add link preview

src/utils/hooks/useEvent.tsx

@@ -0,0 +1,57 @@
+import { RelayContext } from "@shared/relayProvider";
+import { useActiveAccount } from "@stores/accounts";
+import { READONLY_RELAYS } from "@stores/constants";
+import { createNote, getNoteByID } from "@utils/storage";
+import { getParentID } from "@utils/transform";
+import { useContext } from "react";
+import useSWR from "swr";
+import useSWRSubscription from "swr/subscription";
+
+const fetcher = ([, id]) => getNoteByID(id);
+
+export function useEvent(id: string) {
+	const pool: any = useContext(RelayContext);
+	const account = useActiveAccount((state: any) => state.account);
+
+	const { data: cache } = useSWR(["event", id], fetcher);
+	const { data: newest } = useSWRSubscription(
+		!cache ? id : null,
+		(key, { next }) => {
+			const unsubscribe = pool.subscribe(
+				[
+					{
+						ids: [key],
+					},
+				],
+				READONLY_RELAYS,
+				(event: any) => {
+					const parentID = getParentID(event.tags, event.id);
+					// insert event to local database
+					createNote(
+						event.id,
+						account.id,
+						event.pubkey,
+						event.kind,
+						event.tags,
+						event.content,
+						event.created_at,
+						parentID,
+					);
+					// update state
+					next(null, event);
+				},
+				undefined,
+				undefined,
+				{
+					unsubscribeOnEose: true,
+				},
+			);
+
+			return () => {
+				unsubscribe();
+			};
+		},
+	);
+
+	return cache ? cache : newest;
+}