	(throw 'exit nil))

      (goto-char beg)
      (while (and (looking-at (concat "[ \t]*" org-keyword-time-regexp))
		  (not (equal (match-string 1) org-clock-string)))
	;; Planning info, skip to after it
	(beginning-of-line 2)
	(or (bolp) (newline)))
      (when (or (eq org-clock-into-drawer t)
		(stringp org-clock-into-drawer)
		(and (integerp org-clock-into-drawer)
		     (< org-clock-into-drawer 2)))
	(insert ":" drawer ":\n:END:\n")
	(beginning-of-line -1)
	(org-indent-line-function)
	(org-flag-drawer t)
	(beginning-of-line 2)
	(org-indent-line-function)
	(beginning-of-line)
	(or org-log-states-order-reversed
	    (and (re-search-forward org-property-end-re nil t)
		 (goto-char (match-beginning 0))))))))

(defun org-clock-out (&optional fail-quietly at-time)
  "Stop the currently running clock.
If there is no running clock, throw an error, unless FAIL-QUIETLY is set."
  (interactive)
  (catch 'exit
    (if (not (marker-buffer org-clock-marker))
	(if fail-quietly (throw 'exit t) (error "No active clock")))
    (let (ts te s h m remove)
      (save-excursion
	(set-buffer (marker-buffer org-clock-marker))
	(save-restriction
	  (widen)
	  (goto-char org-clock-marker)
	  (beginning-of-line 1)
	  (if (and (looking-at (concat "[ \t]*" org-keyword-time-regexp))
		   (equal (match-string 1) org-clock-string))
	      (setq ts (match-string 2))
	    (if fail-quietly (throw 'exit nil) (error "Clock start time is gone")))
	  (goto-char (match-end 0))
	  (delete-region (point) (point-at-eol))
	  (insert "--")
	  (setq te (org-insert-time-stamp (or at-time (current-time))
					  'with-hm 'inactive))
	  (setq s (- (org-float-time (apply 'encode-time (org-parse-time-string te)))
		     (org-float-time (apply 'encode-time (org-parse-time-string ts))))
		h (floor (/ s 3600))
		s (- s (* 3600 h))
		m (floor (/ s 60))
		s (- s (* 60 s)))
	  (insert " => " (format "%2d:%02d" h m))
	  (when (setq remove (and org-clock-out-remove-zero-time-clocks
				  (= (+ h m) 0)))
	    (beginning-of-line 1)
	    (delete-region (point) (point-at-eol))
	    (and (looking-at "\n") (> (point-max) (1+ (point)))
		 (delete-char 1)))
	  (move-marker org-clock-marker nil)
	  (move-marker org-clock-hd-marker nil)
	  (when org-log-note-clock-out
	    (org-add-log-setup 'clock-out nil nil nil nil
			       (concat "# Task: " (org-get-heading t) "\n\n")))
	  (when org-clock-mode-line-timer
	    (cancel-timer org-clock-mode-line-timer)
	    (setq org-clock-mode-line-timer nil))
	  (when org-clock-idle-timer
	    (cancel-timer org-clock-idle-timer)
	    (setq org-clock-idle-timer nil))
	  (setq global-mode-string
		(delq 'org-mode-line-string global-mode-string))
	  (when org-clock-out-switch-to-state
	    (save-excursion
	      (org-back-to-heading t)
	      (let ((org-inhibit-logging t))
		(cond
		 ((functionp org-clock-out-switch-to-state)
		  (looking-at org-complex-heading-regexp)
		  (let ((newstate (funcall org-clock-out-switch-to-state
					   (match-string 2))))
		    (if newstate (org-todo newstate))))
		 ((and org-clock-out-switch-to-state
		       (not (looking-at (concat outline-regexp "[ \t]*"
						org-clock-out-switch-to-state
						"\\>"))))
		  (org-todo org-clock-out-switch-to-state))))))
	  (force-mode-line-update)
	  (message (concat "Clock stopped at %s after HH:MM = " org-time-clocksum-format "%s") te h m
		   (if remove " => LINE REMOVED" ""))
          (run-hooks 'org-clock-out-hook))))))

(defun org-clock-cancel ()
  "Cancel the running clock be removing the start timestamp."
  (interactive)
  (if (not (marker-buffer org-clock-marker))
      (error "No active clock"))
  (save-excursion
    (set-buffer (marker-buffer org-clock-marker))
    (goto-char org-clock-marker)
    (delete-region (1- (point-at-bol)) (point-at-eol))
    ;; Just in case, remove any empty LOGBOOK left over
    (org-remove-empty-drawer-at "LOGBOOK" (point)))
  (move-marker org-clock-marker nil)
  (move-marker org-clock-hd-marker nil)
  (setq global-mode-string
	(delq 'org-mode-line-string global-mode-string))
  (force-mode-line-update)
  (message "Clock canceled")
  (run-hooks 'org-clock-cancel-hook))

