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

(require 'ibuffer)
(require 'ibuf-ext)

(setq ibuffer-expert t)
(setq ibuffer-display-summary nil)

(setq ibuffer-show-empty-filter-groups nil)

;;; Bindings related to buffers

;;;; Quickly switch to the last buffer.

;;;###autoload
(defun durand-switch-to-last-buffer (&optional arg)
  "Switch to the last buffer.

The last buffer is given by `other-buffer'.

If ARG is non-nil, then display the last buffer in a new window."
  (interactive "P")
  (cond
   (arg (switch-to-buffer-other-window nil))
   ((switch-to-buffer nil))))

;;;###autoload
(defun durand-switch-to-last-buffer-other-window ()
  "Switch to the last buffer in a new window."
  (interactive)
  (switch-to-buffer-other-window nil))

;;;###autoload
(defun switch-to-buffer-same-mode (&optional arg)
  "Switch to a buffer with the same major mode as the current
   buffer.
If the optional ARG is non-nil, then produce an IBUFFER buffer
  listing all buffers of the same mode as the current buffer."
  (interactive "P")
  (cond
   ((null arg)
    (let* ((mode (buffer-local-value 'major-mode (current-buffer)))
           (def (buffer-name
                 (car
                  (delete nil
                          (mapcar
                           (lambda (buf)
                             (and
                              (provided-mode-derived-p
                               (buffer-local-value 'major-mode buf)
                               mode)
                              (not (= (aref (buffer-name buf) 0) 32))
                              (not (eq buf (current-buffer)))
                              buf))
                           (buffer-list)))))))
      (switch-to-buffer
       (read-buffer (format
                     "Switch to buffer with major mode %S:"
                     (buffer-local-value 'major-mode (current-buffer)))
                    def t
                    (lambda (name-or-cons)
                      (provided-mode-derived-p
                       (buffer-local-value
                        'major-mode
                        (cond ((consp name-or-cons)
                               (cdr name-or-cons))
                              ((get-buffer name-or-cons))))
                       mode))))))
   ((ibuffer
     nil
     (format "*Buffers for %S*"
             (buffer-local-value 'major-mode (current-buffer)))
     (list (cons 'used-mode
                 (buffer-local-value 'major-mode (current-buffer))))))))

;;;; clear buffers

;;;###autoload
(defvar durand-clear-passlist nil
  "The list of buffers that should not be deleted \
automatically.")

;;;###autoload
(defvar durand-default-clear-passlist
  (list dashboard-buffer-name
        "*Group*"
        ".newsrc-dribble")
  "The default value for `durand-clear-passlist'.")

;; from dashboard.el
(defvar dashboard-buffer-name)

(cond
 ((null dashboard-buffer-name)
  (setq dashboard-buffer-name "")))

(setq durand-clear-passlist durand-default-clear-passlist)

;;;###autoload
(defun durand-reset-clearlist (&optional arg)
  "Remove killed buffers from `durand-clear-passlist'.
If ARG is non-nil, reset `durand-clear-passlist' to
`durand-default-clear-passlist'."
  (interactive "P")
  (setq
   durand-clear-passlist
   (cond
    ((null arg)
     (delq nil
           (mapcar
            (lambda (buf)
              (cond ((and (stringp buf)
                          (get-buffer buf)
                          (buffer-live-p (get-buffer buf)))
                     buf)
                    ((and (bufferp buf) (buffer-live-p buf))
                     buf)))
            durand-clear-passlist)))
    (durand-default-clear-passlist)))
  (message "%s the clear list!"
           (cond
            ((null arg) "Removed killed buffers from")
            ("Reset"))))

(autoload #'durand-member "common.el")

;;;###autoload
(defun durand-born-equal (x y)
  "Return t if two buffers or names X and Y are equal.
X and Y could be a buffer or a string that represents the name of
a buffer.

