path: root/lisp/acdw-org.el

;;; acdw-org.el --- org extras -*- lexical-binding: t; coding: utf-8-unix -*-
;; Author: Various
;; URL: https://tildegit.org/acdw/emacs

;; This file is NOT part of GNU Emacs.

;;; License:

;; Everyone is permitted to do whatever with this software, without
;; limitation.  This software comes without any warranty whatsoever,
;; but with two pieces of advice:
;; - Don't hurt yourself.
;; - Make good choices.

;;; Commentary:

;; This file is for the weird little `org-mode' functions that just take up
;; space in my main init file.  I've tried to give credit where credit is due.

;; 2021-09-13 Hi readers of "Emacs News!"  I just saw that Sacha decided to
;; include this in her weekly newsletter.  Thanks for the gold kind stranger,
;; etc.  If you're looking for stuff in here that /isn't/ just ripped
;; wholesale from something else on the internet, you'll want the following
;; (updated as I write more/remember to update them):

;; `acdw-org/fix-blank-lines-in-buffer'
;; `acdw-org/count-words-stupidly'
;; `acdw/org-next-heading-widen'
;; `acdw/org-previous-heading-widen'
;; `acdw-org/work-month-headings'

;; To be honest, I could easily (and probably should) extract some of these out
;; into their own /real/ libraries.

;; Until then, just require this file /after/ you require org -- i.e.,
;; (with-eval-after-load 'org (require 'acdw-org)) -- or else it'll load every
;; time you start up Emacs.

;;; Code:

(require 'dom)
(require 'org)
(require 'org-element)
(require 'ox)
(require 'subr-x)
(require 'calendar)


;;; unpackaged.el: https://github.com/alphapapa/unpackaged.el

(defun acdw-org/element-descendant-of (type element)
  "Return non-nil if ELEMENT is a descendant of TYPE.
TYPE should be an element type, like `item' or `paragraph'.
ELEMENT should be a list like that returned by `org-element-context'."
  ;; MAYBE: Use `org-element-lineage'.
  (when-let* ((parent (org-element-property :parent element)))
    (or (eq type (car parent))
        (acdw-org/element-descendant-of type parent))))

(defun acdw-org/return-dwim (&optional prefix)
  "A helpful replacement for `org-return'.  With PREFIX, call `org-return'.

On headings, move point to position after entry content.  In
lists, insert a new item or end the list, with checkbox if
appropriate.  In tables, insert a new row or end the table."
  ;; Inspired by John Kitchin:
  ;; http://kitchingroup.cheme.cmu.edu/blog/2017/04/09/A-better-return-in-org-mode/
  (interactive "P")
  ;; Auto-fill if enabled
  (when auto-fill-function
    (if (listp auto-fill-function)
        (dolist (func auto-fill-function)
          (funcall func))
      (funcall auto-fill-function)))
  (if prefix
      ;; Handle prefix args
      (pcase prefix
        ('(4) (newline))
        ('(16) (newline 2))
        ;; this is ... not ideal. but whatever.
        (_ (newline prefix)))
    (cond
     ;; Act depending on context around point.
     ((and org-return-follows-link
           (eq 'link (car (org-element-context))))
      ;; Link: Open it.
      (org-open-at-point-global))

     ((org-at-heading-p)
      ;; Heading: Move to position after entry content.
      ;; NOTE: This is probably the most interesting feature of this function.
      (let ((heading-start (org-entry-beginning-position)))
        (goto-char (org-entry-end-position))
        (cond ((and (org-at-heading-p)
                    (= heading-start (org-entry-beginning-position)))
               ;; Entry ends on its heading; add newline after
               (end-of-line)
               (insert "\n\n"))
              (t
               ;; Entry ends after its heading; back up
               (forward-line -1)
               (end-of-line)
               (when (org-at-heading-p)
                 ;; At the same heading
                 (forward-line)
                 (insert "\n")
                 (forward-line -1))
               (while (not
                       (looking-back
                        (rx (repeat 3 (seq (optional blank) "\n")))
                        nil))
                 (insert "\n"))
               (forward-line -1)))))

     ((org-at-item-checkbox-p)
      ;; Checkbox: Insert new item with checkbox.
      (org-insert-todo-heading nil))

