+package net.pterodactylus.fcp.quelaton;
+
+import java.io.IOException;
+import java.util.Optional;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.concurrent.atomic.AtomicReference;
+
+import net.pterodactylus.fcp.IdentifierCollision;
+import net.pterodactylus.fcp.SubscribeUSK;
+import net.pterodactylus.fcp.SubscribedUSK;
+
+import com.google.common.util.concurrent.ListenableFuture;
+import com.google.common.util.concurrent.ListeningExecutorService;
+import com.google.common.util.concurrent.MoreExecutors;
+
+/**
+ * Default {@link SubscribeUskCommand} implementation based on {@link FcpDialog}.
+ *
+ * @author <a href="mailto:bombe@freenetproject.org">David ‘Bombe’ Roden</a>
+ */
+public class SubscribeUskCommandImpl implements SubscribeUskCommand {
+
+ private static final RandomIdentifierGenerator IDENTIFIER = new RandomIdentifierGenerator();
+ private final ListeningExecutorService threadPool;
+ private final ConnectionSupplier connectionSupplier;
+ private final SubscribeUSK subscribeUSK = new SubscribeUSK(IDENTIFIER.generate());
+
+ public SubscribeUskCommandImpl(ExecutorService threadPool, ConnectionSupplier connectionSupplier) {
+ this.threadPool = MoreExecutors.listeningDecorator(threadPool);
+ this.connectionSupplier = connectionSupplier;
+ }
+
+ @Override
+ public Executable<Optional<UskSubscription>> uri(String uri) {
+ subscribeUSK.setUri(uri);
+ return this::execute;
+ }
+
+ private ListenableFuture<Optional<UskSubscription>> execute() {
+ return threadPool.submit(this::executeDialog);
+ }
+
+ private Optional<UskSubscription> executeDialog() throws IOException, ExecutionException, InterruptedException {
+ try (SubscribeUskDialog subscribeUskDialog = new SubscribeUskDialog()) {
+ return subscribeUskDialog.send(subscribeUSK).get();
+ }
+ }
+
+ private class SubscribeUskDialog extends FcpDialog<Optional<UskSubscription>> {
+
+ private final AtomicBoolean finished = new AtomicBoolean();
+ private final AtomicReference<SubscribedUSK> subscribedUSK = new AtomicReference<>();
+
+ public SubscribeUskDialog() throws IOException {
+ super(threadPool, connectionSupplier.get());
+ }
+
+ @Override
+ protected boolean isFinished() {
+ return finished.get();
+ }
+
+ @Override
+ protected Optional<UskSubscription> getResult() {
+ return Optional.ofNullable(subscribedUSK.get()).map(subscribedUSK -> new UskSubscription() {
+ @Override
+ public String getUri() {
+ return subscribedUSK.getURI();
+ }
+ });
+ }
+
+ @Override
+ protected void consumeSubscribedUSK(SubscribedUSK subscribedUSK) {
+ this.subscribedUSK.set(subscribedUSK);
+ finished.set(true);
+ }
+
+ @Override
+ protected void consumeIdentifierCollision(IdentifierCollision identifierCollision) {
+ finished.set(true);
+ }
+
+ }
+
+}