Added ban command and improvements to moderation service.

Author: andrewlalis

src/main/java/net/javadiscord/javabot2/command/ResponseException.java

@@ -45,4 +45,13 @@ public static Supplier<ResponseException> warning(String message) {
 	public static Supplier<ResponseException> error(String message) {
 		return () -> new ResponseException(Responses.deferredErrorBuilder().message(message));
 	}
+
+	/**
+	 * Standard helper method to generate a supplier of a response exception
+	 * with a simple "invalid argument" warning message.
+	 * @return The exception supplier.
+	 */
+	public static Supplier<ResponseException> invalidArgument() {
+		return () -> new ResponseException(Responses.deferredWarningBuilder().message("Invalid argument."));
+	}
 }

src/main/java/net/javadiscord/javabot2/systems/moderation/BanCommand.java

@@ -0,0 +1,32 @@
+package net.javadiscord.javabot2.systems.moderation;
+
+import net.javadiscord.javabot2.Bot;
+import net.javadiscord.javabot2.command.ResponseException;
+import net.javadiscord.javabot2.command.Responses;
+import net.javadiscord.javabot2.command.SlashCommandHandler;
+import org.javacord.api.entity.user.User;
+import org.javacord.api.interaction.SlashCommandInteraction;
+import org.javacord.api.interaction.callback.InteractionImmediateResponseBuilder;
+
+/**
+ * Command which is used to ban naughty users.
+ */
+public class BanCommand implements SlashCommandHandler {
+	@Override
+	public InteractionImmediateResponseBuilder handle(SlashCommandInteraction interaction) throws ResponseException {
+		User user = interaction.getOptionUserValueByName("user")
+				.orElseThrow(ResponseException.warning("User is required."));
+		String reason = interaction.getOptionStringValueByName("reason")
+				.orElseThrow(ResponseException.warning("Reason is required."));
+		var channel = interaction.getChannel()
+				.orElseThrow(ResponseException.warning("This command can only be performed in a channel."))
+				.asServerTextChannel()
+				.orElseThrow(ResponseException.warning("This command can only be performed in a server text channel."));
+		var moderationService = new ModerationService(interaction.getApi(), Bot.mongoDb, Bot.config.get(channel.getServer()).getModeration());
+		moderationService.ban(user, reason, interaction.getUser(), channel);
+		return Responses.successBuilder(interaction)
+				.title("User Banned")
+				.messageFormat("User %s has been banned.", user.getMentionTag())
+				.build();
+	}
+}

src/main/java/net/javadiscord/javabot2/systems/moderation/ModerationService.java

@@ -4,7 +4,6 @@
 import com.mongodb.client.FindIterable;
 import com.mongodb.client.MongoDatabase;
 import com.mongodb.client.model.Filters;
-import net.javadiscord.javabot2.Bot;
 import net.javadiscord.javabot2.config.guild.ModerationConfig;
 import net.javadiscord.javabot2.systems.moderation.model.WarnSeverity;
 import org.bson.Document;
@@ -17,6 +16,7 @@
 import java.time.Instant;
 import java.time.OffsetDateTime;
 import java.util.Map;
+import java.util.concurrent.CompletableFuture;
 
