Remove trailing whitespace.

[gnus] / lisp / nndiary.el

;;; nndiary.el --- A diary back end for Gnus

;; Copyright (C) 1999, 2000, 2001, 2002, 2003, 2004,
;;   2005, 2006 Free Software Foundation, Inc.

;; Author:        Didier Verna <didier@xemacs.org>
;; Maintainer:    Didier Verna <didier@xemacs.org>
;; Created:       Fri Jul 16 18:55:42 1999
;; Keywords:      calendar mail news

;; 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 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 this program; if not, write to the Free Software
;; Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
;; MA 02110-1301, USA.


;;; Commentary:

;; Contents management by FCM version 0.1.

;; Description:
;; ===========

;; nndiary is a mail back end designed to handle mails as diary event
;; reminders. It is now fully documented in the Gnus manual.


;; Bugs / Todo:
;; ===========

;; * Respooling doesn't work because contrary to the request-scan function,
;;   Gnus won't allow me to override the split methods when calling the
;;   respooling back end functions.
;; * There's a bug in the time zone mechanism with variable TZ locations.
;; * We could allow a keyword like `ask' in X-Diary-* headers, that would mean
;;   "ask for value upon reception of the message".
;; * We could add an optional header X-Diary-Reminders to specify a special
;;   reminders value for this message. Suggested by Jody Klymak.
;; * We should check messages validity in other circumstances than just
;;   moving an article from somewhere else (request-accept). For instance,
;;   when editing / saving and so on.


;; Remarks:
;; =======

;; * nnoo. NNDiary is very similar to nnml. This makes the idea of using nnoo
;;   (to derive nndiary from nnml) natural. However, my experience with nnoo
;;   is that for reasonably complex back ends like this one, noo is a burden
;;   rather than an help. It's tricky to use, not everything can be inherited,
;;   what can be inherited and when is not very clear, and you've got to be
;;   very careful because a little mistake can fuck up your other back ends,
;;   especially because their variables will be use instead of your real ones.
;;   Finally, I found it easier to just clone the needed parts of nnml, and
;;   tracking nnml updates is not a big deal.

;;   IMHO, nnoo is actually badly designed.  A much simpler, and yet more
;;   powerful one would be to make *real* functions and variables for a new
;;   back end based on another. Lisp is a reflexive language so that's a very
;;   easy thing to do: inspect the function's form, replace occurences of
;;   <nnfrom> (even in strings) with <nnto>, and you're done.

;; * nndiary-get-new-mail, nndiary-mail-source and nndiary-split-methods:
;;   NNDiary has some experimental parts, in the sense Gnus normally uses only
;;   one mail back ends for mail retreival and splitting. This back end is
;;   also an attempt to make it behave differently. For Gnus developpers: as
;;   you can see if you snarf into the code, that was not a very difficult
;;   thing to do. Something should be done about the respooling breakage
;;   though.


;;; Code:

(require 'nnoo)
(require 'nnheader)
(require 'nnmail)
(eval-when-compile (require 'cl))

(require 'gnus-start)
(require 'gnus-sum)

;; Compatibility Functions  =================================================

(eval-and-compile
  (if (fboundp 'signal-error)
      (defun nndiary-error (&rest args)
        (apply #'signal-error 'nndiary args))
    (defun nndiary-error (&rest args)
      (apply #'error args))))


;; Back End behavior customization ===========================================

(defgroup nndiary nil
  "The Gnus Diary back end."
  :version "22.1"
  :group 'gnus-diary)

(defcustom nndiary-mail-sources
  `((file :path ,(expand-file-name "~/.nndiary")))
  "*NNDiary specific mail sources.
This variable is used by nndiary in place of the standard `mail-sources'
variable when `nndiary-get-new-mail' is set to non-nil.  These sources
must contain diary messages ONLY."
  :group 'nndiary
  :group 'mail-source
  :type 'sexp)

(defcustom nndiary-split-methods '(("diary" ""))
  "*NNDiary specific split methods.
This variable is used by nndiary in place of the standard
`nnmail-split-methods' variable when `nndiary-get-new-mail' is set to
non-nil."
  :group 'nndiary
  :group 'nnmail-split
  :type '(choice (repeat :tag "Alist" (group (string :tag "Name") regexp))
                 (function-item nnmail-split-fancy)
                 (function :tag "Other")))


(defcustom nndiary-reminders '((0 . day))
  "*Different times when you want to be reminded of your appointements.
Diary articles will appear again, as if they'd been just received.

Entries look like (3 . day) which means something like \"Please
Hortense, would you be so kind as to remind me of my appointments 3 days
before the date, thank you very much. Anda, hmmm... by the way, are you
doing anything special tonight ?\".

The units of measure are 'minute 'hour 'day 'week 'month and 'year (no,
not 'century, sorry).

