Add dynamic cross-protocol support

doc/README.md

@@ -75,6 +75,11 @@ Returns a `Client` instance and perform login.
  * checkTimeoutInterval : default to `10*1000` (10s), check if keepalive received at that period, disconnect otherwise.
  * version : 1.8 or 1.9 : default to 1.8
 
+## mc.createClientAuto(options, cb)
+
+Pings the server and attempts to call `createClient(options)` with the appropriate protocol version.
+When created, calls the callback `cb(err, client)`.
+
 ## mc.Client(isServer,version)
 
 Create a new client, if `isServer` is true then it is a server-side client, otherwise it's a client-side client.

examples/client_auto/client_auto.js

@@ -0,0 +1,31 @@
+var mc = require('minecraft-protocol');
+
+if(process.argv.length < 4 || process.argv.length > 6) {
+  console.log("Usage : node echo.js <host> <port> [<name>] [<password>]");
+  process.exit(1);
+}
+
+mc.createClientAuto({
+  host: process.argv[2],
+  port: parseInt(process.argv[3]),
+  username: process.argv[4] ? process.argv[4] : "echo",
+  password: process.argv[5]
+}, function(err, client) {
+  if (err) throw err;
+
+  client.on('connect', function() {
+    console.info('connected');
+  });
+  client.on('disconnect', function(packet) {
+    console.log('disconnected: '+ packet.reason);
+  });
+  client.on('chat', function(packet) {
+    var jsonMsg = JSON.parse(packet.message);
+    if(jsonMsg.translate == 'chat.type.announcement' || jsonMsg.translate == 'chat.type.text') {
+      var username = jsonMsg.with[0].text;
+      var msg = jsonMsg.with[1];
+      if(username === client.username) return;
+      client.write('chat', {message: msg});
+    }
+  });
+});

examples/client_auto/package.json

@@ -0,0 +1,8 @@
+{
+  "name": "node-minecraft-protocol-example",
+  "version": "0.0.0",
+  "private": true,
+  "dependencies": {
+  },
+  "description": "A node-minecraft-protocol example"
+}

src/createClientAuto.js

@@ -0,0 +1,64 @@
+'use strict';
+
+var ping = require('./ping');
+var assert = require('assert');
+var debug = require('./debug');
+var createClient = require('./createClient');
+
+// see http://wiki.vg/Protocol_version_numbers
+// Get the minecraft-data version string for a protocol version
+// TODO: switch to using https://github.com/PrismarineJS/minecraft-data/pull/92
+function protocol2version(n) {
+  if (n >= 48) return '1.9'; // 1.9 snapshots (15w+), 16w03a is 96
+  if (n >= 6 && n <= 47) return '1.8.9'; // including 1.8 snapshots (14w)
+  if (n >= 4 && n <= 5) return '1.7.10'; // including 1.7 prereleases
+  // TODO: earlier versions "Beginning with the 1.7.1 pre-release (and release 1.7.2), versioning was reset."
+  throw new Error(`unsupported/unknown protocol version: ${versionProtocol}, update protocol2version`);
+}
+
+function createClientAsync(options, cb) {
+  assert.ok(options, 'options is required');
+
+  debug('pinging',options.host);
+  // TODO: refactor with DNS SRV lookup in NMP
+  // TODO: detect ping timeout, https://github.com/PrismarineJS/node-minecraft-protocol/issues/329
+  ping(options, function(err, response) {
+    var client;
+
+    if (err) return cb(err, null);
+    debug('ping response',response);
+    // TODO: could also use ping pre-connect to save description, type, negotiate protocol etc.
+    //  ^ see https://github.com/PrismarineJS/node-minecraft-protocol/issues/327
+    var motd = response.description;
+    debug('Server description:',motd); // TODO: save
+
+    // Pass server-reported version to protocol handler
+    // The version string is interpereted by https://github.com/PrismarineJS/node-minecraft-data
+    var versionName = response.version.name;        // 1.8.9, 1.7.10
+    var versionProtocol = response.version.protocol;//    47,      5
+
+    debug(`Server version: ${versionName}, protocol: ${versionProtocol}`);
+    // Note that versionName is a descriptive version stirng like '1.8.9' on vailla, but other
+    // servers add their own name (Spigot 1.8.8, Glowstone++ 1.8.9) so we cannot use it directly,
+    // even though it is in a format accepted by minecraft-data. Instead, translate the protocol.
+    options.version = protocol2version(versionProtocol);
+
+    // Use the exact same protocol version
+    // Requires https://github.com/PrismarineJS/node-minecraft-protocol/pull/330
+    options.protocolVersion = versionProtocol;
+
+    if (response.modinfo && response.modinfo.type === 'FML') {
+      // Use the list of Forge mods from the server ping, so client will match server
+      var forgeMods = response.modinfo.modList;
+      debug('Using forgeMods:',forgeMods);
+      // TODO: https://github.com/PrismarineJS/node-minecraft-protocol/issues/114
+      //  https://github.com/PrismarineJS/node-minecraft-protocol/pull/326
+      throw new Error('FML/Forge not yet supported');
+    } else {
+      client = createClient(options); // vanilla
+    }
+    cb(null, client);
+  });
+}
+
+module.exports = createClientAsync;

src/index.js

@@ -2,10 +2,12 @@ var Client = require('./client');
 var Server = require('./server');
 var serializer = require("./transforms/serializer");
 var createClient = require("./createClient");
+var createClientAuto = require("./createClientAuto");
 var createServer = require("./createServer");
 
 module.exports = {
   createClient: createClient,
+  createClientAuto: createClientAuto,
   createServer: createServer,
   Client: Client,
   Server: Server,