     ((org-in-item-p)
      ;; Plain list
      (let* ((context (org-element-context))
             (first-item-p (eq 'plain-list (car context)))
             (itemp (eq 'item (car context)))
             (emptyp (eq (org-element-property :contents-begin context)
                         (org-element-property :contents-end context)))
             (item-child-p
              (acdw-org/element-descendant-of 'item context)))
        ;; The original function from unpackaged just tested the (or ...) test
        ;; in this cond, in an if.  However, that doesn't auto-end nested
        ;; lists.  So I made this form a cond and added the (and...) test in
        ;; the first position, which is clunky (the delete-region... stuff
        ;; comes twice) and might not be needed.  More testing, obviously, but
        ;; for now, it works well enough.
        (cond ((and itemp emptyp)
               (delete-region (line-beginning-position) (line-end-position))
               (insert "\n\n"))
              ((or first-item-p
                   (and itemp (not emptyp))
                   item-child-p)
               (org-insert-item))
              (t (delete-region (line-beginning-position) (line-end-position))
                 (insert "\n")))))

     ((when (fboundp 'org-inlinetask-in-task-p)
        (org-inlinetask-in-task-p))
      ;; Inline task: Don't insert a new heading.
      (org-return))

     ((org-at-table-p)
      (cond ((save-excursion
               (beginning-of-line)
               ;; See `org-table-next-field'.
               (cl-loop with end = (line-end-position)
                        for cell = (org-element-table-cell-parser)
                        always (equal (org-element-property :contents-begin cell)
                                      (org-element-property :contents-end cell))
                        while (re-search-forward "|" end t)))
             ;; Empty row: end the table.
             (delete-region (line-beginning-position) (line-end-position))
             (org-return))
            (t
             ;; Non-empty row: call `org-return'.
             (org-return))))
     (t
      ;; All other cases: call `org-return'.
      (org-return)))))

(defun acdw-org/fix-blank-lines (&optional prefix)
  "Ensure blank lines around headings.
Optional PREFIX argument operates on the entire buffer.
Drawers are included with their headings."
  (interactive "P")
  (org-map-entries (lambda ()
                     (org-with-wide-buffer
                      ;; `org-map-entries' narrows the buffer, which
                      ;; prevents us from seeing newlines before the
                      ;; current heading, so we do this part widened.
                      (while (not (looking-back "\n\n" nil))
                        ;; Insert blank lines before heading.
                        (insert "\n")))
                     (let ((end (org-entry-end-position)))
                       ;; Insert blank lines before entry content
                       (forward-line)
                       (while (and (org-at-planning-p)
                                   (< (point) (point-max)))
                         ;; Skip planning lines
                         (forward-line))
                       (while (re-search-forward
                               org-drawer-regexp end t)
                         ;; Skip drawers. You might think that
                         ;; `org-at-drawer-p' would suffice, but for
                         ;; some reason it doesn't work correctly when
                         ;; operating on hidden text.  This works, taken
                         ;; from `org-agenda-get-some-entry-text'.
                         (re-search-forward "^[ \t]*:END:.*\n?" end t)
                         (goto-char (match-end 0)))
                       (unless (or (= (point) (point-max))
                                   (org-at-heading-p)
                                   (looking-at-p "\n"))
                         (insert "\n"))))
                   t
                   (if prefix
                       nil
                     'tree)))


;;; Generate custom IDs:
;; https://amitp.blogspot.com/2021/04/automatically-generate-ids-for-emacs.html

(defun acdw-org/generate-custom-ids ()
  "Generate CUSTOM_ID for any headings that are missing one."
  (let ((existing-ids (org-map-entries (lambda ()
                                         (org-entry-get nil "CUSTOM_ID")))))
    (org-map-entries
     (lambda ()
       (let* ((custom-id (org-entry-get nil "CUSTOM_ID"))
              (heading (org-heading-components))
              (level (nth 0 heading))
              (todo (nth 2 heading))
              (headline (nth 4 heading))
              (slug (acdw-org/title-to-filename headline))
              (duplicate-id (member slug existing-ids)))
         (when (and (not custom-id)
                    (< level 4)
                    (not todo)
                    (not duplicate-id))
           (message "Adding entry '%s' to '%s'" slug headline)
           (org-entry-put nil "CUSTOM_ID" slug)))))))

(defun acdw-org/title-to-filename (title)
  "Convert TITLE to a reasonable filename."
  ;; Based on the slug logic in `org-roam', but `org-roam' also uses a
  ;; timestamp, and I only use the slug.
  (setq title (downcase title))
  (setq title (replace-regexp-in-string "[^a-zA-Z0-9]+" "-" title))
  (setq title (replace-regexp-in-string "-+" "-" title))
  (setq title (replace-regexp-in-string "^-" "" title))
  (setq title (replace-regexp-in-string "-$" "" title))
  title)


