Make avatar support both slash and message commands

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

@@ -0,0 +1,81 @@
+package wtf.beatrice.hidekobot.commands.message;
+
+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.MessageEmbed;
+import net.dv8tion.jda.api.entities.User;
+import net.dv8tion.jda.api.events.message.MessageReceivedEvent;
+import org.jetbrains.annotations.Nullable;
+import wtf.beatrice.hidekobot.Cache;
+import wtf.beatrice.hidekobot.HidekoBot;
+import wtf.beatrice.hidekobot.commands.base.Avatar;
+import wtf.beatrice.hidekobot.objects.commands.MessageCommand;
+
+import java.util.Collections;
+import java.util.LinkedList;
+import java.util.List;
+
+public class AvatarCommand  implements MessageCommand
+{
+
+    @Override
+    public LinkedList<String> getCommandLabels() {
+        return new LinkedList<>(Collections.singletonList("avatar"));
+    }
+
+    @Nullable
+    @Override
+    public List<Permission> getPermissions() {
+        return null; // anyone can use it
+    }
+
+    @Override
+    public boolean passRawArgs() {
+        return false;
+    }
+
+    @Override
+    public void runCommand(MessageReceivedEvent event, String label, String[] args)
+    {
+        int[] acceptedSizes = Cache.getSupportedAvatarResolutions();
+
+        User user = null;
+        int resolution = -1;
+
+        // we have no specific order for user and resolution, so let's try parsing any arg as resolution
+        // (mentions are handled differently by a specific method)
+        boolean resFound = false;
+
+        for (String arg : args) {
+            try {
+                int givenRes = Integer.parseInt(arg);
+                resolution = Avatar.parseResolution(givenRes);
+                resFound = true;
+                break;
+            } catch (NumberFormatException ignored) {
+            }
+        }
+
+        // fallback in case we didn't find any specified resolution
+        if(!resFound) resolution = Avatar.parseResolution(512);
+
+        // check if someone is mentioned
+        Mentions mentions = event.getMessage().getMentions();
+        if(mentions.getMentions().isEmpty())
+        {
+            user = event.getAuthor();
+        } else
+        {
+            String mentionedId = mentions.getMentions().get(0).getId();
+            user = HidekoBot.getAPI().retrieveUserById(mentionedId).complete();
+        }
+
+        // in case of issues, fallback to the sender
+        if(user == null) user = event.getAuthor();
+
+        // send a response
+        MessageEmbed embed = Avatar.buildEmbed(resolution, user);
+        event.getMessage().replyEmbeds(embed).queue();
+    }
+}