;; todo-mode.el -- Major mode for editing TODO list files

;; Copyright (C) 1997 Free Software Foundation, Inc.

;; Author: Oliver.Seidel@cl.cam.ac.uk (was valid on Aug 2, 1997)
;; Created: 2 Aug 1997
;; Version: $Id: todo-mode.el,v 1.21 1997/10/18 13:31:40 os10000 Exp $
;; Keywords: Categorised TODO list editor, todo-mode

;; 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 2, 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; see the file COPYING.  If not, write to the
;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
;; Boston, MA 02111-1307, USA.

;; ---------------------------------------------------------------------------

;;; Commentary:

;;  Preface, Quickstart Installation
;;
;;      To get this to work, make emacs execute the line
;;
;;          (require 'todo-mode) ;; load the TODO package
;;
;;      If you don't like "require", do as Harald Backer prescribes:
;;
;;          "I don't like require statements as they slow down startup
;;          emacs.  As I include .todo-do in diary and start calendar
;;          at startup of emacs, the mode indicator of .todo-do will
;;          make emacs fail, unless the following is defined:"
;;
;;          (autoload 'todo-mode "todo-mode"
;;              "Major mode for editing TODO lists." t)
;;
;;      You may now enter new items by typing "M-x todo-insert-item",
;;      or enter your TODO list file by typing "M-x todo-show".
;;
;;      The TODO list file has a special format and some auxiliary
;;      information, which will be added by the todo-show function if
;;      it attempts to visit an un-initialised file.  Hence it is
;;      recommended to use the todo-show function for the first time,
;;      in order to initialise the file, but it is not necessary
;;      afterwards.
;;
;;      As these commands are quite long to type, I would recommend
;;      the addition of two bindings to your to your global keymap.  I
;;      personally have the following in my initialisation file:
;;
;;          (global-set-key "\C-ct" 'todo-show) ;; switch to TODO buffer
;;	    (global-set-key "\C-ci" 'todo-insert-item) ;; insert new item
;;
;;      Note, however, that this recommendation has prompted some
;;      criticism, since the keys C-c LETTER are reserved for user
;;      functions.  I believe my recommendation is acceptable, since
;;      the Emacs Lisp Manual *Tips* section also details that the
;;      mode itself should not bind any functions to those keys.  The
;;      express aim of the above two bindings is to work outside the
;;      mode, which doesn't need the show function and offers a
;;      different binding for the insert function.  They serve as
;;      shortcuts and are not even needed (since the TODO mode will be
;;      entered by visiting the TODO file, and later by switching to
;;      its buffer).
;;
;;  Version
;;
;;      Which version of todo-mode.el does this documentation refer to?
;;
;;      $Id: todo-mode.el,v 1.21 1997/10/18 13:31:40 os10000 Exp $
;;
;;  Pre-Requisites
;;
;;      This package will require the following packages to be
;;      available on the load-path:
;;
;;          time-stamp
;;          easymenu
;;
;;  Mode Description
;;
;;	TODO is a major mode for EMACS which offers functionality to
;;	treat most lines in one buffer as a list of items one has to
;;	do.  There are facilities to add new items, which are
;;	categorised, to edit or even delete items from the buffer.
;;	The buffer contents are currently compatible with the diary,
;;	so that the list of todo-items will show up in the FANCY diary
;;	mode.
;;
;;	Notice: Besides the major mode, this file also exports the
;;	function "todo-show" which will change to the one specific
;;	TODO file that has been specified in the todo-file-do
;;	variable.  If this file does not conform to the TODO mode
;;	conventions, the todo-show function will add the appropriate
;;	header and footer.  I don't anticipate this to cause much
;;	grief, but be warned, in case you attempt to read a plain text
;;	file.
;;
;;  Operation
;;
;;	You will have the following facilities available:
;;
;;	    M-x todo-show   will enter the todo list screen, here type
;;
;;	    +  to go to next category
;;          -  to go to previous category
;;          d  to file the current entry, including a
;;            			    comment and timestamp
;;          e  to edit the current entry
;;          f  to file the current entry, including a
;;            			    comment and timestamp
;;          i  to insert a new entry
;;	    j  jump to category
;;          k  to kill the current entry
;;          l  to lower the current entry's priority
;;          n  for the next entry
;;          p  for the previous entry
;;	    P  print
;;          q  to save the list and exit the buffer
;;          r  to raise the current entry's priority
;;          s  to save the list
;;	    t  show top priority items for each category
;;
;;	When you add a new entry, you are asked for the text and then