(defun org-clock-goto (&optional select)
  "Go to the currently clocked-in entry, or to the most recently clocked one.
With prefix arg SELECT, offer recently clocked tasks for selection."
  (interactive "@P")
  (let* ((recent nil)
	 (m (cond
	     (select
	      (or (org-clock-select-task "Select task to go to: ")
		  (error "No task selected")))
	     ((marker-buffer org-clock-marker) org-clock-marker)
	     ((and org-clock-goto-may-find-recent-task
		   (car org-clock-history)
		   (marker-buffer (car org-clock-history)))
	      (setq recent t)
	      (car org-clock-history))
	     (t (error "No active or recent clock task")))))
    (switch-to-buffer (marker-buffer m))
    (if (or (< m (point-min)) (> m (point-max))) (widen))
    (goto-char m)
    (org-show-entry)
    (org-back-to-heading t)
    (org-cycle-hide-drawers 'children)
    (recenter)
    (if recent
	(message "No running clock, this is the most recently clocked task"))
    (run-hooks 'org-clock-goto-hook)))

(defvar org-clock-file-total-minutes nil
  "Holds the file total time in minutes, after a call to `org-clock-sum'.")
(make-variable-buffer-local 'org-clock-file-total-minutes)

(defun org-clock-sum (&optional tstart tend)
  "Sum the times for each subtree.
Puts the resulting times in minutes as a text property on each headline.
TSTART and TEND can mark a time range to be considered."
  (interactive)
  (let* ((bmp (buffer-modified-p))
	 (re (concat "^\\(\\*+\\)[ \t]\\|^[ \t]*"
		     org-clock-string
		     "[ \t]*\\(?:\\(\\[.*?\\]\\)-+\\(\\[.*?\\]\\)\\|=>[ \t]+\\([0-9]+\\):\\([0-9]+\\)\\)"))
	 (lmax 30)
	 (ltimes (make-vector lmax 0))
	 (t1 0)
	 (level 0)
	 ts te dt
	 time)
    (if (stringp tstart) (setq tstart (org-time-string-to-seconds tstart)))
    (if (stringp tend) (setq tend (org-time-string-to-seconds tend)))
    (if (consp tstart) (setq tstart (org-float-time tstart)))
    (if (consp tend) (setq tend (org-float-time tend)))
    (remove-text-properties (point-min) (point-max) '(:org-clock-minutes t))
    (save-excursion
      (goto-char (point-max))
      (while (re-search-backward re nil t)
	(cond
	 ((match-end 2)
	  ;; Two time stamps
	  (setq ts (match-string 2)
		te (match-string 3)
		ts (org-float-time
		    (apply 'encode-time (org-parse-time-string ts)))
		te (org-float-time
		    (apply 'encode-time (org-parse-time-string te)))
		ts (if tstart (max ts tstart) ts)
		te (if tend (min te tend) te)
		dt (- te ts)
		t1 (if (> dt 0) (+ t1 (floor (/ dt 60))) t1)))
	 ((match-end 4)
	  ;; A naked time
	  (setq t1 (+ t1 (string-to-number (match-string 5))
		      (* 60 (string-to-number (match-string 4))))))
	 (t ;; A headline
	  (setq level (- (match-end 1) (match-beginning 1)))
	  (when (or (> t1 0) (> (aref ltimes level) 0))
	    (loop for l from 0 to level do
		  (aset ltimes l (+ (aref ltimes l) t1)))
	    (setq t1 0 time (aref ltimes level))
	    (loop for l from level to (1- lmax) do
		  (aset ltimes l 0))
	    (goto-char (match-beginning 0))
	    (put-text-property (point) (point-at-eol) :org-clock-minutes time)))))
      (setq org-clock-file-total-minutes (aref ltimes 0)))
    (set-buffer-modified-p bmp)))

(defun org-clock-sum-current-item (&optional tstart)
  "Returns time, clocked on current item in total"
  (save-excursion
    (save-restriction
      (org-narrow-to-subtree)
      (org-clock-sum tstart)
      org-clock-file-total-minutes)))

