Clarify legacy handling comment

js/videoEventUtils.js

@@ -7,6 +7,73 @@
 const MAGNET_URI_PATTERN = /^magnet:\?/i;
 const HEX_INFO_HASH_PATTERN = /\b[0-9a-f]{40}\b/gi;
 
+function safeTrim(value) {
+  return typeof value === "string" ? value.trim() : "";
+}
+
+function pickFirstString(values = []) {
+  if (!Array.isArray(values)) {
+    return "";
+  }
+
+  for (const value of values) {
+    const trimmed = safeTrim(value);
+    if (trimmed) {
+      return trimmed;
+    }
+  }
+
+  return "";
+}
+
+export function deriveTitleFromEvent({
+  parsedContent = {},
+  tags = [],
+  primaryTitle = "",
+} = {}) {
+  const initial = safeTrim(primaryTitle);
+  if (initial) {
+    return initial;
+  }
+
+  const directCandidates = pickFirstString([
+    parsedContent?.title,
+    parsedContent?.name,
+    parsedContent?.filename,
+    parsedContent?.fileName,
+    parsedContent?.subject,
+    parsedContent?.caption,
+  ]);
+  if (directCandidates) {
+    return directCandidates;
+  }
+
+  const metaTitle = safeTrim(parsedContent?.meta?.title);
+  if (metaTitle) {
+    return metaTitle;
+  }
+
+  if (Array.isArray(tags)) {
+    for (const tag of tags) {
+      if (!Array.isArray(tag) || tag.length < 2) {
+        continue;
+      }
+      const key = safeTrim(tag[0]).toLowerCase();
+      if (!key) {
+        continue;
+      }
+      if (["title", "subject", "caption", "name"].includes(key)) {
+        const candidate = safeTrim(tag[1]);
+        if (candidate) {
+          return candidate;
+        }
+      }
+    }
+  }
+
+  return "";
+}
+
 function extractInfoHashesFromString(value, pushInfoHash) {
   if (typeof value !== "string") {
     return;