Update bot example files and command rework

core/src/test/java/discord4j/core/ExampleClientResponse.java

@@ -17,12 +17,11 @@
 
 package discord4j.core;
 
-import discord4j.core.support.BotSupport;
-import discord4j.core.support.ExtraBotSupport;
+import discord4j.core.command.CommandListener;
+import discord4j.core.support.Commands;
 import discord4j.rest.request.RouteMatcher;
 import discord4j.rest.response.ResponseFunction;
 import discord4j.rest.route.Routes;
-import reactor.core.publisher.Mono;
 
 /**
  * An example bot showcasing how to implement global handlers against some API responses. See
@@ -37,9 +36,9 @@ public static void main(String[] args) {
                 // bad requests (400) while adding reactions will be suppressed
                 .onClientResponse(ResponseFunction.emptyOnErrorStatus(RouteMatcher.route(Routes.REACTION_CREATE), 400))
                 .build()
-                .withGateway(client -> Mono.when(
-                        BotSupport.create(client).eventHandlers(),
-                        ExtraBotSupport.create(client).eventHandlers()
-                ));
+                .withGateway(client -> client.on(CommandListener.createWithPrefix("!!")
+                        .on("echo", Commands::echo)
+                        .on("exit", (req, res) -> res.getClient().logout())
+                        .on("status", Commands::status)));
     }
 }

core/src/test/java/discord4j/core/ExampleLogin.java

@@ -17,12 +17,20 @@
 
 package discord4j.core;
 
-import discord4j.core.support.BotSupport;
+import discord4j.core.command.CommandListener;
+import discord4j.core.support.Commands;
 
 public class ExampleLogin {
 
     public static void main(String[] args) {
-        GatewayDiscordClient client = DiscordClient.create(System.getenv("token")).login().block();
-        BotSupport.create(client).eventHandlers().block();
+        GatewayDiscordClient client = DiscordClient.create(System.getenv("token"))
+                .login()
+                .block();
+
+        client.on(CommandListener.createWithPrefix("!!")
+                .on("echo", Commands::echo)
+                .on("exit", (req, res) -> res.getClient().logout())
+                .on("status", Commands::status))
+                .blockLast();
     }
 }

core/src/test/java/discord4j/core/ExampleVoice.java

@@ -17,19 +17,43 @@
 
 package discord4j.core;
 
-import discord4j.core.support.BotSupport;
-import discord4j.core.support.ExtraBotSupport;
+import discord4j.common.util.Snowflake;
+import discord4j.core.command.CommandListener;
+import discord4j.core.support.Commands;
 import discord4j.core.support.VoiceSupport;
+import discord4j.core.support.AddRandomReaction;
+import discord4j.discordjson.json.ApplicationInfoData;
 import reactor.core.publisher.Mono;
 
+import static discord4j.core.support.Commands.isAuthor;
+
 public class ExampleVoice {
 
     public static void main(String[] args) {
-        GatewayDiscordClient client = DiscordClient.create(System.getenv("token")).login().block();
-        Mono.when(
-                BotSupport.create(client).eventHandlers(),
-                ExtraBotSupport.create(client).eventHandlers(),
-                VoiceSupport.create(client).eventHandlers())
+        GatewayDiscordClient client = DiscordClient.create(System.getenv("token"))
+                .login()
                 .block();
+
+        Mono<Long> ownerId = client.rest().getApplicationInfo()
+                .map(ApplicationInfoData::owner)
+                .map(user -> Snowflake.asLong(user.id()))
+                .cache();
+
+        CommandListener listener = CommandListener.createWithPrefix("!!")
+                .filter(req -> isAuthor(ownerId, req))
+                .on("echo", Commands::echo)
+                .on("exit", (req, res) -> res.getClient().logout())
+                .on("status", Commands::status)
+                .on("requestMembers", Commands::requestMembers)
+                .on("getMembers", Commands::getMembers)
+                .on("addRole", Commands::addRole)
+                .on("changeAvatar", Commands::changeAvatar)
+                .on("changeLogLevel", Commands::logLevelChange)
+                .on("react", new AddRandomReaction())
+                .on("userinfo", Commands::userInfo)
+                .on("reactionRemove", Commands::reactionRemove)
+                .on("leaveGuild", Commands::leaveGuild);
+
+        Mono.when(client.on(listener), VoiceSupport.create(client).eventHandlers()).block();
     }
 }

