Add GuardChecker

SpigotCore_Main/src/de/steamwar/command/GuardChecker.java

@@ -0,0 +1,30 @@
+/*
+ * This file is a part of the SteamWar software.
+ *
+ * Copyright (C) 2020  SteamWar.de-Serverteam
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package de.steamwar.command;
+
+import org.bukkit.command.CommandSender;
+
+@FunctionalInterface
+public interface GuardChecker {
+    /**
+     * While guarding the first parameter of the command the parameter s of this method is {@code null}
+     */
+    boolean guard(CommandSender commandSender, String[] previousArguments, String s);
+}

SpigotCore_Main/src/de/steamwar/command/SWCommand.java

@@ -39,6 +39,7 @@ public abstract class SWCommand {
     private final List<SubCommand> commandList = new ArrayList<>();
     private final List<SubCommand> commandHelpList = new ArrayList<>();
     private final Map<String, TypeMapper<?>> localTypeMapper = new HashMap<>();
+    private final Map<String, GuardChecker> localGuardChecker = new HashMap<>();
 
     protected SWCommand(String command) {
         this(command, new String[0]);
@@ -85,6 +86,13 @@ public abstract class SWCommand {
             addMapper(ClassMapper.class, method, i -> i == 0, false, TypeMapper.class, (anno, typeMapper) -> {
                 (anno.local() ? localTypeMapper : SWCommandUtils.MAPPER_FUNCTIONS).putIfAbsent(anno.value().getTypeName(), typeMapper);
             });
+            addGuard(Guard.class, method, i -> i == 0, false, GuardChecker.class, (anno, guardChecker) -> {
+                (anno.local() ? localGuardChecker : SWCommandUtils.GUARD_FUNCTIONS).putIfAbsent(anno.value(), guardChecker);
+            });
+            addGuard(ClassGuard.class, method, i -> i == 0, false, GuardChecker.class, (anno, guardChecker) -> {
+                (anno.local() ? localGuardChecker : SWCommandUtils.GUARD_FUNCTIONS).putIfAbsent(anno.value().getTypeName(), guardChecker);
+            });
+
             add(Register.class, method, i -> i > 0, true, null, (anno, parameters) -> {
                 if (!anno.help()) return;
                 if (parameters.length != 2) {
@@ -97,7 +105,7 @@ public abstract class SWCommand {
                     Bukkit.getLogger().log(Level.WARNING, () -> "The method '" + method.toString() + "' is lacking the varArgs parameters of type '" + String.class.getTypeName() + "' as last Argument");
                     return;
                 }
-                commandHelpList.add(new SubCommand(this, method, anno.value(), new HashMap<>()));
+                commandHelpList.add(new SubCommand(this, method, anno.value(), new HashMap<>(), localGuardChecker));
             });
         }
         for (Method method : methods) {
@@ -119,7 +127,7 @@ public abstract class SWCommand {
                         return;
                     }
                 }
-                commandList.add(new SubCommand(this, method, anno.value(), localTypeMapper));
+                commandList.add(new SubCommand(this, method, anno.value(), localTypeMapper, localGuardChecker));
             });
 
             this.commandList.sort((o1, o2) -> {
@@ -167,6 +175,17 @@ public abstract class SWCommand {
         });
     }
 
+    private <T extends Annotation> void addGuard(Class<T> annotation, Method method, IntPredicate parameterTester, boolean firstParameter, Class<?> returnType, BiConsumer<T, GuardChecker> consumer) {
+        add(annotation, method, parameterTester, firstParameter, returnType, (anno, parameters) -> {
+            try {
+                method.setAccessible(true);
+                consumer.accept(anno, (GuardChecker) method.invoke(this));
+            } catch (Exception e) {
+                throw new SecurityException(e.getMessage(), e);
+            }
+        });
+    }
+
     public void unregister() {
         SWCommandUtils.knownCommandMap.remove(command.getName());
         command.getAliases().forEach(SWCommandUtils.knownCommandMap::remove);
@@ -207,4 +226,20 @@ public abstract class SWCommand {
 
         boolean local() default false;
     }
+
+    @Retention(RetentionPolicy.RUNTIME)
+    @Target({ElementType.PARAMETER, ElementType.METHOD})
+    protected @interface Guard {
+        String value() default "";
+
+        boolean local() default false;
+    }
+
+    @Retention(RetentionPolicy.RUNTIME)
+    @Target({ElementType.METHOD})
+    protected @interface ClassGuard {
+        Class<?> value();
+
+        boolean local() default false;
+    }
 }

SpigotCore_Main/src/de/steamwar/command/SWCommandUtils.java

@@ -44,6 +44,7 @@ public class SWCommandUtils {
     }
 
     static final Map<String, TypeMapper<?>> MAPPER_FUNCTIONS = new HashMap<>();
+    static final Map<String, GuardChecker> GUARD_FUNCTIONS = new HashMap<>();
 
     static final TypeMapper<?> ERROR_FUNCTION = createMapper(s -> {
         throw new SecurityException();
@@ -100,7 +101,7 @@ public class SWCommandUtils {
         }
     }
 
-    static Object[] generateArgumentArray(CommandSender commandSender, TypeMapper<?>[] parameters, String[] args, Class<?> varArgType, String[] subCommand) throws CommandParseException {
+    static Object[] generateArgumentArray(CommandSender commandSender, TypeMapper<?>[] parameters, GuardChecker[] guards, String[] args, Class<?> varArgType, String[] subCommand) throws CommandParseException {
         Object[] arguments = new Object[parameters.length + 1];
         int index = 0;
         while (index < subCommand.length) {
@@ -116,6 +117,7 @@ public class SWCommandUtils {
         }
 
         for (int i = 0; i < parameters.length - (varArgType != null ? 1 : 0); i++) {
+            if (guards[i] != null && !guards[i].guard(commandSender, Arrays.copyOf(args, index), args[index])) throw new CommandParseException();
             arguments[i + 1] = parameters[i].map(commandSender, Arrays.copyOf(args, index), args[index]);
             index++;
             if (arguments[i + 1] == null) throw new CommandParseException();
@@ -125,6 +127,7 @@ public class SWCommandUtils {
             Object varArgument = arguments[arguments.length - 1];
 
             for (int i = 0; i < length; i++) {
+                if (guards[guards.length - 1] != null && !guards[guards.length - 1].guard(commandSender, Arrays.copyOf(args, index), args[index])) throw new CommandParseException();
                 Object value = parameters[parameters.length - 1].map(commandSender, Arrays.copyOf(args, index), args[index]);
                 if (value == null) throw new CommandParseException();
                 Array.set(varArgument, i, value);
@@ -142,6 +145,14 @@ public class SWCommandUtils {
         MAPPER_FUNCTIONS.putIfAbsent(name, mapper);
     }
 
+    public static void addGuard(Class<?> clazz, GuardChecker guardChecker) {
+        addGuard(clazz.getTypeName(), guardChecker);
+    }
+
+    public static void addGuard(String name, GuardChecker guardChecker) {
+        GUARD_FUNCTIONS.putIfAbsent(name, guardChecker);
+    }
+
     public static <T> TypeMapper<T> createMapper(Function<String, T> mapper, Function<String, List<String>> tabCompleter) {
         return createMapper(mapper, (commandSender, s) -> tabCompleter.apply(s));
     }

SpigotCore_Main/src/de/steamwar/command/SubCommand.java

@@ -19,6 +19,7 @@
 
 package de.steamwar.command;
 
+import org.bukkit.Bukkit;
 import org.bukkit.command.CommandSender;
 
 import java.lang.reflect.InvocationTargetException;
@@ -27,6 +28,7 @@ import java.lang.reflect.Parameter;
 import java.util.*;
 import java.util.function.Function;
 import java.util.function.Predicate;
+import java.util.logging.Level;
 
 import static de.steamwar.command.SWCommandUtils.*;
 
@@ -36,11 +38,13 @@ class SubCommand {
     private Method method;
     String[] subCommand;
     TypeMapper<?>[] arguments;
+    GuardChecker[] guards;
     private Predicate<CommandSender> commandSenderPredicate;
     private Function<CommandSender, ?> commandSenderFunction;
+    private GuardChecker guardChecker;
     Class<?> varArgType = null;
 
-    SubCommand(SWCommand swCommand, Method method, String[] subCommand, Map<String, TypeMapper<?>> localTypeMapper) {
+    SubCommand(SWCommand swCommand, Method method, String[] subCommand, Map<String, TypeMapper<?>> localTypeMapper, Map<String, GuardChecker> localGuardChecker) {
         this.swCommand = swCommand;
         this.method = method;
 
