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

;; Copyright (C) 1985, 1987, 1993, 1994, 2001, 2002, 2003, 2004, 2005,
;;   2006, 2007, 2008, 2009  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 3 of the License, 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.  If not, see <http://www.gnu.org/licenses/>.

;;; Commentary:

;;; Code:

(require 'rmail)
(provide 'rmailout)

(defcustom rmail-output-decode-coding nil
  "If non-nil, do coding system decoding when outputting message as Babyl."
  :type '(choice (const :tag "on" t)
		 (const :tag "off" nil))
  :group 'rmail)

(defcustom 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).
The suggestion is taken if REGEXP matches anywhere in the message buffer.
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."
  :type '(repeat (cons regexp
		       (choice :value ""
			       (string :tag "File Name")
			       sexp)))
  :group 'rmail-output)

(defun rmail-output-read-file-name ()
  "Read the file name to use for `rmail-output'.
Set `rmail-default-file' to this name as well as returning it."
  (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 no suggestion, use same file as last time.
	    (or answer rmail-default-file))))
    (let ((read-file
	   (expand-file-name
	    (read-file-name
	     (concat "Output message to mail file (default "
		     (file-name-nondirectory default-file)
		     "): ")
	     (file-name-directory default-file)
	     (abbreviate-file-name default-file))
	    (file-name-directory default-file))))
      (setq rmail-default-file
	    (if (file-directory-p read-file)
		(expand-file-name (file-name-nondirectory default-file)
				  read-file)
	      (expand-file-name
	       (or read-file (file-name-nondirectory default-file))
	       (file-name-directory default-file)))))))

(defcustom rmail-fields-not-to-output nil
  "Regexp describing fields to exclude when outputting a message to a file."
  :type '(choice (const :tag "None" nil)
		 regexp)
  :group 'rmail-output)

;; Delete from the buffer header fields we don't want output.
;; Buffer should be pre-narrowed to the header.
;; PRESERVE is a regexp for fields NEVER to delete.
(defun rmail-delete-unwanted-fields (preserve)
  (if rmail-fields-not-to-output
      (save-excursion
	(goto-char (point-min))
	(while (re-search-forward rmail-fields-not-to-output nil t)
	  (beginning-of-line)
	  (unless (looking-at preserve)
	    (delete-region (point)
			   (progn (forward-line 1) (point))))))))

(defun rmail-output-as-babyl (file-name nomsg)
  "Convert the current buffer's text to Babyl and output to FILE-NAME.
It alters the current buffer's text, so it should be a temp buffer."
  (let ((coding-system-for-write
	 'emacs-mule-unix))
    (save-restriction
      (goto-char (point-min))
      (search-forward "\n\n" nil 'move)
      (narrow-to-region (point-min) (point))
      (if rmail-fields-not-to-output
	  (rmail-delete-unwanted-fields nil)))

    ;; Convert to Babyl format.
    (rmail-convert-to-babyl-format)
    ;; Write it into the file, or its buffer.
    (let ((buf (find-buffer-visiting file-name))
	  (tembuf (current-buffer)))
      (if (null buf)
	  (write-region (point-min) (point-max) file-name t nomsg)
	(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 ((inhibit-read-only t)
	      (msg (with-no-warnings
		     (and (boundp 'rmail-current-message)
			  rmail-current-message))))
	  ;; If MSG is non-nil, buffer is in RMAIL mode.
	  (if msg
	      (rmail-output-to-babyl-buffer tembuf 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 tembuf)))))))

(defun rmail-output-to-babyl-buffer (tembuf msg)
  "Copy msg in TEMBUF from BEG to END into this old R-mail BABYL buffer.
Do what is necessary to make babyl R-mail know about the new message.
Then display message number MSG."
  (with-no-warnings
    ;; Turn on Auto Save mode, if it's off in this
    ;; buffer but enabled by default.
    (and (not buffer-auto-save-file-name)
	 auto-save-default
	 (auto-save-mode t))
    (rmail-maybe-set-message-counters)
    (widen)
    (narrow-to-region (point-max) (point-max))
    (insert-buffer-substring tembuf)
    (goto-char (point-min))
    (widen)
    (search-backward "\n\^_")
    (narrow-to-region (point) (point-max))
    (rmail-count-new-messages t)
    (if (rmail-summary-exists)
	(rmail-select-summary
	 (rmail-update-summary)))
    (rmail-show-message-1 msg)))

