add Interaction Object for Messages

src/main/java/net/dv8tion/jda/api/entities/Message.java

@@ -22,6 +22,7 @@
 import net.dv8tion.jda.api.Permission;
 import net.dv8tion.jda.api.exceptions.HttpException;
 import net.dv8tion.jda.api.exceptions.InsufficientPermissionException;
+import net.dv8tion.jda.api.interactions.InteractionType;
 import net.dv8tion.jda.api.interactions.components.ActionRow;
 import net.dv8tion.jda.api.interactions.components.Button;
 import net.dv8tion.jda.api.interactions.components.ComponentLayout;
@@ -2491,6 +2492,19 @@ default MessageAction reply(@Nonnull byte[] data, @Nonnull String name, @Nonnull
     @Nonnull
     MessageType getType();
 
+    /**
+     * This is sent on the message object when the message is a response to an {@link net.dv8tion.jda.api.interactions.Interaction Interaction} without an existing message.
+     *
+     * <p>This means responses to Message Components do not include this property, instead including a message reference object as components always exist on preexisting messages.
+     *
+     * @throws java.lang.UnsupportedOperationException
+     *         If this is a system message
+     *
+     * @return The {@link net.dv8tion.jda.api.entities.Message.Interaction Interaction} of this message.
+     */
+    @Nullable
+    Interaction getInteraction();
+
     /**
      * Mention constants, useful for use with {@link java.util.regex.Pattern Patterns}
      */
@@ -3055,4 +3069,87 @@ public boolean isSpoiler()
         }
 
     }
+
+    /**
+     * Represents an {@link net.dv8tion.jda.api.interactions.Interaction Interaction} provided with a {@link net.dv8tion.jda.api.entities.Message Message}.
+     */
+    class Interaction implements ISnowflake
+    {
+        private final long id;
+        private final int type;
+        private final String name;
+        private final User user;
+        private final Member member;
+
+        public Interaction(long id, int type, String name, User user, Member member)
+        {
+            this.id = id;
+            this.type = type;
+            this.name = name;
+            this.user = user;
+            this.member = member;
+        }
+
+        @Override
+        public long getIdLong()
+        {
+            return id;
+        }
+
+        /**
+         * The raw interaction type.
+         * <br>It is recommended to use {@link #getType()} instead.
+         *
+         * @return The raw interaction type
+         */
+        public int getTypeRaw()
+        {
+            return type;
+        }
+
+        /**
+         * The {@link net.dv8tion.jda.api.interactions.InteractionType} for this interaction.
+         *
+         * @return The {@link net.dv8tion.jda.api.interactions.InteractionType} or {@link net.dv8tion.jda.api.interactions.InteractionType#UNKNOWN}
+         */
+        @Nonnull
+        public InteractionType getType()
+        {
+            return InteractionType.fromKey(getTypeRaw());
+        }
+
+        /**
+         * The command name.
+         *
+         * @return The command name
+         */
+        @Nonnull
+        public String getName()
+        {
+            return name;
+        }
+
+        /**
+         * The {@link User} who caused this interaction.
+         *
+         * @return The {@link User}
+         */
+        @Nonnull
+        public User getUser()
+        {
+            return user;
+        }
+
+        /**
+         * The {@link Member} who caused this interaction.
+         * <br>This is null if the interaction is not from a guild.
+         *
+         * @return The {@link Member}
+         */
+        @Nullable
+        public Member getMember()
+        {
+            return member;
+        }
+    }
 }

src/main/java/net/dv8tion/jda/internal/entities/AbstractMessage.java

@@ -604,4 +604,12 @@ public MessageType getType()
         unsupported();
         return null;
     }
+
+    @Nullable
+    @Override
+    public Message.Interaction getInteraction()
+    {
+        unsupported();
+        return null;
+    }
 }

src/main/java/net/dv8tion/jda/internal/entities/EntityBuilder.java

@@ -1285,13 +1285,24 @@ else if (MISSING_CHANNEL.equals(ex.getMessage()))
                     .collect(Collectors.toList());
         }
 
