;;; jao-minibuffer.el --- using the minibuffer to report status  -*- lexical-binding: t; -*-

;; Copyright (C) 2020, 2021  jao

;; Author: jao <mail@jao.io>
;; Keywords: extensions

;; 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:

;; Simple asynchronous display of information in the minibuffer.

;;; Code:

(defvar jao-minibuffer-info ())
(defvar jao-minibuffer-msg-info '(""))
(defvar jao-minibuffer-notification nil)
(defvar jao-minibuffer-align-right-p t)
(defvar jao-minibuffer-right-margin (if window-system 0 1))
(defvar jao-minibuffer-maximized-frames-p nil)
(defvar jao-minibuffer-frame-width nil)
(defvar jao-minibuffer-notification-timeout 5)
(defvar jao-minibuffer-enabled-p t)
(defvar jao-minibuffer-active-buffer-line-color "azure4")
(defvar jao-minibuffer-inactive-buffer-line-color "grey25")

(defconst jao-minibuffer--name " *Minibuf-0*")

(defun jao-minibuffer--trim (s w)
  (if (<= (string-width (or s "")) w)
      (format (format "%%%ds" (if jao-minibuffer-align-right-p w (- w))) s)
    (substring s 0 w)))

(defun jao-minibuffer--current ()
  (with-current-buffer jao-minibuffer--name
    (buffer-substring (point-min) (point-max))))

(defun jao-minibuffer--width ()
  (cond ((numberp jao-minibuffer-frame-width) jao-minibuffer-frame-width)
        (jao-minibuffer-maximized-frames-p (frame-width))
        (t (min (frame-width) (window-width (minibuffer-window))))))

(defun jao-minibuffer--format-info (&optional info)
  (mapconcat 'string-trim
             (seq-filter (lambda (s) (not (string-blank-p s)))
                         (mapcar 'format-mode-line
                                 (if jao-minibuffer-align-right-p
                                     (or info jao-minibuffer-info)
                                   (reverse (or info jao-minibuffer-info)))))
             " "))

(defun jao-minibuffer--aligned (&optional w currentp)
  (let* ((msg (cond (currentp (jao-minibuffer--current))
                    (jao-minibuffer-notification
                     (format-mode-line jao-minibuffer-notification))
                    (t (jao-minibuffer--format-info))))
         (msg (if jao-minibuffer-align-right-p
                  (string-trim msg)
                (string-trim-left msg)))
         (msg (propertize msg :minibuffer-message t)))
    (when (not (string-empty-p msg))
      (let* ((mw (jao-minibuffer--width))
             (w (mod (or w (string-pixel-width (or (current-message) ""))) mw))
             (w (- mw w jao-minibuffer-right-margin)))
        (if (> w 0) (jao-minibuffer--trim msg w) "")))))

(defun jao-minibuffer--insert (msg)
  (with-current-buffer jao-minibuffer--name
    (erase-buffer)
    (insert msg)))

(defun jao-minibuffer--format-msg (msg)
  (let* ((msgs (split-string msg "\n"))
         (prefix (when-let (p (string-join (butlast msgs) "\n"))
                   (unless (string-blank-p p) (concat p "\n"))))
         (msg (car (last msgs)))
         (msg (string-trim (replace-regexp-in-string "\n" " " msg)))
         (msg (if (string-blank-p msg) msg (concat msg "  "))))
    (if jao-minibuffer-align-right-p
        (concat prefix msg (jao-minibuffer--aligned (string-width (or msg ""))))
      (concat prefix
              (jao-minibuffer--aligned (+ 3 (string-width (or msg ""))))
              "   " msg))))

(defun jao-minibuffer--set-message (msg)
  (if (or (not jao-minibuffer-enabled-p)
          (and msg
               (not (string-blank-p msg))
               (bound-and-true-p current-minibuffer-command)))
      msg
    (jao-minibuffer--format-msg msg)))

(defvar-local w3m-current-title nil)
(defvar-local eww-data nil)
(defvar-local jao-notmuch--tree-buffer nil)
(defvar circe-chat-target nil)
(defvar exwm-class-name nil)

