;;; nnspool.el --- spool access for GNU Emacs

;; Copyright (C) 1988,89,90,93,94,95 Free Software Foundation, Inc.

;; Author: Masanobu UMEDA <umerin@flab.flab.fujitsu.junet>
;; 	Lars Magne Ingebrigtsen <larsi@ifi.uio.no>
;; 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:

(require 'nnheader)
(require 'nntp)
(require 'timezone)

(defvar nnspool-inews-program news-inews-program
  "Program to post news.
This is most commonly `inews' or `injnews'.")

(defvar nnspool-inews-switches '("-h")
  "Switches for nnspool-request-post to pass to `inews' for posting news.
If you are using Cnews, you probably should set this variable to nil.")

(defvar nnspool-spool-directory news-path
  "Local news spool directory.")

(defvar nnspool-nov-directory (concat nnspool-spool-directory "over.view/")
  "Local news nov directory.")

(defvar nnspool-lib-dir "/usr/lib/news/"
  "Where the local news library files are stored.")

(defvar nnspool-active-file (concat nnspool-lib-dir "active")
  "Local news active file.")

(defvar nnspool-newsgroups-file (concat nnspool-lib-dir "newsgroups")
  "Local news newsgroups file.")

(defvar nnspool-distributions-file (concat nnspool-lib-dir "distributions")
  "Local news distributions file.")

(defvar nnspool-history-file (concat nnspool-lib-dir "history")
  "Local news history file.")

(defvar nnspool-active-times-file (concat nnspool-lib-dir "active.times")
  "Local news active date file.")

(defvar nnspool-large-newsgroup 50
  "The number of the articles which indicates a large newsgroup.
If the number of the articles is greater than the value, verbose
messages will be shown to indicate the current status.")

(defvar nnspool-nov-is-evil nil
  "Non-nil means that nnspool will never return NOV lines instead of headers.")

(defconst nnspool-sift-nov-with-sed nil
  "If non-nil, use sed to get the relevant portion from the overview file.
If nil, nnspool will load the entire file into a buffer and process it
there.")



(defconst nnspool-version "nnspool 2.0"
  "Version numbers of this version of NNSPOOL.")

(defvar nnspool-current-directory nil
  "Current news group directory.")

(defvar nnspool-current-group nil)
(defvar nnspool-status-string "")



(defvar nnspool-current-server nil)
(defvar nnspool-server-alist nil)
(defvar nnspool-server-variables 
  (list
   (list 'nnspool-inews-program nnspool-inews-program)
   (list 'nnspool-inews-switches nnspool-inews-switches)
   (list 'nnspool-spool-directory nnspool-spool-directory)
   (list 'nnspool-nov-directory nnspool-nov-directory)
   (list 'nnspool-lib-dir nnspool-lib-dir)
   (list 'nnspool-active-file nnspool-active-file)
   (list 'nnspool-newsgroups-file nnspool-newsgroups-file)
   (list 'nnspool-distributions-file nnspool-distributions-file)
   (list 'nnspool-history-file nnspool-history-file)
   (list 'nnspool-active-times-file nnspool-active-times-file)
   (list 'nnspool-large-newsgroup nnspool-large-newsgroup)
   (list 'nnspool-nov-is-evil nnspool-nov-is-evil)
   (list 'nnspool-sift-nov-with-sed nnspool-sift-nov-with-sed)
   '(nnspool-current-directory nil)
   '(nnspool-current-group nil)
   '(nnspool-status-string "")))


;;; Interface functions.

(defun nnspool-retrieve-headers (sequence &optional newsgroup server)
  "Retrieve the headers for the articles in SEQUENCE.
Newsgroup must be selected before calling this function."
  (save-excursion
    (set-buffer nntp-server-buffer)
    (erase-buffer)
    (let* ((number (length sequence))
	   (count 0)
	   (do-message (and (numberp nnspool-large-newsgroup)
			    (> number nnspool-large-newsgroup)))
	   file beg article)
      (if (not (nnspool-possibly-change-directory newsgroup))
	  ()
	(if (and (numberp (car sequence))
		 (nnspool-retrieve-headers-with-nov sequence))
	    'nov
	  (while sequence
	    (setq article (car sequence))
	    (if (stringp article)
		(progn
		  (setq file (nnspool-find-article-by-message-id article))
		  (setq article 0))
	      (setq file (concat nnspool-current-directory 
				 (int-to-string article))))
	    (and file (file-exists-p file)
		 (progn
		   (insert (format "221 %d Article retrieved.\n" article))
		   (setq beg (point))
		   (nnheader-insert-head file)
		   (goto-char beg)
		   (search-forward "\n\n" nil t)
		   (forward-char -1)
		   (insert ".\n")
		   (delete-region (point) (point-max))))
	    (setq sequence (cdr sequence))
	    
