Support for permission expression (complex permissions that looks like boolean expressions)

Core/pom.xml

@@ -52,6 +52,12 @@
 		    <version>4.8.108</version>
             <scope>compile</scope>
 		</dependency>
+		
+		<dependency>
+			<groupId>com.fathzer</groupId>
+			<artifactId>javaluator</artifactId>
+			<version>3.0.3</version>
+		</dependency> 
     </dependencies>
     
     <build>

Core/src/main/java/fr/pandacube/lib/core/permissions/PermEntity.java

@@ -101,12 +101,19 @@ public abstract class PermEntity {
 	
 	public Boolean hasPermission(String permission, String server, String world) {
 		Boolean ret = Permissions.resolver.getEffectivePermission(name, type, permission, server, world);
-		if (Log.isDebugEnabled()) {
-			Log.debug("[Perm] For " + type.toString().toLowerCase() + " " + getName() + ", '" + permission + "' is " + ret);
-		}
+		Log.debug("[Perm] For " + type.toString().toLowerCase() + " " + getName() + ", '" + permission + "' is " + ret);
 		return ret;
 	}
 	
+	public boolean hasPermissionOr(String permission, String server, String world, boolean deflt) {
+		Boolean ret = hasPermission(permission, server, world);
+		return ret != null ? ret : deflt;
+	}
+	
+	public boolean hasPermissionExpression(String permExpression, String server, String world) {
+		return PermissionExpressionParser.evaluate(permExpression, p -> hasPermissionOr(p, server, world, false));
+	}
+	
 	
 	public DisplayTreeNode debugPermission(String permission) {
 		return debugPermission(permission, null, null);

Core/src/main/java/fr/pandacube/lib/core/permissions/PermissionExpressionParser.java

