;;; remember --- a mode for quickly jotting down things to remember

;; Copyright (C) 1999-2001, 2003-2013 Free Software Foundation, Inc.

;; Author: John Wiegley <johnw@gnu.org>
;; Created: 29 Mar 1999
;; Version: 2.0
;; Keywords: data memory todo pim
;; URL: http://gna.org/projects/remember-el/

;; 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:

;; * The idea
;;
;; Todo lists, schedules, phone databases... everything we use
;; databases for is really just a way to extend the power of our
;; memory.  To be able to remember what our conscious mind may not
;; currently have access to.
;;
;; There are many different databases out there -- and good ones --
;; which this mode is not trying to replace.  Rather, it's how that
;; data gets there that's the question.  Most of the time, we just
;; want to say "Remember so-and-so's phone number, or that I have to
;; buy dinner for the cats tonight."  That's the FACT.  How it's
;; stored is really the computer's problem.  But at this point in
;; time, it's most definitely also the user's problem, and sometimes
;; so laboriously so that people just let data slip, rather than
;; expend the effort to record it.
;;
;; "Remember" is a mode for remembering data.  It uses whatever
;; back-end is appropriate to record and correlate the data, but it's
;; main intention is to allow you to express as _little_ structure as
;; possible up front.  If you later want to express more powerful
;; relationships between your data, or state assumptions that were at
;; first too implicit to be recognized, you can "study" the data later
;; and rearrange it.  But the initial "just remember this" impulse
;; should be as close to simply throwing the data at Emacs as
;; possible.
;;
;; * Implementation
;;
;; Hyperbole, as a data presentation tool, always struck me as being
;; very powerful, but it seemed to require a lot of "front-end" work
;; before that data was really available.  The problem with BBDB, or
;; keeping up a Bibl-mode file, is that you have to use different
;; functions to record the data, and it always takes time to stop what
;; you're doing, format the data in the manner expected by that
;; particular data interface, and then resume your work.
;;
;; With "remember", you just hit `M-x remember' (you'd probably want
;; to bind this to an easily accessible keystroke, like C-x M-r), slam
;; in your text however you like, and then hit C-c C-c.  It will file
;; the data away for later retrieval, and possibly indexing.
;;
;; Indexing is to data what "studying" is in the real world.  What you
;; do when you study (or lucubrate, for some of us) is to realize
;; certain relationships implicit in the data, so that you can make
;; use of those relationships.  Expressing that a certain quote you
;; remembered was a religious quote, and that you want the ability to
;; pull up all quotes of a religious nature, is what studying does.
;; This is a more labor intensive task than the original remembering
;; of the data, and it's typical in real life to set aside a special
;; period of time for doing this work.
;;
;; "Remember" works in the same way.  When you enter data, either by
;; typing it into a buffer, or using the contents of the selected
;; region, it will store that data -- unindexed, uninterpreted -- in a
;; data pool.  It will also try to remember as much context
;; information as possible (any text properties that were set, where
;; you copied it from, when, how, etc).  Later, you can walk through
;; your accumulated set of data (both organized, and unorganized) and
;; easily begin moving things around, and making annotations that will
;; express the full meaning of that data, as far as you know it.
;;
;; Obviously this latter stage is more user-interface intensive, and
;; it would be nice if "remember" could do it as elegantly as
;; possible, rather than requiring a billion keystrokes to reorganize
;; your hierarchy.  Well, as the future arrives, hopefully experience
;; and user feedback will help to make this as intuitive a tool as
;; possible.
;;
;; * Future Goals
;;
;; This tool hopes to track (and by doing it with as little new code
;; as possible):
;;
;;  - The raw data that gets entered
;;
;;  - The relationships between that data (either determined
;;    implicitly by parsing the input, or explicitly by the user's
;;    studying the data).
;;
;;  - Revisioning of the data
;;
;;  - Where it came from, and any context information that can be
;;    programmatically determined.
;;
;;  - Allowing particular views of the initially amorphous data pool
;;    (ala the Xanadu concept).
;;
;;  - Storage of the data in a manner most appropriate to that data,
;;    such as keeping address-book type information in BBDB, etc.
;;
;; * Using "remember"
;;
;; As a rough beginning, what I do is to keep my .notes file in
;; outline-mode format, with a final entry called "* Raw data".  Then,
;; at intervals, I can move the data that gets appended there into
;; other places.  But certainly this should evolve into an intuitive
;; mechanism for shuffling data off to its appropriate corner of the
;; universe.
;;
;; To map the primary remember function to the keystroke F8, do the
;; following.
;;
;;   (autoload 'remember "remember" nil t)
;;
;;   (define-key global-map [f8] 'remember)
;;
;; * Feedback
;;
;; If Emacs could become a more intelligent data store, where
;; brainstorming would focus on the IDEAS involved -- rather than the
;; structuring and format of those ideas, or having to stop your
;; current flow of work in order to record them -- it would map much
;; more closely to how the mind (well, at least mine) works, and hence
;; would eliminate that very manual-ness which computers from the very
;; beginning have been championed as being able to reduce.
;;
;; Have you ever noticed that having a laptop to write on doesn't
;; _actually_ increase the amount of quality material that you turn
;; out, in the long run?  Perhaps its because the time we save
;; electronically in one way, we're losing electronically in another;
;; the tool should never dominate one's focus.  As the mystic
;; Faridu'd-Din `Attar wrote: "Be occupied as little as possible with
;; things of the outer world but much with things of the inner world;
;; then right action will overcome inaction."
;;
;; * Diary integration
;;
;; To use, add the following to your .emacs:
;;
;;   ;; This should be before other entries that may return t
;;   (add-to-list 'remember-handler-functions 'remember-diary-extract-entries)
;;
;; This module recognizes entries of the form
;;
;;   DIARY: ....
;;
;; and puts them in your ~/.diary (or remember-diary-file) together
;; with an annotation.  Dates in the form YYYY.MM.DD are converted to
;; YYYY-MM-DD so that diary can understand them.
;;
;; For example:
;;
;;   DIARY: 2003.08.12 Sacha's birthday
;;
;; is stored as
;;
;;   2003.08.12 Sacha's birthday