+        Message.Interaction messageInteraction = null;
+        if (!jsonObject.isNull("interaction"))
+        {
+            GuildImpl guild = null;
+            if (channel instanceof GuildChannel)
+            {
+                guild = (GuildImpl) ((GuildChannel) (channel)).getGuild();
+            }
+            messageInteraction = createMessageInteraction(guild, jsonObject.getObject("interaction"));
+        }
+
         if (type == MessageType.UNKNOWN)
             throw new IllegalArgumentException(UNKNOWN_MESSAGE_TYPE);
         if (!type.isSystem())
         {
             message = new ReceivedMessage(id, channel, type, messageReference, fromWebhook,
                     mentionsEveryone, mentionedUsers, mentionedRoles, tts, pinned,
-                    content, nonce, user, member, activity, editTime, reactions, attachments, embeds, stickers, components, flags);
+                    content, nonce, user, member, activity, editTime, reactions, attachments, embeds, stickers, components, flags, messageInteraction);
         }
         else
         {
@@ -1536,6 +1547,29 @@ public MessageSticker createSticker(DataObject content)
         return new MessageSticker(id, name, description, packId, asset, format, tags);
     }
 
+    public Message.Interaction createMessageInteraction(GuildImpl guildImpl, DataObject content)
+    {
+        final long id = content.getLong("id");
+        final int type = content.getInt("type");
+        final String name = content.getString("name");
+        DataObject userJson = content.getObject("user");
+        User user = null;
+        MemberImpl member = null;
+        if (!content.isNull("member") && guildImpl != null)
+        {
+            DataObject memberJson = content.getObject("member");
+            memberJson.put("user", userJson);
+            member = createMember(guildImpl, memberJson);
+            user = member.getUser();
+        }
+        else
+        {
+            user = createUser(userJson);
+        }
+
+        return new Message.Interaction(id, type, name, user, member);
+    }
+
     @Nullable
     public PermissionOverride createPermissionOverride(DataObject override, AbstractChannelImpl<?, ?> chan)
     {

src/main/java/net/dv8tion/jda/internal/entities/ReceivedMessage.java

@@ -75,6 +75,7 @@ public class ReceivedMessage extends AbstractMessage
     protected final TLongSet mentionedUsers;
     protected final TLongSet mentionedRoles;
     protected final int flags;
+    protected final Message.Interaction interaction;
 
     protected InteractionHook interactionHook = null; // late-init
 
@@ -93,7 +94,7 @@ public ReceivedMessage(
         long id, MessageChannel channel, MessageType type, MessageReference messageReference,
         boolean fromWebhook, boolean mentionsEveryone, TLongSet mentionedUsers, TLongSet mentionedRoles, boolean tts, boolean pinned,
         String content, String nonce, User author, Member member, MessageActivity activity, OffsetDateTime editTime,
-        List<MessageReaction> reactions, List<Attachment> attachments, List<MessageEmbed> embeds, List<MessageSticker> stickers, List<ActionRow> components, int flags)
+        List<MessageReaction> reactions, List<Attachment> attachments, List<MessageEmbed> embeds, List<MessageSticker> stickers, List<ActionRow> components, int flags, Message.Interaction interaction)
     {
         super(content, nonce, tts);
         this.id = id;
@@ -116,6 +117,7 @@ public ReceivedMessage(
         this.mentionedUsers = mentionedUsers;
         this.mentionedRoles = mentionedRoles;
         this.flags = flags;
+        this.interaction = interaction;
     }
 
     public ReceivedMessage withHook(InteractionHook hook)
@@ -301,6 +303,13 @@ public MessageType getType()
         return type;
     }
 
+    @Nullable
+    @Override
+    public Interaction getInteraction()
+    {
+        return interaction;
+    }
+
     @Override
     public long getIdLong()
     {

src/main/java/net/dv8tion/jda/internal/entities/SystemMessage.java

@@ -38,7 +38,7 @@ public SystemMessage(
         List<MessageReaction> reactions, List<Attachment> attachments, List<MessageEmbed> embeds, List<MessageSticker> stickers, int flags)
     {
         super(id, channel, type, messageReference, fromWebhook, mentionsEveryone, mentionedUsers, mentionedRoles,
-            tts, pinned, content, nonce, author, member, activity, editTime, reactions, attachments, embeds, stickers, Collections.emptyList(), flags);
+            tts, pinned, content, nonce, author, member, activity, editTime, reactions, attachments, embeds, stickers, Collections.emptyList(), flags, null);
     }
 
     @Nonnull