;;; bandali-utils.el --- useful utilities            -*- lexical-binding: t; -*-

;; Copyright (C) 2020  Amin Bandali

;; Author: Amin Bandali <bandali@gnu.org>
;; Keywords: lisp, tools

;; This program 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.

;; This program 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 this program.  If not, see <https://www.gnu.org/licenses/>.

;;; Commentary:

;; A small collection of useful utilities used through my init files.

;;; Code:

(require 'cl-lib)

(defmacro csetq (&rest args)
  "Set the value of user option VAR to VALUE.

More generally, you can use multiple variables and values, as in
  (csetq VAR VALUE VAR VALUE...)
This sets each user option VAR's value to the corresponding VALUE.

\(fn [VAR VALUE]...)"
  (declare (debug setq))
  `(progn
     ,@(cl-loop for (var value) on args by 'cddr
                collect
                `(funcall (or (get ',var 'custom-set) #'set-default)
                          ',var ,value))))

(defun b/start-process (program &rest args)
  "Same as `start-process', but doesn't bother about name and buffer."
  (let ((process-name (concat program "_process"))
        (buffer-name  (generate-new-buffer-name
                       (concat program "_output"))))
    (apply #'start-process
           process-name buffer-name program args)))

(defun b/dired-start-process (program &optional args)
  "Open current file with a PROGRAM."
  ;; Shell command looks like this: "program [ARGS]... FILE" (ARGS can
  ;; be nil, so remove it).
  (declare-function dired-get-file-for-visit "dired")
  (apply #'b/start-process
         program
         (remove nil (list args (dired-get-file-for-visit)))))

(defun b/add-elisp-section ()
  (interactive)
  (insert "\n")
  (forward-line -1)
  (insert "\n\n;;; "))

;; (defvar b/fill-column 47
;;   "My custom `fill-column'.")

(defconst b/asterism "* * *")

(defun b/insert-asterism ()
  "Insert a centred asterism."
  (interactive)
  (insert
   (concat
    "\n"
    (make-string (floor (/ (- fill-column (length b/asterism)) 2))
                 ?\s)
    b/asterism
    "\n")))

(defun b/no-mouse-autoselect-window ()
  "Conveniently disable `focus-follows-mouse'.
For disabling the behaviour for certain buffers and/or modes."
  (make-local-variable 'mouse-autoselect-window)
  (setq mouse-autoselect-window nil))

(defun b/kill-current-buffer ()
  "Kill the current buffer."
  ;; also see https://redd.it/64xb3q
  (interactive)
  (kill-buffer (current-buffer)))

(defun b/move-indentation-or-beginning-of-line (arg)
  "Move to the indentation or to the beginning of line."
  (interactive "^p")
  ;; (if (bolp)
  ;;     (back-to-indentation)
  ;;   (move-beginning-of-line arg))
  (if (= (point)
         (progn (back-to-indentation)
                (point)))
      (move-beginning-of-line arg)))

(defun b/join-line-top ()
  "Like `join-line', but join next line to the current line."
  (interactive)
  (join-line 1))

(defun b/duplicate-line-or-region (&optional n)
  "Duplicate the current line, or region (if active).
Make N (default: 1) copies of the current line or region."
  (interactive "*p")
  (let ((u-r-p (use-region-p))          ; if region is active
        (n1 (or n 1)))
    (save-excursion
      (let ((text
             (if u-r-p
                 (buffer-substring (region-beginning) (region-end))
               (prog1 (thing-at-point 'line)
                 (end-of-line)
                 (if (eobp)
                     (newline)
                   (forward-line 1))))))
        (dotimes (_ (abs n1))
          (insert text))))))

(provide 'bandali-utils)
;;; bandali-utils.el ends here