VoidShell/services/dbus.ts

import Gio from "gi://Gio";
import GObject, { register } from "astal/gobject";
import { getDbusXml } from "@/utils";
import GLib from "gi://GLib";

let dbusConnectionResolve: ((connection: any) => void) | null = null;
export const Connection: Promise<any> = new Promise<any>(
  (resolve) => (dbusConnectionResolve = resolve),
);

const ownerId = Gio.bus_own_name(
  Gio.BusType.SESSION,
  "dev.ezri.VoidShell",
  Gio.BusNameOwnerFlags.NONE,
  (connection) => {
    dbusConnectionResolve?.(connection);
  },
  () => {},
  () => {},
);

@register()
export class DBusObject extends GObject.Object {
  protected dbusObj: Gio.DBusExportedObject | null = null;
  #objectPath: string;

  constructor(iface: string, objectPath: string) {
    super();
    this.#objectPath = objectPath;
    getDbusXml(iface).then(async (xml) => {
      try {
        this.dbusObj = Gio.DBusExportedObject.wrapJSObject(xml, this.proxify());
        this.dbusObj.export(await Connection, objectPath);
      } catch (e) {
        console.error(`Error exporting to D-Bus: ${e}`);
      }
    });
  }

  /**
   * Creates a proxy of the dbus object that returns object paths of DBusObjects
   * rather than the objects themselves.
   * This proxy should be used with the DBus export, and should not be used in any other context.
   *
   * Due to the way this works, setting DBus object paths is NOT SUPPORTED! Use a method if you really need to do that.
   */
  private proxify() {
    return new Proxy(this, {
      get(target, property: keyof DBusObject) {
        const marshall_func = `marshall_${String(property)}` as string &
          keyof typeof target;
        if (
          marshall_func in target &&
          typeof target[marshall_func] === "function"
        ) {
          const variant: GLib.Variant = target[marshall_func]();
          return variant.deepUnpack();
        }
        if (!(property in target)) {
          return undefined;
        }
        if (target[property] instanceof DBusObject) {
          return target[property].objectPath;
        }
        if (target[property] instanceof Array) {
          return target[property].map((prop) =>
            prop instanceof DBusObject ? prop.objectPath : prop,
          );
        }
        return target[property];
      },
    });
  }

  private marshallValue(
    property: string & keyof this,
    value: any,
  ): GLib.Variant | null {
    const marshall_func_name = `marshall_${property}` as string & keyof this;
    if (
      marshall_func_name in this &&
      typeof this[marshall_func_name] === "function"
    ) {
      return this[marshall_func_name]();
    }
    switch (typeof value) {
      case "string":
        return GLib.Variant.new_string(value);
      case "number":
        return GLib.Variant.new_double(value);
      case "bigint":
        return GLib.Variant.new_int64(Number(value));
      case "boolean":
        return GLib.Variant.new_boolean(value);
      case "symbol":
        return null;
      case "object":
        if (value instanceof Array) {
          if (value.every((val) => val instanceof DBusObject)) {
            return new GLib.Variant(
              "ao",
              value.map((val) => val.objectPath),
            );
          }
          return new GLib.Variant(
            "av",
            value.map(this.marshallValue.bind(this)),
          );
        } else {
          console.warn(
            "No marshall function found for object type, cannot implicitly marshall JS objects. Returning null.",
          );
          return null;
        }
      case "undefined":
        return null;
      case "function":
        return null;
    }
  }

  // private deepMarshallObject(obj: Object): GLib.Variant {
  //   if (obj instanceof DBusObject) {
  //     return GLib.Variant.new_object_path(obj.objectPath);
  //   }
  //   if (obj instanceof Array) {
  //     return new GLib.Variant(
  //       "av",
  //       obj.map(this.marshallValue.bind(this)).filter((val) => val !== null),
  //     );
  //   }
  //   const newObj = Object.entries(obj).reduce((obj, [key, value]) => {
  //     const toEmit = this.marshallValue(, value);
  //     if (toEmit !== null) {
  //       obj[key] = toEmit;
  //     }
  //     return obj;
  //   }, {} as any);
  //   return new GLib.Variant("a{sv}", newObj);
  // }

  protected emitDBusProperty<Prop extends keyof this & string>(property: Prop) {
    const toEmit = this.marshallValue(property, this[property]);
    if (!toEmit) {
      return;
    }
    this.dbusObj?.emit_property_changed(property, toEmit);
  }

  get objectPath(): string {
    return this.#objectPath;
  }
}