Implement avatar grabber command

src/main/java/wtf/beatrice/hidekobot/listeners/SlashCommandListener.java

@@ -12,6 +12,7 @@ public class SlashCommandListener extends ListenerAdapter
     public void onSlashCommandInteraction(@NotNull SlashCommandInteractionEvent event)
     {
         switch (event.getName().toLowerCase()) {
+            case "avatar" -> new AvatarCommand(event);
             case "clear" -> new ClearChatCommand(event);
             case "coinflip" -> new CoinFlipCommand(event);
             case "die" -> new DieCommand(event);

src/main/java/wtf/beatrice/hidekobot/slashcommands/AvatarCommand.java

@@ -0,0 +1,51 @@
+package wtf.beatrice.hidekobot.slashcommands;
+
+import net.dv8tion.jda.api.entities.User;
+import net.dv8tion.jda.api.events.interaction.command.SlashCommandInteractionEvent;
+import net.dv8tion.jda.api.interactions.commands.OptionMapping;
+import org.jetbrains.annotations.NotNull;
+
+public class AvatarCommand
+{
+    // discord api returns a broken image if you don't use specific sizes (powers of 2), so we limit it to these
+    private final int[] acceptedSizes = { 16, 32, 64, 128, 256, 512, 1024 };
+
+    public AvatarCommand(@NotNull SlashCommandInteractionEvent event)
+    {
+        event.deferReply().queue();
+
+        User user;
+        int size;
+
+        OptionMapping userArg = event.getOption("user");
+        if(userArg != null)
+        {
+            user = userArg.getAsUser();
+        } else {
+            user = event.getUser();
+        }
+
+        OptionMapping sizeArg = event.getOption("size");
+        if(sizeArg != null)
+        {
+            size = sizeArg.getAsInt();
+
+            // method to find closest value to accepted values
+            int distance = Math.abs(acceptedSizes[0] - size);
+            int idx = 0;
+            for(int c = 1; c < acceptedSizes.length; c++){
+                int cdistance = Math.abs(acceptedSizes[c] - size);
+                if(cdistance < distance){
+                    idx = c;
+                    distance = cdistance;
+                }
+            }
+            size = acceptedSizes[idx];
+
+        } else {
+            size = 512;
+        }
+
+        event.getHook().sendMessage(user.getEffectiveAvatar().getUrl(size)).queue();
+    }
+}

src/main/java/wtf/beatrice/hidekobot/utils/SlashCommandsUtil.java

@@ -20,6 +20,9 @@ public class SlashCommandsUtil
 
     static List<CommandData> allCommands = new ArrayList<>()
     {{
+        add(Commands.slash("avatar", "Get someone's profile picture.")
+                .addOption(OptionType.USER, "user", "User you want to grab the avatar of.")
+                .addOption(OptionType.INTEGER, "size", "The size of the returned image."));
         add(Commands.slash("die", "Stop the bot's process")
                 .setDefaultPermissions(DefaultMemberPermissions.DISABLED));
         add(Commands.slash("clear", "Clear the current channel's chat.")