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

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

;; Copyright (C) 1995, 1996, 1997, 1998, 1999, 2000, 2002, 2003, 2004,
;;   2005, 2006 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., 51 Franklin Street, Fifth Floor,
;; Boston, MA 02110-1301, 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
  :link '(url-link "http://www.xs4all.nl/~rosalind/nocemreg/nocemreg.html")
  :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 'pgg-verify
  "*Function called to verify that the NoCeM message is valid.
One likely value is `pgg-verify'.  If the function in this variable
isn't bound, the message will be used unconditionally."
  :group 'gnus-nocem
  :type '(radio (function-item pgg-verify)
		(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))

;;;###autoload
(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)))
		(setq check-headers (last (nreverse check-headers)
					  gnus-nocem-check-article-limit))
		(let ((i 0)
		      (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\\( SIGNED\\)? MESSAGE-----"
	     nil t)
	(delete-region (point-min) (match-beginning 0)))
      (when (re-search-forward
	     "-----END PGP \\(MESSAGE\\|SIGNATURE\\)-----\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 "type"))
	(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)
	  (when (string-match condition type)
	    (setq wanted t)))
	 ((and (consp condition)
	       (eq (car condition) 'not)
	       (stringp (cadr condition)))
	  (when (string-match (cadr condition) type)
	    (setq wanted nil)))
	 (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 (functionp 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-nocem-real-group-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 (if gnus-nocem-hashtb
			(gnus-gethash id gnus-nocem-hashtb)
		      (setq gnus-nocem-hashtb (gnus-make-hashtable))
		      nil)
	      ;; 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)))

;;;###autoload
(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
e84b4b86	3	;; Copyright (C) 1995, 1996, 1997, 1998, 1999, 2000, 2002, 2003, 2004,
88e6695f	4	;; 2005, 2006 Free Software Foundation, Inc.
eec82323	5
6748645f	6	;; Author: Lars Magne Ingebrigtsen <larsi@gnus.org>
eec82323 LMI	7	;; Keywords: news
	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 by
	13	;; the Free Software Foundation; either version 2, or (at your option)
	14	;; any later version.
	15
	16	;; GNU Emacs is distributed in the hope that it will be useful,
	17	;; but WITHOUT ANY WARRANTY; without even the implied warranty of
	18	;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	19	;; GNU General Public License for more details.
	20
	21	;; You should have received a copy of the GNU General Public License
	22	;; along with GNU Emacs; see the file COPYING. If not, write to the
3a35cf56 LK	23	;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
3a35cf56 LK	24	;; Boston, MA 02110-1301, USA.
eec82323 LMI	25
	26	;;; Commentary:
	27
	28	;;; Code:
	29
0b9d8890 RS	30	(eval-when-compile (require 'cl))
0b9d8890 RS	31
eec82323 LMI	32	(require 'gnus)
	33	(require 'nnmail)
	34	(require 'gnus-art)
	35	(require 'gnus-sum)
	36	(require 'gnus-range)
	37
	38	(defgroup gnus-nocem nil
80a14ae0	39	"NoCeM pseudo-cancellation treatment."
eec82323 LMI	40	:group 'gnus-score)
	41
	42	(defcustom gnus-nocem-groups
	43	'("news.lists.filters" "news.admin.net-abuse.bulletins"
	44	"alt.nocem.misc" "news.admin.net-abuse.announce")
6748645f	45	"*List of groups that will be searched for NoCeM messages."
eec82323 LMI	46	:group 'gnus-nocem
	47	:type '(repeat (string :tag "Group")))
	48
	49	(defcustom gnus-nocem-issuers
f49c4ef7 DL	50	'("AutoMoose-1" ; CancelMoose[tm]
	51	"clewis@ferret.ocunix" ; Chris Lewis
	52	"cosmo.roadkill"
	53	"SpamHippo"
	54	"hweede@snafu.de")
6748645f LMI	55	"*List of NoCeM issuers to pay attention to.
6748645f LMI	56
f49c4ef7 DL	57	This can also be a list of `(ISSUER CONDITION ...)' elements.
