Implement basic kick command

src/main/java/wtf/beatrice/hidekobot/HidekoBot.java

@@ -145,6 +145,7 @@ public class HidekoBot
         messageCommandListener.registerCommand(new wtf.beatrice.hidekobot.commands.message.DiceRollCommand());
         messageCommandListener.registerCommand(new wtf.beatrice.hidekobot.commands.message.HelpCommand());
         messageCommandListener.registerCommand(new wtf.beatrice.hidekobot.commands.message.InviteCommand());
+        messageCommandListener.registerCommand(new wtf.beatrice.hidekobot.commands.message.KickCommand());
         messageCommandListener.registerCommand(new wtf.beatrice.hidekobot.commands.message.LoveCalculatorCommand());
         messageCommandListener.registerCommand(new wtf.beatrice.hidekobot.commands.message.MagicBallCommand());
         messageCommandListener.registerCommand(new wtf.beatrice.hidekobot.commands.message.SayCommand());

src/main/java/wtf/beatrice/hidekobot/commands/message/KickCommand.java

@@ -0,0 +1,146 @@
+package wtf.beatrice.hidekobot.commands.message;
+
+import net.dv8tion.jda.api.EmbedBuilder;
+import net.dv8tion.jda.api.Permission;
+import net.dv8tion.jda.api.entities.IMentionable;
+import net.dv8tion.jda.api.entities.Mentions;
+import net.dv8tion.jda.api.entities.User;
+import net.dv8tion.jda.api.entities.channel.concrete.TextChannel;
+import net.dv8tion.jda.api.events.message.MessageReceivedEvent;
+import net.dv8tion.jda.api.requests.restaction.AuditableRestAction;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+import wtf.beatrice.hidekobot.Cache;
+import wtf.beatrice.hidekobot.HidekoBot;
+import wtf.beatrice.hidekobot.objects.commands.CommandCategory;
+import wtf.beatrice.hidekobot.objects.commands.MessageCommand;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.LinkedList;
+import java.util.List;
+
+public class KickCommand implements MessageCommand
+{
+
+    @Override
+    public LinkedList<String> getCommandLabels() {
+        return new LinkedList<>(Collections.singletonList("kick"));
+    }
+
+    @Nullable
+    @Override
+    public List<Permission> getPermissions() {
+        return new ArrayList<Permission>(Collections.singletonList(Permission.KICK_MEMBERS));
+    }
+
+    @Override
+    public boolean passRawArgs() {
+        return false;
+    }
+
+    @NotNull
+    @Override
+    public CommandCategory getCategory() {
+        return CommandCategory.MODERATION;
+    }
+
+    @NotNull
+    @Override
+    public String getDescription() {
+        return "Kick the mentioned user.";
+    }
+
+    @Nullable
+    @Override
+    public String getUsage() {
+        return "<mentioned user> [reason]";
+    }
+
+    @Override
+    public void runCommand(MessageReceivedEvent event, String label, String[] args)
+    {
+        if(!(event.getChannel() instanceof TextChannel))
+        {
+            // todo nicer looking with emojis
+            event.getMessage().reply("Sorry! I can't kick people in DMs.").queue();
+            return;
+        }
+
+        Mentions msgMentions = event.getMessage().getMentions();
+        List<IMentionable> mentions = msgMentions.getMentions();
+
+        if(args.length == 0 ||mentions.isEmpty())
+        {
+            // todo nicer looking with emojis
+            event.getMessage().reply("You have to tell me who to kick!").queue();
+            return;
+        }
+
+        String mentionedId = mentions.get(0).getId();
+        User mentioned = null;
+
+        try {
+             mentioned = HidekoBot.getAPI().retrieveUserById(mentionedId).complete();
+        } catch (Exception e)
+        {
+            // todo nicer looking with emojis
+            event.getMessage().reply("I can't kick that user!").queue();
+            return;
+        }
+
+        StringBuilder reasonBuilder = new StringBuilder();;
+        String reason = "";
+        if(args.length > 1)
+        {
+            for(int i = 1; i < args.length; i++)
+            {
+                String arg = args[i];
+                reasonBuilder.append(arg);
+
+                if(i + 1 != arg.length())
+                    reasonBuilder.append(" "); // separate args with a space except on last iteration.
+            }
+
+            reason = reasonBuilder.toString();
+        }
+
+        if(mentioned == null)
+        {
+            // todo nicer looking with emojis
+            event.getMessage().reply("I can't kick that user!").queue();
+            return;
+        }
+
+        AuditableRestAction<Void> kickAction = event.getGuild().kick(mentioned);
+        if(!reason.isEmpty() && !reasonBuilder.isEmpty()) kickAction.reason(reason);
+
+        final String finalReason = reason;
+        final IMentionable finalMentioned = mentioned;
+
+        kickAction.queue(success -> {
+            String embedReason = finalReason;
+
+            EmbedBuilder embedBuilder = new EmbedBuilder();
+
+            embedBuilder.setAuthor(event.getAuthor().getAsTag(), null,event.getAuthor().getAvatarUrl());
+            embedBuilder.setColor(Cache.getBotColor());
+            embedBuilder.setTitle("User kicked");
+
+            embedBuilder.addField("\uD83D\uDC64 User", finalMentioned.getAsMention(), true);
+            embedBuilder.addField("✂️ By", event.getAuthor().getAsMention(), true);
+
+            if(embedReason.isEmpty())
+                embedReason = "*No reason specified*";
+
+            embedBuilder.addField("\uD83D\uDCD6 Reason", embedReason, false);
+
+
+            event.getMessage().replyEmbeds(embedBuilder.build()).queue();
+        }, throwable -> {
+            // todo nicer looking with emojis
+            event.getMessage().reply("Sorry, I couldn't kick " + finalMentioned.getAsMention() + "!").queue();
+        });
+
+    }
+}