command utils

17 files changed, 682 insertions, 0 deletions

diff --git a/src/main/java/cc/polyfrost/oneconfig/OneConfig.java b/src/main/java/cc/polyfrost/oneconfig/OneConfig.java
index 60bb37e..c1301d3 100644
--- a/src/main/java/cc/polyfrost/oneconfig/OneConfig.java
+++ b/src/main/java/cc/polyfrost/oneconfig/OneConfig.java
@@ -11,7 +11,9 @@ import cc.polyfrost.oneconfig.lwjgl.BlurHandler;
 import cc.polyfrost.oneconfig.lwjgl.RenderManager;
 import cc.polyfrost.oneconfig.lwjgl.font.Fonts;
 import cc.polyfrost.oneconfig.lwjgl.image.Images;
+import cc.polyfrost.oneconfig.test.TestCommand;
 import cc.polyfrost.oneconfig.test.TestConfig;
+import cc.polyfrost.oneconfig.utils.commands.CommandManager;
 import cc.polyfrost.oneconfig.utils.hypixel.HypixelUtils;
 import net.minecraft.launchwrapper.Launch;
 import net.minecraftforge.client.ClientCommandHandler;
@@ -50,6 +52,7 @@ public class OneConfig {
     public void onFMLInitialization(net.minecraftforge.fml.common.event.FMLInitializationEvent event) {
         BlurHandler.INSTANCE.load();
         testConfig = new TestConfig();
+        CommandManager.registerCommand(new TestCommand());
         ClientCommandHandler.instance.registerCommand(new OneConfigCommand());
         EventManager.INSTANCE.register(new HudCore());
         EventManager.INSTANCE.register(HypixelUtils.INSTANCE);
diff --git a/src/main/java/cc/polyfrost/oneconfig/test/TestCommand.java b/src/main/java/cc/polyfrost/oneconfig/test/TestCommand.java
new file mode 100644
index 0000000..753c353
--- /dev/null
+++ b/src/main/java/cc/polyfrost/oneconfig/test/TestCommand.java
@@ -0,0 +1,39 @@
+package cc.polyfrost.oneconfig.test;
+
+import cc.polyfrost.oneconfig.libs.universal.UChat;
+import cc.polyfrost.oneconfig.utils.commands.annotations.Command;
+import cc.polyfrost.oneconfig.utils.commands.annotations.Main;
+import cc.polyfrost.oneconfig.utils.commands.annotations.Name;
+import cc.polyfrost.oneconfig.utils.commands.annotations.SubCommand;
+
+@Command(value = "test", aliases = {"t"})
+public class TestCommand {
+
+    @Main
+    private static void main() {  // /test
+        UChat.chat("Main command");
+    }
+
+    @SubCommand(value = "subcommand", aliases = {"s"})
+    private static class TestSubCommand {
+
+        @Main(priority = 999)
+        private static void main(int a, float b, @Name("named c") String c) { // /test subcommand <a> <b> <c>
+            UChat.chat("Integer main: " + a + " " + b + " " + c);
+        }
+
+        @Main(priority = 10001)
+        private static void main(double a, double b, @Name("named c") String c) { // /test subcommand <a> <b> <c>
+            UChat.chat("Double main: " + a + " " + b + " " + c);
+        }
+
+        @SubCommand(value = "subsubcommand", aliases = {"ss"})
+        private static class TestSubSubCommand {
+
+            @Main
+            private static void main(String a, String b, @Name("named c") String c) { // /test subcommand subsubcommand <a> <b> <c>
+                UChat.chat(a + " " + b + " " + c);
+            }
+        }
+    }
+}
diff --git a/src/main/java/cc/polyfrost/oneconfig/utils/commands/CommandHelper.java b/src/main/java/cc/polyfrost/oneconfig/utils/commands/CommandHelper.java
new file mode 100644
index 0000000..bc57fc2
--- /dev/null
+++ b/src/main/java/cc/polyfrost/oneconfig/utils/commands/CommandHelper.java
@@ -0,0 +1,19 @@
+package cc.polyfrost.oneconfig.utils.commands;
+
+/**
+ * A helper class for commands.
