index.js

const { mapToImage, supportedVersions } = require('./lib/util.js')
const { promises: fs } = require('fs')
const path = require('path')
const EventEmitter = require('events')

/**
 * @typedef MapPacket
 * @property {number} itemDamage
 * @property {number} scale
 * @property {boolean} trackingPosition
 * @property {Array<unknown>} icons
 * @property {number} columns
 * @property {number?} rows
 * @property {number?} x
 * @property {number?} y
 * @property {Buffer?} data
 */

/**
 * @param {import('mineflayer').Bot} bot
 */
function mineflayerPlugin (bot, options = {}) {
  if (!supportedVersions.includes(bot.majorVersion)) {
    console.error('Map downloader: Version not supported')
    return
  }

  const outputDir = options['mapDownloader-outputDir'] ?? path.join('.')
  const saveToFile = options['mapDownloader-saveToFile'] ?? true
  const saveInternal = options['mapDownloader-saveInternal'] ?? true
  const filePrefix = options["mapDownloader-filePrefix"] ?? ''
  const fileSuffix = options["mapDownloader-fileSuffix"] ?? ''

  bot.mapDownloader = new MapSaver(bot.version, { outputDir, saveToFile, saveInternal, filePrefix, fileSuffix })

  bot._client.on('map', (data) => {
    bot.mapDownloader.onMapPacket(data)
  })

  bot.mapDownloader.on('new_map', data => {
    bot.emit('new_map', data)
  })

  bot.mapDownloader.on('new_map_saved', data => {
    bot.emit('new_map_saved', data)
  })
}

class MapSaver extends EventEmitter {
  constructor (version, options = {}) {
    super()
    this.isActive = true
    this.outputDir = options.outputDir ?? path.join('.')
    this.saveToFile = options.saveToFile ?? true
    this.saveInternal = options.saveInternal ?? true
    this.filePrefix = options.filePrefix ?? ''
    this.fileSuffix = options.fileSuffix ?? ''
    this.version = version
    this.maps = {}
    // Mojang fixed columns and rows having negative numbers for 1.17
    this.fullColumnRow = require('minecraft-data')(this.version).version['>']('1.16.5') ? 128 : -128
    this.majorVersion = require('minecraft-data')(this.version).version.majorVersion
  }

  /** @param {MapPacket} data */
  onMapPacket (data) {
    if (!this.isActive) return
    const mapId = data.itemDamage
    if (!(mapId in this.maps) && data.data && data.columns === this.fullColumnRow && data.rows === this.fullColumnRow) {
      mapToImage(data.data, data.itemDamage, this.majorVersion)
        .then((pngBuf) => {
          const mapName = `${this.filePrefix}map_${mapId.toString().padStart(6, '0')}${this.fileSuffix}.png`
          this.emit('new_map', {
            name: mapName,
            png: pngBuf,
            id: mapId,
          })
          if (this.saveInternal) this.maps[mapId] = pngBuf
          if (!this.saveToFile) return
          fs.mkdir(this.outputDir, { recursive: true }).then(() => {
            fs.writeFile(path.join(this.outputDir, mapName), pngBuf).then(() => {
              this.emit('new_map_saved', {
                name: mapName,
                id: mapId,
              })
            });
          })
        })
        .catch(console.error)
      return true
    }
    return false
  }

  activate() {
    this.isActive = true
  }

  deactivate() {
    this.isActive = false
  }
}

module.exports = {
  mapDownloader: mineflayerPlugin,
  MapSaver,
  supportedVersions
}