refactor: move directory

src/nostr/useSubscription.ts

@@ -0,0 +1,82 @@
+import { createSignal, createEffect, onCleanup } from 'solid-js';
+import type { Event as NostrEvent, Filter, SubscriptionOptions } from 'nostr-tools';
+import usePool from '@/nostr/usePool';
+
+export type UseSubscriptionProps = {
+  relayUrls: string[];
+  filters: Filter[];
+  options?: SubscriptionOptions;
+  // subscribe not only stored events but also new events published after the subscription
+  // default is true
+  continuous?: boolean;
+  onEvent?: (event: NostrEvent) => void;
+  onEOSE?: () => void;
+  signal?: AbortSignal;
+};
+
+const sortEvents = (events: NostrEvent[]) =>
+  Array.from(events).sort((a, b) => b.created_at - a.created_at);
+
+const useSubscription = (propsProvider: () => UseSubscriptionProps | null) => {
+  const pool = usePool();
+  const [events, setEvents] = createSignal<NostrEvent[]>([]);
+
+  createEffect(() => {
+    const props = propsProvider();
+    if (props == null) return;
+
+    const { relayUrls, filters, options, onEvent, onEOSE, continuous = true } = props;
+
+    const sub = pool().sub(relayUrls, filters, options);
+    let pushed = false;
+    let eose = false;
+    const storedEvents: NostrEvent[] = [];
+
+    sub.on('event', (event: NostrEvent) => {
+      if (onEvent != null) {
+        onEvent(event);
+      }
+      if (!eose) {
+        pushed = true;
+        storedEvents.push(event);
+      } else {
+        // いったん50件だけ保持
+        setEvents((prevEvents) => sortEvents([event, ...prevEvents].slice(0, 50)));
+      }
+    });
+
+    sub.on('eose', () => {
+      if (onEOSE != null) {
+        onEOSE();
+      }
+
+      eose = true;
+      setEvents(sortEvents(storedEvents));
+
+      if (!continuous) {
+        sub.unsub();
+      }
+    });
+
+    // avoid updating an array too rapidly while this is fetching stored events
+    const intervalId = setInterval(() => {
+      if (eose) {
+        clearInterval(intervalId);
+        return;
+      }
+      if (pushed) {
+        pushed = false;
+        setEvents(sortEvents(storedEvents));
+      }
+    }, 100);
+
+    onCleanup(() => {
+      sub.unsub();
+      clearInterval(intervalId);
+    });
+  });
+
+  return { events };
+};
+
+export default useSubscription;