WIP: upower stuff for bluetooth battery level display

modules/gui.nix

@@ -22,6 +22,8 @@ lib.mkIf config.sbruder.gui.enable {
   # steam (and other high quality software) still ships 32 bit binaries
   hardware.opengl.driSupport32Bit = lib.mkDefault pkgs.stdenv.isx86_64;
 
+  services.upower.enable = true;
+
   environment.systemPackages = with pkgs; [
     pkgs.gnome3.adwaita-icon-theme # lutris requires system-wide installation
   ];

users/simon/modules/sway/upower.py

@@ -0,0 +1,61 @@
+from xml.etree import ElementTree
+import dbus
+import re
+
+
+def undbusify_dict_inner(tup):
+    k, v = tup
+    k = str(k)
+
+    if type(v) == dbus.String:
+        v = str(v)
+    elif type(v) == dbus.Double:
+        v = float(v)
+    elif type(v) == dbus.UInt32 or type(v) == dbus.UInt64 or type(v) == dbus.Int64:
+        v = int(v)
+    elif type(v) == dbus.Boolean:
+        v = bool(v)
+
+    return k, v
+
+
+def undbusify_dict(d):
+    return dict(map(undbusify_dict_inner, d.items()))
+
+
+def get_upower_devices(bus):
+    obj = bus.get_object("org.freedesktop.UPower", "/org/freedesktop/UPower/devices")
+    iface = dbus.Interface(obj, "org.freedesktop.DBus.Introspectable")
+
+    for child in ElementTree.fromstring(iface.Introspect()):
+        yield child.attrib["name"]
+
+
+def get_upower_device_props(bus, device):
+    obj = bus.get_object(
+        "org.freedesktop.UPower", f"/org/freedesktop/UPower/devices/{device}"
+    )
+    return undbusify_dict(
+        obj.GetAll(
+            "org.freedesktop.UPower.Device",
+            dbus_interface="org.freedesktop.DBus.Properties",
+        )
+    )
+
+
+def device_pred(device: str) -> bool:
+    return re.match("gaming_input_hid_.*_battery", device)
+
+
+bus = dbus.SystemBus()
+
+devices = filter(device_pred, get_upower_devices(bus))
+for device in devices:
+    props = get_upower_device_props(bus, device)
+    pretty_device_name = (
+        props["Vendor"]
+        + " " * bool(props["Vendor"]) * bool(props["Model"])
+        + props["Model"]
+    )
+    percentage = props["Percentage"]
+    print(pretty_device_name, percentage)