Audience.java

/*
 * This file is part of adventure, licensed under the MIT License.
 *
 * Copyright (c) 2017-2021 KyoriPowered
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in all
 * copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */
package net.kyori.adventure.audience;

import java.util.Arrays;
import java.util.stream.Collector;
import net.kyori.adventure.bossbar.BossBar;
import net.kyori.adventure.identity.Identified;
import net.kyori.adventure.identity.Identity;
import net.kyori.adventure.inventory.Book;
import net.kyori.adventure.pointer.Pointered;
import net.kyori.adventure.sound.Sound;
import net.kyori.adventure.sound.SoundStop;
import net.kyori.adventure.text.Component;
import net.kyori.adventure.text.ComponentLike;
import net.kyori.adventure.title.Title;
import org.checkerframework.checker.nullness.qual.NonNull;

/**
 * A receiver of Minecraft media.
 *
 * <p><code>Audience</code> is designed to be a universal interface for any player,
 * command sender, console, or otherwise who can receive text, titles,
 * boss bars, and other Minecraft media. It is also designed for a group of
 * receivers such as a team, server, world, or permission.</p>
 * <p>In the past, Minecraft platforms have typically reserved methods such as
 * <code>showTitle</code> for a <code>Player</code> interface. While this is good
 * textbook object-oriented design, it presents two key drawbacks: 1) there
 * is no abstraction for groups of players, such as a <code>Server</code> or a
 * <code>Team</code> and 2) it add boilerplate for handling special cases like
 * console or command senders.</p>
 * <p>Consider the use-case of sending a message and title to every player on a
 * server, and also sending a message to console. Without an <code>Audience</code>,
 * the code might look like this:</p>
 * <pre>
 *   Server server;
 *   for (Player player : server.getPlayers()) {
 *     player.sendMessage(...);
 *     player.showTitle(...);
 *   }
 *   server.getConsole().sendMessage(...);</pre>
 * <p>Now, if <code>Server</code> implemented <code>Audience</code>, its unified interface
 * would allow users to easily send media without if-guarding console or
 * iterating through the list of players:</p>
 * <pre>
 *   Server server;
 *   server.sendMessage(...); // Sends a message to players and console
 *   server.showTitle(...); // Shows a title to players, silently ignored by console</pre>
 * <p>When an <code>Audience</code> is unable to perform an operation, such as sending
 * a boss bar to console, it will silently fail, without logging. This
 * requirement allows users to easily send media to a group of
 * <code>Audience</code>s without checking each for compatibility.</p>
 * <p>While the scope of <code>Audience</code> may be expanded in the future to support
 * new Minecraft media such as the player list, its interface will remain stateless
 * and any new methods will be stubbed by default.</p>
 *
 * @see ForwardingAudience
 * @since 4.0.0
 */
public interface Audience extends Pointered {
  /**
   * Gets an audience that does nothing.
   *
   * @return a do-nothing audience
   * @since 4.0.0
   */
  static @NonNull Audience empty() {
    return EmptyAudience.INSTANCE;
  }

  /**
   * Creates an audience that forwards to many other audiences.
   *
   * @param audiences an array of audiences, can be empty
   * @return an audience
   * @see ForwardingAudience
   * @since 4.0.0
   */
  static @NonNull Audience audience(final @NonNull Audience@NonNull... audiences) {
    final int length = audiences.length;
    if(length == 0) {
      return empty();
    } else if(length == 1) {
      return audiences[0];
    }
    return audience(Arrays.asList(audiences));
  }

  /**
   * Creates an audience that forwards to many other audiences.
   *
   * <p>The underlying <code>Iterable</code> is not copied, therefore any changes
   * made will be reflected in <code>Audience</code>.</p>
   *
   * @param audiences an iterable of audiences, can be empty
   * @return an audience
   * @see ForwardingAudience
   * @since 4.0.0
   */
  static @NonNull ForwardingAudience audience(final @NonNull Iterable<? extends Audience> audiences) {
    return () -> audiences;
  }

  /**
   * Provides a collector to create a forwarding audience from a stream of audiences.
   *
   * <p>The audience produced is immutable and can be reused as desired.</p>
   *
   * @return a collector to create a forwarding audience
   * @since 4.0.0
   */
  static @NonNull Collector<? super Audience, ?, ForwardingAudience> toAudience() {
    return Audiences.COLLECTOR;
  }

  /**
   * Sends a chat message with a {@link Identity#nil() nil} identity to this {@link Audience}.
   *
   * @param message a message
   * @see Component
   * @see #sendMessage(Identified, ComponentLike)
   * @see #sendMessage(Identity, ComponentLike)
   * @since 4.1.0
   */
  @ForwardingAudienceOverrideNotRequired
  default void sendMessage(final @NonNull ComponentLike message) {
    this.sendMessage(Identity.nil(), message);
  }