core/src/test/java/discord4j/core/command/Command.java

@@ -0,0 +1,25 @@
+/*
+ * This file is part of Discord4J.
+ *
+ * Discord4J is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Discord4J is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with Discord4J. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package discord4j.core.command;
+
+import org.reactivestreams.Publisher;
+
+import java.util.function.BiFunction;
+
+public interface Command extends BiFunction<CommandRequest, CommandResponse, Publisher<Void>> {
+}

core/src/test/java/discord4j/core/command/CommandHandler.java

@@ -0,0 +1,48 @@
+/*
+ * This file is part of Discord4J.
+ *
+ * Discord4J is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Discord4J is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with Discord4J. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package discord4j.core.command;
+
+import org.reactivestreams.Publisher;
+
+import java.util.Objects;
+import java.util.function.BiFunction;
+import java.util.function.Predicate;
+
+class CommandHandler implements BiFunction<CommandRequest, CommandResponse, Publisher<Void>>,
+        Predicate<CommandRequest> {
+
+    final Predicate<? super CommandRequest> condition;
+    final BiFunction<? super CommandRequest, ? super CommandResponse, ? extends Publisher<Void>> handler;
+
+    public CommandHandler(
+            Predicate<? super CommandRequest> condition,
+            BiFunction<? super CommandRequest, ? super CommandResponse, ? extends Publisher<Void>> handler) {
+        this.condition = Objects.requireNonNull(condition, "condition");
+        this.handler = Objects.requireNonNull(handler, "handler");
+    }
+
+    @Override
+    public Publisher<Void> apply(CommandRequest request, CommandResponse response) {
+        return handler.apply(request, response);
+    }
+
+    @Override
+    public boolean test(CommandRequest request) {
+        return condition.test(request);
+    }
+}

core/src/test/java/discord4j/core/command/CommandListener.java

@@ -0,0 +1,110 @@
+/*
+ * This file is part of Discord4J.
+ *
+ * Discord4J is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Discord4J is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with Discord4J. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package discord4j.core.command;
+
+import discord4j.common.annotations.Experimental;
+import discord4j.core.event.ReactiveEventAdapter;
+import discord4j.core.event.domain.message.MessageCreateEvent;
+import discord4j.core.object.entity.User;
+import org.reactivestreams.Publisher;
+import reactor.core.publisher.Flux;
+import reactor.core.publisher.Mono;
+import reactor.util.function.Tuples;
+
+import java.util.Objects;
+import java.util.concurrent.CopyOnWriteArrayList;
+import java.util.function.Function;
+import java.util.function.Predicate;
+
+@Experimental
+public class CommandListener extends ReactiveEventAdapter {
+
+    private final Function<MessageCreateEvent, Publisher<String>> prefixFunction;
+    private final Function<? super CommandRequest, Mono<Boolean>> filter;
+    private final CopyOnWriteArrayList<CommandHandler> handlers = new CopyOnWriteArrayList<>();
+
+    CommandListener(Function<MessageCreateEvent, Publisher<String>> prefixFunction,
+                    Function<? super CommandRequest, Mono<Boolean>> filter) {
+        this.prefixFunction = prefixFunction;
+        this.filter = filter;
+    }
+
+    CommandListener(CommandListener source) {
+        this.prefixFunction = source.prefixFunction;
+        this.filter = source.filter;
+    }
+
+    public static CommandListener create() {
+        return createWithPrefix(__ -> Mono.just(""));
+    }
+
+    public static CommandListener createWithPrefix(String prefix) {
+        return createWithPrefix(__ -> Mono.justOrEmpty(prefix));
+    }
+
+    public static CommandListener createWithPrefix(Function<MessageCreateEvent, Publisher<String>> prefixFunction) {
+        return new CommandListener(Objects.requireNonNull(prefixFunction, "prefixFunction"), __ -> Mono.just(true));
+    }
+
+    public CommandListener filter(Function<? super CommandRequest, Mono<Boolean>> condition) {
+        return new CommandListener(this.prefixFunction,
+                req -> this.filter.apply(req).flatMap(result -> condition.apply(req)));
+    }
+
+    public CommandListener on(String command, Command handler) {
+        return handle(request -> request.command().equals(command), handler);
+    }
+
+    public CommandListener handle(Predicate<? super CommandRequest> condition, Command handler) {
+        handlers.add(new CommandHandler(condition, handler));
+        return this;
+    }
+
+    public CommandListener handle(Command handler) {
+        handlers.add(new CommandHandler(__ -> true, handler));
+        return this;
+    }
+
+    @Override
+    public Publisher<?> onMessageCreate(MessageCreateEvent event) {
+        if (event.getMessage().getAuthor().map(User::isBot).orElse(true)) {
+            return Mono.empty();
+        } else {
+            String content = event.getMessage().getContent();
+            return Flux.defer(() -> prefixFunction.apply(event))
+                    .filter(content::startsWith)
+                    .map(prefix -> {
+                        String trimmed = content.substring(prefix.length()).trim();
+                        int endIndex = (trimmed.indexOf(' ') < 0) ? trimmed.length() : trimmed.indexOf(' ');
+                        String commandName = trimmed.substring(0, endIndex);
+                        String remaining = trimmed.substring(commandName.length()).trim();
+                        return Tuples.of(
+                                new DefaultCommandRequest(event, commandName, remaining),
+                                new DefaultCommandResponse(event)
+                        );
+                    })
+                    .filterWhen(exchange -> filter.apply(exchange.getT1()))
+                    .flatMap(exchange -> handlers.stream()
+                            .filter(handler -> handler.test(exchange.getT1()))
+                            .map(handler -> handler.apply(exchange.getT1(), exchange.getT2()))
+                            .findFirst()
+                            .orElse(Mono.empty()));
+            // TODO: use CommandResponse to manage event lifecycle
+        }
+    }
+}

