post text to a Nostr relay

post.ts

import {
  Event,
  Relay,
  UnsignedEvent,
  getEventHash,
  getPublicKey,
  nip19,
  relayInit,
  signEvent,
} from "nostr-tools";
import "websocket-polyfill";

const connectToRelay = async (relayUrl: string) => {
  const relay = relayInit(relayUrl);
  relay.on("connect", () => {
    console.log("connected to the relay");
  });
  relay.on("error", () => {
    console.log("failed to connect to the relay");
  });
  await relay.connect();
  return relay;
};

const sendEvent = async (relay: Relay, event: Event) => {
  return new Promise<void>((resolve, reject) => {
    const pub = relay.publish(event);
    pub.on("ok", () => {
      resolve();
    });
    pub.on("failed", (reason: unknown) => {
      console.log("failed to send event:", reason);
      reject(Error("failed to send event"));
    });
  });
};

const NSEC = process.env["NSEC"] as string;

const post = async (
  content: string,
  currTime: number = Math.floor(new Date().getTime() / 1000)
) => {
  const relay = await connectToRelay("wss://relay-jp.nostr.wirednet.jp");

  const { type, data } = nip19.decode(NSEC);
  if (type !== "nsec") {
    console.log("NSEC is not an nsec");
    return;
  }
  const senderPrivkey = data as string;
  const senderPubkey = getPublicKey(senderPrivkey);

  const ev: UnsignedEvent = {
    kind: 1,
    pubkey: senderPubkey,
    content: content,
    created_at: currTime,
    tags: [],
  };
  const evId = getEventHash(ev);
  const evSig = signEvent(ev, senderPrivkey);

  await sendEvent(relay, { ...ev, id: evId, sig: evSig });

  relay.close();
};

// usage: NSEC=<nsec> node -r esbuild-register post.ts <content>
if (process.argv.length <= 2) {
  console.log("please specify content to post");
}
const content = process.argv[2] as string;
post(content).catch((e) => console.error(e));