nostr-web-components/lib/metadata.js

collection of web components that provide quick access to basic nostr things

import { SimplePool } from "nostr-tools/pool";
import { decode, npubEncode } from "nostr-tools/nip19";
import { queryProfile } from "nostr-tools/nip05";
import LRUCache from "mnemonist/lru-cache";
const pool = window.nostrSharedPool || new SimplePool();
const metadataCache = window.nostrMetadataCache || new LRUCache(2e3);
function fetchMetadata(pubkey, hints) {
  let metadata = metadataCache.get(pubkey);
  if (metadata)
    return metadata;
  const relays = ["wss://purplepag.es", "wss://user.kindpag.es", "wss://relay.nos.social"];
  relays.push(...hints);
  let promise = new Promise(
    (resolve, reject) => pool.subscribeManyEose(
      relays,
      [
        {
          kinds: [0],
          authors: [pubkey]
        }
      ],
      {
        onevent(evt) {
          try {
            resolve(JSON.parse(evt.content));
          } catch (err) {
          }
        },
        onclose: reject
      }
    )
  );
  metadataCache.set(pubkey, promise);
  return promise;
}
async function inputToPubkey(input) {
  try {
    const { type, data } = decode(input);
    if (type === "nprofile") {
      return [data.pubkey, data.relays || []];
    } else if (type === "npub") {
      return [data, []];
    }
  } catch (err) {
    if (input.match(/[0-9a-f]{64}/)) {
      return [input, []];
    } else if (input.match(".")) {
      let res = await queryProfile(input);
      if (!res)
        return [void 0];
      return [res.pubkey, res.relays || []];
    }
  }
  return [void 0];
}
function getShortName(pubkey, metadata) {
  let name = metadata.name || metadata.display_name;
  if (name)
    return name;
  let npub = npubEncode(pubkey);
  return shortenNpub(npub);
}
function shortenNpub(npub) {
  return npub.substring(0, 7) + "\u2026" + npub.substring(57);
}
export {
  fetchMetadata,
  getShortName,
  inputToPubkey,
  shortenNpub
};