	58
	59	See <URL:http://www.xs4all.nl/~rosalind/nocemreg/nocemreg.html> for an
	60	issuer registry."
eec82323	61	:group 'gnus-nocem
23f87bed	62	:link '(url-link "http://www.xs4all.nl/~rosalind/nocemreg/nocemreg.html")
6748645f	63	:type '(repeat (choice string sexp)))
eec82323 LMI	64
	65	(defcustom gnus-nocem-directory
	66	(nnheader-concat gnus-article-save-directory "NoCeM/")
	67	"*Directory where NoCeM files will be stored."
	68	:group 'gnus-nocem
	69	:type 'directory)
	70
	71	(defcustom gnus-nocem-expiry-wait 15
	72	"*Number of days to keep NoCeM headers in the cache."
	73	:group 'gnus-nocem
	74	:type 'integer)
	75
84861437	76	(defcustom gnus-nocem-verifyer 'pgg-verify
eec82323	77	"*Function called to verify that the NoCeM message is valid.
84861437	78	One likely value is `pgg-verify'. If the function in this variable
eec82323 LMI	79	isn't bound, the message will be used unconditionally."
eec82323 LMI	80	:group 'gnus-nocem
84861437 MB	81	:type '(radio (function-item pgg-verify)
84861437 MB	82	(function-item mc-verify)
eec82323 LMI	83	(function :tag "other")))
	84
	85	(defcustom gnus-nocem-liberal-fetch nil
	86	"*If t try to fetch all messages which have @@NCM in the subject.
	87	Otherwise don't fetch messages which have references or whose message-id
1dda7cc8	88	matches a previously scanned and verified nocem message."
eec82323 LMI	89	:group 'gnus-nocem
	90	:type 'boolean)
	91
fd1d9d98	92	(defcustom gnus-nocem-check-article-limit 500
e76ef45b MB	93	"*If non-nil, the maximum number of articles to check in any NoCeM group."
e76ef45b MB	94	:group 'gnus-nocem
f49c4ef7	95	:version "21.1"
e76ef45b MB	96	:type '(choice (const :tag "unlimited" nil)
	97	(integer 1000)))
	98
f49c4ef7 DL	99	(defcustom gnus-nocem-check-from t
	100	"Non-nil means check for valid issuers in message bodies.
	101	Otherwise don't bother fetching articles unless their author matches a
	102	valid issuer, which is much faster if you are selective about the issuers."
	103	:group 'gnus-nocem
	104	:version "21.1"
	105	:type 'boolean)
	106
eec82323 LMI	107	;;; Internal variables
	108
	109	(defvar gnus-nocem-active nil)
	110	(defvar gnus-nocem-alist nil)
	111	(defvar gnus-nocem-touched-alist nil)
	112	(defvar gnus-nocem-hashtb nil)
	113	(defvar gnus-nocem-seen-message-ids nil)
	114
	115	;;; Functions
	116
	117	(defun gnus-nocem-active-file ()
	118	(concat (file-name-as-directory gnus-nocem-directory) "active"))
	119
	120	(defun gnus-nocem-cache-file ()
	121	(concat (file-name-as-directory gnus-nocem-directory) "cache"))
	122
a8151ef7 LMI	123	;;
	124	;; faster lookups for group names:
	125	;;
	126
	127	(defvar gnus-nocem-real-group-hashtb nil
	128	"Real-name mappings of subscribed groups.")
	129
	130	(defun gnus-fill-real-hashtb ()
6748645f	131	"Fill up a hash table with the real-name mappings from the user's active file."
a8151ef7 LMI	132	(setq gnus-nocem-real-group-hashtb (gnus-make-hashtable
	133	(length gnus-newsrc-alist)))
	134	(mapcar (lambda (group)
	135	(setq group (gnus-group-real-name (car group)))
	136	(gnus-sethash group t gnus-nocem-real-group-hashtb))
	137	gnus-newsrc-alist))
	138
ea8ae765	139	;;;###autoload
eec82323 LMI	140	(defun gnus-nocem-scan-groups ()
	141	"Scan all NoCeM groups for new NoCeM messages."
	142	(interactive)
	143	(let ((groups gnus-nocem-groups)
	144	(gnus-inhibit-demon t)
16409b0b	145	group active gactive articles check-headers)
eec82323 LMI	146	(gnus-make-directory gnus-nocem-directory)
	147	;; Load any previous NoCeM headers.
