samp-query.js

var dgram = require('dgram')

var query = function (options, callback) {

    var self = this

    if(typeof options === 'string') options.host = options
    options.port = options.port || 7777
    options.timeout = options.timeout || 1000
    
    if(!options.host) 
        return callback.apply(options, [ 'Invalid host' ])

    if(!isFinite(options.port) || options.port < 1 || options.port > 65535) 
        return callback.apply(options, [ 'Invalid port' ])

    var response = {}

    request.call(self, options, 'i', function(error, information) {
        if(error) return callback.apply(options, [ error ])

        response.address = options.host
        response.port = options.port
        response.hostname = information.hostname
        response.gamemode = information.gamemode
        response.mapname = information.mapname
        response.passworded = information.passworded === 1
        response.maxplayers = information.maxplayers
        response.online = information.players

        request.call(self, options, 'r', function(error, rules) {
            if(error) return callback.apply(options, [ error ])

            rules.lagcomp = rules.lagcomp === 'On'

            rules.weather = parseInt(rules.weather, 10)

            response.rules = rules

            if(response.online > 100) {
                response.players = []

                return callback.apply(options, [ false, response ])
            }
            else {
                request.call(self, options, 'd', function(error, players) {
                    if(error) return callback.apply(options, [ error ])

                    response.players = players

                    return callback.apply(options, [ false, response ])
                })
            }
        })
    })
}

var request = function(options, opcode, callback) {

    var socket = dgram.createSocket("udp4")
    var packet = new Buffer(10 + opcode.length)

    packet.write('SAMP')

    for(var i = 0; i < 4; ++i) 
    packet[i + 4] = options.host.split('.')[i]

    packet[8] = options.port & 0xFF
    packet[9] = options.port >> 8 & 0xFF
    packet[10] = opcode.charCodeAt(0)

    try {
        socket.send(packet, 0, packet.length, options.port, options.host, function(error, bytes) {
            if(error) return callback.apply(options, [ error ])
        })
    } catch(error) {
        return callback.apply(options, [ error ])
    }

    var controller = undefined

    var onTimeOut = function() {
        socket.close()
        return callback.apply(options, [ 'Host unavailable' ])
    }

    controller = setTimeout(onTimeOut, options.timeout)

    socket.on('message', function (message) {

        if(controller)
            clearTimeout(controller)

        if(message.length < 11) return callback.apply(options, [ true ])
        else {
            socket.close()

            message = message.slice(11)

            var object = {}
            var array = []
            var strlen = 0
            var offset = 0

            try {

                if(opcode == 'i') {               

                    object.passworded = message.readUInt8(offset)
                    offset += 1

                    object.players = message.readUInt16LE(offset)
                    offset += 2

                    object.maxplayers = message.readUInt16LE(offset)
                    offset += 2

                    strlen = message.readUInt16LE(offset)
                    offset += 4

                    object.hostname = decode(message.slice(offset, offset += strlen))

                    strlen = message.readUInt16LE(offset)
                    offset += 4

                    object.gamemode = decode(message.slice(offset, offset += strlen))

                    strlen = message.readUInt16LE(offset)
                    offset += 4

                    object.mapname = decode(message.slice(offset, offset += strlen))

                    return callback.apply(options, [ false, object ])

                }

                if(opcode == 'r') {

                    var rulecount  = message.readUInt16LE(offset)
                    offset += 2

                    var property, value = undefined

                    while(rulecount) {

                        strlen = message.readUInt8(offset)
                        ++offset

                        property = decode(message.slice(offset, offset += strlen))

                        strlen = message.readUInt8(offset)
                        ++offset

                        value = decode(message.slice(offset, offset += strlen))

                        object[property] = value

                        --rulecount
                    }

                    return callback.apply(options, [ false, object ])
                }

                if(opcode == 'd') {

                    var playercount = message.readUInt16LE(offset)
                    offset += 2

                    var player = undefined;

                    while(playercount) {

                        player = {}

                        player.id = message.readUInt8(offset)
                        ++offset

                        strlen = message.readUInt8(offset)
                        ++offset

                        player.name = decode(message.slice(offset, offset += strlen))

                        player.score = message.readUInt16LE(offset)
                        offset += 4

                        player.ping = message.readUInt16LE(offset)
                        offset += 4

                        array.push(player)

                        --playercount
                    }

                    return callback.apply(options, [ false, array ])
                }

            } catch (exception) {
                return callback.apply(options, [ exception ])
            }
        }
    })
}

var decode = function(buffer) {
    var charset = ''
    for (var i = 0; i < 128; i++) charset += String.fromCharCode(i)
    charset += '€�‚ƒ„…†‡�‰�‹�����‘’“”•–—�™�›���� ΅Ά£¤¥¦§¨©�«¬­®―°±²³΄µ¶·ΈΉΊ»Ό½ΎΏΐΑΒΓΔΕΖΗΘΙΚΛΜΝΞΟΠΡ�ΣΤΥΦΧΨΩΪΫάέήίΰαβγδεζηθικλμνξοπρςστυφχψωϊϋόύώ�'
    var charsetBuffer = new Buffer(charset, 'ucs2')
    var decodeBuffer = new Buffer(buffer.length * 2)
    for(var i = 0; i < buffer.length; i++) {
        decodeBuffer[i * 2] = charsetBuffer[buffer[i] * 2]
        decodeBuffer[i * 2 + 1] = charsetBuffer[buffer[i] * 2 + 1]
    }
    return decodeBuffer.toString('ucs2')
}

module.exports = query