 /**
  * This service provides methods for performing moderation actions, like banning
@@ -48,8 +48,9 @@ public ModerationService(DiscordApi api, MongoDatabase db, ModerationConfig conf
 	 * @param reason The reason for this warning.
 	 * @param warnedBy The user who issued the warning.
 	 * @param channel The channel in which the warning was issued.
+	 * @return A future that completes when all warn operations are complete.
 	 */
-	public void warn(User user, WarnSeverity severity, String reason, User warnedBy, ServerTextChannel channel) {
+	public CompletableFuture<Void> warn(User user, WarnSeverity severity, String reason, User warnedBy, ServerTextChannel channel) {
 		var warns = db.getCollection("warn");
 		Instant now = Instant.now();
 		warns.insertOne(new Document(Map.of(
@@ -64,13 +65,12 @@ public void warn(User user, WarnSeverity severity, String reason, User warnedBy,
 			totalSeverity += WarnSeverity.getWeightOrDefault(warnDoc.getString("severity"));
 		}
 		var warnEmbed = buildWarnEmbed(user, severity, reason, warnedBy, now, totalSeverity);
-		Bot.asyncPool.submit(() -> {
-			user.openPrivateChannel().thenAcceptAsync(privateChannel -> privateChannel.sendMessage(warnEmbed));
-			channel.sendMessage(warnEmbed);
-		});
+		var future = channel.sendMessage(warnEmbed)
+				.thenComposeAsync(unused -> user.openPrivateChannel().thenAcceptAsync(privateChannel -> privateChannel.sendMessage(warnEmbed)));
 		if (totalSeverity > config.getMaxWarnSeverity()) {
-			ban(user, "Too many warnings.", warnedBy, channel);
+			return future.thenComposeAsync(unused -> ban(user, "Too many warnings.", warnedBy, channel));
 		}
+		return future;
 	}
 
 	/**
@@ -79,15 +79,19 @@ public void warn(User user, WarnSeverity severity, String reason, User warnedBy,
 	 * @param reason The reason for banning the user.
 	 * @param bannedBy The user who is responsible for banning this user.
 	 * @param channel The channel in which the ban was issued.
+	 * @return A future that completes once all ban operations are done.
 	 */
-	public void ban(User user, String reason, User bannedBy, ServerTextChannel channel) {
+	public CompletableFuture<Void> ban(User user, String reason, User bannedBy, ServerTextChannel channel) {
 		var banEmbed = buildBanEmbed(user, reason, bannedBy);
-		Bot.asyncPool.submit(() -> {
-			channel.sendMessage(banEmbed);
-			user.openPrivateChannel()
+		if (channel.getServer().canBanUser(bannedBy, user)) {
+			return channel.getServer().banUser(user, BAN_DELETE_DAYS, reason)
+					.thenComposeAsync(unused -> user.openPrivateChannel())
 					.thenComposeAsync(privateChannel -> privateChannel.sendMessage(banEmbed))
-					.thenRunAsync(() -> channel.getServer().banUser(user, BAN_DELETE_DAYS, reason));
-		});
+					.thenComposeAsync(unused -> channel.sendMessage(banEmbed))
+					.thenApply(msg -> null);
+		} else {
+			return CompletableFuture.failedFuture(new PermissionException("You don't have permission to ban this user."));
+		}
 	}
 
 	private FindIterable<Document> findActiveWarns(User user) {

src/main/java/net/javadiscord/javabot2/systems/moderation/PermissionException.java

@@ -0,0 +1,18 @@
+package net.javadiscord.javabot2.systems.moderation;
+
+/**
+ * An exception that's thrown when a user doesn't have permission to do something.
+ */
+public class PermissionException extends Exception {
+	/**
+	 * Constructs a new exception with the specified detail message.  The
+	 * cause is not initialized, and may subsequently be initialized by
+	 * a call to {@link #initCause}.
+	 *
+	 * @param message the detail message. The detail message is saved for
+	 *                later retrieval by the {@link #getMessage()} method.
+	 */
+	public PermissionException(String message) {
+		super(message);
+	}
+}

src/main/resources/commands/moderation.yaml

@@ -42,3 +42,20 @@
       description: The reason for this user's warning.
       type: STRING
       required: true
+
+- name: ban
+  description: Ban a user.
+  handler: net.javadiscord.javabot2.systems.moderation.BanCommand
+  enabledByDefault: false
+  privileges:
+    - type: ROLE
+      id: moderation.staffRoleId
+  options:
+    - name: user
+      description: The user to ban.
+      type: USER
+      required: true
+    - name: reason
+      description: The reason for banning this user.
+      type: STRING
+      required: true