Add lightbox support and Hydrogen URL hashes relative to the room

.eslintrc.json

@@ -5,7 +5,7 @@
     "node": true
   },
   "parserOptions": {
-    "ecmaVersion": 2018,
+    "ecmaVersion": 2022,
     "sourceType": "script"
   },
   "plugins": ["node"],

shared/hydrogen-vm-render-script.js

@@ -23,6 +23,7 @@ const {
 const ArchiveView = require('matrix-public-archive-shared/ArchiveView');
 const RightPanelContentView = require('matrix-public-archive-shared/RightPanelContentView');
 const MatrixPublicArchiveURLCreator = require('matrix-public-archive-shared/lib/url-creator');
+const InMemoryHistory = require('matrix-public-archive-shared/lib/in-memory-history');
 
 const fromTimestamp = window.matrixPublicArchiveContext.fromTimestamp;
 assert(fromTimestamp);
@@ -87,11 +88,15 @@ async function mountHydrogen() {
   });
 
   const navigation = createNavigation();
+  const inMemoryHistory = new InMemoryHistory(roomData.id);
   platform.setNavigation(navigation);
   const urlRouter = createRouter({
     navigation: navigation,
-    history: platform.history,
+    //history: platform.history,
+    history: inMemoryHistory,
   });
+  // Populate the `Navigation` with segments to work from
+  urlRouter.tryRestoreLastUrl();
 
   // We use the timeline to setup the relations between entries
   const timeline = new Timeline({

shared/lib/in-memory-history.js

@@ -0,0 +1,62 @@
+'use strict';
+
+const { BaseObservableValue } = require('hydrogen-view-sdk');
+const assert = require('./assert');
+
+// A Hydrogen History implementation that doesn't touch the URL. This way
+// Hydrogen can still route internally while keeping our external facing URL the
+// same.
+//
+// ex. https://hydrogen.element.io/#/session/123/room/!abc:m.org/lightbox/$abc
+// and the hash is handling the `#/session/123/room/!abc:m.org/lightbox/$abc`
+// part
+class InMemoryHistory extends BaseObservableValue {
+  #hash = '#/session/123/room/!abc:m.org';
+
+  constructor(roomId) {
+    super();
+
+    assert(roomId);
+
+    // Since we're viewing an archive of a room, let's mimic the URL of the room
+    // view
+    this.#hash = `#/session/123/room/${roomId}`;
+  }
+
+  get() {
+    return this.#hash;
+  }
+
+  /** does not emit */
+  replaceUrlSilently(url) {
+    this.#hash = url;
+  }
+
+  /** does not emit */
+  pushUrlSilently(url) {
+    this.#hash = url;
+  }
+
+  pushUrl(url) {
+    this.#hash = url;
+  }
+
+  urlAsPath(url) {
+    if (url.startsWith('#')) {
+      return url.substr(1);
+    } else {
+      return url;
+    }
+  }
+
+  pathAsUrl(path) {
+    return `#${path}`;
+  }
+
+  getLastUrl() {
+    //throw new Error('Not implemented in InMemoryHistory');
+    return this.#hash;
+  }
+}
+
+module.exports = InMemoryHistory;