  /**
   * Sends a chat message from the given {@link Identified} to this {@link Audience}.
   *
   * @param source the source of the message
   * @param message a message
   * @see Component
   * @since 4.0.0
   */
  @ForwardingAudienceOverrideNotRequired
  default void sendMessage(final @NonNull Identified source, final @NonNull ComponentLike message) {
    this.sendMessage(source, message.asComponent());
  }

  /**
   * Sends a chat message from the entity represented by the given {@link Identity} (or the game using {@link Identity#nil()}) to this {@link Audience}.
   *
   * @param source the identity of the source of the message
   * @param message a message
   * @see Component
   * @since 4.0.0
   */
  @ForwardingAudienceOverrideNotRequired
  default void sendMessage(final @NonNull Identity source, final @NonNull ComponentLike message) {
    this.sendMessage(source, message.asComponent());
  }

  /**
   * Sends a chat message with a {@link Identity#nil() nil} identity to this {@link Audience}.
   *
   * @param message a message
   * @see Component
   * @see #sendMessage(Identified, Component)
   * @see #sendMessage(Identity, Component)
   * @since 4.1.0
   */
  @ForwardingAudienceOverrideNotRequired
  default void sendMessage(final @NonNull Component message) {
    this.sendMessage(Identity.nil(), message);
  }

  /**
   * Sends a chat message from the given {@link Identified} to this {@link Audience}.
   *
   * @param source the source of the message
   * @param message a message
   * @see Component
   * @since 4.0.0
   */
  @ForwardingAudienceOverrideNotRequired
  default void sendMessage(final @NonNull Identified source, final @NonNull Component message) {
    this.sendMessage(source, message, MessageType.SYSTEM);
  }

  /**
   * Sends a chat message from the entity represented by the given {@link Identity} (or the game using {@link Identity#nil()}) to this {@link Audience}.
   *
   * @param source the identity of the source of the message
   * @param message a message
   * @see Component
   * @since 4.0.0
   */
  @ForwardingAudienceOverrideNotRequired
  default void sendMessage(final @NonNull Identity source, final @NonNull Component message) {
    this.sendMessage(source, message, MessageType.SYSTEM);
  }

  /**
   * Sends a chat message with a {@link Identity#nil() nil} identity to this {@link Audience}.
   *
   * @param message a message
   * @param type the type
   * @see Component
   * @see #sendMessage(Identified, ComponentLike, MessageType)
   * @see #sendMessage(Identity, ComponentLike, MessageType)
   * @since 4.1.0
   */
  @ForwardingAudienceOverrideNotRequired
  default void sendMessage(final @NonNull ComponentLike message, final @NonNull MessageType type) {
    this.sendMessage(Identity.nil(), message, type);
  }

  /**
   * Sends a chat message from the given {@link Identified} to this {@link Audience}.
   *
   * @param source the source of the message
   * @param message a message
   * @param type the type
   * @see Component
   * @since 4.0.0
   */
  @ForwardingAudienceOverrideNotRequired
  default void sendMessage(final @NonNull Identified source, final @NonNull ComponentLike message, final @NonNull MessageType type) {
    this.sendMessage(source, message.asComponent(), type);
  }

  /**
   * Sends a chat message from the entity represented by the given {@link Identity} (or the game using {@link Identity#nil()}) to this {@link Audience}.
   *
   * @param source the identity of the source of the message
   * @param message a message
   * @param type the type
   * @see Component
   * @since 4.0.0
   */
  @ForwardingAudienceOverrideNotRequired
  default void sendMessage(final @NonNull Identity source, final @NonNull ComponentLike message, final @NonNull MessageType type) {
    this.sendMessage(source, message.asComponent(), type);
  }

  /**
   * Sends a chat message with a {@link Identity#nil() nil} identity to this {@link Audience}.
   *
   * @param message a message
   * @param type the type
   * @see Component
   * @see #sendMessage(Identified, Component, MessageType)
   * @see #sendMessage(Identity, Component, MessageType)
   * @since 4.1.0
   */
  @ForwardingAudienceOverrideNotRequired
  default void sendMessage(final @NonNull Component message, final @NonNull MessageType type) {
    this.sendMessage(Identity.nil(), message, type);
  }

  /**
   * Sends a chat message.
   *
   * @param source the source of the message
   * @param message a message
   * @param type the type
   * @see Component
   * @since 4.0.0
   */
  default void sendMessage(final @NonNull Identified source, final @NonNull Component message, final @NonNull MessageType type) {
    this.sendMessage(source.identity(), message, type);
  }

  /**
   * Sends a chat message.
   *
   * @param source the identity of the source of the message
   * @param message a message
   * @param type the type
   * @see Component
   * @since 4.0.0
   */
  default void sendMessage(final @NonNull Identity source, final @NonNull Component message, final @NonNull MessageType type) {
  }

  /**
   * Sends a message on the action bar.
   *
   * @param message a message
   * @see Component
   * @since 4.0.0
   */
  @ForwardingAudienceOverrideNotRequired
  default void sendActionBar(final @NonNull ComponentLike message) {
    this.sendActionBar(message.asComponent());
  }