core/src/test/java/discord4j/core/command/CommandRequest.java

@@ -0,0 +1,56 @@
+/*
+ * This file is part of Discord4J.
+ *
+ * Discord4J is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Discord4J is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with Discord4J. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package discord4j.core.command;
+
+import discord4j.core.GatewayDiscordClient;
+import discord4j.core.event.domain.message.MessageCreateEvent;
+import discord4j.core.object.entity.Message;
+import discord4j.core.object.entity.User;
+import discord4j.core.object.entity.channel.GuildChannel;
+import discord4j.rest.util.PermissionSet;
+import reactor.core.publisher.Mono;
+
+import java.util.Optional;
+
+public interface CommandRequest {
+
+    MessageCreateEvent event();
+
+    String command();
+
+    String parameters();
+
+    default GatewayDiscordClient getClient() {
+        return event().getClient();
+    }
+
+    default Message getMessage() {
+        return event().getMessage();
+    }
+
+    default Optional<User> getAuthor() {
+        return event().getMessage().getAuthor();
+    }
+
+    default Mono<Boolean> hasPermission(PermissionSet requiredPermissions) {
+        return Mono.justOrEmpty(getAuthor().map(User::getId))
+                .flatMap(authorId -> getMessage().getChannel().ofType(GuildChannel.class)
+                        .flatMap(channel -> channel.getEffectivePermissions(authorId))
+                        .map(set -> set.containsAll(requiredPermissions)));
+    }
+}

core/src/test/java/discord4j/core/command/CommandResponse.java

@@ -0,0 +1,34 @@
+/*
+ * This file is part of Discord4J.
+ *
+ * Discord4J is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Discord4J is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with Discord4J. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package discord4j.core.command;
+
+import discord4j.core.GatewayDiscordClient;
+import discord4j.core.object.entity.channel.MessageChannel;
+import discord4j.core.object.entity.channel.PrivateChannel;
+import reactor.core.publisher.Mono;
+
+public interface CommandResponse {
+
+    GatewayDiscordClient getClient();
+
+    Mono<MessageChannel> getReplyChannel();
+
+    Mono<PrivateChannel> getPrivateChannel();
+
+    // TODO: add error(...) methods for common error handling
+}