9.0.4

common/lib/src/util/backend.dart

@@ -0,0 +1,165 @@
+import 'dart:io';
+
+import 'package:ini/ini.dart';
+import 'package:reboot_common/common.dart';
+import 'package:shelf/shelf_io.dart';
+import 'package:shelf_proxy/shelf_proxy.dart';
+import 'package:sync/semaphore.dart';
+
+final Directory backendDirectory = Directory("${assetsDirectory.path}\\backend");
+final File backendStartExecutable = File("${backendDirectory.path}\\lawinserver.exe");
+final File matchmakerConfigFile = File("${backendDirectory.path}\\Config\\config.ini");
+final Semaphore _semaphore = Semaphore();
+String? _lastIp;
+String? _lastPort;
+
+Future<Process> startEmbeddedBackend(bool detached) async => startProcess(
+    executable: backendStartExecutable,
+    window: detached,
+);
+
+Future<HttpServer> startRemoteBackendProxy(Uri uri) async => await serve(proxyHandler(uri), kDefaultBackendHost, kDefaultBackendPort);
+
+Future<bool> isBackendPortFree() async => await pingBackend(kDefaultBackendHost, kDefaultBackendPort) == null;
+
+Future<bool> freeBackendPort() async {
+  await killProcessByPort(kDefaultBackendPort);
+  final standardResult = await isBackendPortFree();
+  if(standardResult) {
+    return true;
+  }
+
+  return false;
+}
+
+Future<Uri?> pingBackend(String host, int port, [bool https=false]) async {
+  var hostName = _getHostName(host);
+  var declaredScheme = _getScheme(host);
+  try{
+    var uri = Uri(
+        scheme: declaredScheme ?? (https ? "https" : "http"),
+        host: hostName,
+        port: port,
+        path: "unknown"
+    );
+    var client = HttpClient()
+      ..connectionTimeout = const Duration(seconds: 5);
+    var request = await client.getUrl(uri);
+    var response = await request.close();
+    return response.statusCode == 200 || response.statusCode == 404 ? uri : null;
+  }catch(_){
+    return https || declaredScheme != null || isLocalHost(host) ? null : await pingBackend(host, port, true);
+  }
+}
+
+String? _getHostName(String host) => host.replaceFirst("http://", "").replaceFirst("https://", "");
+
+String? _getScheme(String host) => host.startsWith("http://") ? "http" : host.startsWith("https://") ? "https" : null;
+
+Stream<String?> watchMatchmakingIp() async* {
+  if(!matchmakerConfigFile.existsSync()){
+    return;
+  }
+
+  var observer = matchmakerConfigFile.parent.watch(events: FileSystemEvent.modify);
+  yield* observer.where((event) => event.path == matchmakerConfigFile.path).asyncMap((event) async {
+    try {
+      var config = Config.fromString(await matchmakerConfigFile.readAsString());
+      var ip = config.get("GameServer", "ip");
+      if(ip == null) {
+        return null;
+      }
+
+      var port = config.get("GameServer", "port");
+      if(port == null) {
+        return null;
+      }
+
+      if(_lastIp == ip && _lastPort == port) {
+        return null;
+      }
+
+      return port == kDefaultGameServerPort ? ip : "$ip:$port";
+    }finally {
+      try {
+        _semaphore.release();
+      } on StateError catch(_) {
+        // Intended behaviour
+      }
+    }
+  });
+}
+
+Future<void> writeMatchmakingIp(String text) async {
+  var exists = await matchmakerConfigFile.exists();
+  if(!exists) {
+    return;
+  }
+
+  _semaphore.acquire();
+  var splitIndex = text.indexOf(":");
+  var ip = splitIndex != -1 ? text.substring(0, splitIndex) : text;
+  var port = splitIndex != -1 ? text.substring(splitIndex + 1) : kDefaultGameServerPort;
+  if(port.isBlank) {
+    port = kDefaultGameServerPort;
+  }
+
+  _lastIp = ip;
+  _lastPort = port;
+  var config = Config.fromString(await matchmakerConfigFile.readAsString());
+  config.set("GameServer", "ip", ip);
+  config.set("GameServer", "port", port);
+  await matchmakerConfigFile.writeAsString(config.toString(), flush: true);
+}
+
+Future<bool> isMatchmakerPortFree() async => await pingMatchmaker(kDefaultMatchmakerHost, kDefaultMatchmakerPort) == null;
+
+Future<bool> freeMatchmakerPort() async {
+  await killProcessByPort(kDefaultMatchmakerPort);
+  final standardResult = await isMatchmakerPortFree();
+  if(standardResult) {
+    return true;
+  }
+
+  return false;
+}
+
+Future<Uri?> pingMatchmaker(String host, int port, [bool wss=false]) async {
+  var hostName = _getHostName(host);
+  var declaredScheme = _getScheme(host);
+  try{
+    var uri = Uri(
+        scheme: declaredScheme ?? (wss ? "wss" : "ws"),
+        host: hostName,
+        port: port
+    );
+    var completer = Completer<bool>();
+    var socket = await WebSocket.connect(uri.toString());
+    socket.listen(
+          (data) {
+        if(!completer.isCompleted) {
+          completer.complete(true);
+        }
+      },
+      onError: (error) {
+        if(!completer.isCompleted) {
+          completer.complete(false);
+        }
+      },
+      onDone: () {
+        if(!completer.isCompleted) {
+          completer.complete(false);
+        }
+      },
+    );
+    var result = await completer.future;
+    await socket.close();
+    return result ? uri : null;
+  }catch(_){
+    return wss || declaredScheme != null || isLocalHost(host) ? null : await pingMatchmaker(host, port, true);
+  }
+}
+
+String? _getHostName(String host) => host.replaceFirst("ws://", "").replaceFirst("wss://", "");
+
+String? _getScheme(String host) => host.startsWith("ws://") ? "ws" : host.startsWith("wss://") ? "wss" : null;