[bpt/emacs.git] / lisp / gnus / gnus-nocem.el

;;; gnus-nocem.el --- NoCeM pseudo-cancellation treatment

;; Copyright (C) 1995, 1996, 1997, 1998, 1999, 2000 Free Software Foundation, Inc.

;; Author: Lars Magne Ingebrigtsen <larsi@gnus.org>
;; Keywords: 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, 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:

;;; Code:

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

(require 'gnus)
(require 'nnmail)
(require 'gnus-art)
(require 'gnus-sum)
(require 'gnus-range)

(defgroup gnus-nocem nil
  "NoCeM pseudo-cancellation treatment"
  :group 'gnus-score)

(defcustom gnus-nocem-groups
  '("news.lists.filters" "news.admin.net-abuse.bulletins"
    "alt.nocem.misc" "news.admin.net-abuse.announce")
  "*List of groups that will be searched for NoCeM messages."
  :group 'gnus-nocem
  :type '(repeat (string :tag "Group")))

(defcustom gnus-nocem-issuers
  '("AutoMoose-1"			; CancelMoose[tm]
    "clewis@ferret.ocunix"		; Chris Lewis
    "cosmo.roadkill"
    "SpamHippo"
    "hweede@snafu.de")
  "*List of NoCeM issuers to pay attention to.

This can also be a list of `(ISSUER CONDITION ...)' elements.

See <URL:http://www.xs4all.nl/~rosalind/nocemreg/nocemreg.html> for an
issuer registry."
  :group 'gnus-nocem
  :type '(repeat (choice string sexp)))

(defcustom gnus-nocem-directory
  (nnheader-concat gnus-article-save-directory "NoCeM/")
  "*Directory where NoCeM files will be stored."
  :group 'gnus-nocem
  :type 'directory)

(defcustom gnus-nocem-expiry-wait 15
  "*Number of days to keep NoCeM headers in the cache."
  :group 'gnus-nocem
  :type 'integer)

(defcustom gnus-nocem-verifyer 'mc-verify
  "*Function called to verify that the NoCeM message is valid.
One likely value is `mc-verify'.  If the function in this variable
isn't bound, the message will be used unconditionally."
  :group 'gnus-nocem
  :type '(radio (function-item mc-verify)
		(function :tag "other")))

(defcustom gnus-nocem-liberal-fetch nil
  "*If t try to fetch all messages which have @@NCM in the subject.
Otherwise don't fetch messages which have references or whose message-id
matches a previously scanned and verified nocem message."
  :group 'gnus-nocem
  :type 'boolean)

(defcustom gnus-nocem-check-article-limit 500
  "*If non-nil, the maximum number of articles to check in any NoCeM group."
  :group 'gnus-nocem
  :version "21.1"
  :type '(choice (const :tag "unlimited" nil)
		 (integer 1000)))

(defcustom gnus-nocem-check-from t
  "Non-nil means check for valid issuers in message bodies.
Otherwise don't bother fetching articles unless their author matches a
valid issuer, which is much faster if you are selective about the issuers."
  :group 'gnus-nocem
  :version "21.1"
  :type 'boolean)

;;; Internal variables

(defvar gnus-nocem-active nil)
(defvar gnus-nocem-alist nil)
(defvar gnus-nocem-touched-alist nil)
(defvar gnus-nocem-hashtb nil)
(defvar gnus-nocem-seen-message-ids nil)

;;; Functions

(defun gnus-nocem-active-file ()
  (concat (file-name-as-directory gnus-nocem-directory) "active"))

(defun gnus-nocem-cache-file ()
  (concat (file-name-as-directory gnus-nocem-directory) "cache"))

;;
;; faster lookups for group names:
;;

(defvar gnus-nocem-real-group-hashtb nil
  "Real-name mappings of subscribed groups.")

