Support @n

modules/mapping/api/src/main/java/org/bitbucket/_newage/commandhook/util/VersionUtil.java

@@ -0,0 +1,25 @@
+package org.bitbucket._newage.commandhook.util;
+
+import org.bukkit.Bukkit;
+
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+
+public class VersionUtil {
+    private static final Pattern BUKKIT_VERSION_PATTERN = Pattern.compile("(\\d+\\.\\d+(\\.\\d+)?)");
+    private static final Pattern MINOR_VERSION_PATTERN = Pattern.compile("\\d+\\.(\\d+)(\\.\\d+)?");
+
+    public static String getMinecraftVersion() {
+        final Matcher bukkitVersionMatcher = BUKKIT_VERSION_PATTERN.matcher(Bukkit.getServer().getBukkitVersion());
+
+        if (bukkitVersionMatcher.find()) {
+            return bukkitVersionMatcher.group();
+        }
+        return null;
+    }
+    public static int getMinorVersion(String minecraftVersion) {
+        final Matcher minorVersionMatcher = MINOR_VERSION_PATTERN.matcher(minecraftVersion);
+        minorVersionMatcher.find();
+        return Integer.parseInt(minorVersionMatcher.group(1));
+    }
+}

modules/mapping/spigot/provider/src/main/java/org/bitbucket/_newage/commandhook/mapping/SpigotMappingSelector.java

@@ -5,13 +5,13 @@
 
 import org.bitbucket._newage.commandhook.mapping.api.IMapping;
 import org.bitbucket._newage.commandhook.mapping.api.MappingSelector;
+import org.bitbucket._newage.commandhook.util.VersionUtil;
 import org.bukkit.Bukkit;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
 public class SpigotMappingSelector extends MappingSelector {
     private static final Pattern NMS_PATTERN = Pattern.compile("(v\\d+_\\d+_\\w+)");
-    private static final Pattern BUKKIT_VERSION_PATTERN = Pattern.compile("(\\d+\\.\\d+(\\.\\d+)?)");
     private static final Logger log = LoggerFactory.getLogger(SpigotMappingSelector.class);
 
     @Override
@@ -30,11 +30,10 @@ public IMapping getMapping() {
     }
 
     private IMapping getMappingFromBukkitVersion() {
-        final Matcher bukkitVersionMatcher = BUKKIT_VERSION_PATTERN.matcher(Bukkit.getServer().getBukkitVersion());
+        String version = VersionUtil.getMinecraftVersion();
 
         IMapping mapping = null;
-        if (bukkitVersionMatcher.find()) {
-            String version = bukkitVersionMatcher.group();
+        if (version != null) {
             log.info("Minecraft version found: {}", version);
             mapping = fromMinecraftVersion(version);
         }

modules/plugin/src/main/java/org/bitbucket/_newage/commandhook/CommandBlockListener.java

@@ -4,6 +4,7 @@
 import java.util.regex.Pattern;
 
 import org.bitbucket._newage.commandhook.mapping.api.IMapping;
+import org.bitbucket._newage.commandhook.util.VersionUtil;
 import org.bukkit.Bukkit;
 import org.bukkit.command.BlockCommandSender;
 
@@ -16,10 +17,15 @@
 public class CommandBlockListener implements Listener {
 
     private static final Pattern SELECTOR_PATTERN = Pattern.compile("@[aeprs]([^a-zA-Z0-9]|$)");
+    private static final Pattern SELECTOR_PATTERN_WITH_AT_N = Pattern.compile("@[aenprs]([^a-zA-Z0-9]|$)");
+
     private final IMapping mapping;
+    private final Pattern selectorPattern;
 
-    public CommandBlockListener(IMapping mapping) {
+    public CommandBlockListener(IMapping mapping, String minecraftVersion) {
         this.mapping = mapping;
+        int minorVersion = VersionUtil.getMinorVersion(minecraftVersion);
+        selectorPattern = minorVersion >= 21 ? SELECTOR_PATTERN_WITH_AT_N : SELECTOR_PATTERN;
     }
 
     @EventHandler(priority = EventPriority.MONITOR)
@@ -34,7 +40,7 @@ public void onCommandBlockDispatch(ServerCommandEvent e) {
                 return;
             }
 
-            if (SELECTOR_PATTERN.matcher(cmd).find()) {
+            if (selectorPattern.matcher(cmd).find()) {
                 String selector = getSelectorWithArguments(cmd);
                 List<Entity> entities = mapping.getEntitiesFromSelector(selector, ((BlockCommandSender) e.getSender()).getBlock());
 

modules/plugin/src/main/java/org/bitbucket/_newage/commandhook/CommandHook.java

@@ -3,6 +3,7 @@
 import org.bitbucket._newage.commandhook.mapping.MappingProvider;
 import org.bitbucket._newage.commandhook.mapping.ServerBrand;
 import org.bitbucket._newage.commandhook.mapping.api.IMapping;
+import org.bitbucket._newage.commandhook.util.VersionUtil;
 import org.bukkit.plugin.java.JavaPlugin;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -19,7 +20,7 @@ public void onEnable() {
             return;
         }
 
-        CommandBlockListener listener = new CommandBlockListener(mapping);
+        CommandBlockListener listener = new CommandBlockListener(mapping, VersionUtil.getMinecraftVersion());
         getServer().getPluginManager().registerEvents(listener, this);
     }
 

modules/plugin/src/test/java/org/bitbucket/_newage/commandhook/SelectorParserTest.java

@@ -23,6 +23,14 @@ void testSelectorNoArgumentsAtTheEnd() {
         assertEquals("@a", result);
     }
 
+    @Test
+    void testSelectorAtN() {
+        final String selector = "tp @n[type=player] ~ ~1 ~";
+        final String result = getSelectorWithArguments(selector);
+
+        assertEquals("@n[type=player]", result);
+    }
+
     @Test
     void testSelectorWithArguments() {
         final String selector = "/kick @e[type=player,distance=..2] Too close to me";

modules/plugin/src/test/java/org/bitbucket/_newage/commandhook/SelectorRegexTest.java

@@ -13,7 +13,7 @@ class SelectorRegexTest {
 
     private final BlockCommandSender sender = mock();
     private final IMapping mapping = mock();
-    private final CommandBlockListener listener = new CommandBlockListener(mapping);
+    private final CommandBlockListener listener = new CommandBlockListener(mapping, "1.21");
 
     @Test
     void verifyNoInteractionsForMinecraftVanillaCommand() {