BORN is an abbreviation of \"Buffer OR Name\"."
  (let ((flag 0))
    (cond
     ((stringp x) (setq flag (logior flag 1)))
     ((bufferp x))
     ((error "X is not a string nor a buffer")))
    (cond
     ((stringp y) (setq flag (logior flag 2)))
     ((bufferp y))
     ((error "Y is not a string nor a buffer")))
    (cond
     ;; both are buffers
     ((= flag 0) (eq x y))
     ;; X = string, Y = buffer
     ((= flag 1) (string= x (buffer-name y)))
     ;; X = buffer, Y = string
     ((= flag 2) (string= (buffer-name x) y))
     ;; both are strings
     ((= flag 3) (string= x y))
     ((error "Invalid flag: %d" flag)))))

;; This is not defined via `define-ibuffer-op' as this is supposed to
;; clear ALL buffers by default, not only operating on marked buffers,
;; which is the default behaviour for functions defined by
;; `define-ibuffer-op'.

;;;###autoload
(defun durand-ibuffer-clear (&optional arg)
  "Kill every buffer except for those in `durand-clear-passlist'.
If the optional ARG is non-nil, then restrict the range to the
marked buffers."
  (interactive "P")
  (cond
   ((derived-mode-p 'ibuffer-mode))
   ((user-error "durand-ibuffer-clear should only be used in \
derived modes of `ibuffer-mode'.")))
  (cond
   ((null arg)
    (mapc (function
           (lambda (buffer)
             (cond
              ((durand-member (buffer-name buffer)
                              durand-clear-passlist
                              #'durand-born-equal))
              ((kill-buffer buffer)))))
          (cons
           (current-buffer)
           (mapcar #'car (ibuffer-current-state-list))))
    (let ((current (current-buffer)))
      (pop-to-buffer dashboard-buffer-name '((display-buffer-same-window)))
      (goto-char (point-max))
      (recenter -1)
      (pop-to-buffer current '((display-buffer-same-window)))))
   (t
    (mapc (function
           (lambda (buffer-and-mark)
             (cond
              ((or (/= (cdr buffer-and-mark)
                       ibuffer-marked-char)
                   (durand-member (buffer-name (car buffer-and-mark))
                                  durand-clear-passlist
                                  #'durand-born-equal)))
              ((kill-buffer (car buffer-and-mark))))))
          (cons
           (cons (current-buffer) 32)
           (ibuffer-current-state-list)))
    (ibuffer-update nil t))))

;;;; Protect buffers

;; NOTE: I know there is `emacs-lock-mode' which seems to do the same
;; thing.  But in my opinion my needs are different: indeed I do not
;; want to kill certain buffers, which functionality appears to be
;; covered by the afore-mentionned mode, but in fact, I am actually
;; not trying to protect those buffers from `kill-buffer'.  I might
;; actually delete those buffers at a later point, without first
;; unprotecting them.  The purpose of this protection is to ensure
;; that the specific operation that I define here for ibuffer does
;; kill those protected buffers.

;;;###autoload
(defvar durand-ibuffer-reset-marks nil
  "Whether to reset the marks in ibuffer.")

;;;###autoload
(defun durand-ibuffer-restore-mark-before-advice ()
  (ibuffer-assert-ibuffer-mode)
  (cond
   ((null (ibuffer-marked-buffer-names))
    (setq durand-ibuffer-reset-marks t))))

;;;###autoload
(define-ibuffer-op ibuffer-do-protect ()
  "Add the marked buffers to `durand-clear-passlist'."
  (:opstring "protected"
   :active-opstring "protect"
   :modifier-p nil
   :after (cond
           (durand-ibuffer-reset-marks
            (setq durand-ibuffer-reset-marks nil)
            (ibuffer-set-mark 32)))
   :complex t)
  (cond
   ((durand-member buf durand-clear-passlist #'durand-born-equal) nil)
   ((setq durand-clear-passlist (cons buf durand-clear-passlist)) t)))

(advice-add #'ibuffer-do-protect :before
            #'durand-ibuffer-restore-mark-before-advice)

(define-ibuffer-op ibuffer-do-unprotect ()
  "Remove the marked buffers from `durand-clear-passlist'."
  (:opstring "unprotected"
   :active-opstring "unprotect"
   :modifier-p nil
   :after (cond
           (durand-ibuffer-reset-marks
            (setq durand-ibuffer-reset-marks nil)
            (ibuffer-set-mark 32)))   
   :complex t)
  (cond
   ((durand-member buf durand-clear-passlist #'durand-born-equal)
    (setq durand-clear-passlist (delq buf durand-clear-passlist))
    t)))