;;	for the category.  I for example have categories for things
;;	that I want to do in the office (like mail my mum), that I
;;	want to do in town (like buy cornflakes) and things I want to
;;	do at home (move my suitcases).  The categories can be
;;	selected with the cursor keys and if you type in the name of a
;;	category which didn't exist before, an empty category of the
;;	desired name will be added and filled with the new entry.
;;
;;  Configuration
;;
;;  Variable todo-prefix
;;
;;	I would like to recommend that you use the prefix "*/*" (by
;;	leaving the variable 'todo-prefix' untouched) so that the
;;	diary displays each entry every day.
;;
;;	To understand what I mean, please read the documentation that
;;	goes with the calendar since that will tell you how you can
;;	set up the fancy diary display and use the #include command to
;;	include your todo list file as part of your diary.
;;
;;	If you have the diary package set up to usually display more
;;	than one day's entries at once, consider using
;;
;;	    "&%%(equal (calendar-current-date) date)"
;;
;;	as the value of `todo-prefix'.  Please note that this may slow
;;	down the processing of your diary file some.
;;
;;  Variable todo-file-do
;;
;;	This variable is fairly self-explanatory.  You have to store
;;	your TODO list somewhere.  This variable tells the package
;;	where to go and find this file.
;;
;;  Variable todo-file-done
;;
;;	Even when you're done, you may wish to retain the entries.
;;	Given that they're timestamped and you are offered to add a
;;	comment, this can make a useful diary of past events.  It will
;;	even blend in with the EMACS diary package.  So anyway, this
;;	variable holds the name of the file for the filed todo-items.
;;
;;  Variable todo-mode-hook
;;
;;	Just like other modes, too, this mode offers to call your
;;	functions before it goes about its business.  This variable
;;	will be inspected for any functions you may wish to have
;;	called once the other TODO mode preparations have been
;;	completed.
;;
;;  Variable todo-insert-threshold
;;
;;     	Another nifty feature is the insertion accuracy.  If you have
;;     	8 items in your TODO list, then you may get asked 4 questions
;;     	by the binary insertion algorithm.  However, you may not
;;     	really have a need for such accurate priorities amongst your
;;     	TODO items.  If you now think about the binary insertion
;;     	halfing the size of the window each time, then the threshhold
;;     	is the window size at which it will stop.  If you set the
;;     	threshhold to zero, the upper and lower bound will coincide at
;;     	the end of the loop and you will insert your item just before
;;     	that point.  If you set the threshhold to i.e. 8, it will stop
;;     	as soon as the window size drops below that amount and will
;;     	insert the item in the approximate centre of that window.  I
;;     	got the idea for this feature after reading a very helpful
;;     	e-mail reply from Trey Jackson <trey@cs.berkeley.edu> who
;;     	corrected some of my awful coding and pointed me towards some
;;     	good reading.  Thanks Trey!
;;
;;  Things to do
;;
;;      These originally were my ideas, but now also include all the
;;      suggestions that I included before forgetting them:
;;
;;      o   Automatic save of top-priorities to file, for inclusion in
;;          .diary, at save of .todo-do, ref. automatic save of .bbdb
;;          in gnus
;;      o   Fancy fonts for todo/top-priority buffer
;;      o   Remove todo-prefix option in todo-top-priorities
;;      o   Rename category
;;      o   Move entry from one category to another one
;;      o   Entries which both have the generic */* prefix and a
;;          "deadline" entry which are understood by diary, indicating
;;          an event (unless marked by &)
;;      o   The optional COUNT variable of todo-forward-item should be
;;          applied to the other functions performing similar tasks
;;      o   Modularization could be done for repeaded elements of
;;          the code, like the completing-read lines of code.  
;;	o   license / version function
;;	o   export to diary file
;;	o   todo-report-bug
;;	o   GNATS support
;;	o   elide multiline (as in bbdb, or, to a lesser degree, in
;;          outline mode)
;;	o   rewrite complete package to store data as lisp objects
;;          and have display modes for display, for diary export,
;;          etc. (Richard Stallman pointed out this is a bad idea)
;;      o   so base todo-mode.el on generic-mode.el instead
;;
;;  History and Gossip
;;
;;	Many thanks to all the ones who have contributed to the
;;	evolution of this package!  I hope I have listed all of you
;;	somewhere in the documentation or at least in the RCS history!
;;
;;	Enjoy this package and express your gratitude by sending nice
;;	things to my parents' address!
;;
;;	Oliver Seidel
;;	(Lessingstr. 8, 65760 Eschborn, Federal Republic of Germany)
;;