+ * Extend this class and run {@link CommandHelper#preload()} (which does nothing,
+ * just makes loading look nicer lol)
+ *
+ * @see cc.polyfrost.oneconfig.utils.commands.annotations.Command
+ */
+public abstract class CommandHelper {
+
+    public CommandHelper() {
+        CommandManager.registerCommand(this);
+    }
+
+    public void preload() {
+
+    }
+}
diff --git a/src/main/java/cc/polyfrost/oneconfig/utils/commands/CommandManager.java b/src/main/java/cc/polyfrost/oneconfig/utils/commands/CommandManager.java
new file mode 100644
index 0000000..a4e2569
--- /dev/null
+++ b/src/main/java/cc/polyfrost/oneconfig/utils/commands/CommandManager.java
@@ -0,0 +1,295 @@
+package cc.polyfrost.oneconfig.utils.commands;
+
+import cc.polyfrost.oneconfig.libs.universal.ChatColor;
+import cc.polyfrost.oneconfig.libs.universal.UChat;
+import cc.polyfrost.oneconfig.utils.commands.annotations.*;
+import cc.polyfrost.oneconfig.utils.commands.arguments.*;
+import net.minecraft.command.CommandBase;
+import net.minecraft.command.ICommandSender;
+import net.minecraftforge.client.ClientCommandHandler;
+
+import java.lang.reflect.InvocationTargetException;
+import java.lang.reflect.Method;
+import java.lang.reflect.Modifier;
+import java.lang.reflect.Parameter;
+import java.util.*;
+import java.util.stream.Collectors;
+
+/**
+ * Handles the registration of OneConfig commands.
+ *
+ * @see Command
+ */
+public class CommandManager {
+    private static final HashMap<Class<?>, ArgumentParser<?>> parsers = new HashMap<>();
+    private static final String NOT_FOUND_TEXT = "Command not found! Type /@ROOT_COMMAND@ help for help.";
+    private static final String METHOD_RUN_ERROR = "Error while running @ROOT_COMMAND@ method! Please report this to the developer.";
+
+    /**
+     * Adds a parser to the parsers map.
+     *
+     * @param parser The parser to add.
+     * @param clazz The class of the parser.
+     */
+    public static void addParser(ArgumentParser<?> parser, Class<?> clazz) {
+        parsers.put(clazz, parser);
+    }
+
+    /**
+     * Adds a parser to the parsers map.
+     * @param parser The parser to add.
+     */
+    public static void addParser(ArgumentParser<?> parser) {
+        addParser(parser, parser.typeClass);
+    }
+
+    static {
+        addParser(new StringParser());
+        addParser(new IntegerParser());
+        addParser(new IntegerParser(), int.class);
+        addParser(new DoubleParser());
+        addParser(new DoubleParser(), double.class);
+        addParser(new FloatParser());
+        addParser(new FloatParser(), float.class);
+        addParser(new BooleanParser());
+        addParser(new BooleanParser(), boolean.class);
+    }
+
+    /**
+     * Registers the provided command.
+     *
+     * @param command The command to register.
