1;;; gnus-mlspl.el --- a group params-based mail splitting mechanism
2
3;; Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004,
4;;   2005, 2006, 2007 Free Software Foundation, Inc.
5
6;; Author: Alexandre Oliva <oliva@lsd.ic.unicamp.br>
7;; Keywords: news, mail
8
9;; This file is part of GNU Emacs.
10
11;; GNU Emacs is free software; you can redistribute it and/or modify
12;; it under the terms of the GNU General Public License as published
13;; by the Free Software Foundation; either version 2, or (at your
14;; option) any later version.
15
16;; GNU Emacs is distributed in the hope that it will be useful, but
17;; WITHOUT ANY WARRANTY; without even the implied warranty of
18;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
19;; General Public License for more details.
20
21;; You should have received a copy of the GNU General Public License
22;; along with this program; see the file COPYING.  If not, write to
23;; the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
24;; Boston, MA 02110-1301, USA.
25
26;;; Commentary:
27
28;;; Code:
29
30(eval-when-compile (require 'cl))
31(require 'gnus)
32(require 'gnus-sum)
33(require 'gnus-group)
34(require 'nnmail)
35
36(defvar gnus-group-split-updated-hook nil
37  "Hook called just after nnmail-split-fancy is updated by
38gnus-group-split-update.")
39
40(defvar gnus-group-split-default-catch-all-group "mail.misc"
41  "Group name (or arbitrary fancy split) with default splitting rules.
42Used by gnus-group-split and gnus-group-split-update as a fallback
43split, in case none of the group-based splits matches.")
44
45;;;###autoload
46(defun gnus-group-split-setup (&optional auto-update catch-all)
47  "Set up the split for nnmail-split-fancy.
48Sets things up so that nnmail-split-fancy is used for mail
49splitting, and defines the variable nnmail-split-fancy according with
50group parameters.
51
52If AUTO-UPDATE is non-nil (prefix argument accepted, if called
53interactively), it makes sure nnmail-split-fancy is re-computed before
54getting new mail, by adding gnus-group-split-update to
55nnmail-pre-get-new-mail-hook.
56
57A non-nil CATCH-ALL replaces the current value of
58gnus-group-split-default-catch-all-group.  This variable is only used
59by gnus-group-split-update, and only when its CATCH-ALL argument is
60nil.  This argument may contain any fancy split, that will be added as
61the last split in a `|' split produced by gnus-group-split-fancy,
62unless overridden by any group marked as a catch-all group.  Typical
63uses are as simple as the name of a default mail group, but more
64elaborate fancy splits may also be useful to split mail that doesn't
65match any of the group-specified splitting rules.  See
66`gnus-group-split-fancy' for details."
67  (interactive "P")
68  (setq nnmail-split-methods 'nnmail-split-fancy)
69  (when catch-all
70    (setq gnus-group-split-default-catch-all-group catch-all))
71  (gnus-group-split-update)
72  (when auto-update
73    (add-hook 'nnmail-pre-get-new-mail-hook 'gnus-group-split-update)))
74
75;;;###autoload
76(defun gnus-group-split-update (&optional catch-all)
77  "Computes nnmail-split-fancy from group params and CATCH-ALL.
78It does this by calling by calling (gnus-group-split-fancy nil
79nil CATCH-ALL).
80
81If CATCH-ALL is nil, gnus-group-split-default-catch-all-group is used
82instead.  This variable is set by gnus-group-split-setup."
83  (interactive)
84  (setq nnmail-split-fancy
85	(gnus-group-split-fancy
86	 nil (null nnmail-crosspost)
87	 (or catch-all gnus-group-split-default-catch-all-group)))
88  (run-hooks 'gnus-group-split-updated-hook))
89
90;;;###autoload
91(defun gnus-group-split ()
92  "Uses information from group parameters in order to split mail.
93See `gnus-group-split-fancy' for more information.
94
95gnus-group-split is a valid value for nnmail-split-methods."
96  (let (nnmail-split-fancy)
97    (gnus-group-split-update)
98    (nnmail-split-fancy)))
99
100;;;###autoload
101(defun gnus-group-split-fancy
102  (&optional groups no-crosspost catch-all)
103  "Uses information from group parameters in order to split mail.
104It can be embedded into `nnmail-split-fancy' lists with the SPLIT
105
106\(: gnus-group-split-fancy GROUPS NO-CROSSPOST CATCH-ALL\)
107
108GROUPS may be a regular expression or a list of group names, that will
109be used to select candidate groups.  If it is omitted or nil, all
110existing groups are considered.
111
112if NO-CROSSPOST is omitted or nil, a & split will be returned,
113otherwise, a | split, that does not allow crossposting, will be
114returned.
115
116For each selected group, a SPLIT is composed like this: if SPLIT-SPEC
117is specified, this split is returned as-is (unless it is nil: in this
118case, the group is ignored).  Otherwise, if TO-ADDRESS, TO-LIST and/or
119EXTRA-ALIASES are specified, a regexp that matches any of them is
120constructed (extra-aliases may be a list).  Additionally, if
121SPLIT-REGEXP is specified, the regexp will be extended so that it
122matches this regexp too, and if SPLIT-EXCLUDE is specified, RESTRICT
123clauses will be generated.