;; ---------------------------------------------------------------------------

;;; Change Log:

;; $Log: todo-mode.el,v $
;; Revision 1.20  1997/10/17  15:41:57  os10000
;; Thanks to Harald Backer <harald.backer@fou.telenor.no>, we now have
;; the following facilities available:
;;
;; Added todo-print, todo-top-priorities and todo-jump with matching
;; variables; Parameterized todo-header, todo-category-beg,
;; todo-category-end and todo-category-sep; Added autoload comments;
;; todo-category-select: Modified regexp to make category names unique;
;; todo-forward-item: Added optional COUNT vaiable; todo-insert-item:
;; Rewrote completing read entry.
;;
;; Also, check out the extended list of things left to be done to this
;; package at the end of the documentation!
;;
;; Revision 1.19  1997/10/16  21:21:16  os10000
;; Jari Aalto <jari.aalto@poboxes.com> writes:
;;
;;     I just downloaded your package and after reading the docs I
;;     decided to do some reformatting.  Hope you don't mind.  Now
;;     they are in such a format that the html page can be
;;     automatically generated from the source file.  As an example, I
;;     generated the attached page using the following command:
;;     ripdoc.pls < todo-mode.el | t2html.pls -a "Oliver.Seidel" -e \
;;     Oliver.Seidel@cl.cam.ac.uk -simple -base
;;
;; And of course I appreciate it.  Jari's stuff can be found at:
;; ftp://cs.uta.fi/pub/ssjaaa/, while I'm making the rev 1.18 page
;; available at http://www.cl.cam.ac.uk/users/os10000/doc/todo-mode.html
;; (That link will be valid until 10/1998 or slightly longer.)
;;
;; Revision 1.18  1997/10/15  17:18:11  os10000
;; Everything seems to work in Harald Melands Emacs 20.02 and
;; my Emacs 19.34.  Beware of the spelling in some of the
;; variable names.  I looked up "threshold" in a dictionary
;; and here in Britain this appears to be the way to spell it.
;;
;; Revision 1.17  1997/10/15  14:30:41  os10000
;; Attempted to reconcile Harald's changes with mine since 1.15.
;;
;; Revision 1.16  1997/10/15  14:00:12  os10000
;; Fixed 'file-item' and added 20.02 split-string function.
;;
;; Revision 1.15  1997/10/14  22:22:35  os10000
;; Added string-split (which I stole from ediff-util), changed
;; pop-to-buffer to switch-to-buffer and added message on how
;; to exit the multi-line-edit mode.
;;
;; Revision 1.14  1997/10/09  09:24:50  os10000
;; Harald Meland <harald.meland@usit.uio.no> asked for
;; the latest version, got 1.13, and returned this.
;; He writes:
;;
;; Thanks a lot for the new version of todo-mode.el.  As you will see I
;; have messed it up a bit, hopefully for the better -- I don't like
;; short, cryptic names for variables and functions, so I renamed most of
;; them, and `defalias'ed the old function names.  I hope you don't mind
;; too much, I just kinda couldn't stop myself.
;;
;; Additionally, I included some support for multiline entries, cleaned
;; up (IMHO :) a lot of the code, included completion-support for which
;; category to install a new entry in, and possibly some other changes I
;; can't remember :)
;;
;; It's getting rather late, and I have just done some preliminary
;; testing on whether all of this really works, but so far it looks
;; good.
;;
;; Revision 1.13  1997/08/19  14:00:36  seidel
;; - changed name to todo-mode
;; - fixed menu descriptions
;; - fixed "pressing abort while filing"
;; - attempted Emacs Lisp Manual *Tips* section compliance
;;
;; Revision 1.12  1997/08/06  10:56:15  os10000
;; Fixed header, typos, layout, documentation.
;;
;; Revision 1.11  1997/08/06  09:14:25  os10000
;; Applied patch from Istvan Marko <istvan@cmdmail.amd.com>
;; to make menus work anywhere.
;;
;; Revision 1.10  1997/08/06  08:56:03  os10000
;; Acted upon suggestion from Shane Holder <holder@rsn.hp.com>:
;; Cancelling the editing of an entry will not delete it any more.
;;
;; Revision 1.9  1997/08/06 08:12:03  os10000
;; Improved documentation.  Broke some lines to comply with
;; Richard Stallman's email to please keep in sync with the
;; rest of the Emacs distribution files.
;;
;; Revision 1.8  1997/08/05 22:39:04  os10000
;; Made todo-mode.el available under GPL.
;;
;; Revision 1.7  1997/08/05 22:34:14  os10000
;; Fixed insertion routine with help from Trey Jackson
;; <trey@cs.berkeley.edu>; added todo-inst-tresh;
;; fixed keyboard layout to remove unwanted keys.
;;
;; Revision 1.6  1997/08/05 16:47:01  os10000
;; Incorporated menus for XEmacs from Allan.Cochrane@soton.sc.philips.com,
;; fixed TYPO, fixed todo-file-cmd, cleaned up rcs history.
;;
;; Revision 1.5  1997/08/05  14:43:39  os10000
;; Added improvements from Ron Gut <rgut@aware.com>.
;; Added category management.
;;
;; Revision 1.4  1997/08/04  16:18:45  os10000
;; Added Raise/Lower item.
;;
;; Revision 1.3  1997/08/03  12:47:26  os10000
;; Cleaned up variables, prefix and cursor position.
;;
;; Revision 1.2  1997/08/03 12:15:28  os10000
;; It appears to work.
;;
;; Revision 1.1  1997/08/03 12:15:13  os10000
;; Initial revision
;;