(defun org-clock-display (&optional total-only)
  "Show subtree times in the entire buffer.
If TOTAL-ONLY is non-nil, only show the total time for the entire file
in the echo area."
  (interactive)
  (org-clock-remove-overlays)
  (let (time h m p)
    (org-clock-sum)
    (unless total-only
      (save-excursion
	(goto-char (point-min))
	(while (or (and (equal (setq p (point)) (point-min))
			(get-text-property p :org-clock-minutes))
		   (setq p (next-single-property-change
			    (point) :org-clock-minutes)))
	  (goto-char p)
	  (when (setq time (get-text-property p :org-clock-minutes))
	    (org-clock-put-overlay time (funcall outline-level))))
	(setq h (/ org-clock-file-total-minutes 60)
	      m (- org-clock-file-total-minutes (* 60 h)))
	;; Arrange to remove the overlays upon next change.
	(when org-remove-highlights-with-change
	  (org-add-hook 'before-change-functions 'org-clock-remove-overlays
			nil 'local))))
    (if org-time-clocksum-use-fractional
	(message (concat "Total file time: " org-time-clocksum-fractional-format
			 " (%d hours and %d minutes)")
		 (/ (+ (* h 60.0) m) 60.0) h m)
      (message (concat "Total file time: " org-time-clocksum-format
		       " (%d hours and %d minutes)") h m h m))))

(defvar org-clock-overlays nil)
(make-variable-buffer-local 'org-clock-overlays)

(defun org-clock-put-overlay (time &optional level)
  "Put an overlays on the current line, displaying TIME.
If LEVEL is given, prefix time with a corresponding number of stars.
This creates a new overlay and stores it in `org-clock-overlays', so that it
will be easy to remove."
  (let* ((c 60) (h (floor (/ time 60))) (m (- time (* 60 h)))
	 (l (if level (org-get-valid-level level 0) 0))
	 (fmt (concat "%s " (if org-time-clocksum-use-fractional
				org-time-clocksum-fractional-format
			      org-time-clocksum-format) "%s"))
	 (off 0)
	 ov tx)
    (org-move-to-column c)
    (unless (eolp) (skip-chars-backward "^ \t"))
    (skip-chars-backward " \t")
    (setq ov (org-make-overlay (1- (point)) (point-at-eol))
	  tx (concat (buffer-substring (1- (point)) (point))
		     (make-string (+ off (max 0 (- c (current-column)))) ?.)
		     (org-add-props (if org-time-clocksum-use-fractional
					(format fmt
						(make-string l ?*)
						(/ (+ (* h 60.0) m) 60.0)
						(make-string (- 16 l) ?\ ))
				      (format fmt
					      (make-string l ?*) h m
					      (make-string (- 16 l) ?\ )))
			 (list 'face 'org-clock-overlay))
		     ""))
    (if (not (featurep 'xemacs))
	(org-overlay-put ov 'display tx)
      (org-overlay-put ov 'invisible t)
      (org-overlay-put ov 'end-glyph (make-glyph tx)))
    (push ov org-clock-overlays)))

(defun org-clock-remove-overlays (&optional beg end noremove)
  "Remove the occur highlights from the buffer.
BEG and END are ignored.  If NOREMOVE is nil, remove this function
from the `before-change-functions' in the current buffer."
  (interactive)
  (unless org-inhibit-highlight-removal
    (mapc 'org-delete-overlay org-clock-overlays)
    (setq org-clock-overlays nil)
    (unless noremove
      (remove-hook 'before-change-functions
		   'org-clock-remove-overlays 'local))))

(defvar state) ;; dynamically scoped into this function
(defun org-clock-out-if-current ()
  "Clock out if the current entry contains the running clock.
This is used to stop the clock after a TODO entry is marked DONE,
and is only done if the variable `org-clock-out-when-done' is not nil."
  (when (and org-clock-out-when-done
	     (member state org-done-keywords)
	     (equal (or (buffer-base-buffer (marker-buffer org-clock-marker))
			(marker-buffer org-clock-marker))
		    (or (buffer-base-buffer (current-buffer))
			(current-buffer)))
	     (< (point) org-clock-marker)
	     (> (save-excursion (outline-next-heading) (point))
		org-clock-marker))
    ;; Clock out, but don't accept a logging message for this.
    (let ((org-log-note-clock-out nil))
      (org-clock-out))))

(add-hook 'org-after-todo-state-change-hook
	  'org-clock-out-if-current)

;;;###autoload
(defun org-get-clocktable (&rest props)
  "Get a formatted clocktable with parameters according to PROPS.
The table is created in a temporary buffer, fully formatted and
fontified, and then returned."
  ;; Set the defaults
  (setq props (plist-put props :name "clocktable"))
  (unless (plist-member props :maxlevel)
    (setq props (plist-put props :maxlevel 2)))
  (unless (plist-member props :scope)
    (setq props (plist-put props :scope 'agenda)))
  (with-temp-buffer
    (org-mode)
    (org-create-dblock props)
    (org-update-dblock)
    (font-lock-fontify-buffer)
    (forward-line 2)
    (buffer-substring (point) (progn
				(re-search-forward "^#\\+END" nil t)
				(point-at-bol)))))

