#+title: Emacs Config
#+property: header-args:elisp :mkdirp yes :results silent :padline no
#+property: header-args:elisp+ :tangle "~/.config/emacs/init.el"

* General
** Settings
Quality of life settings.
#+begin_src elisp
  (setq-default
   help-window-select t
   delete-by-moving-to-trash t
   sentence-end-double-space nil
   confirm-kill-emacs 'yes-or-no-p
   scroll-conservatively 101
   cursor-in-non-selected-windows nil)
#+end_src

** Startup Screen
Disable default startup screen.
#+begin_src elisp
  (setq-default inhibit-startup-screen t)
#+end_src

** GUI Bars
Disable GUI bars.
#+begin_src elisp
  (tool-bar-mode -1)
  (menu-bar-mode -1)
  (scroll-bar-mode -1)
#+end_src

** Minibuffer
Enable vertical minibuffer.
#+begin_src elisp
  (fido-vertical-mode)
#+end_src

** Behaviour
Automatically move cursor point on window split.
#+begin_src elisp
  (advice-add 'split-window-below
              :after (lambda (&rest r) (other-window 1)))
  (advice-add 'split-window-right
              :after (lambda (&rest r) (other-window 1)))
#+end_src

Add advice to copy line at cursor point or region.
#+begin_src elisp
  (defadvice kill-ring-save (before dwim-copy activate compile)
    "Copy the current line at cursor point or region."
    (interactive
     (if mark-active
         (list (region-beginning) (region-end))
       (message "Line copied")
       (list (line-beginning-position)
             (line-beginning-position 2)))))
#+end_src

Add advice to cut line or region at cursor point.
#+begin_src elisp
  (defadvice kill-region (before dwim-cut activate compile)
    "Cut the current line at point or region."
    (interactive
     (if mark-active (list (region-beginning) (region-end))
       (list (line-beginning-position)
             (line-beginning-position 2)))))
#+end_src

Add advice to enable ~query-replace~ to search the whole buffer or region if selected, as the original default behaviour would only begin to replace from the cursor point position.
#+begin_src elisp
  (defun +advice-goto-top-no-region (func &rest args)
    "Move point to top of buffer when no region applying ARGS to FUNC."
    (save-excursion
      (when (not (use-region-p))
        (goto-char (point-min)))
      (apply func args)))

  (advice-add 'query-replace :around #'+advice-goto-top-no-region)
  (advice-add 'query-replace-regexp :around #'+advice-goto-top-no-region)
#+end_src

** Editor
Tab behaviour settings.
#+begin_src elisp
  (setq-default
   tab-width 4
   tab-always-indent 'complete
   backward-delete-char-untabify-method 'hungry
   indent-tabs-mode nil)
#+end_src

Replace selected region when yanking text.
#+begin_src elisp
  (delete-selection-mode)
#+end_src

Auto update buffer on any file changes.
#+begin_src elisp
  (global-auto-revert-mode)
#+end_src

Automatically remove trailing whitespace on file-save.
#+begin_src elisp
  (add-hook 'before-save-hook #'whitespace-cleanup)
#+end_src

Increase default column width.
#+begin_src elisp
  (setq-default fill-column 80)
#+end_src

Set whitespace column length and symbols.
#+begin_src elisp
  (with-eval-after-load 'whitespace
    (setq-default
     whitespace-line-column fill-column
     whitespace-display-mappings '((space-mark ?\s [?·] [?.])
                                   (newline-mark ?\n [?↴ ?\n])
                                   (tab-mark ?\t [?➔ ?\t] [?\\ ?\t]))))
#+end_src

Enable pairing brackets.
#+begin_src elisp
  (electric-pair-mode)
#+end_src

** Theme
Enable theme.
#+begin_src elisp
  (load-theme 'modus-vivendi)
#+end_src

** Modeline
Enable column number in modeline.
#+begin_src elisp
  (column-number-mode)
#+end_src

** Completion
Enable completions previews.
#+begin_src elisp
  (add-hook 'prog-mode-hook
            #'completion-preview-mode)
#+end_src

