add prototype choices implementation

lib/src/main/java/net/tomatentum/marinara/interaction/annotation/AutoComplete.java

@@ -0,0 +1,5 @@
+package net.tomatentum.marinara.interaction.annotation;
+
+public @interface AutoComplete {
+    
+}

lib/src/main/java/net/tomatentum/marinara/interaction/commands/ChoiceValueProvider.java

@@ -0,0 +1,5 @@
+package net.tomatentum.marinara.interaction.commands;
+
+public interface ChoiceValueProvider<T> {
+    T getChoiceValue();
+}

lib/src/main/java/net/tomatentum/marinara/interaction/commands/EnumChoices.java

@@ -0,0 +1,74 @@
+package net.tomatentum.marinara.interaction.commands;
+
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+import java.lang.reflect.ParameterizedType;
+import java.lang.reflect.Type;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+
+import io.leangen.geantyref.AnnotationFormatException;
+import io.leangen.geantyref.GenericTypeReflector;
+import io.leangen.geantyref.TypeFactory;
+import net.tomatentum.marinara.interaction.commands.annotation.SlashCommandOptionChoice;
+
+public record EnumChoices(Class<? extends Enum<?>> enumClass, ChoiceType type, SlashCommandOptionChoice[] choices) {
+
+    private static Method method;
+
+    static {
+        try {
+            method = ChoiceValueProvider.class.getMethod("getChoiceValue");
+        } catch (NoSuchMethodException | SecurityException e) {
+            e.printStackTrace();
+        }
+    }
+
+    public static EnumChoices of(Class<? extends Enum<?>> enumClass) {
+        if (!ChoiceValueProvider.class.isAssignableFrom(enumClass))
+            throw new IllegalArgumentException("Provided class needs to implement the ChoiceValueProvider interface.");
+        ChoiceType type = parseChoiceType(enumClass);
+        SlashCommandOptionChoice[] choices = parseChoices(enumClass, type);
+        return new EnumChoices(enumClass, type, choices);
+    }
+
+    private static ChoiceType parseChoiceType(Class<? extends Enum<?>> enumClass) {
+        ParameterizedType type = (ParameterizedType) GenericTypeReflector.getExactSuperType(enumClass, ChoiceValueProvider.class);
+        Type typeParam = type.getActualTypeArguments()[0];
+
+        if (!(typeParam instanceof Class<?>))
+            throw new IllegalArgumentException("ChoiceValueProvider need either a String or Number type parameter.");
+
+        if (String.class.isAssignableFrom((Class<?>) typeParam))
+            return ChoiceType.String;
+        else if (Number.class.isAssignableFrom((Class<?>) typeParam))
+            return ChoiceType.Number;
+        else
+            throw new IllegalArgumentException("ChoiceValueProvider need either a String or Number type parameter.");
+    }
+
+    private static SlashCommandOptionChoice[] parseChoices(Class<? extends Enum<?>> enumClass, ChoiceType type) {
+        Enum<? extends Enum<?>>[] constants = enumClass.getEnumConstants();
+        List<SlashCommandOptionChoice> choices = new ArrayList<>();
+        for (Enum<? extends Enum<?>> enumInstance : constants) {
+            Object value;
+            try {
+                value = method.invoke(enumInstance);
+                if (type.equals(ChoiceType.String))
+                    choices.add(TypeFactory.annotation(SlashCommandOptionChoice.class, Map.of("name", enumInstance.name(), "stringValue", value)));
+                else if (type.equals(ChoiceType.Number))
+                    choices.add(TypeFactory.annotation(SlashCommandOptionChoice.class, Map.of("name", enumInstance.name(), "longValue", value)));
+            } catch (IllegalAccessException | InvocationTargetException | AnnotationFormatException e) {
+                e.printStackTrace();
+                return null;
+            }
+        }
+        return choices.toArray(new SlashCommandOptionChoice[0]);
+    }
+
+    public static enum ChoiceType {
+        String,
+        Number
+    }
+}

lib/src/main/java/net/tomatentum/marinara/interaction/commands/ExecutableSlashCommandDefinition.java

@@ -2,6 +2,7 @@ package net.tomatentum.marinara.interaction.commands;
 
 import net.tomatentum.marinara.interaction.commands.annotation.SlashCommand;
 import net.tomatentum.marinara.interaction.commands.annotation.SlashCommandOption;
+import net.tomatentum.marinara.interaction.commands.annotation.SlashCommandOptionChoice;
 import net.tomatentum.marinara.interaction.commands.annotation.SubCommand;
 import net.tomatentum.marinara.interaction.commands.annotation.SubCommandGroup;
 
@@ -11,6 +12,13 @@ public record ExecutableSlashCommandDefinition(
     SubCommandGroup subCommandGroup, 
     SlashCommandOption[] options) {
 
+    public static SlashCommandOptionChoice[] getActualChoices(SlashCommandOption option) {
+        SlashCommandOptionChoice[] choices = option.choices();
+        if (choices.length <= 0)
+            choices = EnumChoices.of(option.choiceEnum()).choices();
+        return choices;
+    }
+
     @Override
     public final boolean equals(Object o) {
         if (!(o instanceof ExecutableSlashCommandDefinition))

lib/src/main/java/net/tomatentum/marinara/interaction/commands/annotation/SlashCommandOption.java

@@ -14,4 +14,10 @@ public @interface SlashCommandOption {
     public String description() default "";
     public SlashCommandOptionType type() default SlashCommandOptionType.STRING;
     public boolean required() default false;
+    public SlashCommandOptionChoice[] choices() default {};
+    public Class<? extends Enum<?>> choiceEnum() default PlaceHolderEnum.class;
+
+    public static enum PlaceHolderEnum {
+
+    }
 }

lib/src/main/java/net/tomatentum/marinara/interaction/commands/annotation/SlashCommandOptionChoice.java

@@ -0,0 +1,7 @@
+package net.tomatentum.marinara.interaction.commands.annotation;
+
+public @interface SlashCommandOptionChoice {
+    public String name();
+    public long longValue() default Long.MAX_VALUE;
+    public String stringValue() default "";
+}