+     */
+    public static void registerCommand(Object command) {
+        Class<?> clazz = command.getClass();
+        if (clazz.isAnnotationPresent(Command.class)) {
+            final Command annotation = clazz.getAnnotation(Command.class);
+            ArrayList<InternalCommand.InternalCommandInvoker> mainCommandFuncs = new ArrayList<>();
+
+            for (Method method : clazz.getDeclaredMethods()) {
+                if (method.isAnnotationPresent(Main.class) && method.getParameterCount() == 0) {
+                    mainCommandFuncs.add(new InternalCommand.InternalCommandInvoker(annotation.value(), annotation.aliases(), method));
+                    break;
+                }
+            }
+
+            final InternalCommand root = new InternalCommand(annotation.value(), annotation.aliases(), annotation.description().trim().isEmpty() ? "Main command for " + annotation.value() : annotation.description(), mainCommandFuncs);
+            addToInvokers(clazz.getDeclaredClasses(), root);
+            ClientCommandHandler.instance.registerCommand(new CommandBase() {
+                @Override
+                public String getCommandName() {
+                    return annotation.value();
+                }
+
+                @Override
+                public String getCommandUsage(ICommandSender sender) {
+                    return "/" + annotation.value();
+                }
+
+                @Override
+                public void processCommand(ICommandSender sender, String[] args) {
+                    if (args.length == 0) {
+                        if (!root.invokers.isEmpty()) {
+                            try {
+                                root.invokers.stream().findFirst().get().method.invoke(null);
+                            } catch (IllegalAccessException | InvocationTargetException | IllegalArgumentException | ExceptionInInitializerError e) {
+                                UChat.chat(ChatColor.RED.toString() + ChatColor.BOLD + METHOD_RUN_ERROR);
+                            }
+                        }
+                    } else {
+                        if (annotation.helpCommand() && args[0].equalsIgnoreCase("help")) {
+                            UChat.chat(sendHelpCommand(root));
+                        } else {
+                            for (InternalCommand command : root.children) {
+                                String result = runThroughCommands(command, 0, args);
+                                if (result == null) {
+                                    return;
+                                } else if (!result.equals(NOT_FOUND_TEXT)) {
+                                    UChat.chat(ChatColor.RED.toString() + ChatColor.BOLD + result.replace("@ROOT_COMMAND@", getCommandName()));
+                                    return;
+                                }
+                            }
+                            UChat.chat(ChatColor.RED.toString() + ChatColor.BOLD + NOT_FOUND_TEXT.replace("@ROOT_COMMAND@", getCommandName()));
+                        }
+                    }
+                }
+
+                @Override
+                public int getRequiredPermissionLevel() {
+                    return -1;
+                }
+            });
+        }
+    }
+
+    private static String sendHelpCommand(InternalCommand root) {
+        StringBuilder builder = new StringBuilder();
+        builder.append(ChatColor.GOLD.toString() + "Help for " + ChatColor.BOLD + root.name + ChatColor.RESET + ChatColor.GOLD + ":\n");
+        builder.append("\n");
+        for (InternalCommand command : root.children) {
+            runThroughCommandsHelp(root.name, root, builder);
+        }
+        builder.append("\n" + ChatColor.GOLD + "Aliases: " + ChatColor.BOLD);
+        int index = 0;
+        for (String alias : root.aliases) {
+            ++index;
+            builder.append(alias + (index < root.aliases.length ? ", " : ""));
+        }
+        builder.append("\n");
+        return builder.toString();
+    }
+
+    private static void runThroughCommandsHelp(String append, InternalCommand command, StringBuilder builder) {
+        for (InternalCommand.InternalCommandInvoker invoker : command.invokers) {
+            builder.append("\n" + ChatColor.GOLD + "/" + append + " " + command.name);
+            for (Parameter parameter : invoker.method.getParameters()) {
+                String name = parameter.getName();
+                if (parameter.isAnnotationPresent(Name.class)) {
+                    name = parameter.getAnnotation(Name.class).value();
+                }
+                builder.append(" <" + name + ">");
+            }
+            if (!command.description.trim().isEmpty()) {
+                builder.append(": " + ChatColor.BOLD + command.description);
+            }
+        }
+        for (InternalCommand subCommand : command.children) {
+            runThroughCommandsHelp(append + " " + command.name, subCommand, builder);
+        }
+    }
+
+    private static String runThroughCommands(InternalCommand command, int layer, String[] args) {
+        int newLayer = layer + 1;
+        if (command.isEqual(args[layer]) && !command.invokers.isEmpty()) {