(defun rmail-convert-to-babyl-format ()
  (let ((count 0) (start (point-min))
	(case-fold-search nil)
	(buffer-undo-list t))
    (goto-char (point-min))
    (save-restriction
      (unless (looking-at "^From ")
	(error "Invalid mbox message"))
      (insert "\^L\n0, unseen,,\n*** EOOH ***\n")
      (rmail-nuke-pinhead-header)
      ;; Decode base64 or quoted printable contents, Rmail style.
      (let* ((header-end (save-excursion
			   (and (re-search-forward "\n\n" nil t)
				(1- (point)))))
	     (case-fold-search t)
	     (quoted-printable-header-field-end
	      (save-excursion
		(re-search-forward
		 "^content-transfer-encoding:\\(\n?[\t ]\\)*quoted-printable\\(\n?[\t ]\\)*"
		 header-end t)))
	     (base64-header-field-end
	      (and
	       ;; Don't decode non-text data.
	       (save-excursion
		 (re-search-forward
		  "^content-type:\\(\n?[\t ]\\)\\(text\\|message\\)/"
		  header-end t))
	       (save-excursion
		 (re-search-forward
		  "^content-transfer-encoding:\\(\n?[\t ]\\)*base64\\(\n?[\t ]\\)*"
		  header-end t)))))

	(goto-char (point-max))
	(if quoted-printable-header-field-end
	    (save-excursion
	      (unless (mail-unquote-printable-region
		       header-end (point) nil t t)
		(message "Malformed MIME quoted-printable message"))
	      ;; Change "quoted-printable" to "8bit",
	      ;; to reflect the decoding we just did.
	      (goto-char quoted-printable-header-field-end)
	      (delete-region (point) (search-backward ":"))
	      (insert ": 8bit")))
	(if base64-header-field-end
	    (save-excursion
	      (when (condition-case nil
			(progn
			  (base64-decode-region
			   (1+ header-end)
			   (save-excursion
			     ;; Prevent base64-decode-region
			     ;; from removing newline characters.
			     (skip-chars-backward "\n\t ")
			     (point)))
			  t)
		      (error nil))
		;; Change "base64" to "8bit", to reflect the
		;; decoding we just did.
		(goto-char base64-header-field-end)
		(delete-region (point) (search-backward ":"))
		(insert ": 8bit")))))
      ;; Transform anything within the message text
      ;; that might appear to be the end of a Babyl-format message.
      (save-excursion
	(save-restriction
	  (narrow-to-region start (point))
	  (goto-char (point-min))
	  (while (search-forward "\n\^_" nil t) ; single char
	    (replace-match "\n^_"))))		; 2 chars: "^" and "_"
      ;; This is for malformed messages that don't end in newline.
      ;; There shouldn't be any, but some users say occasionally
      ;; there are some.
      (or (bolp) (newline))
      (insert ?\^_)
      (setq last-coding-system-used nil)
      ;; Decode coding system, following specs in the message header,
      ;; and record what coding system was decoded.
      (if rmail-output-decode-coding
	  (let ((mime-charset
		 (if (save-excursion
		       (goto-char start)
		       (search-forward "\n\n" nil t)
		       (let ((case-fold-search t))
			 (re-search-backward
			  rmail-mime-charset-pattern
			  start t)))
		     (intern (downcase (match-string 1))))))
	    (rmail-decode-region start (point) mime-charset)))
      (save-excursion
	(goto-char start)
	(forward-line 3)
	(insert "X-Coding-System: "
		(symbol-name last-coding-system-used)
		"\n")))))