(defun org-clock-report (&optional arg)
  "Create a table containing a report about clocked time.
If the cursor is inside an existing clocktable block, then the table
will be updated.  If not, a new clocktable will be inserted.
When called with a prefix argument, move to the first clock table in the
buffer and update it."
  (interactive "P")
  (org-clock-remove-overlays)
  (when arg
    (org-find-dblock "clocktable")
    (org-show-entry))
  (if (org-in-clocktable-p)
      (goto-char (org-in-clocktable-p))
    (org-create-dblock (append (list :name "clocktable")
			       org-clock-clocktable-default-properties)))
  (org-update-dblock))

(defun org-in-clocktable-p ()
  "Check if the cursor is in a clocktable."
  (let ((pos (point)) start)
    (save-excursion
      (end-of-line 1)
      (and (re-search-backward "^#\\+BEGIN:[ \t]+clocktable" nil t)
	   (setq start (match-beginning 0))
	   (re-search-forward "^#\\+END:.*" nil t)
	   (>= (match-end 0) pos)
	   start))))

(defun org-clock-special-range (key &optional time as-strings)
  "Return two times bordering a special time range.
Key is a symbol specifying the range and can be one of `today', `yesterday',
`thisweek', `lastweek', `thismonth', `lastmonth', `thisyear', `lastyear'.
A week starts Monday 0:00 and ends Sunday 24:00.
The range is determined relative to TIME.  TIME defaults to the current time.
The return value is a cons cell with two internal times like the ones
returned by `current time' or `encode-time'. if AS-STRINGS is non-nil,
the returned times will be formatted strings."
  (if (integerp key) (setq key (intern (number-to-string key))))
  (let* ((tm (decode-time (or time (current-time))))
	 (s 0) (m (nth 1 tm)) (h (nth 2 tm))
	 (d (nth 3 tm)) (month (nth 4 tm)) (y (nth 5 tm))
	 (dow (nth 6 tm))
	 (skey (symbol-name key))
	 (shift 0)
	 s1 m1 h1 d1 month1 y1 diff ts te fm txt w date)
    (cond
     ((string-match "^[0-9]+$" skey)
      (setq y (string-to-number skey) m 1 d 1 key 'year))
     ((string-match "^\\([0-9]+\\)-\\([0-9]\\{1,2\\}\\)$" skey)
      (setq y (string-to-number (match-string 1 skey))
	    month (string-to-number (match-string 2 skey))
	    d 1 key 'month))
     ((string-match "^\\([0-9]+\\)-[wW]\\([0-9]\\{1,2\\}\\)$" skey)
      (require 'cal-iso)
      (setq y (string-to-number (match-string 1 skey))
	    w (string-to-number (match-string 2 skey)))
      (setq date (calendar-gregorian-from-absolute
		  (calendar-absolute-from-iso (list w 1 y))))
      (setq d (nth 1 date) month (car date) y (nth 2 date)
	    dow 1
	    key 'week))
     ((string-match "^\\([0-9]+\\)-\\([0-9]\\{1,2\\}\\)-\\([0-9]\\{1,2\\}\\)$" skey)
      (setq y (string-to-number (match-string 1 skey))
	    month (string-to-number (match-string 2 skey))
	    d (string-to-number (match-string 3 skey))
	    key 'day))
     ((string-match "\\([-+][0-9]+\\)$" skey)
      (setq shift (string-to-number (match-string 1 skey))
	    key (intern (substring skey 0 (match-beginning 1))))))
    (when (= shift 0)
      (cond ((eq key 'yesterday) (setq key 'today shift -1))
	    ((eq key 'lastweek)  (setq key 'week  shift -1))
	    ((eq key 'lastmonth) (setq key 'month shift -1))
	    ((eq key 'lastyear)  (setq key 'year  shift -1))))
    (cond
     ((memq key '(day today))
      (setq d (+ d shift) h 0 m 0 h1 24 m1 0))
     ((memq key '(week thisweek))
      (setq diff (+ (* -7 shift) (if (= dow 0) 6 (1- dow)))
	    m 0 h 0 d (- d diff) d1 (+ 7 d)))
     ((memq key '(month thismonth))
      (setq d 1 h 0 m 0 d1 1 month (+ month shift) month1 (1+ month) h1 0 m1 0))
     ((memq key '(year thisyear))
      (setq m 0 h 0 d 1 month 1 y (+ y shift) y1 (1+ y)))
     (t (error "No such time block %s" key)))
    (setq ts (encode-time s m h d month y)
	  te (encode-time (or s1 s) (or m1 m) (or h1 h)
			  (or d1 d) (or month1 month) (or y1 y)))
    (setq fm (cdr org-time-stamp-formats))
    (cond
     ((memq key '(day today))
      (setq txt (format-time-string "%A, %B %d, %Y" ts)))
     ((memq key '(week thisweek))
      (setq txt (format-time-string "week %G-W%V" ts)))
     ((memq key '(month thismonth))
      (setq txt (format-time-string "%B %Y" ts)))
     ((memq key '(year thisyear))
      (setq txt (format-time-string "the year %Y" ts))))
    (if as-strings
	(list (format-time-string fm ts) (format-time-string fm te) txt)
      (list ts te txt))))

