Nostrのリレーから過去ログをあさってくるnode.js

nostr_history.js

const relay = 'wss://relay-jp.nostr.wirednet.jp'
const authors = ['634bd19e5c87db216555c814bf88e66ace175805291a6be90b15ac3b2247da9b']

function history (until = Math.floor(new Date() / 1000)) {
  let socket
  if (typeof (WebSocket) === 'undefined') {
    const WebSocket = require('websocket').w3cwebsocket
    socket = new WebSocket(relay)
  } else {
    socket = new WebSocket(relay)
  }

  socket.onmessage = message => {
    const event = JSON.parse(message.data)
    if (event[0] === 'EOSE') {
      socket.send(JSON.stringify(['CLOSE', event[1]]))
    } else if (event.length < 3) {
      socket.close()
    } else {
      const e = event[2]
      console.log(e)
      socket.send(JSON.stringify(['REQ', crypto.randomUUID(), {
        authors,
        until: e.created_at - 1,
        limit: 1
      }]))
    }
  }
  socket.onopen = () => {
    socket.send(JSON.stringify(['REQ', crypto.randomUUID(), {
      authors,
      until,
      limit: 1
    }]))
  }
  socket.onclose = () => {
    console.log('Websocket is closed.')
  }
  socket.onerror = (e) => {
    console.log('Websocket encountered error: ', e.message)
  }
}

history()