	    (and do-message
		 (zerop (% (setq count (1+ count)) 20))
		 (message "NNSPOOL: Receiving headers... %d%%"
			  (/ (* count 100) number))))
	  
	  (and do-message (message "NNSPOOL: Receiving headers...done"))
	  
	  ;; Fold continuation lines.
	  (goto-char (point-min))
	  (while (re-search-forward "\\(\r?\n[ \t]+\\)+" nil t)
	    (replace-match " " t t))
	  'headers)))))

(defun nnspool-open-server (server &optional defs)
  (nnheader-init-server-buffer)
  (if (equal server nnspool-current-server)
      t
    (if nnspool-current-server
	(setq nnspool-server-alist 
	      (cons (list nnspool-current-server
			  (nnheader-save-variables nnspool-server-variables))
		    nnspool-server-alist)))
    (let ((state (assoc server nnspool-server-alist)))
      (if state 
	  (progn
	    (nnheader-restore-variables (nth 1 state))
	    (setq nnspool-server-alist (delq state nnspool-server-alist)))
	(nnheader-set-init-variables nnspool-server-variables defs)))
    (setq nnspool-current-server server)))

(defun nnspool-close-server (&optional server)
  t)

(defun nnspool-server-opened (&optional server)
  (and (equal server nnspool-current-server)
       nntp-server-buffer
       (buffer-name nntp-server-buffer)))

(defun nnspool-status-message (&optional server)
  "Return server status response as string."
  nnspool-status-string)

(defun nnspool-request-article (id &optional newsgroup server buffer)
  "Select article by message ID (or number)."
  (nnspool-possibly-change-directory newsgroup)
  (let ((file (if (stringp id)
		  (nnspool-find-article-by-message-id id)
		(concat nnspool-current-directory (prin1-to-string id))))
	(nntp-server-buffer (or buffer nntp-server-buffer)))
    (if (and (stringp file)
	     (file-exists-p file)
	     (not (file-directory-p file)))
	(save-excursion
	  (nnspool-find-file file)))))

(defun nnspool-request-body (id &optional newsgroup server)
  "Select article body by message ID (or number)."
  (nnspool-possibly-change-directory newsgroup)
  (if (nnspool-request-article id)
      (save-excursion
	(set-buffer nntp-server-buffer)
	(goto-char (point-min))
	(if (search-forward "\n\n" nil t)
	    (delete-region (point-min) (point)))
	t)))

(defun nnspool-request-head (id &optional newsgroup server)
  "Select article head by message ID (or number)."
  (nnspool-possibly-change-directory newsgroup)
  (if (nnspool-request-article id)
      (save-excursion
	(set-buffer nntp-server-buffer)
	(goto-char (point-min))
	(if (search-forward "\n\n" nil t)
	    (delete-region (1- (point)) (point-max)))
	t)))

(defun nnspool-request-group (group &optional server dont-check)
  "Select news GROUP."
  (let ((pathname (nnspool-article-pathname
		   (nnspool-replace-chars-in-string group ?. ?/)))
	dir)
    (if (not (file-directory-p pathname))
	(progn
	  (setq nnspool-status-string
		"Invalid group name (no such directory)")
	  nil)
      (setq nnspool-current-directory pathname)
      (setq nnspool-status-string "")
      (if (not dont-check)
	  (progn
	    (setq dir (directory-files pathname nil "^[0-9]+$" t))
	    ;; yes, completely empty spool directories *are* possible
	    ;; Fix by Sudish Joseph <joseph@cis.ohio-state.edu>
	    (and dir
		 (setq dir
		       (sort 
			(mapcar
			 (function
			  (lambda (name)
			    (string-to-int name)))
			 dir)
			'<)))
	    (save-excursion
	      (set-buffer nntp-server-buffer)
	      (erase-buffer)
	      (if dir
		  (insert
		   (format "211 %d %d %d %s\n" (length dir) (car dir)
			   (progn (while (cdr dir) (setq dir (cdr dir)))
				  (car dir))
			   group))
		(insert (format "211 0 0 0 %s\n" group))))))
      t)))