;; Delete the "From ..." line, creating various other headers with
;; information from it if they don't already exist.  Now puts the
;; original line into a mail-from: header line for debugging and for
;; use by the rmail-output function.
(defun rmail-nuke-pinhead-header ()
  (save-excursion
    (save-restriction
      (let ((start (point))
  	    (end (progn
		   (condition-case ()
		       (search-forward "\n\n")
		     (error
		      (goto-char (point-max))
		      (insert "\n\n")))
		   (point)))
	    has-from has-date)
	(narrow-to-region start end)
	(let ((case-fold-search t))
	  (goto-char start)
	  (setq has-from (search-forward "\nFrom:" nil t))
	  (goto-char start)
	  (setq has-date (and (search-forward "\nDate:" nil t) (point)))
	  (goto-char start))
	(let ((case-fold-search nil))
	  (if (re-search-forward (concat "^" rmail-unix-mail-delimiter) nil t)
	      (replace-match
		(concat
		  "Mail-from: \\&"
		  ;; Keep and reformat the date if we don't
		  ;;  have a Date: field.
		  (if has-date
		      ""
		    (concat
		     "Date: \\2, \\4 \\3 \\9 \\5 "

		     ;; The timezone could be matched by group 7 or group 10.
		     ;; If neither of them matched, assume EST, since only
		     ;; Easterners would be so sloppy.
		     ;; It's a shame the substitution can't use "\\10".
		     (cond
		      ((/= (match-beginning 7) (match-end 7)) "\\7")
		      ((/= (match-beginning 10) (match-end 10))
		       (buffer-substring (match-beginning 10)
					 (match-end 10)))
		      (t "EST"))
		     "\n"))
		  ;; Keep and reformat the sender if we don't
		  ;; have a From: field.
		  (if has-from
		      ""
		    "From: \\1\n"))
		t)))))))

(defun rmail-output-as-mbox (file-name nomsg &optional as-seen)
  "Convert the current buffer's text to mbox Babyl and output to FILE-NAME.
It alters the current buffer's text, so call with a temp buffer current.
If FILE-NAME is visited, output into its buffer instead.
AS-SEEN is non-nil if we are copying the message \"as seen\"."
  (let ((case-fold-search t)
	mail-from mime-version content-type)

    ;; Preserve the Mail-From and MIME-Version fields
    ;; even if they have been pruned.
    (search-forward "\n\n" nil 'move)
    (narrow-to-region (point-min) (point))

    (rmail-delete-unwanted-fields
     (if rmail-enable-mime "Mail-From"
       "Mail-From\\|MIME-Version\\|Content-type"))

    (widen)

    ;; Make sure message ends with blank line.
    (goto-char (point-max))
    (unless (bolp)
       (insert "\n"))
    (unless (looking-back "\n\n")
      (insert "\n"))

    ;; Generate a From line from other header fields
    ;; if necessary.
    (goto-char (point-min))
    (unless (looking-at "From ")
      (insert "From "
	      (mail-strip-quoted-names
	       (save-excursion
		 (save-restriction
		   (goto-char (point-min))
		   (narrow-to-region
		    (point)
		    (or (search-forward "\n\n" nil)
			(point-max)))
		   (or (mail-fetch-field "from")
		       (mail-fetch-field "really-from")
		       (mail-fetch-field "sender")
		       "unknown"))))
	      " " (current-time-string) "\n"))

    (let ((buf (find-buffer-visiting file-name))
	  (tembuf (current-buffer)))
      (if (null buf)
	  (let ((coding-system-for-write 'raw-text-unix))
	    (write-region (point-min) (point-max) file-name t nomsg))
	(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 ((inhibit-read-only t)
	      (msg (and (boundp 'rmail-current-message)
			rmail-current-message)))
	  (and msg as-seen
	       (error "Can't output \"as seen\" to a visited Rmail file"))
	  (if msg
	      (rmail-output-to-rmail-buffer tembuf 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 tembuf)))))))

