Refactors services with defaultConfig and polled data.

Much more simpler code base. Each service requires a poll functioon to poll its
status. If type is defined, and the registered '+service.ts' exports a poll
ServicePoller, it will be used. Otherwise, a generic poll mechanism is used.

src/lib/services/services.ts

@@ -1,21 +1,45 @@
-import type { ServiceHandler } from './service';
+import type { ServiceConfig } from '$lib/config';
+import type { ServiceData, ServicePoller } from './service';
 
-const services: Record<string, ServiceHandler> = {};
-
-const components: Record<string, any> = {};
-
-function registerService(type: string, handler: ServiceHandler) {
-	services[type] = handler;
+interface ServiceRecord {
+	poll: ServicePoller;
+	config: Partial<ServiceConfig>;
 }
 
+const services: Record<string, ServiceRecord> = {};
+
+//eslint-disable-next-line @typescript-eslint/no-explicit-any
+const components: Record<string, any> = {};
+
+async function pollURL(config: ServiceConfig): Promise<ServiceData> {
+	try {
+		const resp = await fetch(config.url);
+		return { status: resp.ok ? 'online' : 'offline' };
+	} catch (error) {
+		console.warn(`could not poll '${config.url}': ` + error);
+		return { status: 'offline' };
+	}
+}
+
+function registerService(type: string, service: Partial<ServiceRecord>) {
+	const record: ServiceRecord = {
+		poll: service.poll || pollURL,
+		config: service.config || {}
+	};
+
+	services[type] = record;
+}
+
+//eslint-disable-next-line @typescript-eslint/no-explicit-any
 function registerComponent(type: string, component: any) {
 	components[type] = component;
 }
 
-export function getServiceHandler(type: string): ServiceHandler | undefined {
-	return services[type];
+export function getServiceRecord(type: string): ServiceRecord {
+	return services[type] || { poll: pollURL, config: {} };
 }
 
+//eslint-disable-next-line @typescript-eslint/no-explicit-any
 export function getServiceComponent(type: string): any {
 	return components[type];
 }
@@ -25,12 +49,13 @@ export async function initServices() {
 
 	for (const [modulePath, load] of Object.entries(services)) {
 		try {
-			const { handle } = (await load()) as any;
-			if (handle == undefined) {
-				throw new Error(`${modulePath} does not export 'handle'`);
+			//eslint-disable-next-line @typescript-eslint/no-explicit-any
+			const { poll, config } = (await load()) as any;
+			if (poll == undefined && config == undefined) {
+				throw new Error(`${modulePath} does not export 'poll' or 'config'`);
 			}
 			const typeName = modulePath.slice(18, -12);
-			registerService(typeName, handle);
+			registerService(typeName, { poll, config });
 		} catch (err) {
 			console.error(`Could not load service definition from '${modulePath}': ${err}`);
 		}
@@ -42,6 +67,7 @@ export async function initComponents() {
 
 	for (const [componentPath, load] of Object.entries(services)) {
 		try {
+			//eslint-disable-next-line @typescript-eslint/no-explicit-any
 			const module = (await load()) as any;
 
 			if (module == undefined) {