tdlib-session-container/src/main/java/it/tdlight/tdlibsession/td/direct/AsyncTdDirectImpl.java

package it.tdlight.tdlibsession.td.direct;

import it.tdlight.common.TelegramClient;
import it.tdlight.jni.TdApi;
import it.tdlight.jni.TdApi.AuthorizationStateClosed;
import it.tdlight.jni.TdApi.Close;
import it.tdlight.jni.TdApi.Function;
import it.tdlight.jni.TdApi.Object;
import it.tdlight.jni.TdApi.Ok;
import it.tdlight.jni.TdApi.UpdateAuthorizationState;
import it.tdlight.tdlibsession.td.TdResult;
import it.tdlight.tdlight.ClientManager;
import it.tdlight.utils.MonoUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import reactor.core.publisher.Flux;
import reactor.core.publisher.Mono;
import reactor.core.publisher.Sinks;
import reactor.core.publisher.Sinks.One;
import reactor.core.scheduler.Schedulers;

public class AsyncTdDirectImpl implements AsyncTdDirect {

	private static final Logger logger = LoggerFactory.getLogger(AsyncTdDirect.class);

	private final One<TelegramClient> td = Sinks.one();

	private final String botAlias;

	public AsyncTdDirectImpl(String botAlias) {
		this.botAlias = botAlias;
	}

	@Override
	public <T extends TdApi.Object> Mono<TdResult<T>> execute(Function request, boolean synchronous) {
		if (synchronous) {
			return td.asMono().single().flatMap(td -> MonoUtils.fromBlockingSingle(() -> {
				if (td != null) {
					return TdResult.<T>of(td.execute(request));
				} else {
					if (request.getConstructor() == Close.CONSTRUCTOR) {
						return TdResult.<T>of(new Ok());
					}
					throw new IllegalStateException("TDLib client is destroyed");
				}
			}));
		} else {
			return td.asMono().single().flatMap(td -> Mono.<TdResult<T>>create(sink -> {
				if (td != null) {
					td.send(request, v -> sink.success(TdResult.of(v)), sink::error);
				} else {
					if (request.getConstructor() == Close.CONSTRUCTOR) {
						logger.trace("Sending close success to sink " + sink.toString());
						sink.success(TdResult.<T>of(new Ok()));
					} else {
						logger.trace("Sending close error to sink " + sink.toString());
						sink.error(new IllegalStateException("TDLib client is destroyed"));
					}
				}
			})).single();
		}
	}

	@Override
	public Flux<TdApi.Object> receive(AsyncTdDirectOptions options) {
		// If closed it will be either true or false
		final One<Boolean> closedFromTd = Sinks.one();
		return Flux.<TdApi.Object>create(emitter -> {
			var client = ClientManager.create((Object object) -> {
				emitter.next(object);
				// Close the emitter if receive closed state
				if (object.getConstructor() == UpdateAuthorizationState.CONSTRUCTOR
						&& ((UpdateAuthorizationState) object).authorizationState.getConstructor()
						== AuthorizationStateClosed.CONSTRUCTOR) {
					logger.debug("Received closed status from tdlib");
					closedFromTd.tryEmitValue(true);
					emitter.complete();
				}
			}, emitter::error, emitter::error);
			try {
				this.td.tryEmitValue(client).orThrow();
			} catch (Exception ex) {
				emitter.error(ex);
			}

			// Send close if the stream is disposed before tdlib is closed
			emitter.onDispose(() -> {
				// Try to emit false, so that if it has not been closed from tdlib, now it is explicitly false.
				closedFromTd.tryEmitValue(false);

				closedFromTd.asMono()
						.filter(isClosedFromTd -> !isClosedFromTd)
						.doOnNext(x -> {
							logger.warn("The stream has been disposed without closing tdlib. Sending TdApi.Close()...");
							client.send(new Close(),
									result -> logger.warn("Close result: {}", result),
									ex -> logger.error("Error when disposing td client", ex)
							);
						})
						.subscribeOn(Schedulers.single())
						.subscribe();
			});
		});
	}
}