(defun org-clocktable-shift (dir n)
  "Try to shift the :block date of the clocktable at point.
Point must be in the #+BEGIN: line of a clocktable, or this function
will throw an error.
DIR is a direction, a symbol `left', `right', `up', or `down'.
Both `left' and `down' shift the block toward the past, `up' and `right'
push it toward the future.
N is the number of shift steps to take.  The size of the step depends on
the currently selected interval size."
  (setq n (prefix-numeric-value n))
  (and (memq dir '(left down)) (setq n (- n)))
  (save-excursion
    (goto-char (point-at-bol))
    (if (not (looking-at "#\\+BEGIN: clocktable\\>.*?:block[ \t]+\\(\\S-+\\)"))
	(error "Line needs a :block definition before this command works")
      (let* ((b (match-beginning 1)) (e (match-end 1))
	     (s (match-string 1))
	     block shift ins y mw d date wp m)
	(cond
	 ((equal s "yesterday") (setq s "today-1"))
	 ((equal s "lastweek") (setq s "thisweek-1"))
	 ((equal s "lastmonth") (setq s "thismonth-1"))
	 ((equal s "lastyear") (setq s "thisyear-1")))
	(cond
	 ((string-match "^\\(today\\|thisweek\\|thismonth\\|thisyear\\)\\([-+][0-9]+\\)?$" s)
	  (setq block (match-string 1 s)
		shift (if (match-end 2)
			  (string-to-number (match-string 2 s))
			0))
	  (setq shift (+ shift n))
	  (setq ins (if (= shift 0) block (format "%s%+d" block shift))))
	 ((string-match "\\([0-9]+\\)\\(-\\([wW]?\\)\\([0-9]\\{1,2\\}\\)\\(-\\([0-9]\\{1,2\\}\\)\\)?\\)?" s)
	  ;;               1        1  2   3       3  4                4  5   6                6  5   2
	  (setq y (string-to-number (match-string 1 s))
		wp (and (match-end 3) (match-string 3 s))
		mw (and (match-end 4) (string-to-number (match-string 4 s)))
		d (and (match-end 6) (string-to-number (match-string 6 s))))
	  (cond
	   (d (setq ins (format-time-string
			 "%Y-%m-%d"
			 (encode-time 0 0 0 (+ d n) m y))))
	   ((and wp mw (> (length wp) 0))
	    (require 'cal-iso)
	    (setq date (calendar-gregorian-from-absolute (calendar-absolute-from-iso (list (+ mw n) 1 y))))
	    (setq ins (format-time-string
		       "%G-W%V"
		       (encode-time 0 0 0 (nth 1 date) (car date) (nth 2 date)))))
	   (mw
	    (setq ins (format-time-string
		       "%Y-%m"
		       (encode-time 0 0 0 1 (+ mw n) y))))
	   (y
	    (setq ins (number-to-string (+ y n))))))
	 (t (error "Cannot shift clocktable block")))
	(when ins
	  (goto-char b)
	  (insert ins)
	  (delete-region (point) (+ (point) (- e b)))
	  (beginning-of-line 1)
	  (org-update-dblock)
	  t)))))

(defun org-dblock-write:clocktable (params)
  "Write the standard clocktable."
  (catch 'exit
    (let* ((hlchars '((1 . "*") (2 . "/")))
	   (ins (make-marker))
	   (total-time nil)
	   (scope (plist-get params :scope))
	   (tostring (plist-get  params :tostring))
	   (multifile (plist-get  params :multifile))
	   (header (plist-get  params :header))
	   (maxlevel (or (plist-get params :maxlevel) 3))
	   (step (plist-get params :step))
	   (emph (plist-get params :emphasize))
	   (timestamp (plist-get params :timestamp))
	   (ts (plist-get params :tstart))
	   (te (plist-get params :tend))
	   (block (plist-get params :block))
	   (link (plist-get params :link))
	   ipos time p level hlc hdl tsp props content recalc formula pcol
	   cc beg end pos tbl tbl1 range-text rm-file-column scope-is-list st)
      (setq org-clock-file-total-minutes nil)
      (when step
	(unless (or block (and ts te))
	  (error "Clocktable `:step' can only be used with `:block' or `:tstart,:end'"))
	(org-clocktable-steps params)
	(throw 'exit nil))
      (when block
	(setq cc (org-clock-special-range block nil t)
	      ts (car cc) te (nth 1 cc) range-text (nth 2 cc)))
      (when (integerp ts) (setq ts (calendar-gregorian-from-absolute ts)))
      (when (integerp te) (setq te (calendar-gregorian-from-absolute te)))
      (when (and ts (listp ts))
	(setq ts (format "%4d-%02d-%02d" (nth 2 ts) (car ts) (nth 1 ts))))
      (when (and te (listp te))
	(setq te (format "%4d-%02d-%02d" (nth 2 te) (car te) (nth 1 te))))
      ;; Now the times are strings we can parse.
      (if ts (setq ts (org-float-time
		       (apply 'encode-time (org-parse-time-string ts)))))
      (if te (setq te (org-float-time
		       (apply 'encode-time (org-parse-time-string te)))))
      (move-marker ins (point))
      (setq ipos (point))

