;;; zen-writer.el --- Zen Writer   -*- lexical-binding: t; -*-

;; Copyright (C) 2021  Yann Esposito

;; Author: Yann Esposito <https://github.com/yogsototh>
;; Version: 0.0.1
;; Created: November 7, 2021
;; Keywords: custom themes, faces
;; Homepage: https://github.com/hlissner/emacs-doom-themes
;; Package-Requires: ((emacs "25.1") (cl-lib "0.5") (doom-themes "2.2.1") (hl-sentence "3"))
;; License: GPL v3.0

;; 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 <http://www.gnu.org/licenses/>.

;;; Commentary:

;; This package update the theme depending of the time of the day
;;

;;; Code:

;; code goes here

(require 'doom-themes)
(require 'hl-sentence)
(defvar doom-theme)

;;;###autoload
(when (and (boundp 'custom-theme-load-path) load-file-name )
  (let* ((base (file-name-directory load-file-name))
         (dir (expand-file-name "themes/" base)))
    (add-to-list 'custom-theme-load-path
                 (or (and (file-directory-p dir) dir)
                     base))))

;; configuration
(defvar zen-writer-light-theme 'doom-zen-writer
  "The theme for Zen Writer in light mode.")
(defvar zen-writer-dark-theme 'doom-zen-writer-dark
  "The theme for Zen Writer in dark mode.")
(defvar zen-writer-theme zen-writer-light-theme
  "The theme for Zen Writer when zen-auto-dark-theme is nil. By default it uses the light theme.")
(defvar zen-writer-auto-dark-theme t)

(defvar zen-writer--pre-zen-doom-theme doom-theme)

;; internal private state
(define-minor-mode zen-writer-mode
  ;; doc
  nil
  ;; init value
  nil
  ;; modeline indicator
  nil
  ;; key-bindings
  nil
  ;; body
  (if zen-writer-mode
      (progn
        ;; save theme before enabling ZenWriter
        (setq zen-writer--pre-zen-doom-theme doom-theme)
        (zen-writer-on))
    (zen-writer-off)))

(defun zen-writer-select-user-theme ()
  "Change the theme back to the theme prior to the Zen Writer theme."
  (setq doom-theme zen-writer--pre-zen-doom-theme)
  (load-theme doom-theme t))

(defun zen-writer-current-hour ()
  "Retrieve current local hour."
  (nth 2 (decode-time (current-time))))

(defun zen-writer-select-theme ()
  "Depending on time and configuration use different theme."
  (if zen-writer-auto-dark-theme
      (let* ((hour (zen-writer-current-hour))
             (dark? (or (> hour 17) (< hour 7)))
             (theme (if dark? zen-writer-dark-theme zen-writer-light-theme)))
        (when (not (equal doom-theme theme))
          (setq doom-theme theme)
          (load-theme doom-theme t))
        ;; run that function again next hour
        (run-at-time (format "%02d:%02d" (+ hour 1) 0) nil 'zen-writer-select-theme))
    (setq doom-theme zen-writer-theme)
    (load-theme doom-theme t)))

(defun zen-writer-on ()
  "Activate Zen Writer."
  (zen-writer-select-theme)
  (hl-sentence-mode +1))

(defun zen-writer-off ()
  "Deactivate Zen Writer."
  (zen-writer-select-user-theme)
  (hl-sentence-mode -1))

;; Full Zen Writer
(define-minor-mode zen-writer-full-mode
  ;; doc
  nil
  ;; init value
  nil
  ;; modeline indicator
  nil
  ;; key-bindings
  nil
  ;; body
  (if zen-writer-full-mode
      (zen-writer-full-on)
    (zen-writer-full-off)))

(defun zen-writer-full-on ()
  "Zen Writer in fullscreen and zoomed."
  (zen-writer-mode +1)
  (toggle-frame-fullscreen)
  (doom-big-font-mode +1))

(defun zen-writer-full-off ()
  "Disable Zen Writer in fullscreen and zoomed."
  (zen-writer-mode -1)
  (toggle-frame-fullscreen)
  (doom-big-font-mode -1))

(map! :leader
      (:prefix ("t W" . "Zen Writer")
       :desc "Full Zen Writer" "W" #'zen-writer-full-mode
       :desc "Zen Writer" "w" #'zen-writer-mode))

(provide 'zen-writer)
;;; zen-writer.el ends here