Set completion keybindings.
#+begin_src elisp
  (with-eval-after-load 'completion-preview
    (let ((map completion-preview-active-mode-map))
      (keymap-set map "M-n" #'completion-preview-next-candidate)
      (keymap-set map "M-p" #'completion-preview-prev-candidate)))
#+end_src

** Which-key
Enable which-key that displays a pop-up window of posisble keybindings sequences.
#+begin_src elisp
  (which-key-mode)
#+end_src

** History
*** Minibuffer History
Enable saving minibuffer history.
#+begin_src elisp :noweb yes
  (savehist-mode)
  (with-eval-after-load 'savehist
    <<savehist-settings>>)
#+end_src

Automatically save history on exit.
#+begin_example elisp :tangle no :noweb-ref savehist-settings
  (add-hook 'kill-emacs-hook #'savehist-save)
#+end_example

Ensure savehist file is loaded.
#+begin_src elisp :tangle no :noweb-ref savehist-settings
  (unless savehist-loaded
    (load-file savehist-file))
#+end_src

Add addtional variable lists to save.
#+begin_src elisp :tangle no :noweb-ref savehist-settings
  (dolist (var '(command-history
                 register-alist
                 mark-ring
                 kill-ring
                 search-ring
                 regexp-search-ring))
    (cl-pushnew var savehist-additional-variables))
#+end_src

*** Recent Files
Enable saving history of recent opened files.
#+begin_src elisp :noweb yes
  (recentf-mode)
  (with-eval-after-load 'recentf
    <<recentf-settings>>)
#+end_src

Recentf settings.
#+begin_src elisp :tangle no :noweb-ref recentf-settings
  (setq-default
   recentf-max-saved-items 50
   recentf-auto-cleanup 'never)
#+end_src

Save recent files and cleanup file list on exit.
#+begin_src elisp :tangle no :noweb-ref recentf-settings
  (add-hook 'kill-emacs-hook #'recentf-cleanup)
  (add-hook 'kill-emacs-hook #'recentf-save-list)
#+end_src

Disallow duplicates in history.
#+begin_src elisp :tangle no :noweb-ref recentf-settings
  (setq-default history-delete-duplicates t)
#+end_src

*** Cursor Point Position
Enable saving cursor point positions.
#+begin_src elisp :noweb yes
  (save-place-mode)
  (with-eval-after-load 'saveplace
    <<saveplace-settings>>)
#+end_src

Save place settings.
#+begin_src elisp :tangle no :noweb-ref saveplace-settings
  (setq-default
   save-place-abbreviate-file-names t
   save-place-limit 800)
#+end_src

*** Bookmarks
Don't display bookmark icon in fringe.
#+begin_src elisp
  (with-eval-after-load 'bookmark
    (setq-default bookmark-fringe-mark nil))
#+end_src

Disable auto-bookmarking org-mode files.
#+begin_src elisp
  (with-eval-after-load 'org
    (setq-default org-bookmark-names-plist nil))
#+end_src

** Spell Checking
Set dictionary.
#+begin_src elisp
  (setq-default ispell-dictionary "british")
#+end_src

Enable spell checking.
#+begin_src elisp
  (add-hook 'text-mode-hook #'flyspell-mode)
  (add-hook 'prog-mode-hook #'flyspell-prog-mode)
#+end_src

Add add word to dictionary function.
#+begin_src elisp
  (defun +flyspell-add-word-to-dictionary ()
    "Save word at point to personal dictionary."
    (interactive)
    (when-let ((loc (point))
               (word (flyspell-get-word)))
      (when (yes-or-no-p
             (format "Add '%s' to dictionary?" (car word)))
        (flyspell-do-correct
         'save nil (car word) loc (cadr word) (caddr word) loc)
        (save-buffer)
        (revert-buffer-quick)
        (message "Added '%s' to personal dictionary" (car word)))))
#+end_src

