chipmunkbot3/plugins/seen.js

function inject (bot) {
  bot.on('player_data_loaded', (player, data) => {
    data.data.seen ??= {}
    const seenData = data.data.seen

    if (seenData.first == null) {
      seenData.first = createSeenValue()
      bot.tellraw([
        { text: 'Welcome ', ...bot.styles.primary },
        { text: player.username, ...bot.styles.secondary },
        ' to the server!'
      ], '@a')
    }
    seenData.last = createSeenValue()
  })

  bot.on('player_data_unloading', (player, data) => {
    const seenData = data.data.seen
    if (seenData != null) seenData.last = createSeenValue()
  })

  function createSeenValue () {
     return { date: new Date(), host: bot.host, port: bot.port ?? 25565 }
  }
}

module.exports = inject