Content of file MessageSupport.java

/*
 * *********************************************************************************************************************
 *
 * TheseFoolishThings: Miscellaneous utilities
 * http://tidalwave.it/projects/thesefoolishthings
 *
 * Copyright (C) 2009 - 2023 by Tidalwave s.a.s. (http://tidalwave.it)
 *
 * *********************************************************************************************************************
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
 * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations under the License.
 *
 * *********************************************************************************************************************
 *
 * git clone https://bitbucket.org/tidalwave/thesefoolishthings-src
 * git clone https://github.com/tidalwave-it/thesefoolishthings-src
 *
 * *********************************************************************************************************************
 */
package it.tidalwave.actor;

import javax.annotation.Nonnegative;
import javax.annotation.Nonnull;
import javax.inject.Provider;
import java.util.Optional;
import java.util.Timer;
import java.util.TimerTask;
import java.util.concurrent.TimeUnit;
import java.io.Serializable;
import it.tidalwave.actor.impl.DefaultCollaboration;
import it.tidalwave.actor.impl.Locator;
import it.tidalwave.actor.spi.CollaborationAwareMessageBus;
import it.tidalwave.util.As;
import lombok.EqualsAndHashCode;
import lombok.experimental.Delegate;
import lombok.extern.slf4j.Slf4j;
import static it.tidalwave.actor.MessageDecorator._MessageDecorator_;

/***********************************************************************************************************************
 *
 * A support class for implementing messages.
 *
 * @stereotype Message
 *
 * @author  Fabrizio Giudici
 *
 **********************************************************************************************************************/
@Slf4j @EqualsAndHashCode(of = "collaboration")
public abstract class MessageSupport implements Collaboration.Provider, As, Serializable
  {
    // TODO: @Inject
    private final Provider<CollaborationAwareMessageBus> messageBus =
            Locator.createProviderFor(CollaborationAwareMessageBus.class);

    @Nonnull
    protected final DefaultCollaboration collaboration;

    private final MessageDecorator sameMessageDecorator = new MessageDecorator.Same<>(this);

//    @Delegate // FIXME: use AsSupport
use AsSupport
//    private AsDelegate asDelegate = AsDelegateProvider.Locator.find().createAsDelegate(this);

    interface Exclusions
      {
        public <T> T maybeAs (Class<? extends T> type);
      }

    @Delegate(excludes = Exclusions.class)
    private final As as = As.forObject(this);

    /*******************************************************************************************************************
     *
     *
     *
     ******************************************************************************************************************/
    protected MessageSupport()
      {
        this.collaboration = DefaultCollaboration.getOrCreateCollaboration(this);
      }

    /*******************************************************************************************************************
     *
     * @param   collaboration   the collaboration
     *
     ******************************************************************************************************************/
    protected MessageSupport (@Nonnull final Collaboration collaboration)
      {
        this.collaboration = (DefaultCollaboration)collaboration;
      }

    /*******************************************************************************************************************
     *
     * Returns the {@link Collaboration} that this message is part of.
     *
     * @return  the {@code Collaboration}
     *
     ******************************************************************************************************************/
    @Override @Nonnull
    public Collaboration getCollaboration()
      {
        return collaboration;
      }

    /*******************************************************************************************************************
     *
     * Sends this message, eventually performing a replacement (see {@link MessageDecorator} for further info).
     *
     * @return  the {@code Collaboration} that this message is part of
     *
     ******************************************************************************************************************/
    @Nonnull @SuppressWarnings("UnusedReturnValue")
    public Collaboration send()
      {
        log.debug("send() - {}", this);
        return findDecoratedMessage().sendDirectly();
      }

    /*******************************************************************************************************************
     *
     * Sends this message directly, not performing any replacement (see {@link MessageDecorator} for further info).
     *
     * @return  the {@code Collaboration} that this message is part of
     *
     ******************************************************************************************************************/
    @Nonnull
    public Collaboration sendDirectly()
      {
        log.debug("sendDirectly() - {}", this);
        collaboration.registerDeliveringMessage(this);
        messageBus.get().publish(this);
        return collaboration;
      }

    /*******************************************************************************************************************
     *
     * Sends this message after a delay, eventually performing a replacement (see {@link MessageDecorator} for
     * further info).
     *
     * @param   delay     the delay
     * @param   timeUnit  the {@link TimeUnit} for the delay
     * @return            the {@code Collaboration} that this message is part of
     *
     ******************************************************************************************************************/
    @Nonnull
    public Collaboration sendLater (@Nonnegative final int delay, @Nonnull final TimeUnit timeUnit)
      {
        log.debug("sendLater({}, {}) - {}", delay, timeUnit, this);
        final var message = findDecoratedMessage();
        collaboration.registerDeliveringMessage(message);

        new Timer().schedule(new TimerTask()
          {
            @Override
            public void run()
              {
                messageBus.get().publish(message);
              }
          }, TimeUnit.MILLISECONDS.convert(delay, timeUnit));

        return collaboration;
      }

    /*******************************************************************************************************************
     *
     * {@inheritDoc}
     *
     ******************************************************************************************************************/
    @Override @Nonnull
    public <T> Optional<T> maybeAs (@Nonnull final Class<? extends T> type)
      {
        final Optional<T> t = as.maybeAs(type);

        return t.isPresent()
               ? t
               : type.equals(MessageDecorator.class) ? Optional.of(type.cast(sameMessageDecorator)) : Optional.empty();
      }

    /*******************************************************************************************************************
     *
     *
     *
     ******************************************************************************************************************/
    @Nonnull
    private MessageSupport findDecoratedMessage()
      {
        final var decoratedMessage = this.as(_MessageDecorator_).getDecoratedMessage();
        return (decoratedMessage == this) ? this : decoratedMessage.findDecoratedMessage();
//        MessageSupport decoratedMessage = this.as(_MessageDecorator_).getDecoratedMessage();
//
//        if (decoratedMessage != this)
//          {
//            log.info("MESSAGE HAS BEEN DECORATED: {} -> {}", this, decoratedMessage);
//            decoratedMessage = decoratedMessage.findDecoratedMessage();
//          }
//
//        return decoratedMessage;
      }
 }