;; ---------------------------------------------------------------------------

;;; Code:

;; User-configurable variables:

(defvar todo-prefix     "*/*"           "*TODO mode prefix for entries.")
(defvar todo-file-do    "~/.todo-do"    "*TODO mode list file.")
(defvar todo-file-done  "~/.todo-done"  "*TODO mode archive file.")
(defvar todo-mode-hook  nil             "*TODO mode hooks.")
(defvar todo-edit-mode-hook nil         "*TODO Edit mode hooks.")
(defvar todo-insert-threshold 0         "*TODO mode insertion accuracy.")
(defvar todo-edit-buffer " *TODO Edit*" "TODO Edit buffer name.")

(defvar todo-print-function 'ps-print-buffer-with-faces
  "*Function to print the current buffer.")
(defvar todo-show-priorities 1
  "*Default number of priorities to show by
  \\[todo-top-priorities].  0 means show all entries.")
(defvar todo-print-priorities 0
  "*Default number of priorities to print by
  \\[todo-print].  0 means print all entries.")
(defvar todo-remove-separator t
  "*Non-nil removes category separators in
 \\[todo-top-priorities] and \\[todo-print].")


;; Thanks for the ISO time stamp format go to Karl Eichwalder <ke@suse.de>
;; My format string for the appt.el package is "%3b %2d, %y, %02I:%02M%p".
;;
(defvar todo-time-string-format
  "%:y-%02m-%02d %02H:%02M"
  "TODO mode time string format for done entries.
For details see the variable `time-stamp-format'.")

(defvar todo-entry-prefix-function 'todo-entry-timestamp-initials
  "*Function producing text to insert at start of todo entry.")
(defvar todo-initials (or (getenv "INITIALS") (user-login-name))
  "*Initials of todo item author.")

(defun todo-entry-timestamp-initials ()
  (let ((time-stamp-format todo-time-string-format))
    (concat (time-stamp-string) " " todo-initials ": ")))

;; ---------------------------------------------------------------------------

;; Get some outside help ...

(require 'time-stamp)
(require 'easymenu)

;; ---------------------------------------------------------------------------

;; Set up some helpful context ...

(defvar todo-categories         nil     "TODO categories.")
(defvar todo-cats               nil     "Old variable for holding the
TODO categories. Use `todo-categories' instead.")
(defvar todo-previous-line      0       "Previous line that I asked about.")
(defvar todo-previous-answer    0       "Previous answer that I got.")
(defvar todo-mode-map           nil     "TODO mode keymap.")
(defvar todo-category-number    0       "TODO category number.")


(defvar todo-category-sep (make-string 75 ?-)
  "Category separator.")
(defvar todo-category-beg " --- "
  "Category start separator to be prepended onto category name.")
(defvar todo-category-end "--- End"
  "Separator after a category.")
(defvar todo-header "-*- mode: todo; "
  "Header of todo files.")