(defun gnus-fill-real-hashtb ()
  "Fill up a hash table with the real-name mappings from the user's active file."
  (setq gnus-nocem-real-group-hashtb (gnus-make-hashtable
				      (length gnus-newsrc-alist)))
  (mapcar (lambda (group)
	    (setq group (gnus-group-real-name (car group)))
	    (gnus-sethash group t gnus-nocem-real-group-hashtb))
	  gnus-newsrc-alist))

(defun gnus-nocem-scan-groups ()
  "Scan all NoCeM groups for new NoCeM messages."
  (interactive)
  (let ((groups gnus-nocem-groups)
	(gnus-inhibit-demon t)
	group active gactive articles check-headers)
    (gnus-make-directory gnus-nocem-directory)
    ;; Load any previous NoCeM headers.
    (gnus-nocem-load-cache)
    ;; Get the group name mappings:
    (gnus-fill-real-hashtb)
    ;; Read the active file if it hasn't been read yet.
    (and (file-exists-p (gnus-nocem-active-file))
	 (not gnus-nocem-active)
	 (ignore-errors
	   (load (gnus-nocem-active-file) t t t)))
    ;; Go through all groups and see whether new articles have
    ;; arrived.
    (while (setq group (pop groups))
      (if (not (setq gactive (gnus-activate-group group)))
	  ()				; This group doesn't exist.
	(setq active (nth 1 (assoc group gnus-nocem-active)))
	(when (and (not (< (cdr gactive) (car gactive))) ; Empty group.
		   (or (not active)
		       (< (cdr active) (cdr gactive))))
	  ;; Ok, there are new articles in this group, se we fetch the
	  ;; headers.
	  (save-excursion
	    (let ((dependencies (make-vector 10 nil))
		  headers header)
	      (with-temp-buffer
		(setq headers
		      (if (eq 'nov
			      (gnus-retrieve-headers
			       (setq articles
				     (gnus-uncompress-range
				      (cons
				       (if active (1+ (cdr active))
					 (car gactive))
				       (cdr gactive))))
			       group))
			  (gnus-get-newsgroup-headers-xover
			   articles nil dependencies)
			(gnus-get-newsgroup-headers dependencies)))
		(while (setq header (pop headers))
		  ;; We take a closer look on all articles that have
		  ;; "@@NCM" in the subject.  Unless we already read
		  ;; this cross posted message.  Nocem messages
		  ;; are not allowed to have references, so we can
		  ;; ignore scanning followups.
		  (and (string-match "@@NCM" (mail-header-subject header))
		       (and gnus-nocem-check-from
			    (let ((case-fold-search t))
			      (catch 'ok
				(mapcar
				 (lambda (author)
				   (if (consp author)
				       (setq author (car author)))
				   (if (string-match
					author (mail-header-from header))
				       (throw 'ok t)))
				 gnus-nocem-issuers)
				nil)))
		       (or gnus-nocem-liberal-fetch
			   (and (or (string= "" (mail-header-references
						 header))
				    (null (mail-header-references header)))
				(not (member (mail-header-message-id header)
					     gnus-nocem-seen-message-ids))))
		       (push header check-headers)))
		(let* ((i 0)
		       (check-headers
			(last check-headers gnus-nocem-check-article-limit))
		       (len (length check-headers)))
		  (dolist (h check-headers)
		    (gnus-message
		     7 "Checking article %d in %s for NoCeM (%d of %d)..."
		     (mail-header-number h) group (incf i) len)
		    (gnus-nocem-check-article group h)))))))
	(setq gnus-nocem-active
	      (cons (list group gactive)
		    (delq (assoc group gnus-nocem-active)
			  gnus-nocem-active)))))
    ;; Save the results, if any.
    (gnus-nocem-save-cache)
    (gnus-nocem-save-active)))