      ;; Get the right scope
      (setq pos (point))
      (cond
       ((and scope (listp scope) (symbolp (car scope)))
	(setq scope (eval scope)))
       ((eq scope 'agenda)
	(setq scope (org-agenda-files t)))
       ((eq scope 'agenda-with-archives)
	(setq scope (org-agenda-files t))
	(setq scope (org-add-archive-files scope)))
       ((eq scope 'file-with-archives)
	(setq scope (org-add-archive-files (list (buffer-file-name)))
	      rm-file-column t)))
      (setq scope-is-list (and scope (listp scope)))
      (save-restriction
	(cond
	 ((not scope))
	 ((eq scope 'file) (widen))
	 ((eq scope 'subtree) (org-narrow-to-subtree))
	 ((eq scope 'tree)
	  (while (org-up-heading-safe))
	  (org-narrow-to-subtree))
	 ((and (symbolp scope) (string-match "^tree\\([0-9]+\\)$"
					     (symbol-name scope)))
	  (setq level (string-to-number (match-string 1 (symbol-name scope))))
	  (catch 'exit
	    (while (org-up-heading-safe)
	      (looking-at outline-regexp)
	      (if (<= (org-reduced-level (funcall outline-level)) level)
		  (throw 'exit nil))))
	  (org-narrow-to-subtree))
	 (scope-is-list
	  (let* ((files scope)
		 (scope 'agenda)
		 (p1 (copy-sequence params))
		 file)
	    (setq p1 (plist-put p1 :tostring t))
	    (setq p1 (plist-put p1 :multifile t))
	    (setq p1 (plist-put p1 :scope 'file))
	    (org-prepare-agenda-buffers files)
	    (while (setq file (pop files))
	      (with-current-buffer (find-buffer-visiting file)
		(setq tbl1 (org-dblock-write:clocktable p1))
		(when tbl1
		  (push (org-clocktable-add-file
			 file
			 (concat "| |*File time*|*"
				 (org-minutes-to-hh:mm-string
				  org-clock-file-total-minutes)
				 "*|\n"
				 tbl1)) tbl)
		  (setq total-time (+ (or total-time 0)
				      org-clock-file-total-minutes))))))))
	(goto-char pos)

