Updated Command System.

Author: RealMangorage

src/main/java/module-info.java

@@ -17,6 +17,7 @@
     requires static org.spongepowered.mixin;
 
     requires com.google.gson;
+    requires guava;
 
     // Config API
     exports org.mangorage.mangobotcore.api.config.v1;
@@ -25,6 +26,9 @@
     exports org.mangorage.mangobotcore.api.jda.command.v1;
     exports org.mangorage.mangobotcore.api.jda.event.v1;
 
+    // Command API
+    exports org.mangorage.mangobotcore.api.command.v1;
+
     // Plugin API
     exports org.mangorage.mangobotcore.api.plugin;
     exports org.mangorage.mangobotcore.api.plugin.v1;

src/main/java/org/mangorage/mangobotcore/api/command/v1/ICommandContext.java

@@ -0,0 +1,6 @@
+package org.mangorage.mangobotcore.api.command.v1;
+
+public interface ICommandContext {
+    <T> T get(Class<T> tClass);
+    boolean hasType(Class<?> tClass);
+}

src/main/java/org/mangorage/mangobotcore/api/command/v1/ICommandDispatcher.java

@@ -0,0 +1,14 @@
+package org.mangorage.mangobotcore.api.command.v1;
+
+import org.mangorage.mangobotcore.internal.command.CommandDispatcher;
+
+public interface ICommandDispatcher {
+    static ICommandDispatcher create(ICommandResult invalid) {
+        return new CommandDispatcher(invalid);
+    }
+
+    void register(ICommandNode commandNode);
+    ICommandNode getCommandNode(String name);
+
+    ICommandResult execute(String input, ICommandContext context);
+}

src/main/java/org/mangorage/mangobotcore/api/command/v1/ICommandExecutor.java

@@ -0,0 +1,7 @@
+package org.mangorage.mangobotcore.api.command.v1;
+
+import org.mangorage.mangobotcore.api.util.misc.Arguments;
+
+public interface ICommandExecutor {
+    ICommandResult execute(ICommandContext context, Arguments arguments);
+}

src/main/java/org/mangorage/mangobotcore/api/command/v1/ICommandNode.java

@@ -0,0 +1,17 @@
+package org.mangorage.mangobotcore.api.command.v1;
+
+import org.mangorage.mangobotcore.internal.command.CommandNodeBuilder;
+
+import java.util.List;
+
+public interface ICommandNode {
+    static ICommandNodeBuilder create(String name) {
+        return new CommandNodeBuilder(name);
+    }
+
+    String getName();
+    String getUsage();
+    List<ICommandNode> getSubNodes();
+
+    ICommandResult execute(ICommandContext commandContext, List<String> arguments);
+}

src/main/java/org/mangorage/mangobotcore/api/command/v1/ICommandNodeBuilder.java

@@ -0,0 +1,12 @@
+package org.mangorage.mangobotcore.api.command.v1;
+
+import java.util.function.Function;
+
+public interface ICommandNodeBuilder {
+    ICommandNodeBuilder usage(String usage);
+    ICommandNodeBuilder then(ICommandNode node);
+    ICommandNodeBuilder requires(Function<ICommandContext, Boolean> requiresChecker);
+    ICommandNodeBuilder executes(ICommandExecutor executor);
+
+    ICommandNode build();
+}

src/main/java/org/mangorage/mangobotcore/api/command/v1/ICommandResult.java

@@ -0,0 +1,5 @@
+package org.mangorage.mangobotcore.api.command.v1;
+
+public interface ICommandResult {
+    String getResultReason();
+}

src/main/java/org/mangorage/mangobotcore/api/jda/command/v1/CommandResult.java

@@ -23,19 +23,21 @@
 package org.mangorage.mangobotcore.api.jda.command.v1;
 
 import net.dv8tion.jda.api.entities.Message;
+import org.mangorage.mangobotcore.api.command.v1.ICommandResult;
 import org.mangorage.mangobotcore.api.util.jda.MessageSettings;
 
 import java.util.HashMap;
 
 
-public record CommandResult(String string) {
+public record CommandResult(String string) implements ICommandResult {
     private static final MessageSettings DEFAULT_SETTINGS = MessageSettings.create().build();
     private static final HashMap<String, CommandResult> CACHE = new HashMap<>();
 
     public static CommandResult of(String content) {
         return CACHE.computeIfAbsent(content, CommandResult::new);
     }
 