(defun gnus-nocem-check-article (group header)
  "Check whether the current article is an NCM article and that we want it."
  ;; Get the article.
  (let ((date (mail-header-date header))
	(gnus-newsgroup-name group)
	issuer b e type)
    (when (or (not date)
	      (time-less-p
	       (time-since (date-to-time date))
	       (days-to-time gnus-nocem-expiry-wait)))
      (gnus-request-article-this-buffer (mail-header-number header) group)
      (goto-char (point-min))
      (when (re-search-forward "-----BEGIN PGP MESSAGE-----" nil t)
	(delete-region (point-min) (match-beginning 0)))
      (when (re-search-forward "-----END PGP MESSAGE-----\n?" nil t)
	(delete-region (match-end 0) (point-max)))
      (goto-char (point-min))
      ;; The article has to have proper NoCeM headers.
      (when (and (setq b (search-forward "\n@@BEGIN NCM HEADERS\n" nil t))
		 (setq e (search-forward "\n@@BEGIN NCM BODY\n" nil t)))
	;; We get the name of the issuer.
	(narrow-to-region b e)
	(setq issuer (mail-fetch-field "issuer")
	      type (mail-fetch-field "issuer"))
	(widen)
	(if (not (gnus-nocem-message-wanted-p issuer type))
	    (message "invalid NoCeM issuer: %s" issuer)
	  (and (gnus-nocem-verify-issuer issuer) ; She is who she says she is.
	       (gnus-nocem-enter-article) ; We gobble the message.
	       (push (mail-header-message-id header) ; But don't come back for
		     gnus-nocem-seen-message-ids))))))) ; second helpings.

(defun gnus-nocem-message-wanted-p (issuer type)
  (let ((issuers gnus-nocem-issuers)
	wanted conditions condition)
    (cond
     ;; Do the quick check first.
     ((member issuer issuers)
      t)
     ((setq conditions (cdr (assoc issuer issuers)))
      ;; Check whether we want this type.
      (while (setq condition (pop conditions))
	(cond
	 ((stringp condition)
	  (setq wanted (string-match condition type)))
	 ((and (consp condition)
	       (eq (car condition) 'not)
	       (stringp (cadr condition)))
	  (setq wanted (not (string-match (cadr condition) type))))
	 (t
	  (error "Invalid NoCeM condition: %S" condition))))
      wanted))))

(defun gnus-nocem-verify-issuer (person)
  "Verify using PGP that the canceler is who she says she is."
  (if (fboundp gnus-nocem-verifyer)
      (ignore-errors
	(funcall gnus-nocem-verifyer))
    ;; If we don't have Mailcrypt, then we use the message anyway.
    t))

(defun gnus-nocem-enter-article ()
  "Enter the current article into the NoCeM cache."
  (goto-char (point-min))
  (let ((b (search-forward "\n@@BEGIN NCM BODY\n" nil t))
	(e (search-forward "\n@@END NCM BODY\n" nil t))
	(buf (current-buffer))
	ncm id group)
    (when (and b e)
      (narrow-to-region b (1+ (match-beginning 0)))
      (goto-char (point-min))
      (while (search-forward "\t" nil t)
	(cond
	 ((not (ignore-errors
		 (setq group (let ((obarray gnus-active-hashtb)) (read buf)))))
	  ;; An error.
	  )
	 ((not (symbolp group))
	  ;; Ignore invalid entries.
	  )
	 ((not (boundp group))
	  ;; Make sure all entries in the hashtb are bound.
	  (set group nil))
	 (t
	  (when (gnus-gethash (gnus-group-real-name (symbol-name group))
			      gnus-nocem-real-group-hashtb)
	    ;; Valid group.
	    (beginning-of-line)
	    (while (eq (char-after) ?\t)
	      (forward-line -1))
	    (setq id (buffer-substring (point) (1- (search-forward "\t"))))
	    (unless (gnus-gethash id gnus-nocem-hashtb)
	      ;; only store if not already present
	      (gnus-sethash id t gnus-nocem-hashtb)
	      (push id ncm))
	    (forward-line 1)
	    (while (eq (char-after) ?\t)
	      (forward-line 1))))))
      (when ncm
	(setq gnus-nocem-touched-alist t)
	(push (cons (let ((time (current-time))) (setcdr (cdr time) nil) time)
		    ncm)
	      gnus-nocem-alist))
      t)))

(defun gnus-nocem-load-cache ()
  "Load the NoCeM cache."
  (interactive)
  (unless gnus-nocem-alist
    ;; The buffer doesn't exist, so we create it and load the NoCeM
    ;; cache.
    (when (file-exists-p (gnus-nocem-cache-file))
      (load (gnus-nocem-cache-file) t t t)
      (gnus-nocem-alist-to-hashtb))))