	(unless scope-is-list
	  (org-clock-sum ts te)
	  (goto-char (point-min))
	  (setq st t)
	  (while (or (and (bobp) (prog1 st (setq st nil))
			  (get-text-property (point) :org-clock-minutes)
			  (setq p (point-min)))
		     (setq p (next-single-property-change (point) :org-clock-minutes)))
	    (goto-char p)
	    (when (setq time (get-text-property p :org-clock-minutes))
	      (save-excursion
		(beginning-of-line 1)
		(when (and (looking-at (org-re "\\(\\*+\\)[ \t]+\\(.*?\\)\\([ \t]+:[[:alnum:]_@:]+:\\)?[ \t]*$"))
			   (setq level (org-reduced-level
					(- (match-end 1) (match-beginning 1))))
			   (<= level maxlevel))
		  (setq hlc (if emph (or (cdr (assoc level hlchars)) "") "")
			hdl (if (not link)
				(match-string 2)
			      (org-make-link-string
			       (format "file:%s::%s"
				       (buffer-file-name)
				       (save-match-data
					 (org-make-org-heading-search-string
					  (match-string 2))))
			       (match-string 2)))
			tsp (when timestamp
			      (setq props (org-entry-properties (point)))
			      (or (cdr (assoc "SCHEDULED" props))
				  (cdr (assoc "TIMESTAMP" props))
				  (cdr (assoc "DEADLINE" props))
				  (cdr (assoc "TIMESTAMP_IA" props)))))
		  (if (and (not multifile) (= level 1)) (push "|-" tbl))
		  (push (concat
			 "| " (int-to-string level) "|"
			 (if timestamp (concat tsp "|") "")
			 hlc hdl hlc " |"
			 (make-string (1- level) ?|)
			 hlc (org-minutes-to-hh:mm-string time) hlc
			 " |") tbl))))))
	(setq tbl (nreverse tbl))
	(if tostring
	    (if tbl (mapconcat 'identity tbl "\n") nil)
	  (goto-char ins)
	  (insert-before-markers
	   (or header
	       (concat
		"Clock summary at ["
		(substring
		 (format-time-string (cdr org-time-stamp-formats))
		 1 -1)
		"]"
		(if block (concat ", for " range-text ".") "")
		"\n\n"))
	   (if scope-is-list "|File" "")
	   "|L|" (if timestamp "Timestamp|" "") "Headline|Time|\n")
	  (setq total-time (or total-time org-clock-file-total-minutes))
	  (insert-before-markers
	   "|-\n|"
	   (if scope-is-list "|" "")
	   (if timestamp "|Timestamp|" "|")
	   "*Total time*| *"
	   (org-minutes-to-hh:mm-string (or total-time 0))
	   "*|\n|-\n")
	  (setq tbl (delq nil tbl))
	  (if (and (stringp (car tbl)) (> (length (car tbl)) 1)
		   (equal (substring (car tbl) 0 2) "|-"))
	      (pop tbl))
	  (insert-before-markers (mapconcat
				  'identity (delq nil tbl)
				  (if scope-is-list "\n|-\n" "\n")))
	  (backward-delete-char 1)
	  (if (setq formula (plist-get params :formula))
	      (cond
	       ((eq formula '%)
		(setq pcol (+ (if scope-is-list 1 0) maxlevel 3))
		(insert
		 (format
		  "\n#+TBLFM: $%d='(org-clock-time%% @%d$%d $%d..$%d);%%.1f"
		  pcol
		  2
		  (+ 3 (if scope-is-list 1 0))
		  (+ (if scope-is-list 1 0) 3)
		  (1- pcol)))
		(setq recalc t))
	       ((stringp formula)
		(insert "\n#+TBLFM: " formula)
		(setq recalc t))
	       (t (error "invalid formula in clocktable")))
	    ;; Should we rescue an old formula?
	    (when (stringp (setq content (plist-get params :content)))
	      (when (string-match "^\\([ \t]*#\\+TBLFM:.*\\)" content)
		(setq recalc t)
		(insert "\n" (match-string 1 (plist-get params :content)))
		(beginning-of-line 0))))
	  (goto-char ipos)
	  (skip-chars-forward "^|")
	  (org-table-align)
	  (when recalc
	    (if (eq formula '%)
		(save-excursion (org-table-goto-column pcol nil 'force)
				(insert "%")))
	    (org-table-recalculate 'all))
	  (when rm-file-column
	    (forward-char 1)
	    (org-table-delete-column)))))))

(defun org-clocktable-steps (params)
  (let* ((p1 (copy-sequence params))
	 (ts (plist-get p1 :tstart))
	 (te (plist-get p1 :tend))
	 (step0 (plist-get p1 :step))
	 (step (cdr (assoc step0 '((day . 86400) (week . 604800)))))
	 (block (plist-get p1 :block))
	 cc range-text)
    (when block
      (setq cc (org-clock-special-range block nil t)
	    ts (car cc) te (nth 1 cc) range-text (nth 2 cc)))
    (if ts (setq ts (org-float-time
		     (apply 'encode-time (org-parse-time-string ts)))))
    (if te (setq te (org-float-time
		     (apply 'encode-time (org-parse-time-string te)))))
    (setq p1 (plist-put p1 :header ""))
    (setq p1 (plist-put p1 :step nil))
    (setq p1 (plist-put p1 :block nil))
    (while (< ts te)
      (or (bolp) (insert "\n"))
      (setq p1 (plist-put p1 :tstart (format-time-string
				      (org-time-stamp-format nil t)
				      (seconds-to-time ts))))
      (setq p1 (plist-put p1 :tend (format-time-string
				    (org-time-stamp-format nil t)
				    (seconds-to-time (setq ts (+ ts step))))))
      (insert "\n" (if (eq step0 'day) "Daily report: " "Weekly report starting on: ")
	      (plist-get p1 :tstart) "\n")
      (org-dblock-write:clocktable p1)
      (re-search-forward "#\\+END:")
      (end-of-line 0))))

(defun org-clocktable-add-file (file table)
  (if table
      (let ((lines (org-split-string table "\n"))
	    (ff (file-name-nondirectory file)))
	(mapconcat 'identity
		   (mapcar (lambda (x)
			     (if (string-match org-table-dataline-regexp x)
				 (concat "|" ff x)
			       x))
			   lines)
		   "\n"))))

