;;; core-popups.el --- taming sudden yet inevitable windows

;; I'd like certain buffers--like help windows, prompts or
;; informational/terminal/temporary buffers--to have less presence among my work
;; buffers (typically, source code buffers). I'd also like them to be easy to
;; both dispose of quickly and invoke from anywhere. It will also hide the
;; mode-line in popups using `doom-hide-modeline-mode'
;;
;; I use `shackle' to make this as consistent as possible, which lets you
;; specify rules on how to treat certain buffers. I go through great lengths to
;; tame helm, flycheck, help buffers--*even* the beast that is org-mode, with
;; the help of `display-buffer-alist' and `shackle'.
;;
;; Be warned, there is a lot of hackery voodoo here that could break with an
;; emacs update, or an update to any of the packages it tries to tame (like helm
;; or org-mode).

(defvar doom-popup-history nil
  "A list of popups that were last closed. Used by `doom/popup-restore' and
`doom*popup-save'.")

(defvar doom-popup-remember-history t
  "If non-nil, DOOM will remember the last popup(s) that were open in
`doom-popup-history'.")

(defvar doom-popup-other-window nil
  "The last window selected before a popup was opened.")

(defvar-local doom-popup-rules nil
  "The shackle rule that caused this buffer to be recognized as a popup.")

(defvar doom-popup-mode-map
  (let ((map (make-sparse-keymap)))
    (define-key map [escape]    'doom/popup-close-maybe)
    (define-key map (kbd "ESC") 'doom/popup-close-maybe)
    map)
  "Active keymap in popup windows.")

(def-setting! :popup (&rest rules)
  "Prepend a new popup rule to `shackle-rules'."
  (if (not (-all-p 'listp rules))
      `(cl-pushnew ',rules shackle-rules :key 'car :test 'equal)
    (let (real-rules)
      (dolist (rule rules)
        (let ((pattern (car rule))
              (plist (cdr rule)))
          ;; Align popups by default (error if this doesn't happen)
          (unless (plist-member plist :align)
            (plist-put plist :align t))
          ;; Select popups by default
          (unless (or (plist-member plist :select)
                      (plist-member plist :noselect))
            (plist-put plist :select t))
          (push (cons pattern plist) real-rules)))
      `(setq shackle-rules (append ',real-rules shackle-rules)))))


;;
;; Bootstrap
;;

(package! shackle :demand t
  :init
  (setq shackle-default-alignment 'below
        shackle-select-reused-windows t)

  :config
  (shackle-mode 1)

  ;;; Baseline popup-window rules
  ;; :noesc and :modeline are custom settings and are not part of shackle. See
  ;; `doom*popup-init' and `doom-popup-buffer' for how they're used.
  (set! :popup
    '("^ ?\\*doom:.+\\*$"      :size 40  :modeline t :regexp t)
    '("^ ?\\*doom .+\\*$"      :size 30  :noselect t :regexp t)
    '("^\\*.+-Profiler-Report .+\\*$" :size 0.3 :regexp t)
    '("*esup*"                 :size 0.4 :noselect t :noesc t)
    '("*minor-modes*"          :size 0.5 :noselect t)
    '("*eval*"                 :size 16  :noselect t)
    '("*Pp Eval Output*"       :size 0.3)
    '("*Apropos*"              :size 0.3)
    '("*Backtrace*"            :size 25  :noselect t)
    '("*Help*"                 :size 16)
    '("*Messages*"             :size 10)
    '("*Warnings*"             :size 10  :noselect t)
    '("*command-log*"          :size 28  :noselect t :align right)
    '("*Shell Command Output*" :size 20 :noselect t)
    '(compilation-mode         :size 15  :noselect t :noesc t)
    '(ivy-occur-grep-mode      :size 25  :noesc t)
    '(eww-mode                 :size 30)
    '(comint-mode              :noesc t)
    '(tabulated-list-mode      :noesc t)))


(define-minor-mode doom-popup-mode
  "Minor mode for pop-up windows."
  :init-value nil
  :keymap doom-popup-mode-map
  (if (and (not doom-popup-mode)
           doom-hide-modeline-mode)
      (doom-hide-modeline-mode -1)
    (let ((modeline (plist-get doom-popup-rules :modeline)))
      (cond ((eq modeline 'nil)
             (doom-hide-modeline-mode +1))
            ((symbolp modeline)
             (let ((doom--hidden-modeline-format (+doom-modeline modeline)))
               (doom-hide-modeline-mode +1))))))
  (mapc (lambda (cfg) (set-window-parameter nil cfg nil))
        '(popup no-other-window noesc))
  (set-window-dedicated-p nil doom-popup-mode))
(put 'doom-popup-mode 'permanent-local t)