(defun gnus-nocem-save-cache ()
  "Save the NoCeM cache."
  (when (and gnus-nocem-alist
	     gnus-nocem-touched-alist)
    (with-temp-file (gnus-nocem-cache-file)
      (gnus-prin1 `(setq gnus-nocem-alist ',gnus-nocem-alist)))
    (setq gnus-nocem-touched-alist nil)))

(defun gnus-nocem-save-active ()
  "Save the NoCeM active file."
  (with-temp-file (gnus-nocem-active-file)
    (gnus-prin1 `(setq gnus-nocem-active ',gnus-nocem-active))))

(defun gnus-nocem-alist-to-hashtb ()
  "Create a hashtable from the Message-IDs we have."
  (let* ((alist gnus-nocem-alist)
	 (pprev (cons nil alist))
	 (prev pprev)
	 (expiry (days-to-time gnus-nocem-expiry-wait))
	 entry)
    (setq gnus-nocem-hashtb (gnus-make-hashtable (* (length alist) 51)))
    (while (setq entry (car alist))
      (if (not (time-less-p (time-since (car entry)) expiry))
	  ;; This entry has expired, so we remove it.
	  (setcdr prev (cdr alist))
	(setq prev alist)
	;; This is ok, so we enter it into the hashtable.
	(setq entry (cdr entry))
	(while entry
	  (gnus-sethash (car entry) t gnus-nocem-hashtb)
	  (setq entry (cdr entry))))
      (setq alist (cdr alist)))))

(gnus-add-shutdown 'gnus-nocem-close 'gnus)

(defun gnus-nocem-close ()
  "Clear internal NoCeM variables."
  (setq gnus-nocem-alist nil
	gnus-nocem-hashtb nil
	gnus-nocem-active nil
	gnus-nocem-touched-alist nil
	gnus-nocem-seen-message-ids nil
	gnus-nocem-real-group-hashtb nil))

(defun gnus-nocem-unwanted-article-p (id)
  "Say whether article ID in the current group is wanted."
  (and gnus-nocem-hashtb
       (gnus-gethash id gnus-nocem-hashtb)))

(provide 'gnus-nocem)

