Command System Functionality!

Author: ZeroMemes

src/main/java/me/zero/client/api/command/ICommand.java

@@ -17,6 +17,7 @@
 package me.zero.client.api.command;
 
 import me.zero.client.api.command.exception.CommandException;
+import me.zero.client.api.command.executor.sender.CommandSender;
 import me.zero.client.api.util.interfaces.Helper;
 import net.minecraft.client.network.NetworkPlayerInfo;
 
@@ -31,14 +32,13 @@
 interface ICommand extends Helper {
 
     /**
-     * Executes this command from the specified player
-     * represented by its {@code NetworkPlayerInfo}. This
-     * can be used to allow other players to execute commands.
+     * Executes this command from the specified sender with
+     * the specified arguments, represented as a {@code String} array
      *
-     * @param sender The NetworkPlayerInfo that executed this command
+     * @param sender The Sender that executed this command
      * @param arguments The arguments that
      */
-    void execute(NetworkPlayerInfo sender, String[] arguments) throws CommandException;
+    void execute(CommandSender sender, String[] arguments) throws CommandException;
 
     /**
      * Returns the array of possible command "headers"

src/main/java/me/zero/client/api/command/exception/UnknownCommandException.java

@@ -0,0 +1,15 @@
+package me.zero.client.api.command.exception;
+
+/**
+ * Thrown when a command was expected, but no command headers
+ * matched the specified command.
+ *
+ * @author Brady
+ * @since 6/11/2017 3:26 PM
+ */
+public final class UnknownCommandException extends CommandException {
+
+    public UnknownCommandException() {
+        super(null);
+    }
+}

src/main/java/me/zero/client/api/command/executor/CommandExecutor.java

@@ -0,0 +1,30 @@
+/*
+ * Copyright 2017 ZeroMemes
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package me.zero.client.api.command.executor;
+
+import me.zero.client.api.command.Command;
+import me.zero.client.api.command.exception.CommandException;
+import me.zero.client.api.command.executor.sender.CommandSender;
+
+/**
+ * @author Brady
+ * @since 6/11/2017 9:26 AM
+ */
+public interface CommandExecutor {
+
+    void execute(Command command, CommandSender sender, String[] arguments) throws CommandException;
+}

src/main/java/me/zero/client/api/command/executor/DirectExecutor.java

@@ -0,0 +1,33 @@
+/*
+ * Copyright 2017 ZeroMemes
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package me.zero.client.api.command.executor;
+
+import me.zero.client.api.command.Command;
+import me.zero.client.api.command.exception.CommandException;
+import me.zero.client.api.command.executor.sender.CommandSender;
+
+/**
+ * @author Brady
+ * @since 6/11/2017 9:27 AM
+ */
+public final class DirectExecutor implements CommandExecutor {
+
+    @Override
+    public void execute(Command command, CommandSender sender, String[] arguments) throws CommandException {
+        command.execute(sender, arguments);
+    }
+}

src/main/java/me/zero/client/api/command/executor/sender/CommandSender.java

@@ -0,0 +1,18 @@
+package me.zero.client.api.command.executor.sender;
+
+import net.minecraft.entity.player.EntityPlayer;
+
+/**
+ * Represents a
+ *
+ * @author Brady
+ * @since 6/11/2017 6:41 PM
+ */
+public interface CommandSender {
+
+    String getName();
+
+    static CommandSender from(EntityPlayer player) {
+        return player::getName;
+    }
+}

src/main/java/me/zero/client/api/command/handler/CommandHandler.java

@@ -16,9 +16,115 @@
 
 package me.zero.client.api.command.handler;
 
+import me.zero.alpine.listener.EventHandler;
+import me.zero.alpine.listener.Listener;
+import me.zero.client.api.Client;
+import me.zero.client.api.command.exception.CommandException;
+import me.zero.client.api.command.exception.UnknownCommandException;
+import me.zero.client.api.command.exception.handler.ExceptionHandler;
+import me.zero.client.api.command.executor.CommandExecutor;
+import me.zero.client.api.command.executor.DirectExecutor;
+import me.zero.client.api.event.defaults.internal.CommandExecutionEvent;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.stream.Collectors;
+
 /**
  * @author Brady
  * @since 6/1/2017 3:03 PM
  */
-public class CommandHandler {
+public final class CommandHandler {
+
+    /**
+     * Handlers to process command exceptions
+     */
+    private final List<ExceptionHandler> handlers = new ArrayList<>();
+
+    /**
+     * Executor that is called to execute commands. The default executor
+     * is set to a {@code DirectExecutor}
+     */
+    private CommandExecutor executor = new DirectExecutor();
+
+    /**
+     * Client that is using this command handler
+     */
+    private final Client client;
+
+    /**
+     * Prefix used to indicate command input. The default
+     * prefix is "."
+     */
+    private String prefix = ".";
+
+    public CommandHandler(Client client) {
+        this.client = client;
+    }
+
+    @EventHandler
+    private final Listener<CommandExecutionEvent> commandExecutionListener = new Listener<>(event -> {
+        try {
+            if (event.getCommand() != null)
+                executor.execute(event.getCommand(), event.getSender(), event.getArguments());
+            else
+                throw new UnknownCommandException();
+        } catch (CommandException e) {
+            List<ExceptionHandler> handlers = findHandlers(e);
+            handlers.forEach(handler -> handler.accept(e));
+        }
+    });
+
+    /**
+     * Finds handlers that target the specified CommandException
+     *
+     * @param exception The command exception
+     * @return The list of handlers, empty if none
+     */
+    private List<ExceptionHandler> findHandlers(CommandException exception) {
+        return handlers.stream().filter(handler -> handler.getType() == exception.getClass()).collect(Collectors.toList());
+    }
+
+    /**
+     * Registers an {@code ExceptionHandler} to the handlers list.
+     */
+    public final void registerHandler(ExceptionHandler handler) {
+        if (!handlers.contains(handler))
+            handlers.add(handler);
+    }
+
+    /**
+     * @return The client that is using this handler
+     */
+    public final Client getClient() {
+        return this.client;
+    }
+
+    /**
+     * Sets the command executor
+     */
+    public final void setExecutor(CommandExecutor executor) {
+        this.executor = executor;
+    }
+
+    /**
+     * @return The command executor in use
+     */
+    public final CommandExecutor getExecutor() {
+        return this.executor;
+    }
+
+    /**
+     * Sets the chat command prefix
+     */
+    public final void setPrefix(String prefix) {
+        this.prefix = prefix;
+    }
+
+    /**
+     * @return The chat command prefix
+     */
+    public final String getPrefix() {
+        return this.prefix;
+    }
 }