;; Tell `window-state-get' and `current-window-configuration' to persist these
;; custom parameters.
(dolist (param '(popup noesc))
  (add-to-list 'window-persistent-parameters (cons param 'writable)))

(defun doom*popup-init (orig-fn &rest args)
  "Enables `doom-popup-mode' in popup windows and returns the window."
  (unless (doom-popup-p)
    (setq doom-popup-other-window (selected-window)))
  (let* ((window (apply orig-fn args))
         (rules (or (nth 2 args) (shackle-match (window-buffer window)))))
    (unless window
      (error "No window was found for %s: %s" (car args) rules))
    (mapc (lambda (cfg) (set-window-parameter window (car cfg) (cdr cfg)))
          (append `((popup . ,rules)
                    (no-other-window . ,t))
                  (when (plist-get rules :noesc)
                    `((noesc . ,t)))))
    (with-selected-window window
      (setq-local doom-popup-rules rules)
      (doom-popup-mode +1))
    ;; NOTE orig-fn returns a window, so `doom*popup-init' must too
    window))
(advice-add 'shackle-display-buffer :around 'doom*popup-init)

(defun doom*popup-save (orig-fn &rest args)
  "Puts aside all popups before executing the original function, usually to
prevent the popups from interfering (or the other way around)."
  (let ((in-popup-p (doom-popup-p))
        (popups (doom-popup-windows))
        (doom-popup-remember-history t))
    (when popups
      (mapc 'doom/popup-close popups))
    (unwind-protect (apply orig-fn args)
      (when popups
        (let ((origin (selected-window)))
          (doom/popup-restore)
          (unless in-popup-p
            (select-window origin)))))))
;; Don't affect popup windows
(advice-add 'balance-windows :around 'doom*popup-save)

(defun doom*popup-close (orig-fn &rest args)
  "Ensure that popups are closed properly."
  (let ((window (car args)))
    (when (doom-popup-p window)
      (with-selected-window window
        (doom-popup-mode -1)
        (when doom-popup-remember-history
          (setq doom-popup-history (list (doom--popup-data window)))))))
  (apply orig-fn args))
(advice-add 'delete-window :around 'doom*popup-close)


;;
;; Hacks
;;

(after! evil
  (let ((map doom-popup-mode-map))
    (define-key map [remap evil-window-delete]           'doom/popup-close)
    (define-key map [remap evil-window-move-very-bottom] 'ignore)
    (define-key map [remap evil-window-move-very-top]    'ignore)
    (define-key map [remap evil-window-move-far-left]    'ignore)
    (define-key map [remap evil-window-move-far-right]   'ignore)
    (define-key map [remap evil-window-split]            'ignore)
    (define-key map [remap evil-window-vsplit]           'ignore)
    (define-key map [remap evil-force-normal-state]      'doom/popup-close-maybe))

  ;; Close popups when you press ESC in normal mode, in any buffer
  (defun doom*popup-evil-close-on-esc ()
    "Close non-repl popups and clean up `doom-popup-windows'."
    (unless (or (minibuffer-window-active-p (minibuffer-window))
                (evil-ex-hl-active-p 'evil-ex-search))
      (doom/popup-close-all)))
  (advice-add 'evil-force-normal-state :after 'doom*popup-evil-close-on-esc)

  ;; Tame the command window
  (defun doom*popup-evil-command-window (hist cmd-key execute-fn)
    "The evil command window has a mind of its own (uses `switch-to-buffer'). We
monkey patch it to use pop-to-buffer, and to remember the previous window."
    (when (eq major-mode 'evil-command-window-mode)
      (user-error "Cannot recursively open command line window"))
    (dolist (win (window-list))
      (when (equal (buffer-name (window-buffer win))
                   "*Command Line*")
        (kill-buffer (window-buffer win))
        (delete-window win)))
    (setq evil-command-window-current-buffer (current-buffer))
    (ignore-errors (kill-buffer "*Command Line*"))
    (with-current-buffer (pop-to-buffer "*Command Line*")
      (setq-local evil-command-window-execute-fn execute-fn)
      (setq-local evil-command-window-cmd-key cmd-key)
      (evil-command-window-mode)
      (evil-command-window-insert-commands hist)))
  (advice-add 'evil-command-window :override 'doom*popup-evil-command-window)

  (defun doom*popup-evil-command-window-execute ()
    "Execute the command under the cursor in the appropriate buffer."
    (interactive)
    (let ((result (buffer-substring (line-beginning-position)
                                    (line-end-position)))
          (execute-fn evil-command-window-execute-fn)
          (popup (selected-window)))
      (select-window doom-popup-other-window)
      (unless (equal evil-command-window-current-buffer (current-buffer))
        (user-error "Originating buffer is no longer active"))
      ;; (kill-buffer "*Command Line*")
      (doom/popup-close popup)
      (funcall execute-fn result)
      (setq evil-command-window-current-buffer nil)))
  (advice-add 'evil-command-window-execute :override 'doom*popup-evil-command-window-execute)

