Refactor shared helpers into utility modules

js/utils/formatters.js

@@ -0,0 +1,70 @@
+// js/utils/formatters.js
+
+/**
+ * Shortens a string by replacing the middle with an ellipsis when it exceeds
+ * the desired length. Ensures the returned string never exceeds `maxLength`.
+ */
+export function truncateMiddle(text, maxLength = 72) {
+  if (!text || typeof text !== "string") {
+    return "";
+  }
+
+  if (text.length <= maxLength) {
+    return text;
+  }
+
+  const ellipsis = "…";
+  const charsToShow = maxLength - ellipsis.length;
+  const front = Math.ceil(charsToShow / 2);
+  const back = Math.floor(charsToShow / 2);
+  return `${text.slice(0, front)}${ellipsis}${text.slice(text.length - back)}`;
+}
+
+/**
+ * Formats a timestamp (in seconds) to a localized string. Falls back to
+ * ISO-8601 formatting if locale formatting fails.
+ */
+export function formatAbsoluteTimestamp(timestamp) {
+  if (!Number.isFinite(timestamp)) {
+    return "Unknown date";
+  }
+
+  const date = new Date(timestamp * 1000);
+  if (Number.isNaN(date.getTime())) {
+    return "Unknown date";
+  }
+
+  try {
+    return date.toLocaleString(undefined, {
+      year: "numeric",
+      month: "short",
+      day: "2-digit",
+      hour: "2-digit",
+      minute: "2-digit",
+    });
+  } catch (err) {
+    return date.toISOString();
+  }
+}
+
+/**
+ * Returns a human readable "time ago" string for a timestamp (in seconds).
+ */
+export function formatTimeAgo(timestamp) {
+  const seconds = Math.floor(Date.now() / 1000 - timestamp);
+  const intervals = {
+    year: 31536000,
+    month: 2592000,
+    week: 604800,
+    day: 86400,
+    hour: 3600,
+    minute: 60,
+  };
+  for (const [unit, secInUnit] of Object.entries(intervals)) {
+    const int = Math.floor(seconds / secInUnit);
+    if (int >= 1) {
+      return `${int} ${unit}${int > 1 ? "s" : ""} ago`;
+    }
+  }
+  return "just now";
+}