feat: add brightness service

flake.nix

@@ -46,6 +46,7 @@
           (ags.packages.${system}.default.override {
             extraPackages = astalPkgs;
           })
+          pkgs.brightnessctl
         ];
       };
     };

service/brightness.ts

@@ -0,0 +1,51 @@
+import GObject, { register, property } from "astal/gobject";
+import { monitorFile, readFileAsync } from "astal/file";
+import { exec, execAsync } from "astal/process";
+
+const get = (args: string) => Number(exec(`brightnessctl ${args}`));
+const screen = exec(`bash -c "ls -w1 /sys/class/backlight | head -1"`);
+
+@register({ GTypeName: "Brightness" })
+export default class Brightness extends GObject.Object {
+    static instance: Brightness;
+    static get_default() {
+        if (!this.instance) this.instance = new Brightness();
+
+        return this.instance;
+    }
+
+    #screenMax = get("max");
+    #screen = get("get") / (this.#screenMax || 1);
+
+    @property(Number)
+    get screen() {
+        return this.#screen;
+    }
+
+    set screen(percent) {
+        console.log(percent);
+        if (percent < 0) percent = 0;
+
+        if (percent > 1) percent = 1;
+
+        execAsync(`brightnessctl set ${Math.floor(percent * 100)}% -q`).then(
+            () => {
+                console.log(percent);
+                this.#screen = percent;
+                this.notify("screen");
+            },
+        );
+    }
+
+    constructor() {
+        super();
+
+        const screenPath = `/sys/class/backlight/${screen}/brightness`;
+
+        monitorFile(screenPath, async (f) => {
+            const value = await readFileAsync(f);
+            this.#screen = Number(value) / this.#screenMax;
+            this.notify("screen");
+        });
+    }
+}