Ensure we send commands/chat the same way a Java client would (#4703)

* Ensure we send commands/chat the same way a Java client would

* yeet static import, move blank check

core/src/main/java/org/geysermc/geyser/translator/protocol/bedrock/BedrockCommandRequestTranslator.java

@@ -26,8 +26,8 @@
 package org.geysermc.geyser.translator.protocol.bedrock;
 
 import org.cloudburstmc.protocol.bedrock.packet.CommandRequestPacket;
-import org.geysermc.geyser.api.util.PlatformType;
 import org.geysermc.geyser.GeyserImpl;
+import org.geysermc.geyser.api.util.PlatformType;
 import org.geysermc.geyser.session.GeyserSession;
 import org.geysermc.geyser.translator.protocol.PacketTranslator;
 import org.geysermc.geyser.translator.protocol.Translator;
@@ -39,15 +39,17 @@ public class BedrockCommandRequestTranslator extends PacketTranslator<CommandReq
     @Override
     public void translate(GeyserSession session, CommandRequestPacket packet) {
         String command = MessageTranslator.convertToPlainText(packet.getCommand());
+        handleCommand(session, MessageTranslator.normalizeSpace(command).substring(1));
+    }
+
+    static void handleCommand(GeyserSession session, String command) {
         if (!(session.getGeyser().getPlatformType() == PlatformType.STANDALONE
-                && GeyserImpl.getInstance().commandManager().runCommand(session, command.substring(1)))) {
+                && GeyserImpl.getInstance().commandManager().runCommand(session, command))) {
             if (MessageTranslator.isTooLong(command, session)) {
                 return;
             }
 
-            // running commands via Bedrock's command select menu adds a trailing whitespace which Java doesn't like
-            // https://github.com/GeyserMC/Geyser/issues/3877
-            session.sendCommand(command.substring(1).stripTrailing());
+            session.sendCommand(command);
         }
     }
 }

core/src/main/java/org/geysermc/geyser/translator/protocol/bedrock/BedrockTextTranslator.java

@@ -36,13 +36,22 @@ public class BedrockTextTranslator extends PacketTranslator<TextPacket> {
 
     @Override
     public void translate(GeyserSession session, TextPacket packet) {
-        String message = MessageTranslator.convertToPlainText(packet.getMessage());
+        // Java trims all messages, and then checks for the leading slash
+        String message = MessageTranslator.convertToPlainText(
+                MessageTranslator.normalizeSpace(packet.getMessage())
+        );
 
         if (message.isBlank()) {
             // Java Edition (as of 1.17.1) just doesn't pass on these messages, so... we won't either!
             return;
         }
 
+        if (message.startsWith("/")) {
+            // Yes, Java actually allows whitespaces before commands and will still see those as valid
+            BedrockCommandRequestTranslator.handleCommand(session, message.substring(1));
+            return;
+        }
+
         if (MessageTranslator.isTooLong(message, session)) {
             return;
         }

core/src/main/java/org/geysermc/geyser/translator/text/MessageTranslator.java

@@ -387,6 +387,39 @@ public class MessageTranslator {
         return false;
     }
 
+    /**
+     * Normalizes whitespaces - a thing a vanilla client apparently does with commands and chat messages.
+     */
+    public static String normalizeSpace(String string) {
+        if (string == null || string.isEmpty()) {
+            return string;
+        }
+        final int size = string.length();
+        final char[] newChars = new char[size];
+        int count = 0;
+        int whitespacesCount = 0;
+        boolean startWhitespaces = true;
+        for (int i = 0; i < size; i++) {
+            final char actualChar = string.charAt(i);
+            final boolean isWhitespace = Character.isWhitespace(actualChar);
+            if (isWhitespace) {
+                if (whitespacesCount == 0 && !startWhitespaces) {
+                    newChars[count++] = ' ';
+                }
+                whitespacesCount++;
+            } else {
+                startWhitespaces = false;
+                // Replace non-breaking spaces with regular spaces for normalization
+                newChars[count++] = (actualChar == '\u00A0' ? ' ' : actualChar);
+                whitespacesCount = 0;
+            }
+        }
+        if (startWhitespaces) {
+            return "";
+        }
+        return new String(newChars, 0, count - (whitespacesCount > 0 ? 1 : 0)).trim();
+    }
+
     public static void init() {
         // no-op
     }