  ;; Tell these functions not to mess with popups
  (advice-add 'doom-evil-window-move        :around 'doom*popup-save)
  (advice-add 'evil-window-move-very-bottom :around 'doom*popup-save)
  (advice-add 'evil-window-move-very-top    :around 'doom*popup-save)
  (advice-add 'evil-window-move-far-left    :around 'doom*popup-save)
  (advice-add 'evil-window-move-far-right   :around 'doom*popup-save)

  ;; Don't block moving to/from popup windows
  (defun doom*ignore-window-parameters-in-popups (dir &optional arg window)
    (window-in-direction
     (cond ((eq dir 'up) 'above)
           ((eq dir 'down) 'below)
           (t dir))
     window t arg windmove-wrap-around t))
  (advice-add 'windmove-find-other-window :override 'doom*ignore-window-parameters-in-popups))

;; (after! magit
;;   ;; Don't open files (from magit) within the magit popup
;;   (advice-add 'magit-display-file-buffer-traditional :around 'doom*popup-save))

(after! neotree
  (defun doom*popup-save-neotree (orig-fun &rest args)
    "Prevents messing up the neotree buffer on window changes."
    (let ((neo-p (and (featurep 'neotree) (neo-global--window-exists-p))))
      (when neo-p
        (neotree-hide)
        (balance-windows))
      (unwind-protect (apply orig-fun args)
        (when neo-p
          (save-selected-window
            (neotree-show))))))

  ;; Prevent neotree from interfering with popups
  (advice-add 'shackle-display-buffer :around 'doom*popup-save-neotree)
  ;; Prevents messing up the neotree buffer on window changes
  (advice-add 'doom-evil-window-move :around 'doom*popup-save-neotree)
  ;; (advice-add 'doom-popup-buffer     :around 'doom*popup-save-neotree)
  ;; Don't let neotree interfere with moving, splitting or rebalancing windows
  (advice-add 'balance-windows :around 'doom*popup-save-neotree)
  (advice-add 'split-window    :around 'doom*popup-save-neotree)
  (advice-add 'shackle-display-buffer :around 'doom*popup-save-neotree)
  (advice-add 'evil-window-move-very-bottom :around 'doom*popup-save-neotree)
  (advice-add 'evil-window-move-very-top    :around 'doom*popup-save-neotree)
  (advice-add 'evil-window-move-far-left    :around 'doom*popup-save-neotree)
  (advice-add 'evil-window-move-far-right   :around 'doom*popup-save-neotree))

(add-hook! org-load
  ;; Ensures org-src-edit yields control of its buffer to shackle.
  (defun doom*org-src-switch-to-buffer (buffer context) (pop-to-buffer buffer))
  (advice-add 'org-src-switch-to-buffer :override 'doom*org-src-switch-to-buffer)

  ;; ...for org-todo, org-link and org-agenda popups
  (defun doom*org-pop-to-buffer-same-window (&optional buffer-or-name norecord label)
    "Pop to buffer specified by BUFFER-OR-NAME in the selected window."
    (display-buffer buffer-or-name))
  (advice-add 'org-pop-to-buffer-same-window :override 'doom*org-pop-to-buffer-same-window)

  (defun doom*org-switch-to-buffer-other-window (&rest args)
    (car-safe
     (mapc (lambda (b)
             (let ((buf (if (stringp b) (get-buffer-create b) b)))
               (pop-to-buffer buf t t)))
           args)))
  (advice-add 'org-switch-to-buffer-other-window :override 'doom*org-switch-to-buffer-other-window)

  (defun doom/popup-org-agenda-quit ()
    "Necessary to finagle org-agenda into shackle popups & behave on quit."
    (interactive)
    (if org-agenda-columns-active
        (org-columns-quit)
      (let ((buf (current-buffer)))
        (and (not (eq org-agenda-window-setup 'current-window))
             (not (one-window-p))
             (delete-window))
        (kill-buffer buf)
        (setq org-agenda-archives-mode nil
              org-agenda-buffer nil))))

  (after! org-agenda
    (after! evil
      (evil-define-key* 'motion org-agenda-mode-map
        [escape] 'doom/popup-org-agenda-quit
        (kbd "ESC") 'doom/popup-org-agenda-quit))

    (let ((map org-agenda-mode-map))
      (define-key map "q" 'doom/popup-org-agenda-quit)
      (define-key map "Q" 'doom/popup-org-agenda-quit))))

(after! repl-toggle
  (add-hook! doom-popup-close
    (setq rtog/--last-buffer nil)))

(provide 'core-popups)
;;; core-popups.el ends here