@@ -0,0 +1,115 @@
+package fr.pandacube.lib.core.permissions;
+
+import java.util.Iterator;
+import java.util.function.Function;
+
+import com.fathzer.soft.javaluator.AbstractEvaluator;
+import com.fathzer.soft.javaluator.BracketPair;
+import com.fathzer.soft.javaluator.Operator;
+import com.fathzer.soft.javaluator.Operator.Associativity;
+import com.fathzer.soft.javaluator.Parameters;
+
+public class PermissionExpressionParser {
+	
+	private static final PermissionEvaluator PERMISSION_EVALUATOR = new PermissionEvaluator();
+
+	public static boolean evaluate(String permString, LitteralPermissionTester permTester) {
+		try {
+			return PERMISSION_EVALUATOR.evaluate(permString, permTester);
+		} catch (IllegalArgumentException e) {
+			throw new IllegalArgumentException("Can’t evaluate the provided permission expression: '" + permString + "'", e);
+		}
+	}
+
+	public interface LitteralPermissionTester extends Function<String, Boolean> { }
+	
+	
+	
+	
+	
+	private static class PermissionEvaluator extends AbstractEvaluator<Boolean> {
+
+		private static final Operator NOT = new Operator("!", 1, Associativity.LEFT, 3);
+		private static final Operator AND = new Operator("&&", 2, Associativity.LEFT, 2);
+		private static final Operator OR = new Operator("||", 2, Associativity.LEFT, 1);
+		
+		
+		private static final Parameters PARAMETERS;
+		
+		static {
+			PARAMETERS = new Parameters();
+			PARAMETERS.add(NOT);
+			PARAMETERS.add(AND);
+			PARAMETERS.add(OR);
+			PARAMETERS.addExpressionBracket(BracketPair.PARENTHESES);
+		}
+		
+		
+		
+		public PermissionEvaluator() {
+			super(PARAMETERS);
+		}
+		
+		@Override
+		protected Boolean toValue(String literal, Object evaluationContext) {
+			if (literal.contains(" ") || literal.contains("|") || literal.contains("&"))
+				throw new IllegalArgumentException("Unable to parse the following part of permission expression as one permission node: '" + literal + "'");
+			return evaluationContext instanceof LitteralPermissionTester pt ? pt.apply(literal) : false;
+		}
+		
+		@Override
+		protected Boolean evaluate(Operator operator, Iterator<Boolean> operands, Object evaluationContext) {
+			if (operator == NOT) {
+				return !operands.next();
+			} else if (operator == OR) {
+				Boolean o1 = operands.next();
+				Boolean o2 = operands.next();
+				return o1 || o2;
+			} else if (operator == AND) {
+				Boolean o1 = operands.next();
+				Boolean o2 = operands.next();
+				return o1 && o2;
+			} else {
+				return super.evaluate(operator, operands, evaluationContext);
+			}
+		}
+	}
+	
+	
+	/*
+	public static void main(String[] args) {
+		java.util.List<String> pList = java.util.Arrays.asList("p1.cmd", "p1.toto", "p2.lol");
+		LitteralPermissionTester tester = p -> pList.contains(p);
+		
+		for (String permExpr : java.util.Arrays.asList(
+				"p1.cmd", // true
+				"p1.notexist", // false
+				"p2lol.lol", // false
+				"!p1.notexist", // true
+				"!p1.cmd", // false
+				"p1.cmd!", // false
+				"p1.cmd! p2.lol", // exception
+				"p1.cmd || p1.toto", // true || true == true
+				"p1.cmd || p1.notexist", // true || false == true
+				"p1.fefef || p2.lol", // false || true == true
+				"p1.fefef || p2.lolilol", // false || false == false
+				"p1.cmd && p1.toto", // true && true == true
+				"p1.cmd && p1.notexist", // true && false == false
+				"p1.fefef && p2.lol", // false && true == false
+				"p1.fefef && p2.lolilol", // false && false == false
+				"p1.cmd && !p1.toto  ", // true && !true == false
+				"   !p1.cmd &&    p1.toto", // !true && true == false
+				"!p1.cmd & p1.toto", // exception
+				"!p1.cmd | p1.toto", // exception
+				"p1.not exist" // exception
+				)) {
+			try {
+				System.out.println(permExpr + " -> " + evaluate(permExpr, tester));
+			} catch (Exception e) {
+				e.printStackTrace();
+			}
+		}
+	}
+	*/
+	
+}

Core/src/main/java/fr/pandacube/lib/core/players/IOffPlayer.java

@@ -123,6 +123,27 @@ public interface IOffPlayer {
 		return res != null ? res : false;
 	}
 	
+	/**
+	 * Tells if this player has the permission resulted from the provided expression.
+	 * If the player is online, this will redirect the
+	 * method call to the {@link IOnlinePlayer} instance,
+	 * that MUST override this current method to avoid recussive
+	 * loop.
+	 * If the player is offline, it just call the Pandacube
+	 * permission system.
+	 * @param permission the permission node to test
+	 * @return whether this player has the provided permission
+	 */
+	public default boolean hasPermissionExpression(String permissionExpression) {
+		IOnlinePlayer online = getOnlineInstance();
+		
+		if (online != null)
+			return online.hasPermissionExpression(permissionExpression);
+		
+		// at this point, the player is offline
+		return getPermissionUser().hasPermissionExpression(permissionExpression, null, null);
+	}
+
 	/**
 	 * Tells if the this player is part of the specified group
 	 * 

Core/src/main/java/fr/pandacube/lib/core/players/IOnlinePlayer.java

@@ -71,6 +71,14 @@ public interface IOnlinePlayer extends IOffPlayer {
 	 */
 	public abstract boolean hasPermission(String permission);
 
+	/**
+	 * Tells if this online player has the permission resulted from the provided expression.
+	 * @implSpec the implementation of this method must not directly or
+	 * indirectly call the method {@link IOffPlayer#hasPermissionExpression(String)},
+	 * or it may result in a {@link StackOverflowError}.
+	 */
+	public abstract boolean hasPermissionExpression(String permission);
+