Set custom spell checking keybindings.
#+begin_src elisp
  (setq-default flyspell-mode-map (make-sparse-keymap))
  (with-eval-after-load 'flyspell
    (keymap-set flyspell-mode-map "C-x c c" #'flyspell-auto-correct-word)
    (keymap-set flyspell-mode-map "C-x c u" #'flyspell-auto-correct-previous-word)
    (keymap-set flyspell-mode-map "C-x c l" #'flyspell-check-previous-highlighted-word)
    (keymap-set flyspell-mode-map "C-x c n" #'flyspell-goto-next-error)
    (keymap-set flyspell-mode-map "C-x c b" #'flyspell-buffer)
    (keymap-set flyspell-mode-map "C-x c d" #'ispell-change-dictionary)
    (keymap-set flyspell-mode-map "C-x c i" #'+flyspell-add-word-to-dictionary))
#+end_src

** Dired
#+begin_src elisp :noweb yes
  (with-eval-after-load 'dired
    <<dired-settings>>)
#+end_src

Dired settings.
#+begin_src elisp :tangle no :noweb-ref dired-settings
  (setq-default
   dired-guess-shell-alist-user '(("\\.pdf$" "zathura"))
   dired-listing-switched "-AFhlv --group-directories-first")
#+end_src

Auto enable omit mode on Dired startup.
#+begin_src elisp :tangle no :noweb-ref dired-settings
  (add-hook 'dired-mode-hook (lambda ()
                               (dired-omit-mode)
                               (toggle-truncate-lines 1)))
#+end_src

Add shred function.
#+begin_src elisp :tangle no :noweb-ref dired-settings
  (if (executable-find "shred")
      (defun +dired-shred-file ()
        "Shred marked files or a file at point in Dired."
        (interactive)
        (mapc (lambda (file) "Run the shred shell command on FILE."
                (if (file-regular-p file)
                    (when (yes-or-no-p (format "Shred %s?" file))
                      (shell-command (format "shred -u \"%s\"" file)))
                  (error "Aborting shred procedure; \"%s\" is not a file!" file)))
              (dired-get-marked-files)))
    (error "Shred command not found!"))
#+end_src

Add additional dired keybindings.
#+begin_src elisp :tangle no :noweb-ref dired-settings
  (keymap-set dired-mode-map "b" #'dired-up-directory)
  (keymap-set dired-mode-map "z" #'+dired-shred-file)
#+end_src

Allow changing file permissions when in a writable dired buffer.
#+begin_src elisp :tangle no :noweb-ref dired-settings
  (with-eval-after-load 'wdired
    (setq-default wdired-allow-to-change-permissions t))
#+end_src

** Search & Replace
Case-sensitive search by default and show match count in minibuffer.
#+begin_src elisp
  (with-eval-after-load 'isearch
    (setq-default
     case-fold-search nil
     isearch-lazy-count t))
#+end_src

** Org
#+begin_src elisp :noweb yes
  (with-eval-after-load 'org
    <<org-settings>>
    <<org-babel-settings>>)
#+end_src

Hide emphasis markers and set ellipse symbol.
#+begin_src elisp :tangle no :noweb-ref org-settings
  (setq-default org-ellipsis "⤵"
                org-hide-emphasis-markers t)
#+end_src

Enable checkbox dependency checking.
#+begin_src elisp :tangle no :noweb-ref org-settings
  (setq-default org-enforce-todo-dependencies t
                org-enforce-todo-checkbox-dependencies t
                org-checkbox-hierarchical-statistics nil)
#+end_src

Try to get the width from attribute tags or fall-back to original image width.
Also redisplay updated images on block execution.
#+begin_src elisp
  (setq-default org-image-actual-width nil)
  (add-hook 'org-babel-after-execute-hook
            (lambda () "Redisplay Org inline images."
              (when org-inline-image-overlays
                (org-redisplay-inline-images))))
#+end_src