;; Called only if rmail-summary-exists, which means rmailsum is loaded.
(declare-function rmail-update-summary "rmailsum" (&rest ignore))

(defun rmail-output-to-rmail-buffer (tembuf msg)
  "Copy msg in TEMBUF from BEG to END into this Rmail buffer.
Do what is necessary to make Rmail know about the new message.
Then display message number MSG."
  (save-excursion
    (rmail-swap-buffers-maybe)
    ;; Turn on Auto Save mode, if it's off in this
    ;; buffer but enabled by default.
    (and (not buffer-auto-save-file-name)
	 auto-save-default
	 (auto-save-mode t))
    (rmail-maybe-set-message-counters)
    (narrow-to-region (point-max) (point-max))
    (insert-buffer-substring tembuf)
    (rmail-count-new-messages t)
    (if (rmail-summary-exists)
	(rmail-select-summary
	 (rmail-update-summary)))
    (rmail-show-message-1 msg)))

;;; There are functions elsewhere in Emacs that use this function;
;;; look at them before you change the calling method.
;;;###autoload
(defun rmail-output (file-name &optional count noattribute from-gnus)
  "Append this message to mail file FILE-NAME.
This works with both mbox format and Babyl format files,
outputting in the appropriate format for each.
The default file name comes from `rmail-default-file',
which is updated to the name you use in this command.

A prefix argument COUNT says to output that many consecutive messages,
starting with the current one.  Deleted messages are skipped and don't count.
When called from Lisp code, COUNT may be omitted and defaults to 1.

This command always outputs the complete message header,
even if the header display is currently pruned.

The optional third argument NOATTRIBUTE, if non-nil, says not
to set the `filed' attribute, and not to display a message.

The optional fourth argument FROM-GNUS is set when called from GNUS."
  (interactive
   (list (rmail-output-read-file-name)
	 (prefix-numeric-value current-prefix-arg)))
  (or count (setq count 1))
  (setq file-name
	(expand-file-name file-name
			  (and rmail-default-file
			       (file-name-directory rmail-default-file))))

  ;; Warn about creating new file.
  (or (find-buffer-visiting file-name)
      (file-exists-p file-name)
      (yes-or-no-p
       (concat "\"" file-name "\" does not exist, create it? "))
      (error "Output file does not exist"))

  (set-buffer rmail-buffer)

  (let ((orig-count count)
	(case-fold-search t)
	(tembuf (get-buffer-create " rmail-output"))
	(babyl-format
	 (and (file-readable-p file-name) (mail-file-babyl-p file-name))))

    (unwind-protect
	(while (> count 0)
	  (with-current-buffer rmail-buffer
	    (let (cur beg end)
	      (setq beg (rmail-msgbeg rmail-current-message)
		    end (rmail-msgend rmail-current-message))
	      ;; All access to the buffer's local variables is now finished...
	      (save-excursion
		;; ... so it is ok to go to a different buffer.
		(if (rmail-buffers-swapped-p) (set-buffer rmail-view-buffer))
		(setq cur (current-buffer))
		(save-restriction
		  (widen)
		  (with-current-buffer tembuf
		    (insert-buffer-substring cur beg end)
		    ;; Convert the text to one format or another and output.
		    (if babyl-format
			(rmail-output-as-babyl file-name (if noattribute 'nomsg))
		      (rmail-output-as-mbox file-name
					    (if noattribute 'nomsg))))))))

	  ;; Mark message as "filed".
	  (unless noattribute
	    (rmail-set-attribute rmail-filed-attr-index t))

	  (setq count (1- count))

	  (or from-gnus
	      (let ((next-message-p
		     (if rmail-delete-after-output
			 (rmail-delete-forward)
		       (if (> count 0)
			   (rmail-next-undeleted-message 1))))
		    (num-appended (- orig-count count)))
		(if (and (> count 0) (not next-message-p))
		    (error "Only %d message%s appended" num-appended
			   (if (= num-appended 1) "" "s"))))))
      (kill-buffer tembuf))))

(defun rmail-output-as-seen (file-name &optional count noattribute from-gnus)
  "Append this message to system-inbox-format mail file named FILE-NAME.
A prefix argument COUNT says to output that many consecutive messages,
starting with the current one.  Deleted messages are skipped and don't count.
When called from Lisp code, COUNT may be omitted and defaults to 1.

