node-gamedig/protocols/openttd.js

import Core from './core.js'

export default class openttd extends Core {
  async run (state) {
    {
      const [reader, version] = await this.query(0, 1, 1, 4)
      if (version >= 4) {
        const numGrf = reader.uint(1)
        state.raw.grfs = []
        for (let i = 0; i < numGrf; i++) {
          const grf = {}
          grf.id = reader.part(4).toString('hex')
          grf.md5 = reader.part(16).toString('hex')
          state.raw.grfs.push(grf)
        }
      }
      if (version >= 3) {
        state.raw.date_current = this.readDate(reader)
        state.raw.date_start = this.readDate(reader)
      }
      if (version >= 2) {
        state.raw.maxcompanies = reader.uint(1)
        state.raw.numcompanies = reader.uint(1)
        state.raw.maxspectators = reader.uint(1)
      }

      state.name = reader.string()
      state.raw.version = reader.string()

      state.raw.language = this.decode(
        reader.uint(1),
        ['any', 'en', 'de', 'fr']
      )

      state.password = !!reader.uint(1)
      state.maxplayers = reader.uint(1)
      state.numplayers = reader.uint(1)
      state.raw.numspectators = reader.uint(1)
      state.map = reader.string()
      state.raw.map_width = reader.uint(2)
      state.raw.map_height = reader.uint(2)

      state.raw.landscape = this.decode(
        reader.uint(1),
        ['temperate', 'arctic', 'desert', 'toyland']
      )

      state.raw.dedicated = !!reader.uint(1)
    }

    {
      const [reader, version] = await this.query(2, 3, -1, -1)
      // we don't know how to deal with companies outside version 6
      if (version === 6) {
        state.raw.companies = []
        const numCompanies = reader.uint(1)
        for (let iCompany = 0; iCompany < numCompanies; iCompany++) {
          const company = {}
          company.id = reader.uint(1)
          company.name = reader.string()
          company.year_start = reader.uint(4)
          company.value = reader.uint(8).toString()
          company.money = reader.uint(8).toString()
          company.income = reader.uint(8).toString()
          company.performance = reader.uint(2)
          company.password = !!reader.uint(1)

          const vehicleTypes = ['train', 'truck', 'bus', 'aircraft', 'ship']
          const stationTypes = ['station', 'truckbay', 'busstation', 'airport', 'dock']

          company.vehicles = {}
          for (const type of vehicleTypes) {
            company.vehicles[type] = reader.uint(2)
          }
          company.stations = {}
          for (const type of stationTypes) {
            company.stations[type] = reader.uint(2)
          }

          company.clients = reader.string()
          state.raw.companies.push(company)
        }
      }
    }
  }

  async query (type, expected, minver, maxver) {
    const b = Buffer.from([0x03, 0x00, type])
    return await this.udpSend(b, (buffer) => {
      const reader = this.reader(buffer)

      const packetLen = reader.uint(2)
      if (packetLen !== buffer.length) {
        this.logger.debug('Invalid reported packet length: ' + packetLen + ' ' + buffer.length)
        return
      }

      const packetType = reader.uint(1)
      if (packetType !== expected) {
        this.logger.debug('Unexpected response packet type: ' + packetType)
        return
      }

      const protocolVersion = reader.uint(1)
      if ((minver !== -1 && protocolVersion < minver) || (maxver !== -1 && protocolVersion > maxver)) {
        throw new Error('Unknown protocol version: ' + protocolVersion + ' Expected: ' + minver + '-' + maxver)
      }

      return [reader, protocolVersion]
    })
  }

  readDate (reader) {
    const daysSinceZero = reader.uint(4)
    const temp = new Date(0, 0, 1)
    temp.setFullYear(0)
    temp.setDate(daysSinceZero + 1)
    return temp.toISOString().split('T')[0]
  }

  decode (num, arr) {
    if (num < 0 || num >= arr.length) {
      return num
    }
    return arr[num]
  }
}