Use custom IDs for links.
#+begin_src elisp
  (with-eval-after-load 'org-id
    (setq-default org-id-link-to-org-use-id
                  'create-if-interactive-and-no-custom-id))
#+end_src

Set org column format.
#+begin_src elisp
  (setq-default org-columns-default-format
                "%70ITEM %TODO %10CLOCKSUM %16DEADLINE")
#+end_src

Enable notes for various actions.
#+begin_src elisp
  (setq-default org-log-done 'time
                org-log-reschedule 'note
                org-log-redeadline 'note
                org-log-into-drawer t
                org-log-note-clock-out t)
#+end_src

*** Org Speed Commands
#+begin_src elisp :noweb yes
  (with-eval-after-load 'org-keys
    <<org-speed-command-settings>>)
#+end_src

Enable org speed commands.
#+begin_src elisp
  (setq-default org-use-speed-commands t)
#+end_src

Add advice to prompt for confirmation before commenting or cutting subtree.
#+begin_src elisp
  (advice-add 'org-cut-subtree
              :before-while (lambda (&rest _)
                              "Prompts for confirmation before cutting subtree."
                              (let ((heading (org-entry-get nil "ITEM")))
                                (y-or-n-p (format "Cut \"%s\" subtree?" heading)))))

  (advice-add 'org-toggle-comment
              :before-while (lambda (&rest _)
                              "Prompt for confirmation before commenting a subtree."
                              (let ((heading (org-entry-get nil "ITEM")))
                                (y-or-n-p (format "Toggle comment on \"%s\" subtree?" heading)))))
#+end_src

Alternative comment key =;= added to be consistent with ~org-toggle-comment~ (=C-c ;=).
#+begin_src elisp  :tangle no :noweb-ref org-speed-command-settings
  (dolist (key '(("P" . org-set-property)
                 ("$" . org-archive-subtree-default-with-confirmation)
                 ("q" . org-set-tags-command)
                 ("]" . org-shiftright)
                 ("[" . org-shiftleft)
                 (";" . org-toggle-comment)
                 ("z" . org-add-note)
                 ("y" . org-copy-subtree)))
    (cl-pushnew key org-speed-commands))
#+end_src

Add ='= key to edit org source blocks, which is consistent with ~org-edit-special~ (=C-c '=).
#+begin_src elisp
  (cl-pushnew '("'" . org-edit-src-code) org-babel-key-bindings)
#+end_src

*** Org Babel
:PROPERTIES:
:header-args:elisp: :tangle no :noweb-ref org-babel-settings
:END:

Add new structure template shortcuts when inserting a block.
#+begin_src elisp
  (cl-pushnew '("se" . "src elisp") org-structure-template-alist)
#+end_src

Add advice to automatically open an edit buffer when inserting a structure template.
#+begin_src elisp
  (defadvice org-insert-structure-template
      (after edit-src activate compile)
    "Auto enter an edit buffer when inserted an Org block."
    (call-interactively 'org-edit-special))
#+end_src

Enable supported org babel languages.
#+begin_src elisp
  (dolist (lang '(shell C latex plantuml))
    (cl-pushnew `(,lang . t) org-babel-load-languages))
#+end_src

* Keybindings
Unlock previously unusable keybinding.
#+begin_src elisp
  (define-key input-decode-map [?\C-\[] (kbd "<C-[>"))
#+end_src

** Global Keybindings
To prevent other packages overriding any custom global keybinding, all custom global keybinding are stored in a global minor mode.
#+begin_src elisp
  (define-minor-mode +global-keys
    "Minor to store my custom global keybindings."
    :global t
    :lighter " +GKEYS"
    :keymap (make-sparse-keymap))

  (+global-keys)
#+end_src

File actions.
#+begin_src elisp
  (keymap-set +global-keys-map "C-x x R" #'rename-visited-file)
  (keymap-set +global-keys-map "C-x x D" #'delete-file)
#+end_src