(defun nnspool-close-group (group &optional server)
  t)

(defun nnspool-request-list (&optional server)
  "List active newsgroups."
  (save-excursion
    (nnspool-find-file nnspool-active-file)))

(defun nnspool-request-list-newsgroups (&optional server)
  "List newsgroups (defined in NNTP2)."
  (save-excursion
    (nnspool-find-file nnspool-newsgroups-file)))

(defun nnspool-request-list-distributions (&optional server)
  "List distributions (defined in NNTP2)."
  (save-excursion
    (nnspool-find-file nnspool-distributions-file)))

;; Suggested by Hallvard B Furuseth <h.b.furuseth@usit.uio.no>.
(defun nnspool-request-newgroups (date &optional server)
  "List groups created after DATE."
  (if (nnspool-find-file nnspool-active-times-file)
      (save-excursion
	;; Find the last valid line.
	(goto-char (point-max))
	(while (and (not (looking-at 
			  "\\([^ ]+\\) +\\([0-9]+\\)[0-9][0-9][0-9] "))
		    (zerop (forward-line -1))))
	(let ((seconds (nnspool-seconds-since-epoch date))
	      groups)
	  ;; Go through lines and add the latest groups to a list.
	  (while (and (looking-at "\\([^ ]+\\) +[0-9]+ ")
		      (progn
			;; We insert a .0 to make the list reader
			;; interpret the number as a float. It is far
			;; too big to be stored in a lisp integer. 
			(goto-char (1- (match-end 0)))
			(insert ".0")
			(> (progn
			     (goto-char (match-end 1))
			     (read (current-buffer)))
			   seconds))
		      (setq groups (cons (buffer-substring
					  (match-beginning 1) (match-end 1))
					 groups))
		      (zerop (forward-line -1))))
	  (erase-buffer)
	  (while groups
	    (insert (car groups) " 0 0 y\n")
	    (setq groups (cdr groups))))
	t)
    nil))

(defun nnspool-request-post (&optional server)
  "Post a new news in current buffer."
  (save-excursion
    (let* ((process-connection-type nil) ; t bugs out on Solaris
	   (inews-buffer (generate-new-buffer " *nnspool post*"))
	   (proc (apply 'start-process "*nnspool inews*" inews-buffer
			nnspool-inews-program nnspool-inews-switches)))
      (set-process-sentinel proc 'nnspool-inews-sentinel)
      (process-send-region proc (point-min) (point-max))
      ;; We slap a condition-case around this, because the process may
      ;; have exited already...
      (condition-case nil
	  (process-send-eof proc)
	(error nil))
      t)))

(defun nnspool-inews-sentinel (proc status)
  (save-excursion
    (set-buffer (process-buffer proc))
    (goto-char (point-min))
    (if (or (zerop (buffer-size))
	    (search-forward "spooled" nil t))
	(kill-buffer (current-buffer))
      ;; Make status message by unfolding lines.
      (subst-char-in-region (point-min) (point-max) ?\n ?\\ 'noundo)
      (setq nnspool-status-string (buffer-string))
      (message "nnspool: %s" nnspool-status-string)
					;(kill-buffer (current-buffer))
      )))

(defalias 'nnspool-request-post-buffer 'nntp-request-post-buffer)


;;; Internal functions.

(defun nnspool-retrieve-headers-with-nov (articles)
  (if (or gnus-nov-is-evil nnspool-nov-is-evil)
      nil
    (let ((nov (concat (file-name-as-directory nnspool-nov-directory)
		       (nnspool-replace-chars-in-string
			nnspool-current-group ?. ?/)
		       "/.overview"))
	  article)
      (if (file-exists-p nov)
	  (save-excursion
	    (set-buffer nntp-server-buffer)
	    (erase-buffer)
	    (if nnspool-sift-nov-with-sed
		(nnspool-sift-nov-with-sed articles nov)
	      (insert-file-contents nov)
	      ;; First we find the first wanted line. We issue a number
	      ;; of search-forwards - the first article we are looking
	      ;; for may be expired, so we have to go on searching until
	      ;; we find one of the articles we want.
	      (while (and articles
			  (setq article (concat (int-to-string 
						 (car articles)) "\t"))
			  (not (or (looking-at article)
				   (search-forward (concat "\n" article) 
						   nil t))))
		(setq articles (cdr articles)))
	      (if (not articles)
		  ()
		(beginning-of-line)
		(delete-region (point-min) (point))
		;; Then we find the last wanted line. We go to the end
		;; of the buffer and search backward much the same way
		;; we did to find the first article.
		;; !!! Perhaps it would be better just to do a (last articles), 
		;; and go forward successively over each line and
		;; compare to avoid this (reverse), like this:
		;; (while (and (>= last (read nntp-server-buffer)))
		;;             (zerop (forward-line 1))))
		(setq articles (reverse articles))
		(goto-char (point-max))
		(while (and articles
			    (not (search-backward 
				  (concat "\n" (int-to-string (car articles))
					  "\t") nil t)))
		  (setq articles (cdr articles)))
		(if articles
		    (progn
		      (forward-line 2)
		      (delete-region (point) (point-max)))))
	      (or articles (progn (erase-buffer) nil))))))))

