import { useMutation, useQuery, useQueryClient } from '@tanstack/react-query';
import { useNostr } from '@nostrify/react';
import { useNostrLogin } from '@nostrify/react/login';
import { useCurrentUser } from '@/hooks/useCurrentUser';
import { hasNip44 as checkNip44 } from '@/lib/signerCapabilities';
import {
  buildEnvelope,
  fetchGroupMessages,
  publishEnvelope,
  type CordnRelay,
} from '@/lib/cordn/client';
import { sealGroupMessage, type Nip44Signer } from '@/lib/cordn/crypto';
import type { CordnEndpoint, CordnMessage } from '@/lib/cordn/types';
import type { NostrEvent, NostrSigner } from '@nostrify/nostrify';

interface UseCordnChatParams {
  /** Resolved coordinator endpoint (relay + group id). `null` disables the chat. */
  endpoint: CordnEndpoint | null;
  /** Full roster (founder + members) — recipients for group encryption. */
  roster: string[];
  /** Whether the viewer is a member (only members query/decrypt). */
  enabled: boolean;
}

/**
 * Crew encrypted group chat over a Cordn coordinator.
 *
 * Fetch-then-poll: an initial bounded backlog fetch, then a light poll for live
 * delivery (5s) — robust in a browser PWA and coordinator-agnostic. Mirrors the
 * NIP-17 `useGroupConversation` / `useSendDirectMessage` API so `CrewChat` can
 * swap transports with no UI change.
 */
export function useCordnChat({ endpoint, roster, enabled }: UseCordnChatParams) {
  const { nostr } = useNostr();
  const { user } = useCurrentUser();
  const { logins } = useNostrLogin();
  const queryClient = useQueryClient();

  const canEncrypt = checkNip44(user, logins);
  const active = !!endpoint && !!user && enabled && canEncrypt;

  const query = useQuery({
    queryKey: ['cordn-chat', endpoint?.relayUrl, endpoint?.groupId, user?.pubkey],
    enabled: active,
    refetchInterval: active ? 5000 : false,
    staleTime: 2000,
    queryFn: async (): Promise<CordnMessage[]> => {
      if (!endpoint || !user) return [];
      const relay = nostr.relay(endpoint.relayUrl) as unknown as CordnRelay;
      const signer = user.signer as unknown as Nip44Signer;
      const signal = AbortSignal.timeout(10000);
      return fetchGroupMessages({
        relay,
        endpoint,
        signer,
        viewerPk: user.pubkey,
        signal,
      });
    },
  });

  const send = useMutation({
    mutationFn: async (text: string) => {
      const body = text.trim();
      if (!body) return;
      if (!endpoint || !user) throw new Error('Crew chat is not available.');
      if (!canEncrypt) throw new Error('Your signer does not support NIP-44 encryption.');

      const signer = user.signer as unknown as Nip44Signer;
      const sealed = await sealGroupMessage(signer, user.pubkey, roster, body);
      const envelope: NostrEvent = await buildEnvelope(
        user.signer as unknown as NostrSigner,
        endpoint,
        JSON.stringify(sealed),
      );

      const relay = nostr.relay(endpoint.relayUrl) as unknown as CordnRelay;
      await publishEnvelope(relay, envelope, AbortSignal.timeout(15000));
    },
    onSuccess: () => {
      queryClient.invalidateQueries({
        queryKey: ['cordn-chat', endpoint?.relayUrl, endpoint?.groupId, user?.pubkey],
      });
    },
  });

  return {
    messages: query.data ?? [],
    isLoading: query.isLoading,
    isError: query.isError,
    canEncrypt,
    send: send.mutateAsync,
    isSending: send.isPending,
  };
}