;;; battery-conf.el --- COnfigurations of the display of battery -*- lexical-binding: t; -*-

;; Copyright (C) 2021  李俊緯

;; Author: 李俊緯 <mmemmew@gmail.com>
;; Keywords: convenience, processes, hardware, unix

;; 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:

;; Some configurations of the display of the information of battery.

;;; Code:

(defun durand-battery-pmset ()
  "Get battery status information using `pmset'.

The following %-sequences are provided:
%L Power source (verbose)
%B Battery status (verbose)
%b Battery status, empty means high, `-' means low,
   `!' means critical, and `+' means charging
%d Battery temperature -- added by Durand

%p Battery load percentage
%h Remaining time in hours
%m Remaining time in minutes
%t Remaining time in the form `h:min'"
  (let (power-source load-percentage battery-status battery-status-symbol
        battery-temp remaining-time hours minutes)
    (with-temp-buffer
      (ignore-errors (call-process "pmset" nil t nil "-g" "ps"))
      (goto-char (point-min))
      (when (re-search-forward "\\(?:Currentl?y\\|Now\\) drawing from '\\(AC\\|Battery\\) Power'" nil t)
        ;; One letter suffices
	(setq power-source (substring (match-string 1) 0 1))
	(when (re-search-forward "^ -InternalBattery-0\\([ \t]+(id=[0-9]+)\\)*[ \t]+" nil t)
	  (when (looking-at "\\([0-9]\\{1,3\\}\\)%")
	    (setq load-percentage (match-string 1))
	    (goto-char (match-end 0))
	    (cond ((looking-at "; charging")
		   (setq battery-status "charging"
			 battery-status-symbol "+"))
		  ((< (string-to-number load-percentage) battery-load-critical)
		   (setq battery-status "critical"
			 battery-status-symbol "!"))
		  ((< (string-to-number load-percentage) battery-load-low)
		   (setq battery-status "low"
			 battery-status-symbol "-"))
		  (t
		   (setq battery-status "high"
			 battery-status-symbol "")))
	    (when (re-search-forward "\\(\\([0-9]+\\):\\([0-9]+\\)\\) remaining"  nil t)
	      (setq remaining-time (match-string 1))
	      (let ((h (string-to-number (match-string 2)))
		    (m (string-to-number (match-string 3))))
		(setq hours (number-to-string (+ h (if (< m 30) 0 1)))
		      minutes (number-to-string (+ (* h 60) m))))))))
      ;; Now battery temperature
      (erase-buffer)
      (call-process "ioreg" nil t nil "-n" "AppleSmartBattery" "-r")
      (goto-char (point-min))
      (re-search-forward "Temperature..=." nil t)
      (re-search-forward "[[:digit:]]+" nil t)
      (setq battery-temp
            (format "%.1f"
                    (/ (string-to-number (match-string-no-properties 0))
                       100.0))))
    (list (cons ?L (or power-source "N/A"))
          (cons ?d (or battery-temp "N/A"))
	  (cons ?p (or load-percentage "N/A"))
	  (cons ?B (or battery-status "N/A"))
	  (cons ?b (or battery-status-symbol ""))
	  (cons ?h (or hours "N/A"))
	  (cons ?m (or minutes "N/A"))
	  (cons ?t (or remaining-time "N/A")))))

(advice-add 'battery-pmset :override 'durand-battery-pmset)

(setq battery-mode-line-format " %d %L %b%p%%%%")
(setq battery-mode-line-limit 59)
(setq battery-update-interval 180)
(setq battery-load-low 20)
(setq battery-load-critical 10)
(add-hook 'after-init-hook #'display-battery-mode)

(provide 'battery-conf)
;;; battery-conf.el ends here