(defun nnspool-sift-nov-with-sed (articles file)
  (let ((first (car articles))
	(last (progn (while (cdr articles) (setq articles (cdr articles)))
		     (car articles))))
    (call-process "awk" nil t nil 
		  (format "BEGIN {firstmsg=%d; lastmsg=%d;}\n $1 >= firstmsg && $1 <= lastmsg {print;}"
			  (1- first) (1+ last))
		  file)))

;; Fixed by fdc@cliwe.ping.de (Frank D. Cringle). 
(defun nnspool-find-article-by-message-id (id)
  "Return full pathname of an article identified by message-ID."
  (save-excursion
    (let ((buf (get-buffer-create " *nnspool work*")))
      (set-buffer buf)
      (erase-buffer)
      (call-process "grep" nil t nil id nnspool-history-file)
      (goto-char (point-min))
      (if (looking-at "<[^>]+>[ \t]+[-0-9~]+[ \t]+\\([^ \t\n]*\\)")
	  (concat nnspool-spool-directory
		  (nnspool-replace-chars-in-string 
		   (buffer-substring (match-beginning 1) (match-end 1)) 
		   ?. ?/))))))

(defun nnspool-find-file (file)
  "Insert FILE in server buffer safely."
  (set-buffer nntp-server-buffer)
  (erase-buffer)
  (condition-case ()
      (progn (insert-file-contents file) t)
    (file-error nil)))

(defun nnspool-possibly-change-directory (newsgroup)
  (if newsgroup
      (let ((pathname (nnspool-article-pathname
		       (nnspool-replace-chars-in-string newsgroup ?. ?/))))
	(if (file-directory-p pathname)
	    (progn
	      (setq nnspool-current-directory pathname)
	      (setq nnspool-current-group newsgroup))
	  (setq nnspool-status-string 
		(format "No such newsgroup: %s" newsgroup))
	  nil))
    t))

(defun nnspool-article-pathname (group)
  "Make pathname for GROUP."
  (concat (file-name-as-directory nnspool-spool-directory) group "/"))

(defun nnspool-replace-chars-in-string (string from to)
  "Replace characters in STRING from FROM to TO."
  (let ((string (substring string 0))	;Copy string.
	(len (length string))
	(idx 0))
    ;; Replace all occurrences of FROM with TO.
    (while (< idx len)
      (if (= (aref string idx) from)
	  (aset string idx to))
      (setq idx (1+ idx)))
    string))

(defun nnspool-number-base-10 (num pos)
  (if (<= pos 0) ""
    (setcdr num (+ (* (% (car num) 10) 65536) (cdr num)))
    (apply
     'concat
     (reverse
      (list
       (char-to-string
	(aref "0123456789" (% (cdr num) 10)))
       (progn
	 (setcdr num (/ (cdr num) 10))
	 (setcar num (/ (car num) 10))
	 (nnspool-number-base-10 num (1- pos))))))))

(defun nnspool-seconds-since-epoch (date)
  (let* ((tdate (mapcar (lambda (ti) (and ti (string-to-int ti)))
			(timezone-parse-date date)))
	 (ttime (mapcar (lambda (ti) (and ti (string-to-int ti)))
			(timezone-parse-time
			 (aref (timezone-parse-date date) 3))))
	 (unix (encode-time (nth 2 ttime) (nth 1 ttime) (nth 0 ttime)
			    (nth 2 tdate) (nth 1 tdate) (nth 0 tdate) (nth 4 tdate))))
    (+ (* (car unix) 65536.0)
       (car (cdr unix)))))

(provide 'nnspool)

;;; nnspool.el ends here