feat: create getZapSplits function

src/utils/zap_split.ts

@@ -0,0 +1,35 @@
+import { NSchema as n, NStore } from '@nostrify/nostrify';
+import { isNumberFrom1To100 } from '@/utils.ts';
+
+type Pubkey = string;
+type ExtraMessage = string;
+/** Number from 1 to 100, stringified. */
+type splitPercentages = string;
+
+type DittoZapSplits = {
+  [key: Pubkey]: [splitPercentages, ExtraMessage];
+};
+
+/** Gets zap splits from NIP-78 in DittoZapSplits format. */
+export async function getZapSplits(store: NStore, pubkey: string): Promise<DittoZapSplits> {
+  const zapSplits: DittoZapSplits = {};
+
+  const [event] = await store.query([{
+    authors: [pubkey],
+    kinds: [30078],
+    '#d': ['pub.ditto.zapSplits'],
+    limit: 1,
+  }]);
+  if (!event) return {};
+
+  for (const tag of event.tags) {
+    if (
+      tag[0] === 'p' && n.id().safeParse(tag[1]).success &&
+      isNumberFrom1To100(tag[2])
+    ) {
+      zapSplits[tag[1]] = [tag[2], tag[3] ?? ''];
+    }
+  }
+
+  return zapSplits;
+}