src/main/java/me/zero/client/api/command/handler/listener/ChatCommandListener.java

@@ -0,0 +1,86 @@
+package me.zero.client.api.command.handler.listener;
+
+import me.zero.alpine.listener.EventHandler;
+import me.zero.alpine.listener.Listener;
+import me.zero.client.api.ClientAPI;
+import me.zero.client.api.command.Command;
+import me.zero.client.api.command.handler.CommandHandler;
+import me.zero.client.api.command.executor.sender.CommandSender;
+import me.zero.client.api.event.defaults.ChatEvent;
+import me.zero.client.api.event.defaults.internal.CommandExecutionEvent;
+import me.zero.client.api.util.interfaces.Helper;
+import net.minecraft.util.text.TextComponentString;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+/**
+ * @author Brady
+ * @since 6/11/2017 1:47 PM
+ */
+public final class ChatCommandListener extends CommandListener implements Helper {
+
+    private static final Pattern REGEX = Pattern.compile("\"([^\"]+)\"|'([^']+)'|([^\\s]+)");
+
+    public ChatCommandListener(CommandHandler handler) {
+        super(handler);
+    }
+
+    @EventHandler
+    private final Listener<ChatEvent.Send> chatListener =  new Listener<>(event -> {
+        String raw = event.getRawMessage();
+
+        // If the user sends a message starting with a backslash, then we'll send whatever follows it.
+        if (raw.startsWith("\\") && raw.length() > 1) {
+            event.setMessage(new TextComponentString(raw.substring(1)));
+            return;
+        }
+
+        if (raw.startsWith(handler.getPrefix())) {
+            try {
+                // No matter what, always cancel the message if it starts with the command prefix
+                event.cancel();
+
+                // Removed the prefix from the message
+                raw = raw.substring(handler.getPrefix().length());
+
+                // Create a matcher to parse the message
+                Matcher matcher = REGEX.matcher(raw);
+
+                List<String> matches = new ArrayList<>();
+                while (matcher.find()) {
+                    matches.add(matcher.group());
+                }
+
+                // Only handle the command if there is at least 1 argument group
+                if (matches.size() > 0) {
+                    Command command = handler.getClient().getCommandManager().getData().stream().filter(cmd -> {
+                        for (String header : cmd.headers()) {
+                            if (header.equalsIgnoreCase(matches.get(0))) {
+                                return true;
+                            }
+                        }
+                        return false;
+                    }).findFirst().orElse(null);
+
+                    // Only handle the command if it's found
+                    if (command != null) {
+                        // Get all matches after the first one, these are treated as arguments
+                        String[] args = new String[matches.size() - 1];
+                        for (int i = 1; i < matches.size(); i++)
+                            args[i - 1] = matches.get(i).replace("\"", "").replace("\'", "");
+
+                        ClientAPI.EVENT_BUS.post(new CommandExecutionEvent(command, CommandSender.from(mc.player), args));
+                    }
+                }
+
+                // This will be interpreted as an unknown command
+                ClientAPI.EVENT_BUS.post(new CommandExecutionEvent(null, null, null));
+            } catch (Exception e) {
+                e.printStackTrace();
+            }
+        }
+    });
+}

src/main/java/me/zero/client/api/command/handler/listener/CommandListener.java

@@ -0,0 +1,16 @@
+package me.zero.client.api.command.handler.listener;
+
+import me.zero.client.api.command.handler.CommandHandler;
+
+/**
+ * @author Brady
+ * @since 6/11/2017 1:47 PM
+ */
+public class CommandListener {
+
+    protected final CommandHandler handler;
+
+    public CommandListener(CommandHandler handler) {
+        this.handler = handler;
+    }
+}

src/main/java/me/zero/client/api/event/defaults/internal/CommandExecutionEvent.java

@@ -0,0 +1,44 @@
+package me.zero.client.api.event.defaults.internal;
+
+import me.zero.client.api.command.Command;
+import me.zero.client.api.command.executor.sender.CommandSender;
+
+/**
+ * @author Brady
+ * @since 6/11/2017 9:42 AM
+ */
+public final class CommandExecutionEvent {
+
+    /**
+     * The command being executed
+     */
+    private final Command command;
+
+    /**
+     * Sender that executed the command
+     */
+    private final CommandSender sender;
+
+    /**
+     * Arguments to be passed to the command
+     */
+    private final String[] arguments;
+
+    public CommandExecutionEvent(Command command, CommandSender sender, String[] arguments) {
+        this.command = command;
+        this.sender = sender;
+        this.arguments = arguments;
+    }
+
+    public final Command getCommand() {
+        return this.command;
+    }
+
+    public final CommandSender getSender() {
+        return this.sender;
+    }
+
+    public final String[] getArguments() {
+        return this.arguments;
+    }
+}