import { useNostr } from '@nostrify/react';
import { useQuery, useMutation, useQueryClient } from '@tanstack/react-query';
import { useCurrentUser } from '@/hooks/useCurrentUser';

/**
 * Cross-device "dismissed crew notifications" set.
 *
 * A crew invite / join-request lives on relays as a public event the recipient
 * *doesn't* own, so they can't delete it — they can only stop it nagging them.
 * Previously that was a per-device localStorage set, which meant dismissing on
 * your phone left it un-dismissed on your laptop.
 *
 * This stores the set as a single private, addressable NIP-78 event (kind
 * 30078) whose content is a NIP-44 payload encrypted to the user's own key —
 * so it syncs across every device the user logs in from, and never leaks which
 * invites/requests they ignored. One list covers both invites and join-requests
 * (both keyed by event id).
 *
 * Graceful degradation: the resolved set is always the UNION of the synced
 * remote list and a local mirror, so dismissals still work instantly, offline,
 * and on signers without NIP-44 (they just don't sync).
 */

const DISMISS_KIND = 30078; // NIP-78 application-specific data (addressable)
export const DISMISS_D = 'skatespots:crew-notif-dismissals';
const LOCAL_KEY = 'skatespots:dismissed-crew-notifs';

// ─── Local mirror (offline + no-NIP-44 fallback) ──────────────────────────────

function readLocal(): string[] {
  try {
    const raw = localStorage.getItem(LOCAL_KEY);
    return raw ? (JSON.parse(raw) as string[]) : [];
  } catch {
    return [];
  }
}

function writeLocal(ids: string[]) {
  try {
    localStorage.setItem(LOCAL_KEY, JSON.stringify(ids));
  } catch {
    // ignore storage errors (private mode, quota, etc.)
  }
}

/** Safely read the signer's nip44 without tripping a throwing getter. */
function getNip44(user: ReturnType<typeof useCurrentUser>['user']) {
  if (!user?.signer) return undefined;
  try {
    return user.signer.nip44;
  } catch {
    return undefined;
  }
}

export function dismissKey(pubkey: string | undefined) {
  return ['crew-dismissals', pubkey] as const;
}

/**
 * Resolve the set of dismissed notification ids for the current user — the
 * union of the encrypted synced list and the local mirror.
 */
export function useCrewDismissals() {
  const { nostr } = useNostr();
  const { user } = useCurrentUser();

  return useQuery({
    queryKey: dismissKey(user?.pubkey),
    // Enabled even when logged out returns just the local mirror (harmless).
    staleTime: 30_000,
    queryFn: async (c): Promise<Set<string>> => {
      const local = new Set(readLocal());
      if (!user?.pubkey) return local;

      const nip44 = getNip44(user);
      // No NIP-44 → can't read the synced list; local mirror is all we have.
      if (!nip44) return local;

      const signal = AbortSignal.any([c.signal, AbortSignal.timeout(6000)]);
      try {
        const events = await nostr.query(
          [{ kinds: [DISMISS_KIND], authors: [user.pubkey], '#d': [DISMISS_D], limit: 1 }],
          { signal },
        );
        const ev = events[0];
        if (ev?.content) {
          const decrypted = await nip44.decrypt(user.pubkey, ev.content);
          const parsed = JSON.parse(decrypted) as { ids?: unknown };
          if (Array.isArray(parsed.ids)) {
            for (const id of parsed.ids) {
              if (typeof id === 'string') local.add(id);
            }
          }
        }
      } catch {
        // Relay hiccup / undecryptable / offline — degrade to the local mirror.
      }

      // Keep the local mirror in sync with whatever we resolved.
      writeLocal([...local]);
      return local;
    },
  });
}

/**
 * Dismiss a notification by its event id. Optimistically updates the cache +
 * local mirror immediately, then (best-effort) publishes the encrypted synced
 * list so other devices catch up.
 */
export function useDismissCrewNotification() {
  const { nostr } = useNostr();
  const { user } = useCurrentUser();
  const queryClient = useQueryClient();

  return useMutation({
    mutationFn: async (id: string) => {
      // 1. Optimistic local update (works for everyone, instantly).
      const key = dismissKey(user?.pubkey);
      const current = queryClient.getQueryData<Set<string>>(key) ?? new Set(readLocal());
      const next = new Set(current);
      next.add(id);
      queryClient.setQueryData(key, next);
      writeLocal([...next]);

      // 2. Best-effort sync via an encrypted NIP-78 event.
      const nip44 = getNip44(user);
      if (!user?.pubkey || !nip44) return; // no NIP-44: local-only, no throw

      try {
        const payload = JSON.stringify({ ids: [...next] });
        const content = await nip44.encrypt(user.pubkey, payload);
        const event = await user.signer.signEvent({
          kind: DISMISS_KIND,
          content,
          created_at: Math.floor(Date.now() / 1000),
          tags: [
            ['d', DISMISS_D],
            ['alt', 'Private: dismissed SkateSpots crew notifications'],
          ],
        });
        await nostr.event(event, { signal: AbortSignal.timeout(10000) });
      } catch {
        // Publishing failed — the local dismissal still holds on this device.
      }
    },
    onSuccess: () => {
      queryClient.invalidateQueries({ queryKey: dismissKey(user?.pubkey) });
    },
  });
}