;;; rmailout.el --- "RMAIL" mail reader for Emacs: output message to a file.

;; Copyright (C) 1985, 1987, 1993 Free Software Foundation, Inc.

;; Maintainer: FSF
;; Keywords: mail

;; 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, 675 Mass Ave, Cambridge, MA 02139, USA.

;;; Code:

;; Temporary until Emacs always has this variable.
(defvar rmail-delete-after-output nil
  "*Non-nil means automatically delete a message that is copied to a file.")

(defvar rmail-output-file-alist nil
  "*Alist matching regexps to suggested output Rmail files.
This is a list of elements of the form (REGEXP . NAME-EXP).
NAME-EXP may be a string constant giving the file name to use,
or more generally it may be any kind of expression that returns
a file name as a string.")

;;; There are functions elsewhere in Emacs that use this function; check
;;; them out before you change the calling method.
(defun rmail-output-to-rmail-file (file-name &optional count)
  "Append the current message to an Rmail file named FILE-NAME.
If the file does not exist, ask if it should be created.
If file is being visited, the message is appended to the Emacs
buffer visiting that file.
If the file exists and is not an Rmail file, 
the message is appended in inbox format.

A prefix argument N says to output N consecutive messages
starting with the current one.  Deleted messages are skipped and don't count."
  (interactive
   (let ((default-file
	   (let (answer tail)
	     (setq tail rmail-output-file-alist)
	     ;; Suggest a file based on a pattern match.
	     (while (and tail (not answer))
	       (save-excursion
		 (goto-char (point-min))
		 (if (re-search-forward (car (car tail)) nil t)
		     (setq answer (eval (cdr (car tail)))))
		 (setq tail (cdr tail))))
	     ;; If not suggestions, use same file as last time.
	     (or answer rmail-last-rmail-file))))
     (list (read-file-name
	    (concat "Output message to Rmail file: (default "
		    (file-name-nondirectory default-file)
		    ") ")
	    (file-name-directory rmail-last-rmail-file)
	    default-file)
	   (prefix-numeric-value current-prefix-arg))))
  (or count (setq count 1))
  (setq file-name
	(expand-file-name file-name
			  (file-name-directory rmail-last-rmail-file)))
  (if (and (file-readable-p file-name) (not (rmail-file-p file-name)))
      (rmail-output file-name count)
    (setq rmail-last-rmail-file file-name)
    (rmail-maybe-set-message-counters)
    (setq file-name (abbreviate-file-name file-name))
    (or (get-file-buffer file-name)
	(file-exists-p file-name)
	(if (yes-or-no-p
	     (concat "\"" file-name "\" does not exist, create it? "))
	    (let ((file-buffer (create-file-buffer file-name)))
	      (save-excursion
		(set-buffer file-buffer)
		(rmail-insert-rmail-file-header)
		(let ((require-final-newline nil))
		  (write-region (point-min) (point-max) file-name t 1)))
	      (kill-buffer file-buffer))
	  (error "Output file does not exist")))
    (while (> count 0)
      (let (redelete)
	(unwind-protect
	    (progn
	      (save-restriction
		(widen)
		(if (rmail-message-deleted-p rmail-current-message)
		    (progn (setq redelete t)
			   (rmail-set-attribute "deleted" nil)))
		;; Decide whether to append to a file or to an Emacs buffer.
		(save-excursion
		  (let ((buf (get-file-buffer file-name))
			(cur (current-buffer))
			(beg (1+ (rmail-msgbeg rmail-current-message)))
			(end (1+ (rmail-msgend rmail-current-message))))
		    (if (not buf)
			(append-to-file beg end file-name)
		      (if (eq buf (current-buffer))
			  (error "Can't output message to same file it's already in"))
		      ;; File has been visited, in buffer BUF.
		      (set-buffer buf)
		      (let ((buffer-read-only nil)
			    (msg (and (boundp 'rmail-current-message)
				      rmail-current-message)))
			;; If MSG is non-nil, buffer is in RMAIL mode.
			(if msg
			    (progn
			      (rmail-maybe-set-message-counters)
			      (widen)
			      (narrow-to-region (point-max) (point-max))
			      (insert-buffer-substring cur beg end)
			      (goto-char (point-min))
			      (widen)
			      (search-backward "\n\^_")
			      (narrow-to-region (point) (point-max))
			      (rmail-count-new-messages t)
			      (rmail-show-message msg))
		;; Output file not in rmail mode => just insert at the end.
		(narrow-to-region (point-min) (1+ (buffer-size)))
		(goto-char (point-max))
		(insert-buffer-substring cur beg end)))))))
	      (rmail-set-attribute "filed" t))
	  (if redelete (rmail-set-attribute "deleted" t))))
      (setq count (1- count))
      (if rmail-delete-after-output
	  (rmail-delete-forward)
	(if (> count 0)
	    (rmail-next-undeleted-message 1))))))

;; Returns t if file FILE is an Rmail file.
(defun rmail-file-p (file)
  (let ((buf (generate-new-buffer " *rmail-file-p*")))
    (unwind-protect
	(save-excursion
	  (set-buffer buf)
	  (insert-file-contents file nil 0 100)
	  (looking-at "BABYL OPTIONS:"))
      (kill-buffer buf))))

;;; There are functions elsewhere in Emacs that use this function; check
;;; them out before you change the calling method.
(defun rmail-output (file-name &optional count)
  "Append this message to Unix mail file named FILE-NAME.
A prefix argument N says to output N consecutive messages
starting with the current one.  Deleted messages are skipped and don't count.
When called from lisp code, N may be omitted."
  (interactive
   (list (read-file-name
	  (concat "Output message to Unix mail file"
		  (if rmail-last-file
		      (concat " (default "
			      (file-name-nondirectory rmail-last-file)
			      "): " )
		    ": "))			
	  (and rmail-last-file (file-name-directory rmail-last-file))
	  rmail-last-file)
	 (prefix-numeric-value current-prefix-arg)))
  (or count (setq count 1))
  (setq file-name
	(expand-file-name file-name
			  (and rmail-last-file
			       (file-name-directory rmail-last-file))))
  (if (and (file-readable-p file) (rmail-file-p file-name))
      (rmail-output-to-rmail-file file-name count)
    (setq rmail-last-file file-name)
    (while (> count 0)
      (let ((rmailbuf (current-buffer))
	    (tembuf (get-buffer-create " rmail-output"))
	    (case-fold-search t))
	(save-excursion
	  (set-buffer tembuf)
	  (erase-buffer)
	  (insert-buffer-substring rmailbuf)
	  (insert "\n")
	  (goto-char (point-min))
	  (insert "From "
		  (mail-strip-quoted-names (or (mail-fetch-field "from")
					       (mail-fetch-field "really-from")
					       (mail-fetch-field "sender")
					       "unknown"))
		  " " (current-time-string) "\n")
	  ;; ``Quote'' "\nFrom " as "\n>From "
	  ;;  (note that this isn't really quoting, as there is no requirement
	  ;;   that "\n[>]+From " be quoted in the same transparent way.)
	  (while (search-forward "\nFrom " nil t)
	    (forward-char -5)
	    (insert ?>))
	  (append-to-file (point-min) (point-max) file-name))
	(kill-buffer tembuf))
      (if (equal major-mode 'rmail-mode)
	  (rmail-set-attribute "filed" t))
      (setq count (1- count))
      (if rmail-delete-after-output
	  (rmail-delete-forward)
	(if (> count 0)
	    (rmail-next-undeleted-message 1)))))

;;; rmailout.el ends here