import { useNostr } from '@nostrify/react';
import { useNostrLogin } from '@nostrify/react/login';
import { useQuery, useMutation, useQueryClient } from '@tanstack/react-query';
import { useCurrentUser } from '@/hooks/useCurrentUser';
import { isInteractiveSigner } from '@/lib/signerCapabilities';
import { useCallback } from 'react';

/**
 * 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();
  const { logins } = useNostrLogin();

  // Amber (NIP-55) prompts on every decrypt. This query is mounted GLOBALLY via
  // the header NotificationBell, so auto-decrypting here would launch Amber on
  // every navigation/focus — the "Amber flashes on every tap" bug. For an
  // interactive signer we therefore rely on the instant local mirror ONLY and
  // never passively decrypt the synced remote list. Dismissals still sync OUT on
  // the write path (useDismissCrewNotification), and a fresh device simply
  // starts from an empty local mirror — a minor, acceptable degradation vs.
  // storming the user with Amber popups just for walking around the app.
  const interactive = isInteractiveSigner(user, logins);

  return useQuery({
    queryKey: dismissKey(user?.pubkey),
    // Enabled even when logged out returns just the local mirror (harmless).
    staleTime: interactive ? Infinity : 30_000,
    // Never re-run passive decryption on window focus (Amber returning focus
    // would otherwise re-trigger this and pop Amber again in a loop).
    refetchOnWindowFocus: false,
    refetchOnReconnect: !interactive,
    queryFn: async (c): Promise<Set<string>> => {
      const local = new Set(readLocal());
      if (!user?.pubkey) return local;

      // Interactive signer (Amber): do NOT decrypt passively. Local mirror only.
      if (interactive) 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.
 *
 * INTERACTIVE SIGNERS (Amber): the cross-device encrypted sync is skipped
 * entirely and the dismissal is kept LOCAL-ONLY. Dismissing is a low-stakes,
 * high-frequency action (fired on accept/decline of every crew invite and on
 * every handled join-request), and the encrypted sync costs an extra
 * encrypt + sign — i.e. one or two additional Amber approval screens per tap.
 *
 * Since accepting a crew invite ALREADY requires the membership-attestation
 * signature (the one that actually makes you a member), forcing a *second*
 * Amber round-trip just to clear the notification on your other devices is
 * poor UX and not worth it. So for Amber:
 *   • Accept invite  → 1 Amber prompt  (the membership attestation only)
 *   • Decline invite → 0 Amber prompts (local dismissal only)
 * The cross-device "also clear it on my laptop" nicety is silently dropped for
 * Amber; the dismissal still holds instantly and permanently on this device.
 *
 * Non-interactive signers (extension / nsec / bunker) still get the silent
 * encrypted cross-device sync — it's free for them (no approval screens).
 */
export function useDismissCrewNotification() {
  const { nostr } = useNostr();
  const { user } = useCurrentUser();
  const { logins } = useNostrLogin();
  const queryClient = useQueryClient();

  const interactive = isInteractiveSigner(user, logins);

  const mutate = useCallback(
    async (id: string) => {
      // 1. Optimistic local update (works for everyone, instantly + offline).
      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. Interactive signer (Amber): stop here — local-only, NO extra prompt.
      if (interactive) return;

      // 3. Non-interactive signer: best-effort encrypted NIP-78 cross-device sync.
      const nip44 = getNip44(user);
      if (!user?.pubkey || !nip44) return; // no NIP-44: local-only, no throw

      try {
        // Data-safety: this list is a single replaceable event whose encrypted
        // content is the WHOLE dismissal set, so we rewrite all of it. If the
        // read query hasn't resolved yet (fresh device: cache empty, local
        // mirror empty), `next` would be just this one id and we'd overwrite —
        // and thus WIPE — the previously-synced dismissals from other devices.
        // So merge in the freshest remote set before publishing. (Low-stakes
        // data — worst case a handled invite re-appears — but we keep the
        // fetch-before-write pattern consistent with Stash/Contacts.)
        const merged = new Set(next);
        try {
          const events = await nostr.query(
            [{ kinds: [DISMISS_KIND], authors: [user.pubkey], '#d': [DISMISS_D], limit: 1 }],
            { signal: AbortSignal.timeout(6000) },
          );
          const remote = events[0];
          if (remote?.content) {
            const decrypted = await nip44.decrypt(user.pubkey, remote.content);
            const parsed = JSON.parse(decrypted) as { ids?: unknown };
            if (Array.isArray(parsed.ids)) {
              for (const rid of parsed.ids) {
                if (typeof rid === 'string') merged.add(rid);
              }
            }
          }
        } catch {
          // Couldn't read the remote set — publish the local union anyway; a
          // dismissal is additive, so at worst we under-merge, never wipe silently.
        }

        // Keep local mirror + cache aligned with what we're about to publish.
        writeLocal([...merged]);
        queryClient.setQueryData(key, merged);

        const payload = JSON.stringify({ ids: [...merged] });
        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.
      }
    },
    [nostr, user, queryClient, interactive],
  );

  return useMutation({
    mutationFn: mutate,
    onSuccess: () => {
      queryClient.invalidateQueries({ queryKey: dismissKey(user?.pubkey) });
    },
  });
}