;;; ADVICE AND TWEAKS

;; I definitely got this from somewhere.
;; Correct `org-delete-backward-char' to use `backward-delete-char-untabify'
(defun acdw-org/delete-backward-char (N)
  "Keep tables aligned while deleting N characters backward.
When deleting backwards, in tables this function will insert
whitespace in front of the next \"|\" separator, to keep the
table aligned.  The table will still be marked for re-alignment
if the field did fill the entire column, because, in this case
the deletion might narrow the column."
  (interactive "p")
  (save-match-data
    (org-check-before-invisible-edit 'delete-backward)
    (if (and (= N 1)
             (not overwrite-mode)
             (not (org-region-active-p))
             (not (eq (char-before) ?|))
             (save-excursion (skip-chars-backward " \t") (not (bolp)))
             (looking-at-p ".*?|")
             (org-at-table-p))
        (progn (forward-char -1) (org-delete-char 1))
      (backward-delete-char-untabify N)
      (org-fix-tags-on-the-fly))))

;; Same here.
(defun acdw-org/org-table-copy-down (n)
  "Call `org-table-copy-down', or `org-return' outside of a table.
N is passed to the functions."
  (interactive "p")
  (if (org-table-check-inside-data-field 'noerror)
      (org-table-copy-down n)
    (acdw-org/return-dwim n)))

;; This isn't the best code, but it'll do.
(defun acdw-org/count-words-stupidly (start end &optional limit)
  "Count words between START and END, ignoring a lot.

Since this function is, for some reason, pricy, the optional
parameter LIMIT sets a word limit at which to stop counting.
Once the function hits that number, it'll return -LIMIT
instead of the true count."
  (interactive (list nil nil))
  (cond ((not (called-interactively-p 'any))
         (let ((words 0)
               (continue t))
           (save-excursion
             (save-restriction
               (narrow-to-region start end)
               (goto-char (point-min))
               (while (and continue
                           (< (point) (point-max)))
                 (cond
                  ;; Ignore comments
                  ((or (org-at-comment-p)
                       (org-in-commented-heading-p))
                   (forward-line))
                  ;; Ignore headings
                  ((or (org-at-heading-p))
                   (forward-line))
                  ;; Ignore property and log drawers
                  ((or (looking-at org-drawer-regexp)
                       (looking-at org-clock-drawer-re))
                   (search-forward ":END:" nil :noerror)
                   (forward-line))
                  ;; Ignore DEADLINE and SCHEDULED keywords
                  ((or (looking-at org-deadline-regexp)
                       (looking-at org-scheduled-regexp)
                       (looking-at org-closed-time-regexp))
                   (forward-line))
                  ;; Ignore tables
                  ((org-at-table-p) (forward-line))
                  ;; Ignore hyperlinks, but count the descriptions
                  ((looking-at org-link-bracket-re)
                   (when-let ((desc (match-string-no-properties 5)))
                     (save-match-data
                       (setq words (+ words
                                      (length (remove ""
                                                      (org-split-string
                                                       desc "\\W")))))))
                   (goto-char (match-end 0)))
                  ;; Ignore source blocks
                  ((org-in-src-block-p) (forward-line))
                  ;; Ignore blank lines
                  ((looking-at "^$")
                   (forward-line))
                  ;; Count everything else
                  (t
                   ;; ... unless it's in a few weird contexts
                   (let ((contexts (org-context)))
                     (cond ((or (assoc :todo-keyword contexts)
                                (assoc :priority contexts)
                                (assoc :keyword contexts)
                                (assoc :checkbox contexts))
                            (forward-word-strictly))
                           
                           (t (setq words (1+ words))
                              (if (and limit
                                       (> words limit))
                                  (setq words (- limit)
                                        continue nil))
                              (forward-word-strictly)))))))))
           words))
        ((use-region-p)
         (message "%d words in region"
                  (acdw-org/count-words-stupidly (region-beginning)
                                                 (region-end))))
        (t
         (message "%d words in buffer"
                  (acdw-org/count-words-stupidly (point-min)
                                                 (point-max))))))


;;; Zero-width spaces
;; https://blog.tecosaur.com/tmio/2021-05-31-async.html#easy-zero-width

(defun insert-zero-width-space ()
  "Insert a zero-width space."
  (interactive)
  (insert "\u200b"))

(defun org-export-remove-zero-width-spaces (text _backend _info)
  "Remove zero-width spaces from TEXT."
  (unless (org-export-derived-backend-p 'org)
    (replace-regexp-in-string "\u200b" "" text)))