(defvar jao-minibuffer--mode-line-position
  '(exwm-class-name ("")
                    ("%n %2c %l "
                     (:eval (format "%d" (line-number-at-pos (point-max)))))))

(defvar jao-minibuffer--mode-line-format
  `("%["
    (:eval (cond ((derived-mode-p 'gnus-group-mode
                                  'gnus-article-mode
                                  'gnus-summary-mode)
                  mode-line-buffer-identification)
                 ((derived-mode-p 'circe-channel-mode)
                  (format "%s [%d]" (buffer-name) (length (circe-channel-nicks))))
                 (jao-notmuch--tree-buffer (buffer-name jao-notmuch--tree-buffer))
                 ((not (null eww-data)) (plist-get eww-data :title))
                 (t "%b")))
    "%]"
    (:propertize " %*%+ " face jao-themes-warning)
    (:propertize mode-name face jao-themes-f00)
    (:propertize ("" minor-mode-alist (vc-mode vc-mode)) face jao-themes-f11)
    (:propertize mode-line-position face jao-themes-f12)
    " "
    global-mode-string))

(defvar jao-minibuffer--original-modeline nil)

(defun jao-minibuffer--add-variable (list-name variable-name &optional order)
  (let ((v `(:eval ,variable-name)))
    (set list-name (remove v (symbol-value list-name)))
    (add-to-ordered-list list-name v order)))

;;;###autoload
(defun jao-minibuffer-add-variable (variable-name &optional order)
  (jao-minibuffer--add-variable 'jao-minibuffer-info variable-name order))

;;;###autoload
(defun jao-minibuffer-add-msg-variable (variable-name &optional order)
  (jao-minibuffer--add-variable 'jao-minibuffer-msg-info variable-name order))

(defun jao-minibuffer-adjust-mode-line-faces ()
  (let ((bg (frame-parameter nil 'background-color)))
    (set-face-attribute 'mode-line nil :box nil :height 1
                        :background bg :foreground bg
                        :overline jao-minibuffer-active-buffer-line-color
                        :underline jao-minibuffer-inactive-buffer-line-color
                        :extend t)
    (set-face-attribute 'mode-line-inactive nil :box nil :height 1
                        :background bg :foreground bg
                        :overline bg
                        :underline jao-minibuffer-inactive-buffer-line-color
                        :extend t)))

;;;###autoload
(defun jao-minibuffer-add-mode-line (order)
  (setq jao-minibuffer--original-modeline mode-line-format)
  (setq-default mode-line-format '(" "))
  (setq-default mode-line-position jao-minibuffer--mode-line-position)
  (dolist (b (buffer-list))
    (with-current-buffer b (setq-local mode-line-format '(" "))))
  (jao-minibuffer-add-variable 'jao-minibuffer--mode-line-format order)
  (jao-minibuffer-adjust-mode-line-faces))

;;;###autoload
(defun jao-minibuffer-toggle ()
  (interactive)
  (setq jao-minibuffer-enabled-p (not jao-minibuffer-enabled-p))
  (if jao-minibuffer-enabled-p
      (jao-minibuffer-refresh)
    (jao-minibuffer--insert "")))

;;;###autoload
(defun jao-minibuffer-refresh (&rest _ignore)
  (interactive)
  (when (and jao-minibuffer-enabled-p
             (not (bound-and-true-p current-minibuffer-command)))
    (let* ((jao-minibuffer-enabled-p nil)
           (window-selection-change-functions nil)
           (msg (jao-minibuffer--format-info jao-minibuffer-msg-info))
           (msg (jao-minibuffer--format-msg (or msg ""))))
      (jao-minibuffer--insert (or msg "")))))

(setq set-message-function #'jao-minibuffer--format-msg)
(setq clear-message-function #'jao-minibuffer-refresh)
;; (add-hook 'window-selection-change-functions #'jao-minibuffer-refresh)
(advice-add 'select-window :after #'jao-minibuffer-refresh)
(advice-add 'force-mode-line-update :after #'jao-minibuffer-refresh)

(provide 'jao-minibuffer)
;;; jao-minibuffer.el ends here