  /**
   * Sends a message on the action bar.
   *
   * @param message a message
   * @see Component
   * @since 4.0.0
   */
  default void sendActionBar(final @NonNull Component message) {
  }

  /**
   * Sends the player list header.
   *
   * <p>Depending on the implementation of this {@code Audience}, an existing footer may be displayed. If you wish
   * to set both the header and the footer, please use {@link #sendPlayerListHeaderAndFooter(ComponentLike, ComponentLike)}.</p>
   *
   * @param header the header
   * @since 4.3.0
   */
  @ForwardingAudienceOverrideNotRequired
  default void sendPlayerListHeader(final @NonNull ComponentLike header) {
    this.sendPlayerListHeader(header.asComponent());
  }

  /**
   * Sends the player list header.
   *
   * <p>Depending on the implementation of this {@code Audience}, an existing footer may be displayed. If you wish
   * to set both the header and the footer, please use {@link #sendPlayerListHeaderAndFooter(Component, Component)}.</p>
   *
   * @param header the header
   * @since 4.3.0
   */
  default void sendPlayerListHeader(final @NonNull Component header) {
    this.sendPlayerListHeaderAndFooter(header, Component.empty());
  }

  /**
   * Sends the player list footer.
   *
   * <p>Depending on the implementation of this {@code Audience}, an existing footer may be displayed. If you wish
   * to set both the header and the footer, please use {@link #sendPlayerListHeaderAndFooter(ComponentLike, ComponentLike)}.</p>
   *
   * @param footer the footer
   * @since 4.3.0
   */
  @ForwardingAudienceOverrideNotRequired
  default void sendPlayerListFooter(final @NonNull ComponentLike footer) {
    this.sendPlayerListFooter(footer.asComponent());
  }

  /**
   * Sends the player list footer.
   *
   * <p>Depending on the implementation of this {@code Audience}, an existing footer may be displayed. If you wish
   * to set both the header and the footer, please use {@link #sendPlayerListHeaderAndFooter(Component, Component)}.</p>
   *
   * @param footer the footer
   * @since 4.3.0
   */
  default void sendPlayerListFooter(final @NonNull Component footer) {
    this.sendPlayerListHeaderAndFooter(Component.empty(), footer);
  }

  /**
   * Sends the player list header and footer.
   *
   * @param header the header
   * @param footer the footer
   * @since 4.3.0
   */
  @ForwardingAudienceOverrideNotRequired
  default void sendPlayerListHeaderAndFooter(final @NonNull ComponentLike header, final @NonNull ComponentLike footer) {
    this.sendPlayerListHeaderAndFooter(header.asComponent(), footer.asComponent());
  }

  /**
   * Sends the player list header and footer.
   *
   * @param header the header
   * @param footer the footer
   * @since 4.3.0
   */
  default void sendPlayerListHeaderAndFooter(final @NonNull Component header, final @NonNull Component footer) {
  }

  /**
   * Shows a title.
   *
   * @param title a title
   * @see Title
   * @since 4.0.0
   */
  default void showTitle(final @NonNull Title title) {
  }

  /**
   * Clears the title, if one is being displayed.
   *
   * @see Title
   * @since 4.0.0
   */
  default void clearTitle() {
  }

  /**
   * Resets the title and timings back to their default.
   *
   * @see Title
   * @since 4.0.0
   */
  default void resetTitle() {
  }

  /**
   * Shows a boss bar.
   *
   * @param bar a boss bar
   * @see BossBar
   * @since 4.0.0
   */
  default void showBossBar(final @NonNull BossBar bar) {
  }

  /**
   * Hides a boss bar.
   *
   * @param bar a boss bar
   * @see BossBar
   * @since 4.0.0
   */
  default void hideBossBar(final @NonNull BossBar bar) {
  }

  /**
   * Plays a sound.
   *
   * @param sound a sound
   * @see Sound
   * @since 4.0.0
   */
  default void playSound(final @NonNull Sound sound) {
  }

  /**
   * Plays a sound at a location.
   *
   * @param sound a sound
   * @param x x coordinate
   * @param y y coordinate
   * @param z z coordinate
   * @see Sound
   * @since 4.0.0
   */
  default void playSound(final @NonNull Sound sound, final double x, final double y, final double z) {
  }

  /**
   * Stops a sound, or many sounds.
   *
   * @param stop a sound stop
   * @see SoundStop
   * @since 4.0.0
   */
  default void stopSound(final @NonNull SoundStop stop) {
  }

  /**
   * Opens a book.
   *
   * <p>When possible, no item should persist after closing the book.</p>
   *
   * @param book a book
   * @see Book
   * @since 4.0.0
   */
  @ForwardingAudienceOverrideNotRequired
  default void openBook(final Book.@NonNull Builder book) {
    this.openBook(book.build());
  }

  /**
   * Opens a book.
   *
   * <p>When possible, no item should persist after closing the book.</p>
   *
   * @param book a book
   * @see Book
   * @since 4.0.0
   */
  default void openBook(final @NonNull Book book) {
  }
}