;;; editing.el --- core editor config -*- lexical-binding: t -*-
;;; Commentary:

;; follow symlinks
(setq vc-follow-symlinks t)

;; complete brackets automatically
(electric-pair-mode 1)
(setq electric-pair-preserve-balance nil)

;; make C-k kill entire line when I'm at the start of line
(setq kill-whole-line t)

;; key binding for copying lines
(defun copy-line (arg)
  "Copy lines (as many as prefix argument) in the kill ring.
   Ease of use features:
   - Move to start of next line.
   - Appends the copy on sequential calls.
   - Use newline as last char even on the last line of the buffer.
   - If region is active, copy its lines."
  (interactive "p")
  (let ((beg (line-beginning-position))
        (end (line-end-position arg)))
    (when mark-active
      (if (> (point) (mark))
          (setq beg (save-excursion (goto-char (mark)) (line-beginning-position)))
        (setq end (save-excursion (goto-char (mark)) (line-end-position)))))
    (if (eq last-command 'copy-line)
        (kill-append (buffer-substring beg end) (< end beg))
      (kill-ring-save beg end)))
  (kill-append "\n" nil)
  (beginning-of-line (or (and arg (1+ arg)) 2))
  (if (and arg (not (= 1 arg))) (message "%d lines copied" arg)))
(global-set-key "\C-cc" #'copy-line)

;; key binding for duplicating lines
(defun duplicate-current-line (&optional n)
  "Duplicate current line, make more than 1 copy given a numeric argument."
  (interactive "p")
  (save-excursion
    (let ((nb (or n 1))
    	  (current-line (thing-at-point 'point)))
      ;; when on last line, insert a newline first
      (when (or (= 1 (forward-line 1)) (eq (point) (point-max)))
    	(insert "\n"))
      ;; now insert as many time as requested
      (while (> n 0)
    	(insert current-line)
    	(cl-decf n)))))
(global-set-key (kbd "\C-cd") #'duplicate-current-line)

;; persistent undo history
(use-package undo-tree
  :hook (after-init . global-undo-tree-mode))

(provide 'editing)
;;; editing.el ends here