feat: prioritize video root pointer for view tracking

js/utils/videoPointer.js

@@ -0,0 +1,51 @@
+// js/utils/videoPointer.js
+
+import { pointerArrayToKey } from "./pointer.js";
+
+const DEFAULT_VIDEO_KIND = 30078;
+
+function normalizeString(value) {
+  return typeof value === "string" ? value.trim() : "";
+}
+
+export function resolveVideoPointer({
+  kind,
+  pubkey,
+  videoRootId,
+  dTag,
+  fallbackEventId,
+} = {}) {
+  const normalizedPubkey = normalizeString(pubkey).toLowerCase();
+  const normalizedKind =
+    typeof kind === "number" && Number.isFinite(kind) ? kind : DEFAULT_VIDEO_KIND;
+  const pointerCandidates = [];
+
+  const rootId = normalizeString(videoRootId);
+  if (rootId && normalizedPubkey) {
+    pointerCandidates.push(["a", `${normalizedKind}:${normalizedPubkey}:${rootId}`]);
+  }
+
+  const normalizedDTag = normalizeString(dTag);
+  if (normalizedDTag && normalizedPubkey) {
+    pointerCandidates.push([
+      "a",
+      `${normalizedKind}:${normalizedPubkey}:${normalizedDTag}`,
+    ]);
+  }
+
+  const fallbackId = normalizeString(fallbackEventId);
+  if (fallbackId) {
+    pointerCandidates.push(["e", fallbackId]);
+  }
+
+  for (const pointer of pointerCandidates) {
+    const key = pointerArrayToKey(pointer);
+    if (key) {
+      return { pointer, key };
+    }
+  }
+
+  return null;
+}
+
+export default resolveVideoPointer;