;; ---------------------------------------------------------------------------

(if todo-mode-map
    nil
  (let ((map (make-keymap)))
    (suppress-keymap map t)
    (define-key map "+" 'todo-forward-category)
    (define-key map "-" 'todo-backward-category)
    (define-key map "e" 'todo-edit-item)
    (define-key map "E" 'todo-edit-multiline)
    (define-key map "d" 'todo-file-item) ;done/delete
    (define-key map "f" 'todo-file-item)
    (define-key map "i" 'todo-insert-item)
    (define-key map "j" 'todo-jump-to-category)
    (define-key map "k" 'todo-delete-item)
    (define-key map "l" 'todo-lower-item)
    (define-key map "n" 'todo-forward-item)
    (define-key map "p" 'todo-backward-item)
    (define-key map "P" 'todo-print)
    (define-key map "q" 'todo-quit)
    (define-key map "r" 'todo-raise-item)
    (define-key map "s" 'todo-save)
    (define-key map "t" 'todo-top-priorities)
    (setq todo-mode-map map)))

(defun todo-category-select ()
  "Make TODO mode display the current category correctly."
  (let ((name (nth todo-category-number todo-categories)))
    (setq mode-line-buffer-identification
          (concat "Category: " name))
    (widen)
    (goto-char (point-min))
    (search-forward-regexp
     (concat "^"
             (regexp-quote (concat todo-prefix todo-category-beg name))
             "$"))
    (let ((begin (1+ (point-at-eol))))
      (search-forward-regexp (concat "^" todo-category-end))
      (narrow-to-region begin (point-at-bol))
      (goto-char (point-min)))))
(defalias 'todo-cat-slct 'todo-category-select)

(defun todo-forward-category () "Go forward to TODO list of next category."
  (interactive)
  (setq todo-category-number
        (mod (1+ todo-category-number) (length todo-categories)))
  (todo-category-select))
(defalias 'todo-cmd-forw 'todo-forward-category)

(defun todo-backward-category () "Go back to TODO list of previous category."
  (interactive)
  (setq todo-category-number
        (mod (1- todo-category-number) (length todo-categories)))
  (todo-category-select))
(defalias 'todo-cmd-back 'todo-backward-category)

(defun todo-backward-item () "Select previous entry of TODO list."
  (interactive)
  (search-backward-regexp (concat "^" (regexp-quote todo-prefix)) nil t)
  (message ""))
(defalias 'todo-cmd-prev 'todo-backward-item)

(defun todo-forward-item (&optional count)
  "Select Nth next entry of TODO list."
  (interactive "P")
  (if (listp count) (setq count (car count)))
  (end-of-line)
  (search-forward-regexp (concat "^" (regexp-quote todo-prefix))
                         nil 'goto-end count)
  (beginning-of-line)
  (message ""))
(defalias 'todo-cmd-next 'todo-forward-item)

(defun todo-save () "Save the TODO list."
  (interactive)
  (save-buffer))
(defalias 'todo-cmd-save 'todo-save)

(defun todo-quit () "Done with TODO list for now."
  (interactive)
  (widen)
  (save-buffer)
  (message "")
  (bury-buffer))
(defalias 'todo-cmd-done 'todo-quit)

(defun todo-edit-item () "Edit current TODO list entry."
  (interactive)
  (let ((item (todo-item-string)))
    (if (todo-string-multiline-p item)
        (todo-edit-multiline)
      (let ((new (read-from-minibuffer "Edit: " item)))
        (todo-remove-item)
        (insert new "\n")
        (todo-backward-item)
        (message "")))))
(defalias 'todo-cmd-edit 'todo-edit-item)

(defun todo-edit-multiline ()
  "Set up a buffer for editing a multiline TODO list entry."
  (interactive)
  (let ((buffer-name (generate-new-buffer-name todo-edit-buffer)))
    (switch-to-buffer
     (make-indirect-buffer
      (file-name-nondirectory todo-file-do) buffer-name))
    (message "To exit, simply kill this buffer and return to list.")
    (todo-edit-mode)
    (narrow-to-region (todo-item-start) (todo-item-end))))

;;;### autoload
(defun todo-add-category (cat) "Add a new category to the TODO list."
  (interactive)
  (save-window-excursion
    (setq todo-categories (cons cat todo-categories))
    (find-file todo-file-do)
    (widen)
    (goto-char (point-min))
    (let ((posn (search-forward "-*- mode: todo; " 17 t)))
      (if (not (null posn)) (goto-char posn))
      (if (equal posn nil)
          (progn
            (insert "-*- mode: todo; \n")
            (forward-char -1))
        (kill-line)))
    (insert (format "todo-categories: %S; -*-" todo-categories))
    (forward-char 1)
    (insert (format "%s%s%s\n%s\n%s %s\n"
                    todo-prefix todo-category-beg cat
                    todo-category-end 
                    todo-prefix todo-category-sep)))
  0)