;;; arch-tag: 0e0c74ea-2f8e-4f3e-8fff-09f767c1adef
;;; gnus-nocem.el ends here
Commit	Line	Data
eec82323	1	;;; gnus-nocem.el --- NoCeM pseudo-cancellation treatment
16409b0b	2
e76ef45b	3	;; Copyright (C) 1995, 1996, 1997, 1998, 1999, 2000 Free Software Foundation, Inc.
eec82323	4
6748645f	5	;; Author: Lars Magne Ingebrigtsen <larsi@gnus.org>
eec82323 LMI	6	;; Keywords: news
	7
	8	;; This file is part of GNU Emacs.
	9
	10	;; GNU Emacs is free software; you can redistribute it and/or modify
	11	;; it under the terms of the GNU General Public License as published by
	12	;; the Free Software Foundation; either version 2, or (at your option)
	13	;; any later version.
	14
	15	;; GNU Emacs is distributed in the hope that it will be useful,
	16	;; but WITHOUT ANY WARRANTY; without even the implied warranty of
	17	;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	18	;; GNU General Public License for more details.
	19
	20	;; You should have received a copy of the GNU General Public License
	21	;; along with GNU Emacs; see the file COPYING. If not, write to the
	22	;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
	23	;; Boston, MA 02111-1307, USA.
	24
	25	;;; Commentary:
	26
	27	;;; Code:
	28
0b9d8890 RS	29	(eval-when-compile (require 'cl))
0b9d8890 RS	30
eec82323 LMI	31	(require 'gnus)
	32	(require 'nnmail)
	33	(require 'gnus-art)
	34	(require 'gnus-sum)
	35	(require 'gnus-range)
	36
	37	(defgroup gnus-nocem nil
	38	"NoCeM pseudo-cancellation treatment"
	39	:group 'gnus-score)
	40
	41	(defcustom gnus-nocem-groups
	42	'("news.lists.filters" "news.admin.net-abuse.bulletins"
	43	"alt.nocem.misc" "news.admin.net-abuse.announce")
6748645f	44	"*List of groups that will be searched for NoCeM messages."
eec82323 LMI	45	:group 'gnus-nocem
	46	:type '(repeat (string :tag "Group")))
	47
	48	(defcustom gnus-nocem-issuers
f49c4ef7 DL	49	'("AutoMoose-1" ; CancelMoose[tm]
	50	"clewis@ferret.ocunix" ; Chris Lewis
	51	"cosmo.roadkill"
	52	"SpamHippo"
	53	"hweede@snafu.de")
6748645f LMI	54	"*List of NoCeM issuers to pay attention to.
6748645f LMI	55
f49c4ef7 DL	56	This can also be a list of `(ISSUER CONDITION ...)' elements.
	57
	58	See <URL:http://www.xs4all.nl/~rosalind/nocemreg/nocemreg.html> for an
	59	issuer registry."
eec82323	60	:group 'gnus-nocem
6748645f	61	:type '(repeat (choice string sexp)))
eec82323 LMI	62
	63	(defcustom gnus-nocem-directory
	64	(nnheader-concat gnus-article-save-directory "NoCeM/")
	65	"*Directory where NoCeM files will be stored."
	66	:group 'gnus-nocem
	67	:type 'directory)
	68
	69	(defcustom gnus-nocem-expiry-wait 15
	70	"*Number of days to keep NoCeM headers in the cache."
	71	:group 'gnus-nocem
	72	:type 'integer)
	73
	74	(defcustom gnus-nocem-verifyer 'mc-verify
	75	"*Function called to verify that the NoCeM message is valid.
	76	One likely value is `mc-verify'. If the function in this variable
	77	isn't bound, the message will be used unconditionally."
	78	:group 'gnus-nocem
	79	:type '(radio (function-item mc-verify)
	80	(function :tag "other")))
	81
	82	(defcustom gnus-nocem-liberal-fetch nil
	83	"*If t try to fetch all messages which have @@NCM in the subject.
	84	Otherwise don't fetch messages which have references or whose message-id
1dda7cc8	85	matches a previously scanned and verified nocem message."
eec82323 LMI	86	:group 'gnus-nocem
	87	:type 'boolean)
	88
fd1d9d98	89	(defcustom gnus-nocem-check-article-limit 500
e76ef45b MB	90	"*If non-nil, the maximum number of articles to check in any NoCeM group."
e76ef45b MB	91	:group 'gnus-nocem
f49c4ef7	92	:version "21.1"
e76ef45b MB	93	:type '(choice (const :tag "unlimited" nil)
	94	(integer 1000)))
	95
f49c4ef7 DL	96	(defcustom gnus-nocem-check-from t
