logos-messaging-dart-bindings/lib/waku.dart

import 'dart:async';
import 'dart:ffi';
import 'package:ffi/ffi.dart';
import 'bindings.dart';

class Waku {
  final Pointer<Void> _context;

  Waku._(this._context);

  static Future<Waku> newInstance(String configJson) async {
    late final NativeCallable<WakuCallBackC> callback;

    final completer = Completer<CallbackResult>();
    void onCallCompleted(
        int callerRet, Pointer<Utf8> msg, int len, Pointer<Void> userData) {
      print("instance is created callback");
      completer.complete(CallbackResult()
        ..callerRet = callerRet
        ..msg = msg.toDartString(length: len));
      callback.close();
    }

    callback = NativeCallable<WakuCallBackC>.listener(onCallCompleted);

    final configPtr = configJson.toNativeUtf8();
    final context = waku_new(configPtr, callback.nativeFunction, nullptr);

    final callResult = await completer.future;

    malloc.free(configPtr);

    final wakuCompleter = Completer<Waku>();

    if (callResult.callerRet != 0) {
      print("Could not create instance");
      wakuCompleter
          .completeError('Failed to create Waku instance: ${callResult.msg}');
    } else {
      wakuCompleter.complete(Waku._(context));
    }

    return wakuCompleter.future;
  }

  Future<CallbackResult> destroyInstance() async {
    late final NativeCallable<WakuCallBackC> callback;

    final completer = Completer<CallbackResult>();
    void onCallCompleted(
        int callerRet, Pointer<Utf8> msg, int len, Pointer<Void> userData) {
      completer.complete(CallbackResult()
        ..callerRet = callerRet
        ..msg = msg.toDartString(length: len));
      callback.close();
    }

    callback = NativeCallable<WakuCallBackC>.listener(onCallCompleted);

    waku_destroy(_context, callback.nativeFunction, nullptr);

    return completer.future;
  }

  Future<CallbackResult> start() async {
    late final NativeCallable<WakuCallBackC> callback;

    final completer = Completer<CallbackResult>();
    void onCallCompleted(
        int callerRet, Pointer<Utf8> msg, int len, Pointer<Void> userData) {
      completer.complete(CallbackResult()
        ..callerRet = callerRet
        ..msg = msg.toDartString(length: len));
      callback.close();
    }

    callback = NativeCallable<WakuCallBackC>.listener(onCallCompleted);

    waku_start(_context, callback.nativeFunction, nullptr);

    return completer.future;
  }

  Future<CallbackResult> stop() async {
    late final NativeCallable<WakuCallBackC> callback;

    final completer = Completer<CallbackResult>();
    void onCallCompleted(
        int callerRet, Pointer<Utf8> msg, int len, Pointer<Void> userData) {
      completer.complete(CallbackResult()
        ..callerRet = callerRet
        ..msg = msg.toDartString(length: len));
      callback.close();
    }

    callback = NativeCallable<WakuCallBackC>.listener(onCallCompleted);

    waku_stop(_context, callback.nativeFunction, nullptr);

    return completer.future;
  }
}