+            Set<InternalCommand.InternalCommandInvoker> invokers = command.invokers.stream().filter(invoker -> newLayer == args.length - invoker.parameterTypes.length).sorted(Comparator.comparingInt((a) -> a.method.getAnnotation(Main.class).priority())).collect(Collectors.toSet());
+            if (!invokers.isEmpty()) {
+                for (InternalCommand.InternalCommandInvoker invoker : invokers) {
+                    try {
+                        String a = tryInvoker(invoker, newLayer, args);
+                        if (a == null) {
+                            return null;
+                        } else if (a.contains(METHOD_RUN_ERROR)) {
+                            return a;
+                        }
+                    } catch (Exception ignored) {
+
+                    }
+                }
+            } else {
+                for (InternalCommand subCommand : command.children) {
+                    String result = runThroughCommands(subCommand, newLayer, args);
+                    if (result == null) {
+                        return null;
+                    } else if (!result.equals(NOT_FOUND_TEXT)) {
+                        return result;
+                    }
+                }
+            }
+        }
+        return NOT_FOUND_TEXT;
+    }
+
+    private static String tryInvoker(InternalCommand.InternalCommandInvoker invoker, int newLayer, String[] args) {
+        try {
+            ArrayList<Object> params = new ArrayList<>();
+            int processed = newLayer;
+            int currentParam = 0;
+            while (processed < args.length) {
+                Parameter param = invoker.method.getParameters()[currentParam];
+                if (param.isAnnotationPresent(Greedy.class) && currentParam + 1 != invoker.method.getParameterCount()) {
+                    return "Parsing failed: Greedy parameter must be the last one.";
+                }
+                ArgumentParser<?> parser = parsers.get(param.getType());
+                if (parser == null) {
+                    return "No parser for " + invoker.method.getParameterTypes()[currentParam].getSimpleName() + "! Please report this to the mod author.";
+                }
+                try {
+                    Arguments arguments = new Arguments(Arrays.copyOfRange(args, processed, args.length), param.isAnnotationPresent(Greedy.class));
+                    try {
+                        Object a = parser.parse(arguments);
+                        if (a != null) {
+                            params.add(a);
+                            processed += arguments.getPosition();
+                            currentParam++;
+                        } else {
+                            return "Failed to parse " + param.getType().getSimpleName() + "! Please report this to the mod author.";
+                        }
+                    } catch (Exception e) {
+                        return "A " + e.getClass().getSimpleName() + " has occured while try to parse " + param.getType().getSimpleName() + "! Please report this to the mod author.";
+                    }
+                } catch (Exception e) {
+                    return "A " + e.getClass().getSimpleName() + " has occured while try to parse " + param.getType().getSimpleName() + "! Please report this to the mod author.";
+                }
+            }
+            invoker.method.invoke(null, params.toArray());
+            return null;
+        } catch (IllegalAccessException | InvocationTargetException | IllegalArgumentException | ExceptionInInitializerError e) {
+            return ChatColor.RED.toString() + ChatColor.BOLD + METHOD_RUN_ERROR;
+        }
+    }
+
+    private static void addToInvokers(Class<?>[] classes, InternalCommand parent) {
+        for (Class<?> clazz : classes) {
+            if (clazz.isAnnotationPresent(SubCommand.class)) {
+                SubCommand annotation = clazz.getAnnotation(SubCommand.class);
+                ArrayList<InternalCommand.InternalCommandInvoker> mainMethods = new ArrayList<>();
+                for (Method method : clazz.getDeclaredMethods()) {
+                    if (method.isAnnotationPresent(Main.class)) {
+                        mainMethods.add(new InternalCommand.InternalCommandInvoker(annotation.value(), annotation.aliases(), method));
+                    }
+                }
+                InternalCommand command = new InternalCommand(annotation.value(), annotation.aliases(), annotation.description(), mainMethods);
+                parent.children.add(command);
+                addToInvokers(clazz.getDeclaredClasses(), command);
+            }
+        }
+    }
+
+    private static class InternalCommand {
+        public final String name;
+        public final String[] aliases;
+        public final String description;
+        public final ArrayList<InternalCommandInvoker> invokers;
+        public final ArrayList<InternalCommand> children = new ArrayList<>();
+
+        public InternalCommand(String name, String[] aliases, String description, ArrayList<InternalCommandInvoker> invokers) {
+            this.name = name;