	97	"Non-nil means check for valid issuers in message bodies.
	98	Otherwise don't bother fetching articles unless their author matches a
	99	valid issuer, which is much faster if you are selective about the issuers."
	100	:group 'gnus-nocem
	101	:version "21.1"
	102	:type 'boolean)
	103
eec82323 LMI	104	;;; Internal variables
	105
	106	(defvar gnus-nocem-active nil)
	107	(defvar gnus-nocem-alist nil)
	108	(defvar gnus-nocem-touched-alist nil)
	109	(defvar gnus-nocem-hashtb nil)
	110	(defvar gnus-nocem-seen-message-ids nil)
	111
	112	;;; Functions
	113
	114	(defun gnus-nocem-active-file ()
	115	(concat (file-name-as-directory gnus-nocem-directory) "active"))
	116
	117	(defun gnus-nocem-cache-file ()
	118	(concat (file-name-as-directory gnus-nocem-directory) "cache"))
	119
a8151ef7 LMI	120	;;
	121	;; faster lookups for group names:
	122	;;
	123
	124	(defvar gnus-nocem-real-group-hashtb nil
	125	"Real-name mappings of subscribed groups.")
	126
	127	(defun gnus-fill-real-hashtb ()
6748645f	128	"Fill up a hash table with the real-name mappings from the user's active file."
a8151ef7 LMI	129	(setq gnus-nocem-real-group-hashtb (gnus-make-hashtable
	130	(length gnus-newsrc-alist)))
	131	(mapcar (lambda (group)
	132	(setq group (gnus-group-real-name (car group)))
	133	(gnus-sethash group t gnus-nocem-real-group-hashtb))
	134	gnus-newsrc-alist))
	135
eec82323 LMI	136	(defun gnus-nocem-scan-groups ()
	137	"Scan all NoCeM groups for new NoCeM messages."
	138	(interactive)
	139	(let ((groups gnus-nocem-groups)
	140	(gnus-inhibit-demon t)
16409b0b	141	group active gactive articles check-headers)
eec82323 LMI	142	(gnus-make-directory gnus-nocem-directory)
	143	;; Load any previous NoCeM headers.
	144	(gnus-nocem-load-cache)
a8151ef7 LMI	145	;; Get the group name mappings:
a8151ef7 LMI	146	(gnus-fill-real-hashtb)
eec82323 LMI	147	;; Read the active file if it hasn't been read yet.
	148	(and (file-exists-p (gnus-nocem-active-file))
	149	(not gnus-nocem-active)
	150	(ignore-errors
	151	(load (gnus-nocem-active-file) t t t)))
	152	;; Go through all groups and see whether new articles have
	153	;; arrived.
	154	(while (setq group (pop groups))
	155	(if (not (setq gactive (gnus-activate-group group)))
	156	() ; This group doesn't exist.
	157	(setq active (nth 1 (assoc group gnus-nocem-active)))
	158	(when (and (not (< (cdr gactive) (car gactive))) ; Empty group.
	159	(or (not active)
	160	(< (cdr active) (cdr gactive))))
	161	;; Ok, there are new articles in this group, se we fetch the
	162	;; headers.
	163	(save-excursion
	164	(let ((dependencies (make-vector 10 nil))
	165	headers header)
16409b0b	166	(with-temp-buffer
eec82323 LMI	167	(setq headers
	168	(if (eq 'nov
	169	(gnus-retrieve-headers
	170	(setq articles
	171	(gnus-uncompress-range
	172	(cons
	173	(if active (1+ (cdr active))
	174	(car gactive))
	175	(cdr gactive))))
	176	group))
	177	(gnus-get-newsgroup-headers-xover
	178	articles nil dependencies)
	179	(gnus-get-newsgroup-headers dependencies)))
	180	(while (setq header (pop headers))
	181	;; We take a closer look on all articles that have
	182	;; "@@NCM" in the subject. Unless we already read
	183	;; this cross posted message. Nocem messages
	184	;; are not allowed to have references, so we can
	185	;; ignore scanning followups.
	186	(and (string-match "@@NCM" (mail-header-subject header))
f49c4ef7 DL	187	(and gnus-nocem-check-from
	188	(let ((case-fold-search t))
	189	(catch 'ok
	190	(mapcar
	191	(lambda (author)
	192	(if (consp author)
	193	(setq author (car author)))
	194	(if (string-match
	195	author (mail-header-from header))
	196	(throw 'ok t)))
	197	gnus-nocem-issuers)
	198	nil)))