;;; History:

;;; Code:

(provide 'remember)

(defconst remember-version "2.0"
  "This version of remember.")

(defgroup remember nil
  "A mode to remember information."
  :group 'data)

;;; User Variables:

(defcustom remember-mode-hook nil
  "Functions run upon entering `remember-mode'."
  :type 'hook
  :options '(flyspell-mode turn-on-auto-fill org-remember-apply-template)
  :group 'remember)

(defcustom remember-in-new-frame nil
  "Non-nil means use a separate frame for capturing remember data."
  :type 'boolean
  :group 'remember)

(defcustom remember-register ?R
  "The register in which the window configuration is stored."
  :type 'character
  :group 'remember)

(defcustom remember-filter-functions nil
  "Functions run to filter remember data.
All functions are run in the remember buffer."
  :type 'hook
  :group 'remember)

(defcustom remember-handler-functions '(remember-append-to-file)
  "Functions run to process remember data.
Each function is called with the current buffer narrowed to what the
user wants remembered.
If any function returns non-nil, the data is assumed to have been
recorded somewhere by that function."
  :type 'hook
  :options '(remember-store-in-mailbox
             remember-append-to-file
             remember-store-in-files
             remember-diary-extract-entries
             org-remember-handler)
  :group 'remember)

(defcustom remember-all-handler-functions nil
  "If non-nil every function in `remember-handler-functions' is called."
  :type 'boolean
  :group 'remember)

;;; Internal Variables:

(defvar remember-buffer "*Remember*"
  "The name of the remember data entry buffer.")

(defcustom remember-save-after-remembering t
  "Non-nil means automatically save after remembering."
  :type 'boolean
  :group 'remember)

;;; User Functions:

(defcustom remember-annotation-functions '(buffer-file-name)
  "Hook that returns an annotation to be inserted into the remember buffer."
  :type 'hook
  :options '(org-remember-annotation buffer-file-name)
  :group 'remember)

(defvar remember-annotation nil
  "Current annotation.")
(defvar remember-initial-contents nil
  "Initial contents to place into *Remember* buffer.")

(defcustom remember-before-remember-hook nil
  "Functions run before switching to the *Remember* buffer."
  :type 'hook
  :group 'remember)

(defcustom remember-run-all-annotation-functions-flag nil
  "Non-nil means use all annotations returned by `remember-annotation-functions'."
  :type 'boolean
  :group 'remember)

;;;###autoload
(defun remember (&optional initial)
  "Remember an arbitrary piece of data.
INITIAL is the text to initially place in the *Remember* buffer,
or nil to bring up a blank *Remember* buffer.

