Split up monolith index.js into multiple files

js/NavigationService.js

@@ -0,0 +1,44 @@
+/**
+ * Service responsible for handling navigation events and browser history.
+ * @class NavigationService
+ */
+export class NavigationService {
+    /**
+     * Creates a new NavigationService instance.
+     * @param {EventBus} eventBus - The event bus for communication.
+     * @param {DocumentService} documentService - The document service.
+     */
+    constructor(eventBus, documentService) {
+        /** @type {EventBus} */
+        this.eventBus = eventBus;
+        /** @type {DocumentService} */
+        this.documentService = documentService;
+        this.setupEventListeners();
+    }
+
+    /**
+     * Sets up browser history and internal link event listeners.
+     * @private
+     */
+    setupEventListeners() {
+        window.addEventListener('popstate', async () => {
+            const search = window.location.search;
+            const hash = window.location.hash;
+            const slug = (search === '' || search === '?') ?
+                window._indexData.defaultPage :
+                search.replace(/^\?/, '').split('#')[0];
+
+            this.eventBus.emit('navigation:requested', { slug, hash });
+        });
+
+        document.addEventListener('click', async (e) => {
+            const target = e.target.closest('a[data-internal="true"]');
+            if (target) {
+                e.preventDefault();
+                const slug = target.href.split('?').pop();
+                history.pushState(null, '', `?${slug}`);
+                this.eventBus.emit('navigation:requested', { slug });
+            }
+        });
+    }
+}