eec82323 LMI	199	(or gnus-nocem-liberal-fetch
	200	(and (or (string= "" (mail-header-references
	201	header))
	202	(null (mail-header-references header)))
	203	(not (member (mail-header-message-id header)
	204	gnus-nocem-seen-message-ids))))
16409b0b	205	(push header check-headers)))
e76ef45b MB	206	(let* ((i 0)
	207	(check-headers
	208	(last check-headers gnus-nocem-check-article-limit))
	209	(len (length check-headers)))
16409b0b GM	210	(dolist (h check-headers)
	211	(gnus-message
	212	7 "Checking article %d in %s for NoCeM (%d of %d)..."
	213	(mail-header-number h) group (incf i) len)
	214	(gnus-nocem-check-article group h)))))))
eec82323 LMI	215	(setq gnus-nocem-active
	216	(cons (list group gactive)
	217	(delq (assoc group gnus-nocem-active)
	218	gnus-nocem-active)))))
	219	;; Save the results, if any.
	220	(gnus-nocem-save-cache)
	221	(gnus-nocem-save-active)))
	222
	223	(defun gnus-nocem-check-article (group header)
	224	"Check whether the current article is an NCM article and that we want it."
	225	;; Get the article.
eec82323	226	(let ((date (mail-header-date header))
f49c4ef7	227	(gnus-newsgroup-name group)
6748645f	228	issuer b e type)
eec82323	229	(when (or (not date)
16409b0b GM	230	(time-less-p
	231	(time-since (date-to-time date))
	232	(days-to-time gnus-nocem-expiry-wait)))
eec82323 LMI	233	(gnus-request-article-this-buffer (mail-header-number header) group)
	234	(goto-char (point-min))
	235	(when (re-search-forward "-----BEGIN PGP MESSAGE-----" nil t)
	236	(delete-region (point-min) (match-beginning 0)))
	237	(when (re-search-forward "-----END PGP MESSAGE-----\n?" nil t)
	238	(delete-region (match-end 0) (point-max)))
	239	(goto-char (point-min))
	240	;; The article has to have proper NoCeM headers.
	241	(when (and (setq b (search-forward "\n@@BEGIN NCM HEADERS\n" nil t))
	242	(setq e (search-forward "\n@@BEGIN NCM BODY\n" nil t)))
	243	;; We get the name of the issuer.
	244	(narrow-to-region b e)
6748645f LMI	245	(setq issuer (mail-fetch-field "issuer")
6748645f LMI	246	type (mail-fetch-field "issuer"))
eec82323	247	(widen)
6748645f LMI	248	(if (not (gnus-nocem-message-wanted-p issuer type))
	249	(message "invalid NoCeM issuer: %s" issuer)
	250	(and (gnus-nocem-verify-issuer issuer) ; She is who she says she is.
	251	(gnus-nocem-enter-article) ; We gobble the message.
	252	(push (mail-header-message-id header) ; But don't come back for
	253	gnus-nocem-seen-message-ids))))))) ; second helpings.
	254
	255	(defun gnus-nocem-message-wanted-p (issuer type)
	256	(let ((issuers gnus-nocem-issuers)
	257	wanted conditions condition)
	258	(cond
	259	;; Do the quick check first.
	260	((member issuer issuers)
	261	t)
	262	((setq conditions (cdr (assoc issuer issuers)))
	263	;; Check whether we want this type.
	264	(while (setq condition (pop conditions))
	265	(cond
	266	((stringp condition)
	267	(setq wanted (string-match condition type)))
	268	((and (consp condition)
	269	(eq (car condition) 'not)
	270	(stringp (cadr condition)))
	271	(setq wanted (not (string-match (cadr condition) type))))
	272	(t
	273	(error "Invalid NoCeM condition: %S" condition))))
	274	wanted))))
eec82323 LMI	275
	276	(defun gnus-nocem-verify-issuer (person)
	277	"Verify using PGP that the canceler is who she says she is."
	278	(if (fboundp gnus-nocem-verifyer)
a8151ef7 LMI	279	(ignore-errors
a8151ef7 LMI	280	(funcall gnus-nocem-verifyer))
eec82323 LMI	281	;; If we don't have Mailcrypt, then we use the message anyway.
	282	t))
	283
	284	(defun gnus-nocem-enter-article ()
	285	"Enter the current article into the NoCeM cache."
	286	(goto-char (point-min))
	287	(let ((b (search-forward "\n@@BEGIN NCM BODY\n" nil t))