@@ -48,8 +52,10 @@ class SubCommand {
         commandSenderPredicate = sender -> parameters[0].getType().isAssignableFrom(sender.getClass());
         commandSenderFunction = sender -> parameters[0].getType().cast(sender);
         this.subCommand = subCommand;
+        guardChecker = getGuardChecker(parameters[0], localGuardChecker);
 
         arguments = new TypeMapper[parameters.length - 1];
+        guards = new GuardChecker[parameters.length - 1];
         for (int i = 1; i < parameters.length; i++) {
             Parameter parameter = parameters[i];
             Class<?> clazz = parameter.getType();
@@ -76,9 +82,22 @@ class SubCommand {
             arguments[i - 1] = localTypeMapper.containsKey(name)
                     ? localTypeMapper.get(name)
                     : MAPPER_FUNCTIONS.getOrDefault(name, ERROR_FUNCTION);
+            guards[i - 1] = getGuardChecker(parameter, localGuardChecker);
         }
     }
 
+    private GuardChecker getGuardChecker(Parameter parameter, Map<String, GuardChecker> localGuardChecker) {
+        SWCommand.Guard guard = parameter.getAnnotation(SWCommand.Guard.class);
+        if (guard != null) {
+            GuardChecker current = localGuardChecker.getOrDefault(guard.value(), GUARD_FUNCTIONS.getOrDefault(guard.value(), null));
+            if (guardChecker == null) {
+                Bukkit.getLogger().log(Level.WARNING, () -> "The guard checker with name '" + guard.value() + "' is neither a local guard checker nor a global one");
+            }
+            return current;
+        }
+        return null;
+    }
+
     boolean invoke(CommandSender commandSender, String[] args) {
         if (args.length < arguments.length + subCommand.length - (varArgType != null ? 1 : 0)) {
             return false;
@@ -90,7 +109,10 @@ class SubCommand {
             if (!commandSenderPredicate.test(commandSender)) {
                 return false;
             }
-            Object[] objects = SWCommandUtils.generateArgumentArray(commandSender, arguments, args, varArgType, subCommand);
+            if (!guardChecker.guard(commandSender, new String[0], null)) {
+                return false;
+            }
+            Object[] objects = SWCommandUtils.generateArgumentArray(commandSender, arguments, guards, args, varArgType, subCommand);
             objects[0] = commandSenderFunction.apply(commandSender);
             method.setAccessible(true);
             method.invoke(swCommand, objects);
@@ -106,6 +128,9 @@ class SubCommand {
         if (varArgType == null && args.length > arguments.length + subCommand.length) {
             return null;
         }
+        if (guardChecker != null && !guardChecker.guard(commandSender, new String[0], null)) {
+            return null;
+        }
         int index = 0;
         List<String> argsList = new LinkedList<>(Arrays.asList(args));
         for (String value : subCommand) {
@@ -117,9 +142,15 @@ class SubCommand {
         for (TypeMapper<?> argument : arguments) {
             String s = argsList.remove(0);
             if (argsList.isEmpty()) {
+                if (guards[index] != null && !guards[index].guard(commandSender, Arrays.copyOf(args, args.length - 1), s)) {
+                    return null;
+                }
                 return argument.tabCompletes(commandSender, Arrays.copyOf(args, args.length - 1), s);
             }
             try {
+                if (guards[index] != null && !guards[index].guard(commandSender, Arrays.copyOf(args, index), s)) {
+                    return null;
+                }
                 if (argument.map(commandSender, Arrays.copyOf(args, index), s) == null) {
                     return null;
                 }
@@ -132,9 +163,15 @@ class SubCommand {
             while (!argsList.isEmpty()) {
                 String s = argsList.remove(0);
                 if (argsList.isEmpty()) {
+                    if (guards[guards.length - 1] != null && !guards[guards.length - 1].guard(commandSender, Arrays.copyOf(args, args.length - 1), s)) {
+                        return null;
+                    }
                     return arguments[arguments.length - 1].tabCompletes(commandSender, Arrays.copyOf(args, args.length - 1), s);
                 }
                 try {
+                    if (guards[guards.length - 1] != null && !guards[guards.length - 1].guard(commandSender, Arrays.copyOf(args, index), s)) {
+                        return null;
+                    }
                     if (arguments[arguments.length - 1].map(commandSender, Arrays.copyOf(args, index), s) == null) {
                         return null;
                     }