gamespy2.js

import Core from './core.js'

export default class gamespy2 extends Core {
  constructor () {
    super()
    this.encoding = 'latin1'
    this.byteorder = 'be'
  }

  async run (state) {
    // Parse info
    {
      const body = await this.sendPacket([0xff, 0, 0])
      const reader = this.reader(body)
      while (!reader.done()) {
        const key = reader.string()
        const value = reader.string()
        if (!key) break
        state.raw[key] = value
      }
      if ('hostname' in state.raw) state.name = state.raw.hostname
      if ('mapname' in state.raw) state.map = state.raw.mapname
      if (this.trueTest(state.raw.password)) state.password = true
      if ('maxplayers' in state.raw) state.maxplayers = parseInt(state.raw.maxplayers)
      if ('hostport' in state.raw) state.gamePort = parseInt(state.raw.hostport)
      if ('gamever' in state.raw) state.version = state.raw.gamever
    }

    // Parse players
    {
      const body = await this.sendPacket([0, 0xff, 0])
      const reader = this.reader(body)
      for (const rawPlayer of this.readFieldData(reader)) {
        state.players.push(rawPlayer)
      }

      if ('numplayers' in state.raw) state.numplayers = parseInt(state.raw.numplayers)
      else state.numplayers = state.players.length
    }

    // Parse teams
    {
      const body = await this.sendPacket([0, 0, 0xff])
      const reader = this.reader(body)
      state.raw.teams = this.readFieldData(reader)
    }

    // Special case for america's army 1 and 2
    // both use gamename = "armygame"
    if (state.raw.gamename === 'armygame') {
      const stripColor = (str) => {
        // uses unreal 2 color codes
        return this.options.stripColors ? str.replace(/\x1b...|[\x00-\x1a]/g, '') : str
      }
      state.name = stripColor(state.name)
      state.map = stripColor(state.map)
      for (const key of Object.keys(state.raw)) {
        if (typeof state.raw[key] === 'string') {
          state.raw[key] = stripColor(state.raw[key])
        }
      }
      for (const player of state.players) {
        if (!('name' in player)) continue
        player.name = stripColor(player.name)
      }
    }
  }

  async sendPacket (type) {
    const request = Buffer.concat([
      Buffer.from([0xfe, 0xfd, 0x00]), // gamespy2
      Buffer.from([0x00, 0x00, 0x00, 0x01]), // ping ID
      Buffer.from(type)
    ])
    return await this.udpSend(request, buffer => {
      const reader = this.reader(buffer)
      const header = reader.uint(1)
      if (header !== 0) return
      const pingId = reader.uint(4)
      if (pingId !== 1) return
      return reader.rest()
    })
  }

  readFieldData (reader) {
    reader.uint(1) // always 0
    const count = reader.uint(1) // number of rows in this data

    // some games omit the count byte entirely if it's 0 or at random (like americas army)
    // Luckily, count should always be <64, and ascii characters will typically be >64,
    // so we can detect this.
    if (count > 64) {
      reader.skip(-1)
      this.logger.debug('Detected missing count byte, rewinding by 1')
    } else {
      this.logger.debug('Detected row count: ' + count)
    }

    this.logger.debug(() => 'Reading fields, starting at: ' + reader.rest())

    const fields = []
    while (!reader.done()) {
      const field = reader.string()
      if (!field) break
      fields.push(field)
      this.logger.debug('field:' + field)
    }

    if (!fields.length) return []

    const units = []
    while (!reader.done()) {
      const unit = {}
      for (let index = 0; index < fields.length; index++) {
        let key = fields[index]
        let value = reader.string()
        if (!value && index === 0) return units

        this.logger.debug('value:' + value)

        // many fields end with "_"
        if (key.endsWith('_')) {
          key = key.slice(0, -1)
        }

        if (key === 'player') key = 'name'
        else if (key === 'team_t') key = 'name'
        else if (key === 'tickets_t') key = 'tickets'

        if (['score', 'deaths', 'ping', 'team', 'kills', 'tickets'].includes(key)) {
          if (value === '') continue
          value = parseInt(value)
        }

        unit[key] = value
      }
      units.push(unit)
    }

    return units
  }
}