;;; Insert links .. DWIM
;; https://xenodium.com/emacs-dwim-do-what-i-mean/

(defun  org-insert-link-dwim ()
  "Like `org-insert-link' but with personal dwim preferences."
  (interactive)
  (let* ((point-in-link (org-in-regexp org-link-any-re 1))
         (clipboard-url (when (string-match-p
                               (rx (sequence bos
                                             (or "http"
                                                 "gemini"
                                                 "gopher")))
                               (current-kill 0))
                          (current-kill 0)))
         (region-content (when (region-active-p)
                           (buffer-substring-no-properties (region-beginning)
                                                           (region-end)))))
    (cond ((and region-content clipboard-url (not point-in-link))
           (delete-region (region-beginning) (region-end))
           (insert (org-link-make-string clipboard-url region-content)))
          ((and clipboard-url (not point-in-link))
           (insert (org-link-make-string
                    clipboard-url
                    (read-string  "title: "
                                  (with-current-buffer
                                      (url-retrieve-synchronously
                                       clipboard-url)
                                    (dom-text
                                     (car
                                      (dom-by-tag (libxml-parse-html-region
                                                   (point-min)
                                                   (point-max))
                                                  'title))))))))
          (t
           (call-interactively 'org-insert-link)))))


;;; Next and previous heading, with widening
(defun acdw/org-next-heading-widen (arg)
  "Find the ARGth next org heading, widening if necessary."
  (interactive "p")
  (let ((current-point (point))
        (point-target (if (> arg 0) (point-max) (point-min))))
    (org-next-visible-heading arg)
    (when (and (buffer-narrowed-p)
               (= (point) point-target)
               (or (and (> arg 0))
                   (and (< arg 0)
                        (= (point) current-point))))
      (widen)
      (org-next-visible-heading arg))))

(defun acdw/org-previous-heading-widen (arg)
  "Find the ARGth previous org heading, widening if necessary."
  (interactive "p")
  (acdw/org-next-heading-widen (- arg)))


;;; Add headings for every day of the work month
;; Gets rid of weekends.

(defun acdw-org/work-month-headings (&optional month year)
  "Create headings for every workday in MONTH and YEAR, or this month.
Workdays are Monday through Friday.  This function inserts a new
heading with an inactive timestamp for each workday of MONTH in YEAR.

I use this function to attempt to organize my work month.  I'll
probably abandon it at some point for a better solution (see:
`org-agenda')."
  (interactive (list
                (read-number "Month: " (car (calendar-current-date)))
                (read-number "Year: " (nth 2 (calendar-current-date)))))
  (let ((month (or month
                   (car (calendar-current-date))))
        (year (or year
                  (car (last (calendar-current-date))))))
    (dotimes (day (calendar-last-day-of-month month year))
      (let* ((day (1+ day))
             (day-of-week (calendar-day-of-week (list month day year))))
        (unless (memq day-of-week '(0 6))           ; weekend
          (end-of-line)
          (org-insert-heading nil t t)
          (insert (concat "[" (mapconcat (lambda (n)
                                           (format "%02d" n))
                                         (list year month day)
                                         "-")
                          " "
                          (nth day-of-week '("Sun" "Mon" "Tue" "Wed" "Thu"
                                             "Fri" "Sat"))
                          "]")))))))

;;; Org task stuff

(defun org-narrow-to-task ()
  "Narrow buffer to the nearest task and its subtree."
  (interactive)
  (save-excursion
    (save-match-data
      (widen)
      (while (not (org-entry-is-todo-p))
        ;; TODO: need a better error message
        (org-previous-visible-heading 1))
      (org-narrow-to-subtree))))


;;; Hide everything but the current headline
;; https://stackoverflow.com/questions/25161792/

(defun acdw-org/show-next-heading-tidily ()
  "Show next entry, keeping other entries closed."
  (interactive)
  (if (save-excursion (end-of-line) (outline-invisible-p))
      (progn (org-show-entry) (outline-show-children))
    (outline-next-heading)
    (unless (and (bolp) (org-at-heading-p))
      (org-up-heading-safe)
      (outline-hide-subtree)
      (error "Boundary reached"))
    (org-overview)
    (org-reveal t)
    (org-show-entry)
    (recenter-top-bottom)
    (outline-show-children)
    (recenter-top-bottom)))

(defun acdw-org/show-previous-heading-tidily ()
  "Show previous entry, keeping other entries closed."
  (interactive)
  (let ((pos (point)))
    (outline-previous-heading)
    (unless (and (< (point) pos) (bolp) (org-at-heading-p))
      (goto-char pos)
      (outline-hide-subtree)
      (error "Boundary reached"))
    (org-overview)
    (org-reveal t)
    (org-show-entry)
    (recenter-top-bottom)
    (outline-show-children)
    (recenter-top-bottom)))


(provide 'acdw-org)
;;; acdw-org.el ends here

;; Local Variables:
;; flymake-inhibit: t
;; End: