Hacky User Installable Apps support

This is a prototype only for fun, a lot of checks were removed and user installable apps when used in a guild that doesn't have the bot just acts like it is a private channel

README.md

@@ -21,7 +21,9 @@ Keep in mind that this repo is constantly `git reset --hard`'d, we always reset
 * Added `JDA#shutdown(closeCode)` and `JDA#shutdownNow(closeCode)`, which is useful if you want to shutdown the WebSocket but don't want to invalidate your current session.
 * Added `getId()` to `StickerFormat`
 * Changed `WebSocketClient#handleEvent` from `protected` to `public`
+* Hacky User Installable Apps support
+    * This is a prototype only for fun, a lot of checks were removed and user installable apps when used in a guild that doesn't have the bot just acts like it is a private channel. Use `setIntegrationTypes(...)` and `setInteractionContextTypes(...)` when registering a command to enable commands in DM and group DMs.
 
 ## 👀 Examples
 
-* [Bot with Session Checkpoint and Gateway Resuming](/src/examples/java/SessionCheckpointAndGatewayResumeExample.kt)
+* [Bot with Session Checkpoint and Gateway Resuming](/src/examples/java/SessionCheckpointAndGatewayResumeExample.kt)

src/main/java/net/dv8tion/jda/api/interactions/commands/Command.java

@@ -284,6 +284,67 @@ public int getId()
         }
     }
 
+    enum IntegrationType
+    {
+        UNKNOWN(-1),
+        GUILD_INSTALL(0),
+        USER_INSTALL(1);
+
+        private final int id;
+
+        IntegrationType(int id)
+        {
+            this.id = id;
+        }
+
+        @Nonnull
+        public static IntegrationType fromId(int id)
+        {
+            for (IntegrationType type : values())
+            {
+                if (type.id == id)
+                    return type;
+            }
+            return UNKNOWN;
+        }
+
+        public int getId()
+        {
+            return id;
+        }
+    }
+
+    enum InteractionContextType
+    {
+        UNKNOWN(-1),
+        GUILD(0),
+        BOT_DM(1),
+        PRIVATE_CHANNEL(2);
+
+        private final int id;
+
+        InteractionContextType(int id)
+        {
+            this.id = id;
+        }
+
+        @Nonnull
+        public static InteractionContextType fromId(int id)
+        {
+            for (InteractionContextType type : values())
+            {
+                if (type.id == id)
+                    return type;
+            }
+            return UNKNOWN;
+        }
+
+        public int getId()
+        {
+            return id;
+        }
+    }
+
     /**
      * Predefined choice used for options.
      *

src/main/java/net/dv8tion/jda/api/interactions/commands/build/CommandData.java

@@ -29,6 +29,7 @@
 
 import javax.annotation.Nonnull;
 import java.util.Collection;
+import java.util.EnumSet;
 import java.util.Map;
 
 /**
@@ -167,6 +168,12 @@ public interface CommandData extends SerializableData
     @Nonnull
     CommandData setNSFW(boolean nsfw);
 
+    @Nonnull
+    CommandData setIntegrationTypes(@Nonnull Command.IntegrationType integrationType, @Nonnull Command.IntegrationType... integrationTypes);
+
+    @Nonnull
+    CommandData setInteractionContextTypes(@Nonnull Command.InteractionContextType interactionContextType, @Nonnull Command.InteractionContextType... interactionContextTypes);
+
     /**
      * The current command name
      *
@@ -203,6 +210,12 @@ public interface CommandData extends SerializableData
     @Nonnull
     DefaultMemberPermissions getDefaultPermissions();
 
+    @Nonnull
+    EnumSet<Command.IntegrationType> getIntegrationTypes();
+
+    @Nonnull
+    EnumSet<Command.InteractionContextType> getInteractionContextTypes();
+
     /**
      * Whether the command can only be used inside a guild.
      * <br>Always true for guild commands.

src/main/java/net/dv8tion/jda/api/interactions/commands/build/SlashCommandData.java

@@ -28,9 +28,11 @@
 import net.dv8tion.jda.internal.interactions.CommandDataImpl;
 import net.dv8tion.jda.internal.utils.Checks;
 import net.dv8tion.jda.internal.utils.localization.LocalizationUtils;
+import org.jetbrains.annotations.NotNull;
 
 import javax.annotation.Nonnull;
 import java.util.Collection;
+import java.util.EnumSet;
 import java.util.List;
 import java.util.Map;
 import java.util.function.Predicate;
@@ -122,6 +124,14 @@ public interface SlashCommandData extends CommandData
     @Nonnull
     SlashCommandData setDescriptionLocalizations(@Nonnull Map<DiscordLocale, String> map);
 
+    @Nonnull
+    @Override
+    CommandData setIntegrationTypes(@Nonnull Command.IntegrationType integrationType, @Nonnull Command.IntegrationType... integrationTypes);
+
+    @Nonnull
+    @Override
+    CommandData setInteractionContextTypes(@Nonnull Command.InteractionContextType interactionContextType, @Nonnull Command.InteractionContextType... interactionContextTypes);
+
     /**
      * The configured description
      *
@@ -138,6 +148,14 @@ public interface SlashCommandData extends CommandData
     @Nonnull
     LocalizationMap getDescriptionLocalizations();
 
+    @Nonnull
+    @Override
+    EnumSet<Command.IntegrationType> getIntegrationTypes();
+
+    @Nonnull
+    @Override
+    EnumSet<Command.InteractionContextType> getInteractionContextTypes();
+
     /**
      * Removes all options that evaluate to {@code true} under the provided {@code condition}.
      * <br>This will not affect options within subcommands.

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

@@ -1508,6 +1508,11 @@ public PrivateChannel createPrivateChannel(DataObject json)
     }
 
     public PrivateChannel createPrivateChannel(DataObject json, UserImpl user)
+    {
+        return createPrivateChannel(json, user, true);
+    }
+
+    public PrivateChannel createPrivateChannel(DataObject json, UserImpl user, boolean addChannelToCache)
     {
         final long channelId = json.getUnsignedLong("id");
         PrivateChannelImpl channel = (PrivateChannelImpl) api.getPrivateChannelById(channelId);
@@ -1542,9 +1547,12 @@ public PrivateChannel createPrivateChannel(DataObject json, UserImpl user)
         {
             recipient.setPrivateChannel(channel);
         }
-        // only add channels to the cache when they come from an event, otherwise we would never remove the channel
-        cachePrivateChannel(channel);
-        api.usedPrivateChannel(channelId);
+        if (addChannelToCache)
+        {
+            // only add channels to the cache when they come from an event, otherwise we would never remove the channel
+            cachePrivateChannel(channel);
+            api.usedPrivateChannel(channelId);
+        }
         return channel;
     }
 

src/main/java/net/dv8tion/jda/internal/handle/InteractionCreateHandler.java

@@ -65,17 +65,19 @@ protected Long handleInternally(DataObject content)
         Guild guild = api.getGuildById(guildId);
         if (api.getGuildSetupController().isLocked(guildId))
             return guildId;
-        if (guildId != 0 && guild == null)
-            return null; // discard event if it is not from a guild we are currently in
+        // Don't discard - Interactions with user installed bots may happen in guilds that we aren't in
+        // if (guildId != 0 && guild == null)
+        //     return null; // discard event if it is not from a guild we are currently in
 
         // Check channel type
         DataObject channelJson = content.getObject("channel");
         ChannelType channelType = ChannelType.fromId(channelJson.getInt("type"));
-        if (!channelType.isMessage() || channelType == ChannelType.GROUP)
-        {
-            WebSocketClient.LOG.debug("Discarding INTERACTION_CREATE event from unexpected channel type. Channel: {}", channelJson);
-            return null;
-        }
+        // Don't discard - Interactions with user installed bots may happen in GDMs
+        // if (!channelType.isMessage() || channelType == ChannelType.GROUP)
+        // {
+        //     WebSocketClient.LOG.debug("Discarding INTERACTION_CREATE event from unexpected channel type. Channel: {}", channelJson);
+        //     return null;
+        // }
 
         switch (InteractionType.fromKey(type))
         {

src/main/java/net/dv8tion/jda/internal/interactions/CommandDataImpl.java

@@ -29,10 +29,12 @@
 import net.dv8tion.jda.internal.interactions.command.localization.LocalizationMapper;
 import net.dv8tion.jda.internal.utils.Checks;
 import net.dv8tion.jda.internal.utils.Helpers;
+import org.jetbrains.annotations.NotNull;
 
 import javax.annotation.Nonnull;
 import java.util.*;
 import java.util.function.Predicate;
+import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
 public class CommandDataImpl implements SlashCommandData
@@ -50,6 +52,9 @@ public class CommandDataImpl implements SlashCommandData
     private boolean guildOnly = false;
     private boolean nsfw = false;
     private DefaultMemberPermissions defaultMemberPermissions = DefaultMemberPermissions.ENABLED;
+    private EnumSet<Command.IntegrationType> integrationTypes = EnumSet.of(Command.IntegrationType.GUILD_INSTALL);
+    // TODO: This is actually not "all", the docs says that it registers all contexts by default but in my experience that's not what happens
+    private EnumSet<Command.InteractionContextType> contexts = EnumSet.of(Command.InteractionContextType.GUILD, Command.InteractionContextType.BOT_DM, Command.InteractionContextType.PRIVATE_CHANNEL);
 
     private final Command.Type type;
 
@@ -108,7 +113,9 @@ public DataObject toData()
                 .put("default_member_permissions", defaultMemberPermissions == DefaultMemberPermissions.ENABLED
                         ? null
                         : Long.toUnsignedString(defaultMemberPermissions.getPermissionsRaw()))
-                .put("name_localizations", nameLocalizations);
+                .put("name_localizations", nameLocalizations)
+                .put("integration_types", DataArray.fromCollection(integrationTypes.stream().map(Command.IntegrationType::getId).collect(Collectors.toList())))
+                .put("contexts", DataArray.fromCollection(contexts.stream().map(Command.InteractionContextType::getId).collect(Collectors.toList())));
 
         if (type == Command.Type.SLASH)
         {
@@ -132,6 +139,20 @@ public DefaultMemberPermissions getDefaultPermissions()
         return defaultMemberPermissions;
     }
 
+    @NotNull
+    @Override
+    public EnumSet<Command.IntegrationType> getIntegrationTypes()
+    {
+        return EnumSet.copyOf(integrationTypes);
+    }
+
+    @NotNull
+    @Override
+    public EnumSet<Command.InteractionContextType> getInteractionContextTypes()
+    {
+        return EnumSet.copyOf(contexts);
+    }
+
     @Override
     public boolean isGuildOnly()
     {
@@ -199,6 +220,28 @@ public CommandDataImpl setNSFW(boolean nsfw)
         return this;
     }
 
+    @Nonnull
+    @Override
+    public CommandData setIntegrationTypes(@Nonnull Command.IntegrationType integrationType, @Nonnull Command.IntegrationType... integrationTypes)
+    {
+        Checks.notNull(integrationType, "Integration Type");
+        Checks.noneNull(integrationTypes, "Integration Type");
+        EnumSet<Command.IntegrationType> set = EnumSet.of(integrationType, integrationTypes);
+        this.integrationTypes = set;
+        return this;
+    }
+
+    @Nonnull
+    @Override
+    public CommandData setInteractionContextTypes(@Nonnull Command.InteractionContextType interactionContextType, @Nonnull Command.InteractionContextType... interactionContextTypes)
+    {
+        Checks.notNull(interactionContextType, "Interaction Context Type");
+        Checks.noneNull(interactionContextTypes, "Interaction Context Type");
+        EnumSet<Command.InteractionContextType> set = EnumSet.of(interactionContextType, interactionContextTypes);
+        this.contexts = set;
+        return this;
+    }
+
     @Nonnull
     @Override
     public CommandDataImpl addOptions(@Nonnull OptionData... options)

src/main/java/net/dv8tion/jda/internal/interactions/InteractionImpl.java

@@ -63,7 +63,8 @@ public InteractionImpl(JDAImpl jda, DataObject data)
         this.id = data.getUnsignedLong("id");
         this.token = data.getString("token");
         this.type = data.getInt("type");
-        this.guild = jda.getGuildById(data.getUnsignedLong("guild_id", 0L));
+        long guildId = data.getUnsignedLong("guild_id", 0L);
+        this.guild = jda.getGuildById(guildId);
         this.channelId = data.getUnsignedLong("channel_id", 0L);
         this.userLocale = DiscordLocale.from(data.getString("locale", "en-US"));
 