+    public static final CommandResult INVALID_COMMAND = of("Invalid Command!");
     public static final CommandResult PASS = of(null);
     public static final CommandResult FAIL = of("An error occurred while executing this command");
     public static final CommandResult NO_PERMISSION = of("You don't have permission to use this command!");
@@ -48,4 +50,9 @@ public void accept(Message message) {
         if (string() != null)
             DEFAULT_SETTINGS.apply(message.reply(string)).queue();
     }
+
+    @Override
+    public String getResultReason() {
+        return string;
+    }
 }

src/main/java/org/mangorage/mangobotcore/internal/command/CommandDispatcher.java

@@ -0,0 +1,45 @@
+package org.mangorage.mangobotcore.internal.command;
+
+import org.mangorage.mangobotcore.api.command.v1.ICommandContext;
+import org.mangorage.mangobotcore.api.command.v1.ICommandDispatcher;
+import org.mangorage.mangobotcore.api.command.v1.ICommandNode;
+import org.mangorage.mangobotcore.api.command.v1.ICommandResult;
+
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+public final class CommandDispatcher implements ICommandDispatcher {
+    private final Map<String, ICommandNode> roots = new HashMap<>();
+    private final ICommandResult defaultInvalid;
+
+    public CommandDispatcher(ICommandResult defaultInvalid) {
+        this.defaultInvalid = defaultInvalid;
+    }
+
+    @Override
+    public void register(ICommandNode commandNode) {
+        roots.put(
+                commandNode.getName(),
+                commandNode
+        );
+    }
+
+    @Override
+    public ICommandNode getCommandNode(String name) {
+        return roots.get(name);
+    }
+
+    @Override
+    public ICommandResult execute(String input, ICommandContext context) {
+        String[] split = input.trim().split("\\s+");
+        if (split.length == 0)
+            return defaultInvalid;
+
+        ICommandNode root = roots.get(split[0]);
+        if (root == null)
+            return defaultInvalid;
+
+        return root.execute(context, List.of(split).subList(1, split.length));
+    }
+}

src/main/java/org/mangorage/mangobotcore/internal/command/CommandNode.java

@@ -0,0 +1,67 @@
+package org.mangorage.mangobotcore.internal.command;
+
+import com.google.common.collect.ImmutableMap;
+import org.mangorage.mangobotcore.api.command.v1.ICommandContext;
+import org.mangorage.mangobotcore.api.command.v1.ICommandExecutor;
+import org.mangorage.mangobotcore.api.command.v1.ICommandNode;
+import org.mangorage.mangobotcore.api.command.v1.ICommandResult;
+import org.mangorage.mangobotcore.api.jda.command.v1.CommandResult;
+import org.mangorage.mangobotcore.api.util.misc.Arguments;
+import java.util.*;
+import java.util.function.Function;
+
+public final class CommandNode implements ICommandNode {
+    private final String name;
+    private final String usage;
+    private final Function<ICommandContext, Boolean> requiresCheck;
+    private final Map<String, ICommandNode> children;
+    private final ICommandExecutor executor;
+
+    public CommandNode(String name, String usage, Function<ICommandContext, Boolean> requiresCheck, Map<String, ICommandNode> children, ICommandExecutor executor) {
+        this.name = name;
+        this.usage = usage;
+        this.requiresCheck = requiresCheck;
+        this.children = ImmutableMap.copyOf(children);
+        this.executor = executor;
+    }
+
+    @Override
+    public String getName() {
+        return name;
+    }
+
+    @Override
+    public String getUsage() {
+        return usage;
+    }
+
+    @Override
+    public List<ICommandNode> getSubNodes() {
+        return null;
+    }
+
+    public ICommandResult execute(ICommandContext ctx, List<String> args) {
+        if (!requiresCheck.apply(ctx)) {
+            return CommandResult.NO_PERMISSION;
+        }
+
+        if (args.isEmpty()) {
+            if (executor == null)
+                throw new RuntimeException("No executor for command: " + name);
+            return executor.execute(ctx, Arguments.empty());
+        }
+
+        String next = args.getFirst();
+        ICommandNode child = children.get(next);
+
+        if (child != null) {
+            return child.execute(ctx, args.subList(1, args.size()));
+        } else {
+            if (executor == null)
+                return CommandResult.FAIL;
+
+            return executor.execute(ctx, Arguments.of(args.toArray(String[]::new)));
+        }
+    }
+}
+