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

;; modified version of https://github.com/lucasgruss/exwm-outer-gaps

;;; Code:


(require 'exwm-workspace)
(require 'exwm-core)
(require 'exwm)
(require 'xelb)
(require 'xcb)

(defgroup exwm-outer-gaps nil
  "Outer gaps for exwm."
  :group 'appearance
  :prefix "exwm-outer-gaps")

(defcustom exwm-outer-gaps-width 15
  "Width between the edge of the monitor and emacs frame for all sides.")

(defcustom exwm-outer-gaps-increment-step 5
  "Default increment/decrement value for gaps.")

(defcustom exwm-outer-max-gaps-width
  (* exwm-outer-gaps-increment-step 20)
  "The maximum size of the gaps.")

(defun exwm-outer-gaps-compute-gaps ()
  "Hook to be ran after exwm-workspace--update-workareas-hook"
  (let (workareas frames)
    (dolist (w exwm-workspace--workareas)
      (setf (aref w 3) (+ (aref w 3) exwm-outer-gaps-width)
            (aref w 4) (+ (aref w 4) exwm-outer-gaps-width)
            (aref w 5) (- (aref w 5) (* 2 exwm-outer-gaps-width))
            (aref w 6) (- (aref w 6) (* 2 exwm-outer-gaps-width))))))

(defun exwm-outer-gaps-apply ()
  "Function used to apply gaps to the emacs frames."
  (exwm-workspace--update-workareas)
  (dolist (f exwm-workspace--list)
    (exwm-workspace--set-fullscreen f)))

(defun exwm-outer-gaps-set (width)
  "Sets the gap width to WIDTH. Automatically clamps the size of the gaps
from 0 to `exwm-outer-max-gaps-width'"
  (setq exwm-outer-gaps-width
	(max 0 (min width exwm-outer-max-gaps-width))))

(defun exwm-outer-gaps-increment ()
  "Increment the outer gaps by exwm-outer-gaps-increment-step"
  (interactive)
  (when exwm-outer-gaps-mode
    (exwm-outer-gaps-set (+ exwm-outer-gaps-width exwm-outer-gaps-increment-step))
    (exwm-outer-gaps-apply)))

(defun exwm-outer-gaps-decrement ()
  "Decrement the outer gaps by exwm-outer-gaps-increment-step"
  (interactive)
  (when exwm-outer-gaps-mode
    (exwm-outer-gaps-set (- exwm-outer-gaps-width exwm-outer-gaps-increment-step))
    (exwm-outer-gaps-apply)))

;;;###autoload
(define-minor-mode exwm-outer-gaps-mode
  "Add useless outer gaps to exwm."
  :global t
  (if exwm-outer-gaps-mode
      (add-hook 'exwm-workspace--update-workareas-hook
                #'exwm-outer-gaps-compute-gaps)
    (remove-hook 'exwm-workspace--update-workareas-hook
                 #'exwm-outer-gaps-compute-gaps))
  (exwm-outer-gaps-apply))


(provide 'exwm-outer-gaps)