;; -*- lexical-binding: t; -*-

;; Buffer-related configuration
(defun kill-other-buffers ()
  "Kill all other buffers."
  (interactive)
  (mapc 'kill-buffer (delq (current-buffer) (buffer-list))))

(defun switch-to-previous-buffer ()
  "Switch to previously open buffer.
Repeated invocations toggle between the two most recently open buffers."
  (interactive)
  (switch-to-buffer (other-buffer (current-buffer) 1)))

(defun get-buffers-matching-mode (mode)
  "Returns a list of buffers where their major-mode is equal to MODE"
  (let ((buffer-mode-matches '()))
    (dolist (buf (buffer-list))
      (with-current-buffer buf
        (if (eq mode major-mode)
            (add-to-list 'buffer-mode-matches buf))))
    buffer-mode-matches))

(defun get-buffer-modes ()
  "Returns a list of all major modes in currenctly open buffers."
  (delete-dups
   (cl-loop for buf in (buffer-list)
            collect (with-current-buffer buf major-mode))))

(defun multi-occur-in-mode (mode regexp)
  "Show all lines matching REGEXP in buffers with this major mode."
  (interactive (list (completing-read "List lines from buffers with mode: "
                                      (get-buffer-modes)
                                      nil
                                      'confirm
                                      nil
                                      nil
                                      major-mode)
                     (read-string "List lines matching regexp: ")))
  (multi-occur (get-buffers-matching-mode mode) regexp))

(defun occur-all (regexp)
  "Show all lines matching REGEXP in all open buffers."
  (interactive "MList lines matching regexp: ")
  (multi-occur-in-matching-buffers ".*" regexp t))

(leader-def-key
  "TAB" #'switch-to-previous-buffer
  "b" '(nil :which-key "buffer")
  "bb" #'switch-to-buffer
  "bd" #'kill-buffer
  "bm" #'kill-other-buffers
  "br" #'rename-buffer
  "bg" #'revert-buffer
  "bo" #'occur-all)

;; A library that provides a hook called on switching buffers
(use-package switch-buffer-functions
  :demand t)

(provide 'init-buffers)