This outputs the message header as you see it.

The default file name comes from `rmail-default-file',
which is updated to the name you use in this command.

The optional third argument NOATTRIBUTE, if non-nil, says not
to set the `filed' attribute, and not to display a message.

The optional fourth argument FROM-GNUS is set when called from GNUS."
  (interactive
   (list (rmail-output-read-file-name)
	 (prefix-numeric-value current-prefix-arg)))
  (or count (setq count 1))
  (setq file-name
	(expand-file-name file-name
			  (and rmail-default-file
			       (file-name-directory rmail-default-file))))
  (set-buffer rmail-buffer)

  ;; Warn about creating new file.
  (or (find-buffer-visiting file-name)
      (file-exists-p file-name)
      (yes-or-no-p
       (concat "\"" file-name "\" does not exist, create it? "))
      (error "Output file does not exist"))

    (if (and (file-readable-p file-name) (mail-file-babyl-p file-name))
	(error "Cannot output `as seen' to a Babyl file"))

  (let ((orig-count count)
	(case-fold-search t)
	(tembuf (get-buffer-create " rmail-output")))

    (unwind-protect
	(while (> count 0)
	  (let (cur beg end)
	    ;; If operating from whole-mbox buffer, get message bounds.
	    (if (not (rmail-buffers-swapped-p))
		(setq beg (rmail-msgbeg rmail-current-message)
		      end (rmail-msgend rmail-current-message)))
	    ;; All access to the buffer's local variables is now finished...
	    (save-excursion
	      (setq cur (current-buffer))
	      (save-restriction
		(widen)
		;; If operating from the view buffer, get the bounds.
		(unless beg
		  (setq beg (point-min)
			end (point-max)))

		(with-current-buffer tembuf
		  (insert-buffer-substring cur beg end)
		  ;; Convert the text to one format or another and output.
		  (rmail-output-as-mbox file-name 
					(if noattribute 'nomsg)
					t)))))

	  ;; Mark message as "filed".
	  (unless noattribute
	    (rmail-set-attribute rmail-filed-attr-index t))

	  (setq count (1- count))

	  (or from-gnus
	      (let ((next-message-p
		     (if rmail-delete-after-output
			 (rmail-delete-forward)
		       (if (> count 0)
			   (rmail-next-undeleted-message 1))))
		    (num-appended (- orig-count count)))
		(if (and (> count 0) (not next-message-p))
		    (error "Only %d message%s appended" num-appended
			   (if (= num-appended 1) "" "s"))))))
      (kill-buffer tembuf))))


;;;###autoload
(defun rmail-output-body-to-file (file-name)
  "Write this message body to the file FILE-NAME.
FILE-NAME defaults, interactively, from the Subject field of the message."
  (interactive
   (let ((default-file
	   (or (mail-fetch-field "Subject")
	       rmail-default-body-file)))
     (list (setq rmail-default-body-file
		 (read-file-name
		  "Output message body to file: "
		  (and default-file (file-name-directory default-file))
		  default-file
		  nil default-file)))))
  (setq file-name
	(expand-file-name file-name
			  (and rmail-default-body-file
			       (file-name-directory rmail-default-body-file))))
  (save-excursion
    (goto-char (point-min))
    (search-forward "\n\n")
    (and (file-exists-p file-name)
	 (not (y-or-n-p (format "File %s exists; overwrite? " file-name)))
	 (error "Operation aborted"))
    (write-region (point) (point-max) file-name))
  (if rmail-delete-after-output
      (rmail-delete-forward)))

;; arch-tag: 4059abf0-f249-4be4-8e0d-602d370d01d1
;;; rmailout.el ends here