jsstats/server/socket.js

const { Block } = require('./db/models')
const chalk = require('chalk')

const { types } = require('@joystream/types')
const { ApiPromise, WsProvider } = require('@polkadot/api')
const wsLocation = 'wss://rome-rpc-endpoint.joystream.org:9944'

module.exports = (io) => {
  const initializeSocket = async () => {
    console.debug(`[Joystream] Connecting to ${wsLocation}`)
    const provider = new WsProvider(wsLocation)
    const api = await ApiPromise.create({ provider, types })
    await api.isReady
    console.debug(`[Joystream] Connected.`)

    api.derive.chain.subscribeNewHeads(async (header) => {
      const id = Number(header.number)
      const exists = await Block.findByPk(id)
      if (exists) return
      const timestamp = (await api.query.timestamp.now()).toNumber()
      const last = await Block.findByPk(id - 1)
      const blocktime = last ? timestamp - last.timestamp : 6000
      const block = await Block.create({
        id,
        timestamp,
        blocktime,
        author: header.author?.toString(),
      })
      console.log('[Joystream] block', block.id, block.blocktime, block.author)
      io.emit('block', block)
    })
  }

  io.on('connection', (socket) => {
    socket.emit('welcome', 'Websockets are awesome!')
    console.log(chalk.green(`[socket.io] Connection: ${socket.id}`))
    socket.on('disconnect', async () => {
      console.log(chalk.red(`[socket.io] Disconnect: ${socket.id}`))
    })
  })
  initializeSocket()
}