next-auth-pubkey/hooks/useNostrExtension.js

A light-weight Lightning and Nostr auth provider for your Next.js app that's entirely self-hosted and plugs seamlessly into the next-auth framework.

"use client";
import { useState, useRef, useEffect } from "react";
import { useRouter } from "next/navigation";
import { hardConfig } from "../main/config/hard.js";
/**
 * A React hook that, on mount, will trigger any installed Nostr extensions or return an error.
 * Once a success Nostr extension event is received from the extension the user will be
 * redirected to the `next-auth` redirect url.
 *
 * This hook is designed for use in both the pages router and the app router.
 *
 * @param {object} session - a session object generated by invoking the `createNostrAuth` method
 *
 * @returns {Object}
 * @returns {String} error - an error message or an empty string
 * @returns {Function} retry - a function used to retry opening the nostr extension
 */
export function useNostrExtension(session) {
    const retryRef = useRef(null);
    const [error, setError] = useState("");
    const [isRetry, setRetry] = useState(true);
    const router = useRouter();
    useEffect(() => {
        const callbackController = new AbortController();
        // cleanup when the hook unmounts of callbacking is successful
        const cleanup = () => {
            callbackController.abort();
        };
        // redirect user to error page if something goes wrong
        function error(e) {
            console.error(e);
            // if no errorUrl exists send to defaul `next-auth` error page
            const params = new URLSearchParams();
            params.append("error", "OAuthSignin");
            window.location.replace(`/api/auth/error?${params.toString()}`);
        }
        // callback the api to authenticate the user
        function callback(event) {
            if (!session?.data?.k1)
                return;
            const k1 = session.data.k1;
            const params = new URLSearchParams({ event: JSON.stringify(event) });
            return fetch(hardConfig.apis.callback, {
                method: "POST",
                headers: { "content-type": "application/x-www-form-urlencoded" },
                body: params,
                cache: "default",
                signal: callbackController.signal,
            })
                .then(function (r) {
                return r.json();
            })
                .then(function (d) {
                if (d && d.success) {
                    cleanup();
                    let url = new URL(session.query.redirectUri);
                    url.searchParams.append("state", session.query.state);
                    url.searchParams.append("code", k1);
                    router.replace(url.toString());
                }
            })
                .catch((e) => {
                if (!callbackController.signal.aborted) {
                    error(e);
                }
            });
        }
        function callWithTimeout(targetFunction, timeoutMs) {
            return new Promise((resolve, reject) => {
                Promise.race([
                    targetFunction(),
                    new Promise((resolve, reject) => setTimeout(() => reject(new Error("timed out after " + timeoutMs + " ms waiting for extension")), timeoutMs)),
                ])
                    .then(resolve)
                    .catch(reject);
            });
        }
        // trigger the nostr extension / handle errors on failure
        function triggerExtension(k1) {
            if (!window.nostr) {
                setRetry(false);
                setError("nostr extension not found");
                return;
            }
            return callWithTimeout(() => window.nostr.signEvent({
                kind: 22242,
                created_at: Math.floor(Date.now() / 1000),
                tags: [["challenge", k1]],
                content: "Authentication",
            }), 5000)
                .then((event) => {
                if (event) {
                    callback(event);
                }
                else {
                    setRetry(true);
                    setError("extension returned empty event");
                }
            })
                .catch((e) => {
                const message = e instanceof Error
                    ? e.message
                    : "nostr extension failed to sign event";
                if (message === "window.nostr call already executing") {
                    return;
                }
                setRetry(true);
                setError(message);
            });
        }
        retryRef.current = () => triggerExtension(session?.data?.k1);
        retryRef.current();
        return () => cleanup();
    }, []);
    return {
        error,
        retry: isRetry && error ? () => retryRef?.current?.() : null,
    };
}