sway: allow overriding or disabling our configs per user

Makefile

@@ -28,7 +28,6 @@ install-sddm:
 
 install-sway: build
 	install -D -m 0644 -pv -t $(DESTDIR)$(SYSCONFDIR)/sway          sway/config
-	install -D -m 0644 -pv -t $(DESTDIR)$(SYSCONFDIR)/sway/config.d sway/50-fedora.conf
 	install -D -m 0644 -pv -t $(DESTDIR)$(DATADIR)/wayland-sessions sway/sway.desktop
 	install -D -m 0644 -pv -t $(DESTDIR)$(DATADIR)/sway/config.d    sway/config.d/*.conf
 	install -D -m 0755 -pv -t $(DESTDIR)$(LIBEXECDIR)/sway          scripts/sway/*

README.md

@@ -1,10 +1,10 @@
 ## Sway config
 
-Sway config is split to 3 parts:
+Sway config is split to 2 parts:
 
  * `sway/config` — is the main config to be installed to `/etc/sway/config`. Some light changes are applied, such as removing things we want to override later (bar, launcher, etc.).
- * `sway/config.d/*.conf` — is a set of small self-contained configuration snippets with each containing the description and the list of required packages. Will be installed as `/usr/share/sway/config.d/*.conf`.
- * `sway/50-fedora.conf` is a list of config snippets included by default.
+ * `sway/config.d/*.conf` — is a set of small self-contained configuration snippets with each containing the description and the list of required packages.
+   Will be installed as `/usr/share/sway/config.d/*.conf` and loaded by default.
 
 ## Upstream config changes sync
 

fedora-sway-configs.spec.rpkg

@@ -103,7 +103,6 @@ to use Sway for the greeter display server.
 %files -n sway-config-fedora
 %license LICENSE
 %config(noreplace) %{_sysconfdir}/sway/config
-%config(noreplace) %{_sysconfdir}/sway/config.d/50-fedora.conf
 # should it be in the swaylock package?
 %dir %{_sysconfdir}/swaylock
 %config(noreplace) %{_sysconfdir}/swaylock/config

scripts/sway/layered-include

@@ -0,0 +1,50 @@
+#!/usr/bin/python3
+"""
+A helper for doing the config layering with sway style `include` expressions
+(which are pretty much just shell/wordexp(3) patterns).
+
+The script is meant to be invoked from sway (i3?) config as following
+```
+include '$(/path/to/the/script "/path1/*.conf" "/path2/*.conf" ...)'
+```
+(note the quoting, it is important), expand each expression to a list of files
+and layer them in a way that the files with the same name matched by a later
+patterns loaded over the earlier matches.
+"""
+
+import os
+import sys
+from hashlib import sha256
+from glob import iglob
+from os.path import basename, expandvars
+from tempfile import gettempdir
+
+
+def wordexp(value: str):
+    """A very bad wordexp(3) approximation"""
+    value = expandvars(value)
+    return iglob(value)
+
+
+configs: dict[str, str] = {}
+
+for arg in sys.argv[1:]:
+    # Expand the expression and collect the paths while overwriting previously
+    # collected entries with the same filename.
+    # Our internal wordexp is quite incomplete, but the calling wordexp should
+    # do all the heavy lifting and expand the variables.
+    for inc in wordexp(arg):
+        configs[basename(inc)] = inc
+
+# Write collected paths as an include directives to a temporary file.
+# This step is required because the filenames may contain $IFS characters
+# (whitespaces — I don't expect this to happen, but can't exclude the
+# possibility), and wordexp(3) will handle that quite bad.
+fnhash = sha256("\n".join(sys.argv).encode("UTF-8"))
+fname = f"{gettempdir()}/sway-{os.getuid()}-{str(fnhash.hexdigest())}.conf"
+fd = os.open(fname, os.O_CREAT | os.O_TRUNC | os.O_WRONLY, mode=0o600)
+with open(fd, mode="w", encoding="UTF-8") as file:
+    for key in sorted(configs):
+        file.write(f"include '{configs[key]}'\n")
+# Send the temporary file name back to a calling wordexp
+print(fname)

sway/50-fedora.conf.in

@@ -1,14 +0,0 @@
-# Enable some configuration snippets by default
-
-include $DATADIR/sway/config.d/20-swayidle.conf
-
-include $DATADIR/sway/config.d/30-bindings-brightness-light.conf
-include $DATADIR/sway/config.d/30-bindings-media-playerctl.conf
-include $DATADIR/sway/config.d/30-bindings-volume-pactl.conf
-
-include $DATADIR/sway/config.d/60-rules-browser.conf
-include $DATADIR/sway/config.d/60-rules-lxqt-policykit-agent.conf
-
-include $DATADIR/sway/config.d/90-bar-waybar.conf
-
-include $DATADIR/sway/config.d/95-autostart-lxqt-policykit-agent.conf

sway/config.d/90-bar-swaybar.conf

@@ -1,17 +0,0 @@
-# Status Bar: swaybar (the upstream default)
-#
-# Read `man 5 sway-bar` for more information about this section.
-
-bar {
-    position top
-
-    # When the status_command prints a new line to stdout, swaybar updates.
-    # The default just shows the current date and time.
-    status_command while date +'%Y-%m-%d %I:%M:%S %p'; do sleep 1; done
-
-    colors {
-        statusline #ffffff
-        background #323232
-        inactive_workspace #32323200 #32323200 #5c5c5c
-    }
-}

sway/config.in

@@ -199,5 +199,25 @@ mode "resize" {
 }
 bindsym $mod+r mode "resize"
 
-# Restricted to .conf files to avoid including .rpmnew/.rpmsave
-include /etc/sway/config.d/*.conf
+# Include configs from 3 locations:
+#  - $DATADIR/sway/config.d
+#  - $SYSCONFDIR/sway/config.d
+#  - $XDG_CONFIG_HOME/sway/config.d ($HOME/.config/sway/config.d)
+#
+# If multiple directories contain the files with the same name, the later
+# directory takes precedence; `$XDG_CONFIG_HOME/sway/config.d/20-swayidle.conf`
+# will always be loaded instead of `$DATADIR/sway/config.d/20-swayidle.conf`
+# or `$SYSCONFDIR/sway/config.d/20-swayidle.conf`
+#
+# This mechanism permits overriding our default configuration per-system
+# ($SYSCONFDIR) or per-user ($XDG_CONFIG_HOME) basis. Just create the file you
+# want to modify/override in the higher-level directory.
+#
+# For example, to disable the default bar from Fedora configs, you'll need to
+#     $ echo -n > "$HOME/.config/sway/config.d/90-bar.conf"
+#
+# Note the quoting, the $() and the arguments quoting. All the parts are equally
+# important to make the magic work. And if you want to learn the secret behind
+# the trick, it's all in the `wordexp(3)`.
+#
+include '$($LIBEXECDIR/sway/layered-include "$DATADIR/sway/config.d/*.conf" "$SYSCONFDIR/sway/config.d/*.conf" "${XDG_CONFIG_HOME:-$HOME/.config}/sway/config.d/*.conf")'

sway/config.test

@@ -6,7 +6,5 @@ set $SYSCONFDIR $SRCDIR
 set $LIBEXECDIR $SRCDIR/scripts
 # Intentionally broken
 set $HOME       $SRCDIR
-# Include base config first to set the variables
-include config
 # Include unprocessed config to allow variable substitution
-include 50-fedora.conf.in
+include config.in