From 60fb3c8d3ded7e1bafac2d68cbcd1d19a56f5443 Mon Sep 17 00:00:00 2001
From: Rutherther <rutherther@protonmail.com>
Date: Sun, 1 Sep 2024 19:00:58 +0200
Subject: [PATCH] feat(home): add support for resetting no longer managed dconf
 keys

---
 home/modules/ruther/home/services/dconf.scm | 69 +++++++++++++++++----
 1 file changed, 57 insertions(+), 12 deletions(-)

diff --git a/home/modules/ruther/home/services/dconf.scm b/home/modules/ruther/home/services/dconf.scm
index 72cb50c..d2ade3a 100644
--- a/home/modules/ruther/home/services/dconf.scm
+++ b/home/modules/ruther/home/services/dconf.scm
@@ -37,21 +37,66 @@ the values in there refer to values to set, ie. cursor-theme='my-pretty-cursors'
   (program-file
    "update-dconf-settings"
    #~(begin
+       (define (get-dconf-keys config)
+         (apply
+          append
+          (apply
+           append
+           (map
+            (lambda (section)
+              (let ((section-name (symbol->string (car section))))
+                (map
+                 (lambda (section-fields)
+                   (map
+                    (lambda (section-field)
+                      (string-append "/" section-name "/" (symbol->string (car section-field))))
+                    section-fields))
+                 (cdr section))))
+            config))))
+
+       (define (get-deleted-dconf-keys old-config new-config)
+         (let ((old-keys (get-dconf-keys old-config))
+               (new-keys (get-dconf-keys new-config)))
+           (filter
+            (lambda (key)
+              (not (member key new-keys)))
+            old-keys)))
+
        (use-modules (ice-9 popen))
-       (let* ((new-home (getenv "GUIX_NEW_HOME"))
-              ;; (old-home (getenv "GUIX_OLD_HOME"))
-              ;; (home-dconf-file (string-append new-home "/" #$home-dconf-settings-file))
-              ;; (dconf-settings (with-input-from-file home-dconf-file read))
+
+       (let* ((dconf #$(file-append dconf "/bin/dconf"))
+
+              (new-home (getenv "GUIX_NEW_HOME"))
+              (old-home (getenv "GUIX_OLD_HOME"))
+              (new-home-dconf-file (string-append new-home "/" #$home-dconf-settings-file))
+              (old-home-dconf-file (when old-home
+                                       (string-append old-home "/" #$home-dconf-settings-file)))
+              (new-dconf-settings (with-input-from-file new-home-dconf-file read))
+              (old-dconf-settings (if old-home-dconf-file
+                                      (with-input-from-file old-home-dconf-file read)
+                                      '()))
+
+              (deleted-dconf-keys (get-deleted-dconf-keys old-dconf-settings new-dconf-settings))
+
               (dconf-ini #$(apply string-append
                                   (serialize-ini-config dconf-config
                                                         #:equal-string "="))))
          ;; Remove settings that are not managed anymore
-         ;;  TODO
+         (display "Removing old dconf keys...")
+         (newline)
+         (for-each
+          (lambda (deleted-key)
+            (system* dconf "reset" deleted-key))
+          deleted-dconf-keys)
          ;; Load the dconf settings
-         (let ((dconf-load-pipe (open-output-pipe (string-append #$(file-append dconf "/bin/dconf")
+         (display "Loading dconf...")
+         (newline)
+         (let ((dconf-load-pipe (open-output-pipe (string-append dconf
                                                                  " load /"))))
            (display dconf-ini dconf-load-pipe)
-           (close-pipe dconf-load-pipe))))))
+           (close-pipe dconf-load-pipe))
+         (display "Configured dconf.")
+         (newline)))))
 
 (define (dconf-activation config)
   #~(primitive-load #$(update-dconf-settings-script (home-dconf-configuration-dconf config)
@@ -64,15 +109,15 @@ the values in there refer to values to set, ie. cursor-theme='my-pretty-cursors'
                  "dconf-settings.scm"
                  #~(call-with-output-file #$output
                      (lambda (port)
-                       (display '#$(home-dconf-configuration-config config) port)))))))))
+                       (write '#$(home-dconf-configuration-config config) port)))))))))
 
-(define (home-dconf-extensions original-config fields)
+(define (home-dconf-extensions original-config sections)
   (home-dconf-configuration
    (inherit original-config)
    (config
-    `(,(append
-        (home-dconf-configuration-config original-config)
-        (apply append fields))))))
+    (append
+     (home-dconf-configuration-config original-config)
+     sections))))
 
 (define home-dconf-service-type
   (service-type
-- 
2.48.1