	148	(gnus-nocem-load-cache)
a8151ef7 LMI	149	;; Get the group name mappings:
a8151ef7 LMI	150	(gnus-fill-real-hashtb)
eec82323 LMI	151	;; Read the active file if it hasn't been read yet.
	152	(and (file-exists-p (gnus-nocem-active-file))
	153	(not gnus-nocem-active)
	154	(ignore-errors
	155	(load (gnus-nocem-active-file) t t t)))
	156	;; Go through all groups and see whether new articles have
	157	;; arrived.
	158	(while (setq group (pop groups))
	159	(if (not (setq gactive (gnus-activate-group group)))
	160	() ; This group doesn't exist.
	161	(setq active (nth 1 (assoc group gnus-nocem-active)))
	162	(when (and (not (< (cdr gactive) (car gactive))) ; Empty group.
	163	(or (not active)
	164	(< (cdr active) (cdr gactive))))
	165	;; Ok, there are new articles in this group, se we fetch the
	166	;; headers.
	167	(save-excursion
	168	(let ((dependencies (make-vector 10 nil))
	169	headers header)
16409b0b	170	(with-temp-buffer
eec82323 LMI	171	(setq headers
	172	(if (eq 'nov
	173	(gnus-retrieve-headers
	174	(setq articles
	175	(gnus-uncompress-range
	176	(cons
	177	(if active (1+ (cdr active))
	178	(car gactive))
	179	(cdr gactive))))
	180	group))
	181	(gnus-get-newsgroup-headers-xover
	182	articles nil dependencies)
	183	(gnus-get-newsgroup-headers dependencies)))
	184	(while (setq header (pop headers))
	185	;; We take a closer look on all articles that have
	186	;; "@@NCM" in the subject. Unless we already read
	187	;; this cross posted message. Nocem messages
	188	;; are not allowed to have references, so we can
	189	;; ignore scanning followups.
	190	(and (string-match "@@NCM" (mail-header-subject header))
f49c4ef7 DL	191	(and gnus-nocem-check-from
	192	(let ((case-fold-search t))
	193	(catch 'ok
	194	(mapcar
	195	(lambda (author)
	196	(if (consp author)
	197	(setq author (car author)))
	198	(if (string-match
	199	author (mail-header-from header))
	200	(throw 'ok t)))
	201	gnus-nocem-issuers)
	202	nil)))
eec82323 LMI	203	(or gnus-nocem-liberal-fetch
	204	(and (or (string= "" (mail-header-references
	205	header))
	206	(null (mail-header-references header)))
	207	(not (member (mail-header-message-id header)
	208	gnus-nocem-seen-message-ids))))
16409b0b	209	(push header check-headers)))
ea8ae765 MB	210	(setq check-headers (last (nreverse check-headers)
	211	gnus-nocem-check-article-limit))
	212	(let ((i 0)
	213	(len (length check-headers)))
16409b0b GM	214	(dolist (h check-headers)
	215	(gnus-message
	216	7 "Checking article %d in %s for NoCeM (%d of %d)..."
	217	(mail-header-number h) group (incf i) len)
	218	(gnus-nocem-check-article group h)))))))
eec82323 LMI	219	(setq gnus-nocem-active
	220	(cons (list group gactive)
	221	(delq (assoc group gnus-nocem-active)
	222	gnus-nocem-active)))))
	223	;; Save the results, if any.
	224	(gnus-nocem-save-cache)
	225	(gnus-nocem-save-active)))
	226
	227	(defun gnus-nocem-check-article (group header)
	228	"Check whether the current article is an NCM article and that we want it."
	229	;; Get the article.
eec82323	230	(let ((date (mail-header-date header))
f49c4ef7	231	(gnus-newsgroup-name group)
6748645f	232	issuer b e type)
eec82323	233	(when (or (not date)
16409b0b GM	234	(time-less-p
	235	(time-since (date-to-time date))
	236	(days-to-time gnus-nocem-expiry-wait)))
eec82323 LMI	237	(gnus-request-article-this-buffer (mail-header-number header) group)
eec82323 LMI	238	(goto-char (point-min))
ea8ae765 MB	239	(when (re-search-forward
	240	"-----BEGIN PGP\\( SIGNED\\)? MESSAGE-----"
	241	nil t)
eec82323	242	(delete-region (point-min) (match-beginning 0)))
ea8ae765 MB	243	(when (re-search-forward
	244	"-----END PGP \\(MESSAGE\\\|SIGNATURE\\)-----\n?"