;;;### autoload
(defun todo-insert-item (ARG)
  "Insert new TODO list entry."
  (interactive "P")
  (let* ((new-item (concat todo-prefix " "
			   (read-from-minibuffer
                            "New TODO entry: "
                                 (if todo-entry-prefix-function
                                     (funcall todo-entry-prefix-function)))))
         (categories todo-categories)
         (history (cons 'categories (1+ todo-category-number)))
	 (category (completing-read 
                    (concat "Category ["
                            (nth todo-category-number todo-categories) "]: ")
                    (todo-category-alist) nil nil nil history)))
    (if (string= "" category)
        (setq category (nth todo-category-number todo-categories)))
    (let ((cat-exists (member category todo-categories)))
      (setq todo-category-number
            (if cat-exists
                (- (length todo-categories) (length cat-exists))
              (todo-add-category category))))
    (if (not ARG)
	(progn
	  (todo-show)
	  (setq todo-previous-line 0)
	  (let ((top 1)
		(bottom (1+ (count-lines (point-min) (point-max)))))
	    (while (> (- bottom top) todo-insert-threshold)
	      (let* ((current (/ (+ top bottom) 2))
		     (answer (if (< current bottom)
				 (todo-more-important-p current) nil)))
		(if answer
		    (setq bottom current)
		  (setq top (1+ current)))))
	    (setq top (/ (+ top bottom) 2))
	    ;; goto-line doesn't have the desired behavior in a narrowed buffer
	    (goto-char (point-min))
	    (forward-line (1- top))))
      (beginning-of-line))
    (insert new-item "\n")
    (todo-backward-item)
    (save-buffer)
    (message "")))
(defalias 'todo-cmd-inst 'todo-insert-item)

(defun todo-more-important-p (line)
  "Ask whether entry is more important than the one at LINE."
  (if (not (equal todo-previous-line line))
      (progn
        (setq todo-previous-line line)
        (goto-char (point-min))
        (forward-line (1- todo-previous-line))
        (let ((item (todo-item-string-start)))
          (setq todo-previous-answer
                (y-or-n-p (concat "More important than '" item "'? "))))))
  todo-previous-answer)
(defalias 'todo-ask-p 'todo-more-important-p)

(defun todo-delete-item () "Delete current TODO list entry."
  (interactive)
  (if (> (count-lines (point-min) (point-max)) 0)
      (let* ((todo-entry (todo-item-string-start))
             (todo-answer (y-or-n-p (concat "Permanently remove '"
                                            todo-entry "'? "))))
        (if todo-answer
            (progn
              (todo-remove-item)
              (todo-backward-item)))
        (message ""))
    (error "No TODO list entry to delete")))
(defalias 'todo-cmd-kill 'todo-delete-item)

(defun todo-raise-item () "Raise priority of current entry."
  (interactive)
  (if (> (count-lines (point-min) (point)) 0)
      (let ((item (todo-item-string)))
        (todo-remove-item)
        (todo-backward-item)
        (save-excursion
          (insert item "\n"))
        (message ""))
    (error "No TODO list entry to raise")))
(defalias 'todo-cmd-rais 'todo-raise-item)

(defun todo-lower-item () "Lower priority of current entry."
  (interactive)
  (if (> (count-lines (point) (point-max)) 1)
      ;; Assume there is a final newline
      (let ((item (todo-item-string)))
        (todo-remove-item)
        (todo-forward-item)
        (save-excursion
          (insert item "\n"))
        (message ""))
    (error "No TODO list entry to lower")))
(defalias 'todo-cmd-lowr 'todo-lower-item)

(defun todo-file-item () "File the current TODO list entry away."
  (interactive)
  (if (> (count-lines (point-min) (point-max)) 0)
      (let ((comment (read-from-minibuffer "Comment: "))
            (time-stamp-format todo-time-string-format))
        (if (> (length comment) 0)
            (progn
              (goto-char (todo-item-end))
              (insert
	       (if (save-excursion (beginning-of-line)
				   (looking-at (regexp-quote todo-prefix)))
		   " "
		 "\n\t")
	       "(" (nth todo-category-number todo-categories) ": "
	       comment ")\n")))
        (goto-char (todo-item-start))
        (let ((temp-point (point)))
          (if (looking-at (regexp-quote todo-prefix))
              (replace-match (time-stamp-string))
	    ;; Standard prefix -> timestamp
            ;; Else prefix non-standard item start with timestamp
            (insert (time-stamp-string)))
          (append-to-file temp-point (todo-item-end) todo-file-done)
          (delete-region temp-point (1+ (todo-item-end))))
        (todo-backward-item)
        (message ""))
    (error "No TODO list entry to file away")))

;; ---------------------------------------------------------------------------

;; Utility functions:


;;;###autoload
(defun todo-top-priorities (&optional nof-priorities category-pr-page)
  "List top priorities for each category.