+            this.aliases = aliases;
+            this.invokers = invokers;
+            this.description = description;
+        }
+
+        public boolean isEqual(String name) {
+            if (this.name.equals(name)) {
+                return true;
+            } else {
+                for (String alias : aliases) {
+                    if (alias.equals(name)) {
+                        return true;
+                    }
+                }
+            }
+            return false;
+        }
+
+        public static class InternalCommandInvoker {
+            public final String name;
+            public final String[] aliases;
+            public final Method method;
+            public final Parameter[] parameterTypes;
+
+            public InternalCommandInvoker(String name, String[] aliases, Method method) {
+                if (!Modifier.isStatic(method.getModifiers())) {
+                    throw new IllegalArgumentException("All command methods must be static!");
+                }
+                this.name = name;
+                this.aliases = aliases;
+                this.method = method;
+                this.parameterTypes = method.getParameters().clone();
+                if (Modifier.isPrivate(method.getModifiers()) || Modifier.isProtected(method.getModifiers())) {
+                    method.setAccessible(true);
+                }
+            }
+        }
+    }
+}
diff --git a/src/main/java/cc/polyfrost/oneconfig/utils/commands/annotations/Command.java b/src/main/java/cc/polyfrost/oneconfig/utils/commands/annotations/Command.java
new file mode 100644
index 0000000..7717d46
--- /dev/null
+++ b/src/main/java/cc/polyfrost/oneconfig/utils/commands/annotations/Command.java
@@ -0,0 +1,115 @@
+package cc.polyfrost.oneconfig.utils.commands.annotations;
+
+import cc.polyfrost.oneconfig.utils.commands.CommandHelper;
+import cc.polyfrost.oneconfig.utils.commands.CommandManager;
+import cc.polyfrost.oneconfig.utils.commands.arguments.ArgumentParser;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * Marks a class as a command.
+ * <p>
+ * To start, create a class which is annotated with this annotation, and then a method which is annotated with {@link Main}.
+ * <pre>{@code
+ *     @literal @Command(name = "test", description = "A test command", aliases = {"t"})
+ *     public class TestCommand {
+ *         @literal @Main
+ *         public static void mainCommandMethod() {
+ *             // do stuff
+ *         }
+ *     }
+ *     }</pre>
+ * <p>
+ * Keep in mind how {@code mainCommandMethod} is a private and static method.
+ * With OneConfig's command utility, methods for commands can be any kind of visibility, and <b><i>must be static</i></b>.
+ * If the methods are not static, the {@link CommandManager} will throw an exception.
+ *
+ * <p>
+ * Command methods can also having multiple parameters of virtually any type, as long as it is a
+ * {@link String}, {@code boolean}, {@code int}, {@code double}, {@code float},
+ * or is added as an {@link ArgumentParser} and added to the
+ * {@link CommandManager} via {@link CommandManager#addParser(ArgumentParser)}.
+ * Parameters can also be annotated with various annotations, such as {@link Name}, which names the parameter
+ * for the user, {@link Greedy}, which takes all following arguments along with itself, and more to come.
+ * For example, the following command method:
+ * <pre>{@code
+ *     @literal @Main
+ *     private static void mainCommandMethod(String arg1, @Name("nameOfSecondArgument") boolean arg2, int arg3, double arg4, float arg5, @Greedy String greedyArgument) {
+ *         // do things here
+ *         System.out.println(greedyArgument); // Greedily takes all remaining arguments after greedyArgument as well as itself. 1984
+ *     }
+ *     }</pre>
+ * </p>
+ *
+ * <p>
+ * Of course, {@link SubCommand}s can be added and "stacked". For example, the following command class:
+ * <pre>{@code
+ *     @literal @Command(name = "mycommand", aliases = {"alias1"}, description = "My command description")
+ *     public class TestCommand {
+ *         @literal @Main
+ *         private static void mainCommandMethod() {
+ *             // do things here
+ *         }
+ *
+ *         @literal @SubCommand(name = "subcommand", aliases = {"subalias1"}, description = "My subcommand description")
+ *         private static class SubCommandClass {
+ *             @literal @Main
+ *             private static void subCommandMethod() {
+ *                 // do things here
+ *             }
+ *
+ *             @literal @SubCommand(name = "subsubcommand", aliases = {"subsubalias1"}, description = "My subsubcommand description")
+ *             private static class SubSubCommandClass {
+ *                 @literal @Main
+ *                 private static void subSubCommandMethod() {
+ *                     // do things here
+ *                 }
+ *             }
+ *         }
+ *     }
+ *     }</pre>
+ * </p>
+ *
+ * To register commands, either extend {@link CommandHelper} and run {@link CommandHelper#preload()} (which does nothing,
+ * just makes loading look nicer lol), or use {@link CommandManager#registerCommand(Object)}.