124
125If CATCH-ALL is nil, no catch-all handling is performed, regardless of
126catch-all marks in group parameters.  Otherwise, if there is no
127selected group whose SPLIT-REGEXP matches the empty string, nor is
128there a selected group whose SPLIT-SPEC is 'catch-all, this fancy
129split (say, a group name) will be appended to the returned SPLIT list,
130as the last element of a '| SPLIT.
131
132For example, given the following group parameters:
133
134nnml:mail.bar:
135\((to-address . \"bar@femail.com\")
136 (split-regexp . \".*@femail\\\\.com\"))
137nnml:mail.foo:
138\((to-list . \"foo@nowhere.gov\")
139 (extra-aliases \"foo@localhost\" \"foo-redist@home\")
140 (split-exclude \"bugs-foo\" \"rambling-foo\")
141 (admin-address . \"foo-request@nowhere.gov\"))
142nnml:mail.others:
143\((split-spec . catch-all))
144
145Calling (gnus-group-split-fancy nil nil \"mail.others\") returns:
146
147\(| (& (any \"\\\\(bar@femail\\\\.com\\\\|.*@femail\\\\.com\\\\)\"
148	   \"mail.bar\")
149      (any \"\\\\(foo@nowhere\\\\.gov\\\\|foo@localhost\\\\|foo-redist@home\\\\)\"
150	   - \"bugs-foo\" - \"rambling-foo\" \"mail.foo\"))
151   \"mail.others\")"
152  (let* ((newsrc (cdr gnus-newsrc-alist))
153	 split)
154    (dolist (info newsrc)
155      (let ((group (gnus-info-group info))
156	    (params (gnus-info-params info)))
157	;; For all GROUPs that match the specified GROUPS
158	(when (or (not groups)
159		  (and (listp groups)
160		       (memq group groups))
161		  (and (stringp groups)
162		       (string-match groups group)))
163	  (let ((split-spec (assoc 'split-spec params)) group-clean)
164	    ;; Remove backend from group name
165	    (setq group-clean (string-match ":" group))
166	    (setq group-clean
167		  (if group-clean
168		      (substring group (1+ group-clean))
169		    group))
170	    (if split-spec
171		(when (setq split-spec (cdr split-spec))
172		  (if (eq split-spec 'catch-all)
173		      ;; Emit catch-all only when requested
174		      (when catch-all
175			(setq catch-all group-clean))
176		    ;; Append split-spec to the main split
177		    (push split-spec split)))
178	      ;; Let's deduce split-spec from other params
179	      (let ((to-address (cdr (assoc 'to-address params)))
180		    (to-list (cdr (assoc 'to-list params)))
181		    (extra-aliases (cdr (assoc 'extra-aliases params)))
182		    (split-regexp (cdr (assoc 'split-regexp params)))
183		    (split-exclude (cdr (assoc 'split-exclude params))))
184		(when (or to-address to-list extra-aliases split-regexp)
185		  ;; regexp-quote to-address, to-list and extra-aliases
186		  ;; and add them all to split-regexp
187		  (setq split-regexp
188			(concat
189			 "\\("
190			 (mapconcat
191			  'identity
192			  (append
193			   (and to-address (list (regexp-quote to-address)))
194			   (and to-list (list (regexp-quote to-list)))
195			   (and extra-aliases
196				(if (listp extra-aliases)
197				    (mapcar 'regexp-quote extra-aliases)
198				  (list extra-aliases)))
199			   (and split-regexp (list split-regexp)))
200			  "\\|")
201			 "\\)"))
202		  ;; Now create the new SPLIT
203		  (push (append
204			 (list 'any split-regexp)
205			 ;; Generate RESTRICTs for SPLIT-EXCLUDEs.
206			 (if (listp split-exclude)
207			     (apply #'append
208				    (mapcar (lambda (arg) (list '- arg))
209					    split-exclude))
210			   (list '- split-exclude))
211			 (list group-clean))
212			split)
213		  ;; If it matches the empty string, it is a catch-all
214		  (when (string-match split-regexp "")
215		    (setq catch-all nil)))))))))
216    ;; Add catch-all if not crossposting
217    (if (and catch-all no-crosspost)
218	(push catch-all split))
219    ;; Move it to the tail, while arranging that SPLITs appear in the
220    ;; same order as groups.
221    (setq split (reverse split))
222    ;; Decide whether to accept cross-postings or not.
223    (push (if no-crosspost '| '&) split)
224    ;; Even if we can cross-post, catch-all should not get
225    ;; cross-posts.
226    (if (and catch-all (not no-crosspost))
227	(setq split (list '| split catch-all)))
228    split))
229
230(provide 'gnus-mlspl)
231
232;;; arch-tag: 62b3381f-1e45-4b61-be1a-29fb27703322
233;;; gnus-mlspl.el ends here
234