	288	(e (search-forward "\n@@END NCM BODY\n" nil t))
	289	(buf (current-buffer))
	290	ncm id group)
	291	(when (and b e)
	292	(narrow-to-region b (1+ (match-beginning 0)))
	293	(goto-char (point-min))
	294	(while (search-forward "\t" nil t)
	295	(cond
	296	((not (ignore-errors
	297	(setq group (let ((obarray gnus-active-hashtb)) (read buf)))))
	298	;; An error.
	299	)
	300	((not (symbolp group))
	301	;; Ignore invalid entries.
	302	)
	303	((not (boundp group))
	304	;; Make sure all entries in the hashtb are bound.
	305	(set group nil))
	306	(t
a8151ef7 LMI	307	(when (gnus-gethash (gnus-group-real-name (symbol-name group))
a8151ef7 LMI	308	gnus-nocem-real-group-hashtb)
eec82323 LMI	309	;; Valid group.
eec82323 LMI	310	(beginning-of-line)
16409b0b	311	(while (eq (char-after) ?\t)
eec82323 LMI	312	(forward-line -1))
	313	(setq id (buffer-substring (point) (1- (search-forward "\t"))))
	314	(unless (gnus-gethash id gnus-nocem-hashtb)
	315	;; only store if not already present
	316	(gnus-sethash id t gnus-nocem-hashtb)
	317	(push id ncm))
	318	(forward-line 1)
16409b0b	319	(while (eq (char-after) ?\t)
eec82323 LMI	320	(forward-line 1))))))
	321	(when ncm
	322	(setq gnus-nocem-touched-alist t)
	323	(push (cons (let ((time (current-time))) (setcdr (cdr time) nil) time)
	324	ncm)
	325	gnus-nocem-alist))
	326	t)))
	327
	328	(defun gnus-nocem-load-cache ()
	329	"Load the NoCeM cache."
	330	(interactive)
	331	(unless gnus-nocem-alist
	332	;; The buffer doesn't exist, so we create it and load the NoCeM
	333	;; cache.
	334	(when (file-exists-p (gnus-nocem-cache-file))
	335	(load (gnus-nocem-cache-file) t t t)
	336	(gnus-nocem-alist-to-hashtb))))
	337
	338	(defun gnus-nocem-save-cache ()
	339	"Save the NoCeM cache."
	340	(when (and gnus-nocem-alist
	341	gnus-nocem-touched-alist)
16409b0b	342	(with-temp-file (gnus-nocem-cache-file)
eec82323 LMI	343	(gnus-prin1 `(setq gnus-nocem-alist ',gnus-nocem-alist)))
	344	(setq gnus-nocem-touched-alist nil)))
	345
	346	(defun gnus-nocem-save-active ()
	347	"Save the NoCeM active file."
16409b0b	348	(with-temp-file (gnus-nocem-active-file)
eec82323 LMI	349	(gnus-prin1 `(setq gnus-nocem-active ',gnus-nocem-active))))
	350
	351	(defun gnus-nocem-alist-to-hashtb ()
	352	"Create a hashtable from the Message-IDs we have."
	353	(let* ((alist gnus-nocem-alist)
	354	(pprev (cons nil alist))
	355	(prev pprev)
16409b0b	356	(expiry (days-to-time gnus-nocem-expiry-wait))
eec82323 LMI	357	entry)
	358	(setq gnus-nocem-hashtb (gnus-make-hashtable (* (length alist) 51)))
	359	(while (setq entry (car alist))
16409b0b	360	(if (not (time-less-p (time-since (car entry)) expiry))
eec82323 LMI	361	;; This entry has expired, so we remove it.
	362	(setcdr prev (cdr alist))
	363	(setq prev alist)
	364	;; This is ok, so we enter it into the hashtable.
	365	(setq entry (cdr entry))
	366	(while entry
	367	(gnus-sethash (car entry) t gnus-nocem-hashtb)
	368	(setq entry (cdr entry))))
	369	(setq alist (cdr alist)))))
	370
	371	(gnus-add-shutdown 'gnus-nocem-close 'gnus)
	372
	373	(defun gnus-nocem-close ()
	374	"Clear internal NoCeM variables."
	375	(setq gnus-nocem-alist nil
	376	gnus-nocem-hashtb nil
	377	gnus-nocem-active nil
	378	gnus-nocem-touched-alist nil
a8151ef7 LMI	379	gnus-nocem-seen-message-ids nil
a8151ef7 LMI	380	gnus-nocem-real-group-hashtb nil))
eec82323 LMI	381
	382	(defun gnus-nocem-unwanted-article-p (id)
	383	"Say whether article ID in the current group is wanted."
6748645f LMI	384	(and gnus-nocem-hashtb
6748645f LMI	385	(gnus-gethash id gnus-nocem-hashtb)))
eec82323 LMI	386
	387	(provide 'gnus-nocem)
	388
ab5796a9	389	;;; arch-tag: 0e0c74ea-2f8e-4f3e-8fff-09f767c1adef
eec82323	390	;;; gnus-nocem.el ends here