+ *
+ * <p>
+ * Note: if you're viewing this in IntelliJ or just see the @literal tag everywhere, please ignore that.
+ * </p>
+ *
+ * @see cc.polyfrost.oneconfig.test.TestCommand
+ * @see Main
+ * @see CommandManager
+ */
+@Retention(RetentionPolicy.RUNTIME)
+@Target({ElementType.TYPE})
+public @interface Command {
+    /**
+     * The name of the command.
+     *
+     * @return The name of the command.
+     */
+    String value();
+
+    /**
+     * The aliases of the command.
+     *
+     * @return The aliases of the command.
+     */
+    String[] aliases() default {};
+
+    /**
+     * The description of the command.
+     *
+     * @return The description of the command.
+     */
+    String description() default "";
+
+    /**
+     * Whether the command generates a help command.
+     */
+    boolean helpCommand() default true;
+}
diff --git a/src/main/java/cc/polyfrost/oneconfig/utils/commands/annotations/Greedy.java b/src/main/java/cc/polyfrost/oneconfig/utils/commands/annotations/Greedy.java
new file mode 100644
index 0000000..31c948d
--- /dev/null
+++ b/src/main/java/cc/polyfrost/oneconfig/utils/commands/annotations/Greedy.java
@@ -0,0 +1,20 @@
+package cc.polyfrost.oneconfig.utils.commands.annotations;
+
+import cc.polyfrost.oneconfig.utils.commands.arguments.Arguments;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * Indicates that the specific parameter should capture all remaining arguments and itself
+ * Can only be used on the last parameter, and only works with {@link cc.polyfrost.oneconfig.utils.commands.arguments.StringParser} by default.
+ *
+ * @see cc.polyfrost.oneconfig.utils.commands.arguments.StringParser#parse(Arguments)
+ * @see Command
+ */
+@Retention(RetentionPolicy.RUNTIME)
+@Target({ElementType.PARAMETER})
+public @interface Greedy {
+}
diff --git a/src/main/java/cc/polyfrost/oneconfig/utils/commands/annotations/Main.java b/src/main/java/cc/polyfrost/oneconfig/utils/commands/annotations/Main.java
new file mode 100644
index 0000000..3c105c7
--- /dev/null
+++ b/src/main/java/cc/polyfrost/oneconfig/utils/commands/annotations/Main.java
@@ -0,0 +1,20 @@
+package cc.polyfrost.oneconfig.utils.commands.annotations;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * Marks a method as the main method of a command.
+ *
+ * @see Command
+ * @see SubCommand
+ * @see cc.polyfrost.oneconfig.utils.commands.CommandManager
+ */
+@Retention(RetentionPolicy.RUNTIME)
+@Target({ElementType.METHOD})
+public @interface Main {
+    String description() default "";
+    int priority() default 1000;
+}
diff --git a/src/main/java/cc/polyfrost/oneconfig/utils/commands/annotations/Name.java b/src/main/java/cc/polyfrost/oneconfig/utils/commands/annotations/Name.java
new file mode 100644
index 0000000..ef178a0
--- /dev/null
+++ b/src/main/java/cc/polyfrost/oneconfig/utils/commands/annotations/Name.java
@@ -0,0 +1,22 @@
+package cc.polyfrost.oneconfig.utils.commands.annotations;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * Marks the name of a parameter.