(defun org-clock-time% (total &rest strings)
  "Compute a time fraction in percent.
TOTAL s a time string like 10:21 specifying the total times.
STRINGS is a list of strings that should be checked for a time.
The first string that does have a time will be used.
This function is made for clock tables."
  (let ((re "\\([0-9]+\\):\\([0-9]+\\)")
	tot s)
    (save-match-data
      (catch 'exit
	(if (not (string-match re total))
	    (throw 'exit 0.)
	  (setq tot (+ (string-to-number (match-string 2 total))
		       (* 60 (string-to-number (match-string 1 total)))))
	  (if (= tot 0.) (throw 'exit 0.)))
	(while (setq s (pop strings))
	  (if (string-match "\\([0-9]+\\):\\([0-9]+\\)" s)
	      (throw 'exit
		     (/ (* 100.0 (+ (string-to-number (match-string 2 s))
				    (* 60 (string-to-number (match-string 1 s)))))
			tot))))
	0))))

(defvar org-clock-loaded nil
  "Was the clock file loaded?")

(defun org-clock-save ()
  "Persist various clock-related data to disk.
The details of what will be saved are regulated by the variable
`org-clock-persist'."
  (when (and org-clock-persist
             (or org-clock-loaded
		 org-clock-has-been-used
		 (not (file-exists-p org-clock-persist-file))))
    (let (b)
      (with-current-buffer (find-file (expand-file-name org-clock-persist-file))
	(progn
	  (delete-region (point-min) (point-max))
	  ;;Store clock
	  (insert (format ";; org-persist.el - %s at %s\n"
			  system-name (format-time-string
				       (cdr org-time-stamp-formats))))
	  (if (and (memq org-clock-persist '(t clock))
		   (setq b (marker-buffer org-clock-marker))
		   (setq b (or (buffer-base-buffer b) b))
		   (buffer-live-p b)
		   (buffer-file-name b)
		   (or (not org-clock-persist-query-save)
		       (y-or-n-p (concat "Save current clock ("
					 (substring-no-properties org-clock-heading)
					 ") "))))
	      (insert "(setq resume-clock '(\""
		      (buffer-file-name (marker-buffer org-clock-marker))
		      "\" . " (int-to-string (marker-position org-clock-marker))
		      "))\n"))
	  ;; Store clocked task history. Tasks are stored reversed to make
	  ;; reading simpler
	  (when (and (memq org-clock-persist '(t history))
		     org-clock-history)
	    (insert
	     "(setq stored-clock-history '("
	     (mapconcat
	      (lambda (m)
		(when (and (setq b (marker-buffer m))
			   (setq b (or (buffer-base-buffer b) b))
			   (buffer-live-p b)
			   (buffer-file-name b))
		  (concat "(\"" (buffer-file-name b)
			  "\" . " (int-to-string (marker-position m))
			  ")")))
	      (reverse org-clock-history) " ") "))\n"))
	  (save-buffer)
	  (kill-buffer (current-buffer)))))))

(defun org-clock-load ()
  "Load clock-related data from disk, maybe resuming a stored clock."
  (when (and org-clock-persist (not org-clock-loaded))
    (let ((filename (expand-file-name org-clock-persist-file))
	  (org-clock-in-resume 'auto-restart)
	  resume-clock stored-clock-history)
      (if (not (file-readable-p filename))
	  (message "Not restoring clock data; %s not found"
		   org-clock-persist-file)
	(message "%s" "Restoring clock data")
	(setq org-clock-loaded t)
	(load-file filename)
	;; load history
	(when stored-clock-history
	  (save-window-excursion
	    (mapc (lambda (task)
		    (if (file-exists-p (car task))
			(org-clock-history-push (cdr task)
						(find-file (car task)))))
		  stored-clock-history)))
	;; resume clock
	(when (and resume-clock org-clock-persist
		   (file-exists-p (car resume-clock))
		   (or (not org-clock-persist-query-resume)
		       (y-or-n-p
			(concat
			 "Resume clock ("
			 (with-current-buffer (find-file (car resume-clock))
			   (save-excursion
			     (goto-char (cdr resume-clock))
			     (org-back-to-heading t)
			     (and (looking-at org-complex-heading-regexp)
				  (match-string 4))))
			 ") "))))
	  (when (file-exists-p (car resume-clock))
	    (with-current-buffer (find-file (car resume-clock))
	      (goto-char (cdr resume-clock))
	      (let ((org-clock-auto-clock-resolution nil))
		(org-clock-in)
		(if (org-invisible-p)
		    (org-show-context))))))))))

;;;###autoload
(defun org-clock-persistence-insinuate ()
  "Set up hooks for clock persistence"
  (add-hook 'org-mode-hook 'org-clock-load)
  (add-hook 'kill-emacs-hook 'org-clock-save))

;; Suggested bindings
(org-defkey org-mode-map "\C-c\C-x\C-e" 'org-clock-modify-effort-estimate)

(provide 'org-clock)

;; arch-tag: 7b42c5d4-9b36-48be-97c0-66a869daed4c

;;; org-clock.el ends here