Add bidirectional host bridge

lib/runtime/scripting/lua_dardo_script_engine.dart

@@ -3,6 +3,7 @@ import 'dart:async' as async;
 import 'package:lua_dardo_plus/lua.dart';
 
 import '../diagnostics/runtime_diagnostics.dart';
+import '../host/runtime_host_bridge.dart';
 import '../models/game_diff.dart';
 import '../models/runtime_event.dart';
 import '../network/runtime_network_manager.dart';
@@ -19,6 +20,7 @@ class LuaDardoScriptEngine implements ScriptEngine {
   late final Map<String, String> _moduleScripts;
   RuntimeScriptServices _services = const RuntimeScriptServices();
   int _networkRequestCounter = 0;
+  int _hostCallCounter = 0;
   final Set<String> _loadingModules = {};
 
   @override
@@ -28,6 +30,7 @@ class LuaDardoScriptEngine implements ScriptEngine {
   }) async {
     _services = services;
     _networkRequestCounter = 0;
+    _hostCallCounter = 0;
     final script = await package.readText(package.manifest.entry);
     _moduleScripts = {};
     for (final entry in package.manifest.modules.entries) {
@@ -135,6 +138,15 @@ class LuaDardoScriptEngine implements ScriptEngine {
     _lua.pushDartFunction(_wsClose);
     _lua.setField(-2, 'ws_close');
 
+    _lua.pushDartFunction(_hostCall);
+    _lua.setField(-2, 'host_call');
+
+    _lua.pushDartFunction(_hostNotify);
+    _lua.setField(-2, 'host_notify');
+
+    _lua.pushDartFunction(_hostRespond);
+    _lua.setField(-2, 'host_respond');
+
     _lua.setGlobal('runtime');
   }
 
@@ -204,6 +216,56 @@ class LuaDardoScriptEngine implements ScriptEngine {
     return 1;
   }
 
+  int _hostCall(LuaState lua) {
+    final host = _requireHostBridge();
+    final options = _requiredMapArgument(1, 'runtime.host_call(options)');
+    final method = _requiredString(options, 'method');
+    final id = _optionalString(options, 'id') ?? _nextHostCallId();
+    async.unawaited(
+      host.callHost(
+        RuntimeHostCall(id: id, method: method, data: options['data']),
+      ),
+    );
+    lua.pushString(id);
+    return 1;
+  }
+
+  int _hostNotify(LuaState lua) {
+    final host = _requireHostBridge();
+    final options = _requiredMapArgument(1, 'runtime.host_notify(options)');
+    final method = _requiredString(options, 'method');
+    lua.pushBoolean(
+      host.notifyHost(
+        RuntimeHostNotification(method: method, data: options['data']),
+      ),
+    );
+    return 1;
+  }
+
+  int _hostRespond(LuaState lua) {
+    final host = _requireHostBridge();
+    final options = _requiredMapArgument(1, 'runtime.host_respond(options)');
+    final id = _requiredString(options, 'id');
+    final error = _optionalString(options, 'error');
+    lua.pushBoolean(
+      host.completeLuaCall(id, result: options['result'], error: error),
+    );
+    return 1;
+  }
+
+  RuntimeHostBridgeManager _requireHostBridge() {
+    final hostBridge = _services.hostBridge;
+    if (hostBridge == null) {
+      throw StateError('Runtime host bridge service is not installed');
+    }
+    return hostBridge;
+  }
+
+  String _nextHostCallId() {
+    _hostCallCounter += 1;
+    return 'lua:$_hostCallCounter';
+  }
+
   RuntimeNetworkManager _requireNetwork() {
     final network = _services.network;
     if (network == null) {