+ *
+ * @see Main
+ * @see Command
+ */
+@Retention(RetentionPolicy.RUNTIME)
+@Target({ElementType.PARAMETER})
+public @interface Name {
+    /**
+     * The name of the parameter.
+     * @return The name of the parameter.
+     */
+    String value();
+}
diff --git a/src/main/java/cc/polyfrost/oneconfig/utils/commands/annotations/Optional.java b/src/main/java/cc/polyfrost/oneconfig/utils/commands/annotations/Optional.java
new file mode 100644
index 0000000..4dbe8b5
--- /dev/null
+++ b/src/main/java/cc/polyfrost/oneconfig/utils/commands/annotations/Optional.java
@@ -0,0 +1,12 @@
+package cc.polyfrost.oneconfig.utils.commands.annotations;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+@Retention(RetentionPolicy.RUNTIME)
+@Target({ElementType.PARAMETER})
+public @interface Optional {
+
+}
diff --git a/src/main/java/cc/polyfrost/oneconfig/utils/commands/annotations/SubCommand.java b/src/main/java/cc/polyfrost/oneconfig/utils/commands/annotations/SubCommand.java
new file mode 100644
index 0000000..b1cf035
--- /dev/null
+++ b/src/main/java/cc/polyfrost/oneconfig/utils/commands/annotations/SubCommand.java
@@ -0,0 +1,34 @@
+package cc.polyfrost.oneconfig.utils.commands.annotations;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * Marks a class as a subcommand. Can be stacked together.
+ *
+ * @see Command
+ * @see cc.polyfrost.oneconfig.utils.commands.CommandManager
+ */
+@Retention(RetentionPolicy.RUNTIME)
+@Target({ElementType.TYPE})
+public @interface SubCommand {
+    /**
+     * The name of the command.
+     * @return The name of the command.
+     */
+    String value();
+
+    /**
+     * The aliases of the command.
+     * @return The aliases of the command.
+     */
+    String[] aliases() default {};
+
+    /**
+     * The description of the command.
+     * @return The description of the command.
+     */
+    String description() default "";
+}
diff --git a/src/main/java/cc/polyfrost/oneconfig/utils/commands/arguments/ArgumentParser.java b/src/main/java/cc/polyfrost/oneconfig/utils/commands/arguments/ArgumentParser.java
new file mode 100644
index 0000000..d9d51b0
--- /dev/null
+++ b/src/main/java/cc/polyfrost/oneconfig/utils/commands/arguments/ArgumentParser.java
@@ -0,0 +1,12 @@
+package cc.polyfrost.oneconfig.utils.commands.arguments;
+
+import com.google.common.reflect.TypeToken;
+import org.jetbrains.annotations.Nullable;
+
+@SuppressWarnings("unstable")
+public abstract class ArgumentParser<T> {
+    private final TypeToken<T> type = new TypeToken<T>(getClass()) {};
+    public final Class<?> typeClass = type.getRawType();
+    @Nullable
+    public abstract T parse(Arguments arguments);
+}
diff --git a/src/main/java/cc/polyfrost/oneconfig/utils/commands/arguments/Arguments.java b/src/main/java/cc/polyfrost/oneconfig/utils/commands/arguments/Arguments.java
new file mode 100644
index 0000000..74a0840
--- /dev/null
+++ b/src/main/java/cc/polyfrost/oneconfig/utils/commands/arguments/Arguments.java
@@ -0,0 +1,33 @@
+package cc.polyfrost.oneconfig.utils.commands.arguments;
+
+public class Arguments {
+    private int position = 0;
+    public final String[] args;
+    public final boolean greedy;
+
+    public Arguments(String[] args, boolean greedy) {
+        this.args = args;
+        this.greedy = greedy;
+    }
+
+    public String poll() {
+        ++position;
+        return args[position - 1];
+    }
+
+    public String peek() {
+        if (hasNext()) {
+            return args[position];
+        } else {
+            return null;
+        }
+    }
+