	245	nil t)
eec82323 LMI	246	(delete-region (match-end 0) (point-max)))
	247	(goto-char (point-min))
	248	;; The article has to have proper NoCeM headers.
	249	(when (and (setq b (search-forward "\n@@BEGIN NCM HEADERS\n" nil t))
	250	(setq e (search-forward "\n@@BEGIN NCM BODY\n" nil t)))
	251	;; We get the name of the issuer.
	252	(narrow-to-region b e)
6748645f	253	(setq issuer (mail-fetch-field "issuer")
84861437	254	type (mail-fetch-field "type"))
eec82323	255	(widen)
6748645f LMI	256	(if (not (gnus-nocem-message-wanted-p issuer type))
	257	(message "invalid NoCeM issuer: %s" issuer)
	258	(and (gnus-nocem-verify-issuer issuer) ; She is who she says she is.
	259	(gnus-nocem-enter-article) ; We gobble the message.
	260	(push (mail-header-message-id header) ; But don't come back for
	261	gnus-nocem-seen-message-ids))))))) ; second helpings.
	262
	263	(defun gnus-nocem-message-wanted-p (issuer type)
	264	(let ((issuers gnus-nocem-issuers)
	265	wanted conditions condition)
	266	(cond
	267	;; Do the quick check first.
	268	((member issuer issuers)
	269	t)
	270	((setq conditions (cdr (assoc issuer issuers)))
	271	;; Check whether we want this type.
	272	(while (setq condition (pop conditions))
	273	(cond
	274	((stringp condition)
84861437 MB	275	(when (string-match condition type)
84861437 MB	276	(setq wanted t)))
6748645f LMI	277	((and (consp condition)
	278	(eq (car condition) 'not)
	279	(stringp (cadr condition)))
84861437 MB	280	(when (string-match (cadr condition) type)
84861437 MB	281	(setq wanted nil)))
6748645f LMI	282	(t
	283	(error "Invalid NoCeM condition: %S" condition))))
	284	wanted))))
eec82323 LMI	285
	286	(defun gnus-nocem-verify-issuer (person)
	287	"Verify using PGP that the canceler is who she says she is."
84861437	288	(if (functionp gnus-nocem-verifyer)
a8151ef7 LMI	289	(ignore-errors
a8151ef7 LMI	290	(funcall gnus-nocem-verifyer))
eec82323 LMI	291	;; If we don't have Mailcrypt, then we use the message anyway.
	292	t))
	293
	294	(defun gnus-nocem-enter-article ()
	295	"Enter the current article into the NoCeM cache."
	296	(goto-char (point-min))
	297	(let ((b (search-forward "\n@@BEGIN NCM BODY\n" nil t))
	298	(e (search-forward "\n@@END NCM BODY\n" nil t))
	299	(buf (current-buffer))
	300	ncm id group)
	301	(when (and b e)
	302	(narrow-to-region b (1+ (match-beginning 0)))
	303	(goto-char (point-min))
	304	(while (search-forward "\t" nil t)
	305	(cond
	306	((not (ignore-errors
23f87bed MB	307	(setq group (let ((obarray gnus-nocem-real-group-hashtb))
23f87bed MB	308	(read buf)))))
eec82323 LMI	309	;; An error.
	310	)
	311	((not (symbolp group))
	312	;; Ignore invalid entries.
	313	)
	314	((not (boundp group))
	315	;; Make sure all entries in the hashtb are bound.