Window actions.
#+begin_src elisp
  (keymap-set +global-keys-map "M-o" #'other-window)
  (keymap-set +global-keys-map "M-O" #'window-swap-states)
  (keymap-set +global-keys-map "M-V" #'scroll-other-window-down)
  (keymap-set +global-keys-map "C-S-V" #'scroll-other-window)
  (keymap-set +global-keys-map "C-M-<" #'beginning-of-buffer-other-window)
  (keymap-set +global-keys-map "C-M->" #'end-of-buffer-other-window)
  (keymap-set +global-keys-map "C-M-]" #'next-buffer)
  (keymap-set +global-keys-map "M-ESC" #'previous-buffer) ; C-M-[ translates to M-ESC
#+end_src

Set meta-key quick actions to mirror =C-x DIGIT= bindings, therefore reducing the need for additional keypresses.
These bindings override their corresponding numerical argument, however these can be can be alternatively called with =C-u DIGIT= or =C-DIGIT=.
#+begin_src elisp
  (keymap-set +global-keys-map "C-M-0" #'kill-buffer-and-window)
  (keymap-set +global-keys-map "C-M--" #'kill-this-buffer)
  (keymap-set +global-keys-map "M-0" #'delete-window)
  (keymap-set +global-keys-map "M-1" #'delete-other-windows)
  (keymap-set +global-keys-map "M-2" #'split-window-below)
  (keymap-set +global-keys-map "M-3" #'split-window-right)
  (keymap-set +global-keys-map "M-4" #'ctl-x-4-prefix)
  (keymap-set +global-keys-map "M-5" #'ctl-x-5-prefix)
  (keymap-set +global-keys-map "M-6" (keymap-global-lookup "C-x 6"))
  (keymap-set +global-keys-map "M-7" (keymap-global-lookup "C-x 7"))
  (keymap-set +global-keys-map "M-8" (keymap-global-lookup "C-x 8"))
  (keymap-set +global-keys-map "M-9" (keymap-global-lookup "C-x 9"))
#+end_src

Tab actions.
#+begin_src elisp
  (keymap-set +global-keys-map "C-x C-<tab>" #'tab-new)
  (keymap-set +global-keys-map "C-x C-<backspace>" #'tab-close)
  (keymap-set +global-keys-map "C-x t l" #'tab-list)
  (keymap-set +global-keys-map "C-x t <tab>" #'toggle-frame-tab-bar)
#+end_src

Improve region text manipulation.
#+begin_src elisp
  (keymap-set +global-keys-map "M-c" #'capitalize-dwim)
  (keymap-set +global-keys-map "M-l" #'downcase-dwim)
  (keymap-set +global-keys-map "M-u" #'upcase-dwim)
  (keymap-set +global-keys-map "M-U" #'upcase-char)
#+end_src

Help actions.
#+begin_src elisp
  (keymap-set +global-keys-map "C-h M" #'describe-keymap)
  (keymap-set +global-keys-map "C-h j" #'describe-char)
#+end_src

Display modes.
#+begin_src elisp
  (keymap-set +global-keys-map "C-x x c" #'display-fill-column-indicator-mode)
  (keymap-set +global-keys-map "C-x x l" #'display-line-numbers-mode)
  (keymap-set +global-keys-map "C-x x h" #'hl-line-mode)
  (keymap-set +global-keys-map "C-x x o" #'overwrite-mode)
  (keymap-set +global-keys-map "C-x x s" #'prettify-symbols-mode)
  (keymap-set +global-keys-map "C-x x w" #'visual-line-mode)
  (keymap-set +global-keys-map "C-x x SPC" #'whitespace-mode)
#+end_src

** Diff-mode
Rebind diff-mode's ~diff-goto-source~ keybinding due to conflict with =M-o=.
#+begin_src elisp
  (with-eval-after-load 'diff-mode
    (keymap-set diff-mode-map "M-j" #'diff-goto-source))
#+end_src