1 files changed, 64 insertions, 0 deletions
diff --git a/src/static/js/client/memorable-details.js b/src/static/js/client/memorable-details.js
new file mode 100644
index 00000000..07482b29
--- /dev/null
+++ b/src/static/js/client/memorable-details.js
@@ -0,0 +1,64 @@
+/* eslint-env browser */
+
+import {stitchArrays} from '../../shared-util/sugar.js';
+
+export const info = {
+  id: 'memorableDetailsInfo',
+
+  details: null,
+  ids: null,
+
+  session: {
+    openDetails: {
+      type: 'json',
+      maxLength: settings => settings.maxOpenDetailsStorage,
+    },
+  },
+
+  settings: {
+    maxOpenDetailsStorage: 1000,
+  },
+};
+
+export function getPageReferences() {
+  info.details =
+    Array.from(document.querySelectorAll('details.memorable'));
+
+  info.ids =
+    info.details.map(details => details.getAttribute('data-memorable-id'));
+}
+
+export function mutatePageContent() {
+  stitchArrays({
+    details: info.details,
+    id: info.ids,
+  }).forEach(({details, id}) => {
+      if (info.session.openDetails?.includes(id)) {
+        details.open = true;
+      }
+    });
+}
+
+export function addPageListeners() {
+  for (const [index, details] of info.details.entries()) {
+    details.addEventListener('toggle', () => {
+      handleDetailsToggled(index);
+    });
+  }
+}
+
+function handleDetailsToggled(index) {
+  const details = info.details[index];
+  const id = info.ids[index];
+
+  if (details.open) {
+    if (info.session.openDetails) {
+      info.session.openDetails = [...info.session.openDetails, id];
+    } else {
+      info.session.openDetails = [id];
+    }
+  } else if (info.session.openDetails?.includes(id)) {
+    info.session.openDetails =
+      info.session.openDetails.filter(item => item !== id);
+  }
+}