NOTE: the units of measure actually express dates, not durations: if you
use 'week, messages will pop up on Sundays at 00:00 (or Mondays if
`nndiary-week-starts-on-monday' is non nil) and *not* 7 days before the
appointement, if you use 'month, messages will pop up on the first day of
each months, at 00:00 and so on.

If you really want to specify a duration (like 24 hours exactly), you can
use the equivalent in minutes (the smallest unit).  A fuzz of 60 seconds
maximum in the reminder is not that painful, I think.  Although this
scheme might appear somewhat weird at a first glance, it is very powerful.
In order to make this clear, here are some examples:

- '(0 . day): this is the default value of `nndiary-reminders'.  It means
  pop up the appointements of the day each morning at 00:00.

- '(1 . day): this means pop up the appointements the day before, at 00:00.

- '(6 . hour): for an appointement at 18:30, this would pop up the
  appointement message at 12:00.

- '(360 . minute): for an appointement at 18:30 and 15 seconds, this would
  pop up the appointement message at 12:30."
  :group 'nndiary
  :type '(repeat (cons :format "%v\n"
                       (integer :format "%v")
                       (choice :format "%[%v(s)%] before...\n"
                               :value day
                               (const :format "%v" minute)
                               (const :format "%v" hour)
                               (const :format "%v" day)
                               (const :format "%v" week)
                               (const :format "%v" month)
                               (const :format "%v" year)))))

(defcustom nndiary-week-starts-on-monday nil
  "*Whether a week starts on monday (otherwise, sunday)."
  :type 'boolean
  :group 'nndiary)


(defcustom nndiary-request-create-group-hooks nil
  "*Hooks to run after `nndiary-request-create-group' is executed.
The hooks will be called with the full group name as argument."
  :group 'nndiary
  :type 'hook)

(defcustom nndiary-request-update-info-hooks nil
  "*Hooks to run after `nndiary-request-update-info-group' is executed.
The hooks will be called with the full group name as argument."
  :group 'nndiary
  :type 'hook)

(defcustom nndiary-request-accept-article-hooks nil
  "*Hooks to run before accepting an article.
Executed near the beginning of `nndiary-request-accept-article'.
The hooks will be called with the article in the current buffer."
  :group 'nndiary
  :type 'hook)

(defcustom nndiary-check-directory-twice t
  "*If t, check directories twice to avoid NFS failures."
  :group 'nndiary
  :type 'boolean)


;; Back End declaration ======================================================

;; Well, most of this is nnml clonage.

(nnoo-declare nndiary)

(defvoo nndiary-directory (nnheader-concat gnus-directory "diary/")
  "Spool directory for the nndiary back end.")

(defvoo nndiary-active-file
    (expand-file-name "active" nndiary-directory)
  "Active file for the nndiary back end.")

(defvoo nndiary-newsgroups-file
    (expand-file-name "newsgroups" nndiary-directory)
  "Newsgroups description file for the nndiary back end.")

(defvoo nndiary-get-new-mail nil
  "Whether nndiary gets new mail and split it.
Contrary to traditional mail back ends, this variable can be set to t
even if your primary mail back end also retreives mail. In such a case,
NDiary uses its own mail-sources and split-methods.")

(defvoo nndiary-nov-is-evil nil
  "If non-nil, Gnus will never use nov databases for nndiary groups.
Using nov databases will speed up header fetching considerably.
This variable shouldn't be flipped much.  If you have, for some reason,
set this to t, and want to set it to nil again, you should always run
the `nndiary-generate-nov-databases' command.  The function will go
through all nnml directories and generate nov databases for them
all.  This may very well take some time.")

(defvoo nndiary-prepare-save-mail-hook nil
  "*Hook run narrowed to an article before saving.")

(defvoo nndiary-inhibit-expiry nil
  "If non-nil, inhibit expiry.")

\f

(defconst nndiary-version "0.2-b14"
  "Current Diary back end version.")

(defun nndiary-version ()
  "Current Diary back end version."
  (interactive)
  (message "NNDiary version %s" nndiary-version))

(defvoo nndiary-nov-file-name ".overview")

(defvoo nndiary-current-directory nil)
(defvoo nndiary-current-group nil)
(defvoo nndiary-status-string "" )
(defvoo nndiary-nov-buffer-alist nil)
(defvoo nndiary-group-alist nil)
(defvoo nndiary-active-timestamp nil)
(defvoo nndiary-article-file-alist nil)

(defvoo nndiary-generate-active-function 'nndiary-generate-active-info)
(defvoo nndiary-nov-buffer-file-name nil)
(defvoo nndiary-file-coding-system nnmail-file-coding-system)

(defconst nndiary-headers
  '(("Minute" 0 59)