(advice-add #'ibuffer-do-unprotect :before
            #'durand-ibuffer-restore-mark-before-advice)

;;;; A custom column

;;;###autoload
(define-ibuffer-column protect
  (:name "P" :inline t)
  (cond
   ((durand-member buffer durand-clear-passlist #'durand-born-equal)
    "P")
   (" ")))

(setq ibuffer-formats
      '((mark
         modified
         read-only
         locked
         protect
         " "
         (name 18 18 :left :elide)
         " "
         (size 9 -1 :right)
         " "
         (mode 16 16 :left :elide)
         " "
         filename-and-process)
        (mark " " (name 16 -1) " " filename)))

(ibuffer-recompile-formats)

;;; key-bindings

(define-key global-map (vector 24 2) #'ibuffer)
(define-key global-map (vector ?\s-h) #'ibuffer)
(define-key global-map (vector ?\M-\s-b) #'switch-to-buffer-same-mode)
(define-key global-map (vector ?\s-b) #'switch-to-buffer)
(define-key global-map (vector ?\s-B) #'switch-to-buffer-other-window)
(define-key global-map (vector ?\s-n) #'durand-switch-to-last-buffer)
(define-key global-map (vector ?\s-N) #'durand-switch-to-last-buffer-other-window)

(define-key ibuffer-mode-map (vector ?d) #'ibuffer-do-delete)
(define-key ibuffer-mode-map (vector ?D) #'ibuffer-mark-for-delete)
(define-key ibuffer-mode-map (vector ?c) #'durand-ibuffer-clear)
(define-key ibuffer-mode-map (vector ?C) #'durand-reset-clearlist)
;; open paren is bound to proect
(define-key ibuffer-mode-map (vector 40) #'ibuffer-do-protect)
;; close paren is bound to unprotect
(define-key ibuffer-mode-map (vector 41) #'ibuffer-do-unprotect)

;;; filter for bongo

;;;###autoload
(define-ibuffer-filter durand-bongo
    "Group bongo buffers together."
  (:description "Bongo buffers together"
                :reader (read-string "no effect: "))
  (cond
   ((not (boundp 'durand-bongo-music-dir))
    (load-config "bongo.el")))
  (with-current-buffer buf
    (cond
     ((derived-mode-p 'dired-mode)
      (let ((bongo-dirs durand-bongo-music-dir)
            found)
        (while (and (not found)
                    (consp bongo-dirs))
          (cond
           ((file-in-directory-p default-directory (car bongo-dirs))
            (setq found t))
           (t (setq bongo-dirs (cdr bongo-dirs)))))
        found))
     ((derived-mode-p 'bongo-playlist-mode 'bongo-library-mode)))))

;;;###autoload
(define-ibuffer-filter durand-directory
    "Limit current view to buffers with directory a subdirectory of \
QUALIFIER.

For a buffer not associated with a file, this matches against the
value of `default-directory' in that buffer."
  (:description "directory name"
                :reader (read-from-minibuffer
                         "Filter by directory name (regex): "))
  (ibuffer-aif (with-current-buffer buf (ibuffer-buffer-file-name))
      (let ((dirname (expand-file-name (file-name-directory it))))
        (cond (dirname (string-match-p qualifier dirname))))
    (when (buffer-local-value default-directory buf)
      (string-match-p
       qualifier
       (expand-file-name
        (buffer-local-value buf default-directory))))))

;;;###autoload
(defun durand-bongo-set-filter ()
  "Set my custom filters."
  (interactive)
  (setq ibuffer-filter-groups
        (list (cons "Bongo" '((durand-bongo)))
              (cons "C" '((mode . c-mode)))
              (cons "ELisp" '((mode . emacs-lisp-mode)))
              (cons "EWW" '((mode . eww-mode)))
              (cons "Roman" '((mode . novel-read-mode)))))
  (let ((ibuf (get-buffer "*Ibuffer*")))
    (when ibuf
      (with-current-buffer ibuf
        ;; (pop-to-buffer ibuf)
        (ibuffer-update nil t)))))

(add-hook 'ibuffer-hook 'durand-bongo-set-filter 10)
(add-hook 'ibuffer-hook 'hl-line-mode)