	316	(set group nil))
	317	(t
a8151ef7 LMI	318	(when (gnus-gethash (gnus-group-real-name (symbol-name group))
a8151ef7 LMI	319	gnus-nocem-real-group-hashtb)
eec82323 LMI	320	;; Valid group.
eec82323 LMI	321	(beginning-of-line)
16409b0b	322	(while (eq (char-after) ?\t)
eec82323 LMI	323	(forward-line -1))
eec82323 LMI	324	(setq id (buffer-substring (point) (1- (search-forward "\t"))))
84861437 MB	325	(unless (if gnus-nocem-hashtb
	326	(gnus-gethash id gnus-nocem-hashtb)
	327	(setq gnus-nocem-hashtb (gnus-make-hashtable))
	328	nil)
eec82323 LMI	329	;; only store if not already present
	330	(gnus-sethash id t gnus-nocem-hashtb)
	331	(push id ncm))
	332	(forward-line 1)
16409b0b	333	(while (eq (char-after) ?\t)
eec82323 LMI	334	(forward-line 1))))))
	335	(when ncm
	336	(setq gnus-nocem-touched-alist t)
	337	(push (cons (let ((time (current-time))) (setcdr (cdr time) nil) time)
	338	ncm)
	339	gnus-nocem-alist))
	340	t)))
	341
ea8ae765	342	;;;###autoload
eec82323 LMI	343	(defun gnus-nocem-load-cache ()
	344	"Load the NoCeM cache."
	345	(interactive)
	346	(unless gnus-nocem-alist
	347	;; The buffer doesn't exist, so we create it and load the NoCeM
	348	;; cache.
	349	(when (file-exists-p (gnus-nocem-cache-file))
	350	(load (gnus-nocem-cache-file) t t t)
	351	(gnus-nocem-alist-to-hashtb))))
	352
	353	(defun gnus-nocem-save-cache ()
	354	"Save the NoCeM cache."
	355	(when (and gnus-nocem-alist
	356	gnus-nocem-touched-alist)
16409b0b	357	(with-temp-file (gnus-nocem-cache-file)
eec82323 LMI	358	(gnus-prin1 `(setq gnus-nocem-alist ',gnus-nocem-alist)))
	359	(setq gnus-nocem-touched-alist nil)))
	360
	361	(defun gnus-nocem-save-active ()
	362	"Save the NoCeM active file."
16409b0b	363	(with-temp-file (gnus-nocem-active-file)
eec82323 LMI	364	(gnus-prin1 `(setq gnus-nocem-active ',gnus-nocem-active))))
	365
	366	(defun gnus-nocem-alist-to-hashtb ()
	367	"Create a hashtable from the Message-IDs we have."
	368	(let* ((alist gnus-nocem-alist)
	369	(pprev (cons nil alist))
	370	(prev pprev)
16409b0b	371	(expiry (days-to-time gnus-nocem-expiry-wait))
eec82323 LMI	372	entry)
	373	(setq gnus-nocem-hashtb (gnus-make-hashtable (* (length alist) 51)))
	374	(while (setq entry (car alist))
16409b0b	375	(if (not (time-less-p (time-since (car entry)) expiry))
eec82323 LMI	376	;; This entry has expired, so we remove it.
	377	(setcdr prev (cdr alist))
	378	(setq prev alist)
	379	;; This is ok, so we enter it into the hashtable.
	380	(setq entry (cdr entry))
	381	(while entry
	382	(gnus-sethash (car entry) t gnus-nocem-hashtb)
	383	(setq entry (cdr entry))))
	384	(setq alist (cdr alist)))))
	385
	386	(gnus-add-shutdown 'gnus-nocem-close 'gnus)
	387
	388	(defun gnus-nocem-close ()
	389	"Clear internal NoCeM variables."
	390	(setq gnus-nocem-alist nil
	391	gnus-nocem-hashtb nil
	392	gnus-nocem-active nil
	393	gnus-nocem-touched-alist nil
a8151ef7 LMI	394	gnus-nocem-seen-message-ids nil
a8151ef7 LMI	395	gnus-nocem-real-group-hashtb nil))
eec82323 LMI	396
	397	(defun gnus-nocem-unwanted-article-p (id)
	398	"Say whether article ID in the current group is wanted."
6748645f LMI	399	(and gnus-nocem-hashtb
6748645f LMI	400	(gnus-gethash id gnus-nocem-hashtb)))
eec82323 LMI	401
	402	(provide 'gnus-nocem)
	403
ab5796a9	404	;;; arch-tag: 0e0c74ea-2f8e-4f3e-8fff-09f767c1adef
eec82323	405	;;; gnus-nocem.el ends here