Instead of opening tuntox buffer, use messages

The Tuntox Proxy buffer is mostly useful to those who know about the low-level operation of crdt.el. So, instead of always opening that process buffer when it is created, leave the process buffer in the background and use process filters to post more user-friendly notifications about tuntox connection status to Messages.

I'm not that familiar with process filters, but I saw that overriding the default filter causes the buffer to no longer get updated by default, so I copied the way the crdt-connect tuntox filter writes to the process buffer into crdt-new-session as well.

Co-authored-by: @artenator

crdt.el

@@ -2389,10 +2389,23 @@ Each element should be one of
                                 "-C" ,(expand-file-name crdt-tuntox-key-path)
                                 "-f" "/dev/stdin" ; do the filtering for safety sake
                                 ,@ (when password-p
-                                     `("-s" ,password))))))
+                                     `("-s" ,password)))
+                              :filter
+                              (lambda (proc string)
+                                (cond
+                                 ((string-match "An UDP connection has been established" string) (message "Connected to Tuntox network."))
+                                 ((string-match "Lost connection to server" string) (warn "Lost connection to Tuntox network!")))
+                                (when (buffer-live-p (process-buffer proc))
+                                  (with-current-buffer (process-buffer proc)
+                                    (let ((moving (= (point) (process-mark proc))))
+                                      (save-excursion
+                                        (goto-char (process-mark proc))
+                                        (insert string)
+                                        (set-marker (process-mark proc) (point)))
+                                      (if moving (goto-char (process-mark proc))))))))))
+          (message "Connecting to Tuntox network...")
           (when password-p
             (process-put proxy-process 'password password))
-          (display-buffer (process-buffer proxy-process))
           (process-put network-process 'tuntox-process proxy-process)
           (process-send-string proxy-process (format "127.0.0.1:%s\n" port)) ; only allow connection to our port
           (process-send-eof proxy-process))
@@ -2578,33 +2591,36 @@ Join with DISPLAY-NAME."
                    (password (or (when (url-filename url)
                                    (cadr (split-string (url-filename url) "?pwd=")))
                                  (read-passwd "tuntox password (empty for no password): "))))
-               (switch-to-buffer-other-window
-                (process-buffer
-                 (make-process
-                  :name "Tuntox Proxy"
-                  :buffer (generate-new-buffer "*Tuntox Proxy*")
-                  :command
-                  `(,crdt-tuntox-executable
-                    "-i" ,(url-host url)
-                    "-L" ,(format "%s:127.0.0.1:%s" port (url-portspec url))
-                    ,@ (when (> (length password) 0)
-                         `("-s" ,password)))
-                  :filter
-                  (let (initialized)
-                    (lambda (proc string)
-                      (when (buffer-live-p (process-buffer proc))
-                        (with-current-buffer (process-buffer proc)
-                          (let ((moving (= (point) (process-mark proc))))
-                            (save-excursion
-                              (goto-char (process-mark proc))
-                              (insert string)
-                              (set-marker (process-mark proc) (point))
-                              (unless initialized
-                                (when (ignore-errors (search-backward "Friend request accepted"))
-                                  (setq initialized t)
-                                  (process-put (start-session :host "127.0.0.1" :service port)
-                                               'tuntox-process proc))))
-                            (if moving (goto-char (process-mark proc)))))))))))
+               (message "Connecting to Tuntox network...")
+               (make-process
+                :name "Tuntox Proxy"
+                :buffer (generate-new-buffer "*Tuntox Proxy*")
+                :command
+                `(,crdt-tuntox-executable
+                  "-i" ,(url-host url)
+                  "-L" ,(format "%s:127.0.0.1:%s" port (url-portspec url))
+                  ,@ (when (> (length password) 0)
+                       `("-s" ,password)))
+                :filter
+                (let (initialized)
+                  (lambda (proc string)
+                    (cond
+                     ((string-match "An UDP connection has been established" string) (message "Connected to Tuntox network, finding host..."))
+                     ((string-match "Lost connection to server" string) (warn "Lost connection to Tuntox network!")))
+                    (when (buffer-live-p (process-buffer proc))
+                      (with-current-buffer (process-buffer proc)
+                        (let ((moving (= (point) (process-mark proc))))
+                          (save-excursion
+                            (goto-char (process-mark proc))
+                            (insert string)
+                            (set-marker (process-mark proc) (point))
+                            (unless initialized
+                              (when (ignore-errors (search-backward "Friend request accepted"))
+                                (setq initialized t)
+                                (message "Connected to host over Tuntox.")
+                                (process-put (start-session :host "127.0.0.1" :service port)
+                                             'tuntox-process proc))))
+                          (if moving (goto-char (process-mark proc)))))))))
                nil))
             (t (error "Unknown protocol \"%s\"" url-type)))
       (push new-session crdt--session-list)