Number of entries for each category is given by NOF-PRIORITIES which
defaults to \'todo-show-priorities\'.

If CATEGORY-PR-PAGE is non-nil, a page separator \'^L\' is inserted
between each category."

  (interactive "P")
  (or nof-priorities (setq nof-priorities todo-show-priorities))
  (if (listp nof-priorities)            ;universal argument
      (setq nof-priorities (car nof-priorities)))
  (let ((todo-print-buffer-name "*Tmp*")
        ;;(todo-print-category-number 0)
        (todo-category-break (if category-pr-page "" ""))
        (cat-end
         (concat
          (if todo-remove-separator
              (concat todo-category-end "\n"
                      (regexp-quote todo-prefix) " " todo-category-sep "\n")
            (concat todo-category-end "\n"))))
        beg end)
    (todo-show)
    (save-excursion
      (save-restriction
        (widen)
        (copy-to-buffer todo-print-buffer-name (point-min) (point-max))
        (set-buffer todo-print-buffer-name)
        (goto-char (point-min))
        (if (re-search-forward (regexp-quote todo-header) nil t)
            (progn
              (beginning-of-line 1)
              (kill-line)))             ;Remove mode line
        (while (re-search-forward       ;Find category start
                (regexp-quote (concat todo-prefix todo-category-beg))
                nil t)
          (setq beg (+ (point-at-eol) 1)) ;Start of first entry.
          (re-search-forward cat-end nil t)
          (setq end (match-beginning 0))
          (replace-match todo-category-break)
          (narrow-to-region beg end)    ;In case we have too few entries.
          (goto-char (point-min))
          (if (= 0 nof-priorities)      ;Traverse entries.
              (goto-char end)            ;All entries
            (todo-forward-item nof-priorities))
          (setq beg (point))
          (delete-region beg end)
          (widen))
        (goto-char (point-min))         ;Due to display buffer
        ))
    ;; Could have used switch-to-buffer as it has a norecord argument,
    ;; which is nice when we are called from e.g. todo-print.
    ;; Else we could have used pop-to-buffer should be used.
    (display-buffer todo-print-buffer-name)
    ;;(switch-to-buffer todo-print-buffer-name t)
    (message "Type C-x 1 to remove %s window.  M-C-v to scroll the help."
             todo-print-buffer-name)
    ))

;;;###autoload
(defun todo-print (&optional category-pr-page)
  "Print todo summary using \\\[todo-print-function].
If CATEGORY-PR-PAGE is non-nil, a page separator \'^L\' is inserted
between each category.

Number of entries for each category is given by
\'todo-print-priorities\'."
  (interactive "P")
  (save-window-excursion
  (save-excursion
    (save-restriction
      (todo-top-priorities todo-print-priorities
                                    category-pr-page)
      (if todo-print-function
          (progn
            (funcall todo-print-function)
            (message "Todo printing done."))
            (message "")                ; To get rid of message from
                                        ; todo-top-priorities.
            )))))

(defun todo-jump-to-category ()
  "Jump to a category.  Default is previous category."
  (interactive)
  (let* ((categories todo-categories)
         (history (cons 'categories (1+ todo-category-number)))
	 (category (completing-read 
                    (concat "Category ["
                            (nth todo-category-number todo-categories) "]: ")
                    (todo-category-alist) nil nil nil history)))
    (if (string= "" category)
        (setq category (nth todo-category-number todo-categories)))
    (setq todo-category-number
          (if (member category todo-categories)
              (- (length todo-categories)
                 (length (member category todo-categories)))
            (todo-add-category category)))
    (todo-show)))

(defun todo-line-string () "Return current line in buffer as a string."
  (buffer-substring (point-at-bol) (point-at-eol)))

(defun todo-item-string-start ()
  "Return the start of this TODO list entry as a string."
  ;; Suitable for putting in the minibuffer when asking the user
  (let ((item (todo-item-string)))
    (if (> (length item) 60)
        (setq item (concat (substring item 0 56) "...")))
    item))

(defun todo-item-start () "Return point at start of current TODO list item."
  (save-excursion
    (beginning-of-line)
    (if (not (looking-at (regexp-quote todo-prefix)))
        (search-backward-regexp
         (concat "^" (regexp-quote todo-prefix)) nil t))
    (point)))

(defun todo-item-end () "Return point at end of current TODO list item."
  (save-excursion
    (end-of-line)
    (search-forward-regexp
     (concat "^" (regexp-quote todo-prefix)) nil 'goto-end)
    (1- (point-at-bol))))

