feat: add core installation event handler

packages/octocat/src/core/InstallationEvent.ts

@@ -0,0 +1,31 @@
+import type { EmitterWebhookEvent } from "@ijsblokje/server";
+import { ApplyOptions, GitHubEvent } from "../index.js";
+
+@ApplyOptions({ event: "installation" })
+export default class extends GitHubEvent {
+	public override async run(event: EmitterWebhookEvent<"installation">) {
+		switch (event.payload.action) {
+			case "created":
+			case "unsuspend":
+				await this.create(event as any);
+				break;
+			case "deleted":
+			case "suspend":
+				this.octocat.installations.cache.delete(event.payload.installation.id);
+				break;
+			case "new_permissions_accepted":
+				break;
+		}
+	}
+
+	/**
+	 * Registers the new installation
+	 * @param event The installation.create event data
+	 */
+	private async create(event: EmitterWebhookEvent<"installation.created" | "installation.suspend">) {
+		const manager = this.octocat.installations;
+		if (manager.allowedInstallations && !manager.allowedInstallations.includes(event.payload.installation.account.login)) return;
+
+		await manager.loadInstallation(event.payload.installation as any);
+	}
+}