@@ -81,22 +82,48 @@ public InteractionImpl(JDAImpl jda, DataObject data)
                 throw new IllegalStateException("Failed to create channel instance for interaction! Channel Type: " + channelJson.getInt("type"));
             this.channel = channel;
         }
-        else
-        {
-            member = null;
+        else if (guildId != 0L) {
+            // User installed application in a guild
+            this.member = null;
             long channelId = channelJson.getUnsignedLong("id");
-            ChannelType type = ChannelType.fromId(channelJson.getInt("type"));
-            if (type != ChannelType.PRIVATE)
-                throw new IllegalArgumentException("Received interaction in unexpected channel type! Type " + type + " is not supported yet!");
-            PrivateChannel channel = jda.getPrivateChannelById(channelId);
-            if (channel == null)
-            {
-                channel = jda.getEntityBuilder().createPrivateChannel(
+
+            // Let's pretend that this is a private channel, in reality this is a guild channel in a guild that we aren't in
+            DataObject memberData = data.getObject("member");
+            DataObject userData = memberData.getObject("user");
+            // We DO NOT WANT to cache this channel AT ALL to avoid issues with clashing IDs and wrong recipients
+            // (the wrong recipients may happen if we reuse the same channel ID, which the bot will use the already created channel)
+            PrivateChannel channel = jda.getEntityBuilder().createPrivateChannel(
                     DataObject.empty()
-                        .put("id", channelId)
-                        .put("recipient", data.getObject("user"))
-                );
+                            .put("id", channelId)
+                            .put("recipient", userData),
+                    null,
+                    false
+            );
+            this.channel = channel;
+
+            User user = channel.getUser();
+            if (user == null)
+            {
+                user = jda.getEntityBuilder().createUser(userData);
+                ((PrivateChannelImpl) channel).setUser(user);
+                ((UserImpl) user).setPrivateChannel(channel);
             }
+            this.user = user;
+        } else {
+            member = null;
+            long channelId = channelJson.getUnsignedLong("id");
+            // ChannelType type = ChannelType.fromId(channelJson.getInt("type"));
+            // if (type != ChannelType.PRIVATE)
+            //     throw new IllegalArgumentException("Received interaction in unexpected channel type! Type " + type + " is not supported yet!");
+            // We DO NOT WANT to cache this channel AT ALL to avoid issues with clashing IDs and wrong recipients
+            // (the wrong recipients may happen if we reuse the same channel ID, which the bot will use the already created channel)
+            PrivateChannel channel = jda.getEntityBuilder().createPrivateChannel(
+                    DataObject.empty()
+                            .put("id", channelId)
+                            .put("recipient", data.getObject("user")),
+                    null,
+                    false
+            );
             this.channel = channel;
 
             User user = channel.getUser();

src/main/java/net/dv8tion/jda/internal/interactions/command/MessageContextInteractionImpl.java

@@ -41,8 +41,9 @@ protected Message parse(DataObject interaction, DataObject resolved)
         {
             long guildId = interaction.getUnsignedLong("guild_id");
             guild = api.getGuildById(guildId);
-            if (guild == null)
-                throw new IllegalStateException("Cannot find guild for resolved message object.");
+            // TODO: Check if the guild is authorized in "authorizing_integration_owners", if yes, then this should NOT be null and should throw
+            // if (guild == null)
+            //     throw new IllegalStateException("Cannot find guild for resolved message object.");
         }
 
         return api.getEntityBuilder().createMessageWithLookup(message, guild, false);