(defun todo-remove-item () "Delete the current entry from the TODO list."
  (delete-region (todo-item-start) (1+ (todo-item-end))))

(defun todo-item-string () "Return current TODO list entry as a string."
  (buffer-substring (todo-item-start) (todo-item-end)))

(defun todo-string-count-lines (string)
  "Return the number of lines STRING spans."
  (length (split-string string "\n")))

(defun todo-string-multiline-p (string)
  "Returns non-nil if STRING spans several lines"
  (> (todo-string-count-lines string) 1))

(defun todo-category-alist ()
  "Generate an alist fro use in `completing-read' from `todo-categories'"
  (mapcar (lambda (cat) (cons cat nil))
          todo-categories))

;; utility functions:  These are available in XEmacs, but not in Emacs 19.34

(if (not (fboundp 'point-at-bol))
    (defun point-at-bol () "Return value of point at beginning of line."
      (save-excursion
        (beginning-of-line)
        (point))))

(if (not (fboundp 'point-at-eol))
    (defun point-at-eol () "Return value of point at end of line."
      (save-excursion
        (end-of-line)
        (point))))

;; splits at a white space, returns a list
(if (not (fboundp 'split-string))
    (defun split-string (string &optional separators)
      "Splits STRING into substrings where there are matches for SEPARATORS.
Each match for SEPARATORS is a splitting point.
The substrings between the splitting points are made into a list
which is returned.
If SEPARATORS is absent, it defaults to \"[ \\f\\t\\n\\r\\v]+\"."
      (let ((rexp (or separators "[ \f\t\n\r\v]+"))
            (start 0)
            (list nil))
        (while (string-match rexp string start)
          (or (eq (match-beginning 0) 0)
              (setq list
                    (cons (substring string start (match-beginning 0))
                          list)))
          (setq start (match-end 0)))
        (or (eq start (length string))
            (setq list
                  (cons (substring string start)
                        list)))
        (nreverse list))))

;; ---------------------------------------------------------------------------

(easy-menu-define todo-menu todo-mode-map "Todo Menu"
                  '("Todo"
                    ["Next category"        todo-forward-category t]
                    ["Previous category"    todo-backward-category t]
                    ["Jump to category"     todo-jump-to-category t]
                    ["Show top priority items" todo-top-priorities t]
                    ["Print categories"     todo-print t]
                    "---"
                    ["Edit item"            todo-edit-item t]
                    ["File item"            todo-file-item t]
                    ["Insert new item"      todo-insert-item t]
                    ["Kill item"            todo-delete-item t]
                    "---"
                    ["Lower item priority"  todo-lower-item t]
                    ["Raise item priority"  todo-raise-item t]
                    "---"
                    ["Next item"            todo-forward-item t]
                    ["Previous item"        todo-backward-item t]
                    "---"
                    ["Save"                 todo-save t]
                    "---"
                    ["Quit"                 todo-quit t]
                    ))

;; As calendar reads .todo-do before todo-mode is loaded.
;;;### autoload
(defun todo-mode () "Major mode for editing TODO lists.\n\n\\{todo-mode-map}"
  (interactive)
  (setq major-mode 'todo-mode)
  (setq mode-name "TODO")
  (use-local-map todo-mode-map)
  (easy-menu-add todo-menu)
  (run-hooks 'todo-mode-hook))

(defun todo-edit-mode ()
  "Major mode for editing items in the TODO list\n\n\\{todo-edit-mode-map}"
  (text-mode)
  (setq major-mode 'todo-edit-mode)
  (setq mode-name "TODO Edit")
  (run-hooks 'todo-edit-mode-hook))

;;;### autoload
(defun todo-show () "Show TODO list."
  (interactive)
  (if (file-exists-p todo-file-do)
      (find-file todo-file-do)
    (todo-initial-setup))
  (if (null todo-categories)
      (if (null todo-cats)
          (error "Error in %s: No categories in list `todo-categories'"
                 todo-file-do)
        (goto-char (point-min))
        (and (search-forward "todo-cats:" nil t)
             (replace-match "todo-categories:"))
        (make-local-variable todo-categories)
        (setq todo-categories todo-cats)))
  (beginning-of-line)
  (todo-category-select))

(defun todo-initial-setup () "Set up things to work properly in TODO mode."
  (find-file todo-file-do)
  (erase-buffer)
  (todo-mode)
  (todo-add-category "Todo"))

(provide 'todo-mode)

;; ---------------------------------------------------------------------------
;;; todo-mode.el ends here
;; ---------------------------------------------------------------------------