+    public boolean hasNext() {
+        return position < args.length;
+    }
+
+    public int getPosition() {
+        return position;
+    }
+}
diff --git a/src/main/java/cc/polyfrost/oneconfig/utils/commands/arguments/BooleanParser.java b/src/main/java/cc/polyfrost/oneconfig/utils/commands/arguments/BooleanParser.java
new file mode 100644
index 0000000..dfdca2d
--- /dev/null
+++ b/src/main/java/cc/polyfrost/oneconfig/utils/commands/arguments/BooleanParser.java
@@ -0,0 +1,11 @@
+package cc.polyfrost.oneconfig.utils.commands.arguments;
+
+import org.jetbrains.annotations.Nullable;
+
+public class BooleanParser extends ArgumentParser<Boolean> {
+
+    @Override
+    public @Nullable Boolean parse(Arguments arguments) {
+        return Boolean.parseBoolean(arguments.poll());
+    }
+}
diff --git a/src/main/java/cc/polyfrost/oneconfig/utils/commands/arguments/DoubleParser.java b/src/main/java/cc/polyfrost/oneconfig/utils/commands/arguments/DoubleParser.java
new file mode 100644
index 0000000..8c85849
--- /dev/null
+++ b/src/main/java/cc/polyfrost/oneconfig/utils/commands/arguments/DoubleParser.java
@@ -0,0 +1,10 @@
+package cc.polyfrost.oneconfig.utils.commands.arguments;
+
+import org.jetbrains.annotations.Nullable;
+
+public class DoubleParser extends ArgumentParser<Double> {
+    @Override
+    public @Nullable Double parse(Arguments arguments) {
+        return Double.parseDouble(arguments.poll());
+    }
+}
diff --git a/src/main/java/cc/polyfrost/oneconfig/utils/commands/arguments/FloatParser.java b/src/main/java/cc/polyfrost/oneconfig/utils/commands/arguments/FloatParser.java
new file mode 100644
index 0000000..7053fcb
--- /dev/null
+++ b/src/main/java/cc/polyfrost/oneconfig/utils/commands/arguments/FloatParser.java
@@ -0,0 +1,11 @@
+package cc.polyfrost.oneconfig.utils.commands.arguments;
+
+import org.jetbrains.annotations.Nullable;
+
+public class FloatParser extends ArgumentParser<Float> {
+
+    @Override
+    public @Nullable Float parse(Arguments arguments) {
+        return Float.parseFloat(arguments.poll());
+    }
+}
diff --git a/src/main/java/cc/polyfrost/oneconfig/utils/commands/arguments/IntegerParser.java b/src/main/java/cc/polyfrost/oneconfig/utils/commands/arguments/IntegerParser.java
new file mode 100644
index 0000000..6910d4b
--- /dev/null
+++ b/src/main/java/cc/polyfrost/oneconfig/utils/commands/arguments/IntegerParser.java
@@ -0,0 +1,8 @@
+package cc.polyfrost.oneconfig.utils.commands.arguments;
+
+public class IntegerParser extends ArgumentParser<Integer> {
+    @Override
+    public Integer parse(Arguments arguments) {
+        return Integer.parseInt(arguments.poll());
+    }
+}
diff --git a/src/main/java/cc/polyfrost/oneconfig/utils/commands/arguments/StringParser.java b/src/main/java/cc/polyfrost/oneconfig/utils/commands/arguments/StringParser.java
new file mode 100644
index 0000000..6a34722
--- /dev/null
+++ b/src/main/java/cc/polyfrost/oneconfig/utils/commands/arguments/StringParser.java
@@ -0,0 +1,18 @@
+package cc.polyfrost.oneconfig.utils.commands.arguments;
+
+public class StringParser extends ArgumentParser<String> {
+
+    @Override
+    public String parse(Arguments arguments) {
+        if (arguments.greedy) {
+            StringBuilder builder = new StringBuilder();
+            while (arguments.hasNext()) {
+                String arg = arguments.poll();
+                builder.append(arg).append(" ");
+            }
+            return builder.toString().trim();
+        } else {
+            return arguments.poll();
+        }
+    }
+}