With a prefix or a visible region, use the region as INITIAL."
  (interactive
   (list (when (or current-prefix-arg
                   (and mark-active
                        transient-mark-mode))
           (buffer-substring (region-beginning) (region-end)))))
  (funcall (if remember-in-new-frame
               #'frame-configuration-to-register
             #'window-configuration-to-register) remember-register)
  (let* ((annotation
          (if remember-run-all-annotation-functions-flag
              (mapconcat 'identity
                         (delq nil
                               (mapcar 'funcall remember-annotation-functions))
                         "\n")
            (run-hook-with-args-until-success
             'remember-annotation-functions)))
         (buf (get-buffer-create remember-buffer)))
    (run-hooks 'remember-before-remember-hook)
    (funcall (if remember-in-new-frame
                 #'switch-to-buffer-other-frame
               #'switch-to-buffer-other-window) buf)
    (if remember-in-new-frame
        (set-window-dedicated-p
         (get-buffer-window (current-buffer) (selected-frame)) t))
    (remember-mode)
    (when (= (point-max) (point-min))
      (when initial (insert initial))
      (setq remember-annotation annotation)
      (when remember-initial-contents (insert remember-initial-contents))
      (when (and (stringp annotation)
                 (not (equal annotation "")))
        (insert "\n\n" annotation))
      (setq remember-initial-contents nil)
      (goto-char (point-min)))
    (message "Use C-c C-c to remember the data.")))

;;;###autoload
(defun remember-other-frame (&optional initial)
  "Call `remember' in another frame."
  (interactive
   (list (when current-prefix-arg
           (buffer-substring (point) (mark)))))
  (let ((remember-in-new-frame t))
    (remember initial)))

(defsubst remember-mail-date (&optional rfc822-p)
  "Return a simple date.  Nothing fancy."
  (if rfc822-p
      (format-time-string "%a, %e %b %Y %T %z" (current-time))
    (format-time-string "%a %b %e %T %Y" (current-time))))

(defun remember-buffer-desc ()
  "Using the first line of the current buffer, create a short description."
  (buffer-substring (point-min)
                    (save-excursion
                      (goto-char (point-min))
                      (end-of-line)
                      (if (> (- (point) (point-min)) 60)
                          (goto-char (+ (point-min) 60)))
                      (point))))

;; Remembering to UNIX mailboxes

(defcustom remember-mailbox "~/Mail/remember"
  "The file in which to store remember data as mail."
  :type 'file
  :group 'remember)

(defcustom remember-default-priority "medium"
  "The default priority for remembered mail messages."
  :type 'string
  :group 'remember)

(defun remember-store-in-mailbox ()
  "Store remember data as if it were incoming mail.
In which case `remember-mailbox' should be the name of the mailbox.
Each piece of pseudo-mail created will have an `X-Todo-Priority'
field, for the purpose of appropriate splitting."
  (let ((who (read-string "Who is this item related to? "))
        (moment (format "%.0f" (float-time)))
        (desc (remember-buffer-desc))
        (text (buffer-string)))
    (with-temp-buffer
      (insert (format "From %s  %s
Date: %s
From: %s
Message-Id: <remember-%s@%s>
X-Todo-Priority: %s
To: %s <%s>
Subject: %s\n\n"
                      (user-login-name)
                      (remember-mail-date)
                      (remember-mail-date t)
                      who
                      moment (system-name)
                      remember-default-priority
                      (user-full-name) user-mail-address
                      desc))
      (let ((here (point)))
        (insert text)
        (unless (bolp)
          (insert "\n"))
        (insert "\n")
        (goto-char here)
        (while (re-search-forward "^\\(From[: ]\\)" nil t)
          (replace-match ">\\1")))
      (append-to-file (point-min) (point-max) remember-mailbox)
      t)))

;; Remembering to plain files

(defcustom remember-data-file (locate-user-emacs-file "notes" ".notes")
  "The file in which to store unprocessed data."
  :type 'file
  :group 'remember)

(defcustom remember-leader-text "** "
  "The text used to begin each remember item."
  :type 'string
  :group 'remember)

(defun remember-append-to-file ()
  "Remember, with description DESC, the given TEXT."
  (let ((text (buffer-string))
        (desc (remember-buffer-desc)))
    (with-temp-buffer
      (insert "\n" remember-leader-text (current-time-string)
              " (" desc ")\n\n" text)
      (if (not (bolp))
          (insert "\n"))
      (if (find-buffer-visiting remember-data-file)
          (let ((remember-text (buffer-string)))
            (set-buffer (get-file-buffer remember-data-file))
            (save-excursion
              (goto-char (point-max))
              (insert remember-text)
              (when remember-save-after-remembering (save-buffer))))
        (append-to-file (point-min) (point-max) remember-data-file)))))

(defun remember-region (&optional beg end)
  "Remember the data from BEG to END.
It is called from within the *Remember* buffer to save the text
that was entered.

If BEG and END are nil, the entire buffer will be remembered.

