/*
    * Licensed to the Apache Software Foundation (ASF) under one or more
    * contributor license agreements.  See the NOTICE file distributed with
    * this work for additional information regarding copyright ownership.
    * The ASF licenses this file to You 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 org.apache.commons.jexl3.parser;
  
  import org.apache.commons.jexl3.JexlException;
  import org.apache.commons.jexl3.JexlFeatures;
  import org.apache.commons.jexl3.JexlInfo;
  import org.apache.commons.jexl3.internal.ScriptVisitor;
  /**
   * Controls that a script only uses enabled features.
   */
  public class FeatureController extends ScriptVisitor {
  
      /** The set of features. */
      private JexlFeatures features;
  
      /**
       * Creates a feature controller.
       */
      public FeatureController(final JexlFeatures features) {
          this.features = features;
      }
  
      /**
       * Sets the features to controlNode.
       * @param fdesc the features
       */
      public void setFeatures(final JexlFeatures fdesc) {
          this.features = fdesc;
      }
  
      /**
       * @return the controlled features
       */
      public JexlFeatures getFeatures() {
          return features;
      }
  
      /**
       * Perform the control on a node.
       * <p>Note that controlNode() does *not* visit node children in this class.
       * @param node the node to controlNode
       * @throws JexlException.Feature if required feature is disabled
       */
      public void controlNode(final JexlNode node) {
          node.jjtAccept(this, null);
      }
  
      @Override
      protected Object visitNode(final JexlNode node, final Object data) {
          // no need to visit them since we close them one by one
          return data;
      }
  
      /**
       * Throws a feature exception.
       * @param feature the feature code
       * @param node    the node that caused it
       */
      public void throwFeatureException(final int feature, final JexlNode node) {
          final JexlInfo dbgInfo = node.jexlInfo();
          throw new JexlException.Feature(dbgInfo, feature, "");
      }
  
      /**
       * Checks whether a node is a string or an integer.
       * @param child the child node
       * @return true if string / integer, false otherwise
       */
      private boolean isArrayReferenceLiteral(final JexlNode child) {
          if (child instanceof ASTStringLiteral) {
              return true;
          }
          if (child instanceof ASTNumberLiteral && ((ASTNumberLiteral) child).isInteger()) {
              return true;
          }
          return false;
      }
  
      @Override
      protected Object visit(final ASTArrayAccess node, final Object data) {
          if (!features.supportsArrayReferenceExpr()) {
              for (int i = 0; i < node.jjtGetNumChildren(); ++i) {
                  final JexlNode child = node.jjtGetChild(i);
                  if (!isArrayReferenceLiteral(child)) {
                     throwFeatureException(JexlFeatures.ARRAY_REF_EXPR, child);
                 }
             }
         }
         return data;
     }
 
     @Override
     protected Object visit(final ASTWhileStatement node, final Object data) {
         if (!features.supportsLoops()) {
             throwFeatureException(JexlFeatures.LOOP, node);
         }
         return data;
     }
 
     @Override
     protected Object visit(final ASTDoWhileStatement node, final Object data) {
         if (!features.supportsLoops()) {
             throwFeatureException(JexlFeatures.LOOP, node);
         }
         return data;
     }
 
     @Override
     protected Object visit(final ASTForeachStatement node, final Object data) {
         if (!features.supportsLoops()) {
             throwFeatureException(JexlFeatures.LOOP, node);
         }
         return data;
     }
 
     @Override
     protected Object visit(final ASTConstructorNode node, final Object data) {
         if (!features.supportsNewInstance()) {
             throwFeatureException(JexlFeatures.NEW_INSTANCE, node);
         }
         return data;
     }
 
     @Override
     protected Object visit(final ASTMethodNode node, final Object data) {
         if (!features.supportsMethodCall()) {
             throwFeatureException(JexlFeatures.METHOD_CALL, node);
         }
         return data;
     }
 
     @Override
     protected Object visit(final ASTAnnotation node, final Object data) {
         if (!features.supportsAnnotation()) {
             throwFeatureException(JexlFeatures.ANNOTATION, node);
         }
         return data;
     }
 
     @Override
     protected Object visit(final ASTArrayLiteral node, final Object data) {
         if (!features.supportsStructuredLiteral()) {
             throwFeatureException(JexlFeatures.STRUCTURED_LITERAL, node);
         }
         return data;
     }
 
     @Override
     protected Object visit(final ASTMapLiteral node, final Object data) {
         if (!features.supportsStructuredLiteral()) {
             throwFeatureException(JexlFeatures.STRUCTURED_LITERAL, node);
         }
         return data;
     }
 
     @Override
     protected Object visit(final ASTSetLiteral node, final Object data) {
         if (!features.supportsStructuredLiteral()) {
             throwFeatureException(JexlFeatures.STRUCTURED_LITERAL, node);
         }
         return data;
     }
 
     @Override
     protected Object visit(final ASTRangeNode node, final Object data) {
         if (!features.supportsStructuredLiteral()) {
             throwFeatureException(JexlFeatures.STRUCTURED_LITERAL, node);
         }
         return data;
     }
 
     private Object controlSideEffect(final JexlNode node, final Object data) {
         final JexlNode lv = node.jjtGetChild(0);
         if (!features.supportsSideEffectGlobal() && lv.isGlobalVar()) {
             throwFeatureException(JexlFeatures.SIDE_EFFECT_GLOBAL, lv);
         }
         if (!features.supportsSideEffect()) {
             throwFeatureException(JexlFeatures.SIDE_EFFECT, lv);
         }
         return data;
     }
 
     @Override
     protected Object visit(final ASTAssignment node, final Object data) {
         return controlSideEffect(node, data);
     }
 
     @Override
     protected Object visit(final ASTSetAddNode node, final Object data) {
         return controlSideEffect(node, data);
     }
 
     @Override
     protected Object visit(final ASTSetMultNode node, final Object data) {
         return controlSideEffect(node, data);
     }
 
     @Override
     protected Object visit(final ASTSetDivNode node, final Object data) {
         return controlSideEffect(node, data);
     }
 
     @Override
     protected Object visit(final ASTSetModNode node, final Object data) {
         return controlSideEffect(node, data);
     }
 
     @Override
     protected Object visit(final ASTSetAndNode node, final Object data) {
         return controlSideEffect(node, data);
     }
 
     @Override
     protected Object visit(final ASTSetOrNode node, final Object data) {
         return controlSideEffect(node, data);
     }
 
     @Override
     protected Object visit(final ASTSetXorNode node, final Object data) {
         return controlSideEffect(node, data);
     }
 
     @Override
     protected Object visit(final ASTSetSubNode node, final Object data) {
         return controlSideEffect(node, data);
     }
 
     @Override
     protected Object visit(final ASTSetShiftLeftNode node, final Object data) {
         return controlSideEffect(node, data);
     }
 
     @Override
     protected Object visit(final ASTSetShiftRightNode node, final Object data) {
         return controlSideEffect(node, data);
     }
 
     @Override
     protected Object visit(final ASTSetShiftRightUnsignedNode node, final Object data) {
         return controlSideEffect(node, data);
     }
 
     @Override
     protected Object visit(final ASTGetDecrementNode node, final Object data) {
         return controlSideEffect(node, data);
     }
 
     @Override
     protected Object visit(final ASTGetIncrementNode node, final Object data) {
         return controlSideEffect(node, data);
     }
 
     @Override
     protected Object visit(final ASTDecrementGetNode node, final Object data) {
         return controlSideEffect(node, data);
     }
 
     @Override
     protected Object visit(final ASTIncrementGetNode node, final Object data) {
         return controlSideEffect(node, data);
     }
 }