mail + gnus: Update mails without mu4e

This is the first and maybe the last step to remove the dependency on
mu4e.  I can now update mails without calling a mu4e function.  That
is virtually the only functionality I use of mu4e since a long time.

I shall have done this a long time ago, but I was too lazy to do so.
;D

2 files changed, 80 insertions, 4 deletions

diff --git a/gnus-conf.el b/gnus-conf.el
index c57f7ff..f409b41 100644
--- a/gnus-conf.el
+++ b/gnus-conf.el
@@ -138,10 +138,10 @@
 
 ;;; Update by mu4e
 
-(autoload 'mu4e-update-mail-and-index "mu4e-utils")
+;; (autoload 'mu4e-update-mail-and-index "mu4e-utils")
 (autoload 'load-config "init")
 
-(defalias 'durand-update-mail #'mu4e-update-mail-and-index)
+;; (defalias 'durand-update-mail #'mu4e-update-mail-and-index)
 
 ;; Let notmuch know about the changes automatically.
 
@@ -151,7 +151,7 @@
 
 (add-hook 'mu4e-index-updated-hook #'notmuch-poll)
 
-(define-key gnus-group-mode-map (vector 117) #'durand-update-mail)
+(define-key gnus-group-mode-map (vector 117) #'durand-mail-update)
 (define-key global-map (vector ?\C-c ?g) 'gnus)
 
 ;;; Use notmuch to search mails
diff --git a/mail.el b/mail.el
index e238fb2..dd35b4d 100644
--- a/mail.el
+++ b/mail.el
@@ -1,7 +1,7 @@
 
 (use-package "/usr/local/share/emacs/site-lisp/mu/mu4e" 'mu4e
   (setq mu4e-maildir-list (list "/Users/durand/mbsync"))
-  (setq user-mail-address "mmemmew@gmail.com")
+  (setq user-mail-address "durand@jsdurand.xyz")
   (setq mu4e-completing-read-function #'completing-read)
   (setq message-confirm-send t)
   (setq mu4e~update-buffer-height 5)
@@ -307,3 +307,79 @@ person."
 (define-key message-mode-map (vector 3 ?f) #'durand-fix-quotation)
 (define-key gnus-summary-mode-map (vector 3 ?f) #'durand-fix-quotation)
 (define-key gnus-article-mode-map (vector 3 ?f) #'durand-fix-quotation)
+
+;;; update mails without mu4e
+
+(defun durand-mail-process-output (output)
+  "Normalize the OUTPUT emitted by mu4e."
+  (let ((splitted (split-string output (rx-to-string (list 'any ?
 ?\n ?\r) t) t)))
+    (or (car (last splitted)) "")))
+
+(defun durand-mail-update-filter (process string)
+  "Insert the ouput STRING into the buffer of PROCESS for updating \
+mails."
+  (let ((buffer (process-buffer process))
+        (output (durand-mail-process-output string)))
+    (cond
+     ((buffer-live-p buffer)
+      (display-buffer
+       buffer
+       (list (list #'display-buffer-in-side-window)
+             (cons 'side 'bottom)
+             (cons 'window-height
+                   #'durand-fit-window-to-buffer-with-max)))
+      (with-current-buffer buffer
+        (cond
+           ((and (stringp output)
+                 (not (string= output "")))
+            (delete-region (point-min) (point-max))
+            (insert output)
+            (set-marker
+             (process-mark process) (point-max) buffer))))))))
+
+(defun durand-mail-update-sentinel (process status)
+  "Handle STATUS changes of the PROCESS for updating mails."
+  (cond
+   ((string= status "finished\n")
+    (let ((buffer (process-buffer process)))
+      (cond
+       ((buffer-live-p buffer)
+        (quit-window nil (get-buffer-window buffer))))))))
+
+(defvar durand-mail-update-command
+  (list "mbsync" "mymail-inbox" "mymail-sent")
+  "Command to update mails.")
+
+(defvar durand-mail-update-buffer "*mail*"
+  "Buffer to display progess of updating mails.")
+
+(defun durand-mail-update (&optional foreground-p)
+  "Update mails.
+If FOREGROUND-P is non-nil, also display the progress in a
+separate buffer."
+  (interactive (list t))
+  (make-process
+   :name "durand-mail-update"
+   :command durand-mail-update-command
+   :filter (cond (foreground-p #'durand-mail-update-filter))
+   :sentinel (cond (foreground-p #'durand-mail-update-sentinel))
+   :buffer (cond
+            (foreground-p
+             (let ((buffer
+                    (get-buffer-create durand-mail-update-buffer)))
+               (buffer-disable-undo buffer)
+               buffer)))))
+
+(defvar durand-mail-update-timer nil
+  "A timer to automatically update mail in the background.")
+
+(defun durand-mail-cancel-timer ()
+  "Cancel `durand-mail-update-timer'."
+  (cancel-timer durand-mail-update-timer))
+
+(cond
+ ((memq #'durand-mail-update
+        (mapcar #'timer--function timer-list)))
+ ((setq
+   durand-mail-update-timer
+   (run-with-timer 0 (* 60 30) #'durand-mail-update))))