If you want to remember a region, supply a universal prefix to
`remember' instead.  For example: \\[universal-argument] \\[remember] RET."
  ;; Sacha: I have no idea where remember.el gets this context information, but
  ;; you can just use remember-annotation-functions.
  (interactive)
  (let ((b (or beg (min (point) (or (mark) (point-min)))))
        (e (or end (max (point) (or (mark) (point-max))))))
    (save-restriction
      (narrow-to-region b e)
      (if remember-all-handler-functions
          (run-hooks 'remember-handler-functions)
        (run-hook-with-args-until-success 'remember-handler-functions))
      (remember-destroy))))

(defcustom remember-data-directory "~/remember"
  "The directory in which to store remember data as files."
  :type 'directory
  :version "24.4"
  :group 'remember)

(defcustom remember-directory-file-name-format "%Y-%m-%d_%T-%z"
  "Format string for the file name in which to store unprocessed data."
  :type 'string
  :version "24.4"
  :group 'remember)

(defun remember-store-in-files ()
  "Store remember data in a file in `remember-data-directory'.
The file is named after `remember-directory-file-name-format' fed through
`format-time-string'."
  (let ((name (format-time-string
	       remember-directory-file-name-format (current-time)))
        (text (buffer-string)))
    (with-temp-buffer
      (insert text)
      (write-file (convert-standard-filename
                   (format "%s/%s" remember-data-directory name))))))

;;;###autoload
(defun remember-clipboard ()
  "Remember the contents of the current clipboard.
Most useful for remembering things from other applications."
  (interactive)
  (remember (current-kill 0)))

(defun remember-finalize ()
  "Remember the contents of the current buffer."
  (interactive)
  (remember-region (point-min) (point-max)))

;; Org needs this
(define-obsolete-function-alias 'remember-buffer 'remember-finalize "23.1")

(defun remember-destroy ()
  "Destroy the current *Remember* buffer."
  (interactive)
  (when (equal remember-buffer (buffer-name))
    (kill-buffer (current-buffer))
    (jump-to-register remember-register)))

;;; Diary integration

(defcustom remember-diary-file nil
  "File for extracted diary entries.
If this is nil, then `diary-file' will be used instead."
  :type 'file
  :group 'remember)

(defun remember-diary-convert-entry (entry)
  "Translate MSG to an entry readable by diary."
  (save-match-data
    (when remember-annotation
        (setq entry (concat entry " " remember-annotation)))
    (if (string-match "\\([0-9]+\\)\\.\\([0-9]+\\)\\.\\([0-9]+\\)" entry)
        (progn
          ;; For calendar-date-style.  This costs us nothing because
          ;; the call to diary-make-entry below loads diary-lib
          ;; which requires calendar.
          (require 'calendar)
          (replace-match
           (let ((style (if (boundp 'calendar-date-style)
                            calendar-date-style
                          ;; Don't complain about obsolescence.
                          (if (with-no-warnings european-calendar-style)
                              'european
                            'american))))
             (cond ((eq style 'european)
                    (concat (match-string 3 entry) "/"
                            (match-string 2 entry) "/"
                            (match-string 1 entry)))
                   ((eq style 'iso)
                    (concat (match-string 1 entry) "-"
                            (match-string 2 entry) "-"
                            (match-string 3 entry)))
                   (t (concat (match-string 2 entry) "/"
                              (match-string 3 entry) "/"
                              (match-string 1 entry)))))
           t t entry))
      entry)))

(autoload 'diary-make-entry "diary-lib")

;;;###autoload
(defun remember-diary-extract-entries ()
  "Extract diary entries from the region."
  (save-excursion
    (goto-char (point-min))
    (let (list)
      (while (re-search-forward "^DIARY:\\s-*\\(.+\\)" nil t)
        (add-to-list 'list (remember-diary-convert-entry (match-string 1))))
      (when list
        (diary-make-entry (mapconcat 'identity list "\n")
                          nil remember-diary-file))
      nil))) ;; Continue processing

;;; Internal Functions:

(defvar remember-mode-map
  (let ((map (make-sparse-keymap)))
    (define-key map "\C-x\C-s" 'remember-finalize)
    (define-key map "\C-c\C-c" 'remember-finalize)
    (define-key map "\C-c\C-k" 'remember-destroy)
    map)
  "Keymap used in Remember mode.")

(define-derived-mode remember-mode indented-text-mode "Remember"
  "Major mode for output from \\[remember].
This buffer is used to collect data that you want to remember.
\\<remember-mode-map>
Just hit \\[remember-finalize] when you're done entering, and it will file
the data away for latter retrieval, and possible indexing.

\\{remember-mode-map}"
  (set-keymap-parent remember-mode-map nil))

;;; remember.el ends here