content: /*
   * Copyright 1999-2017 Alibaba Group.
   *
   * Licensed 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 com.alibaba.p3c.pmd.lang.vm.rule.other;
  
  import java.util.List;
  import java.util.regex.Pattern;
  
  import com.alibaba.p3c.pmd.I18nResources;
  import com.alibaba.p3c.pmd.lang.AbstractXpathRule;
  
  import net.sourceforge.pmd.RuleContext;
  import net.sourceforge.pmd.lang.ast.Node;
  import net.sourceforge.pmd.lang.vm.ast.ASTDirective;
  import net.sourceforge.pmd.lang.vm.ast.AbstractVmNode;
  import net.sourceforge.pmd.lang.vm.ast.Token;
  import net.sourceforge.pmd.lang.vm.ast.VmParserConstants;
  
  /**
   * [Mandatory] Variables must add exclamatory mark when passing to velocity engine from backend, like $!{var}.
   * Note: If attribute is null or does not exist, ${var} will be shown directly on web pages.
   *
   * @author keriezhang
   * @date 2016/12/14
   */
  public class UseQuietReferenceNotationRule extends AbstractXpathRule {
      /**
       * scan file path pattern
       */
      private static final Pattern ALLOW_FILE_PATTERN = Pattern.compile(".*(template|velocity).*");
  
      private static final String UT_FILE_NAME = "n/a";
      private static final String MACRO_NAME = "macro";
  
      /**
       * Check reference between two text nodes. Exclude references scan in method.
       */
      private static final String XPATH =
          "//Reference[matches(@literal, \"^\\$[^!]+\") and ./preceding-sibling::Text and ./following-sibling::Text]";
  
      public UseQuietReferenceNotationRule() {
          setXPath(XPATH);
      }
  
      @Override
      public void evaluate(Node node, RuleContext ctx) {
          // Exclude directories other than template and velocity.
          String sourceCodeFilename = ctx.getSourceCodeFilename();
  
          // If file path is not n/a（unit test），and does not contain 'template', 'velocity'，then skip it。
          if (!UT_FILE_NAME.equals(sourceCodeFilename) && !ALLOW_FILE_PATTERN.matcher(sourceCodeFilename).matches()) {
              return;
          }
  
          // Exclude references inside macro.
          if (checkMacro(node)) {
              return;
          }
  
          super.evaluate(node, ctx);
      }
  
      @Override
      public void addViolation(Object data, Node node, String arg) {
          String name = getIdentifyName((AbstractVmNode)node);
          String text = I18nResources.getMessage("vm.other.UseQuietReferenceNotationRule.violation.msg", name);
          addViolationWithMessage(data, node, text);
      }
  
      private String getIdentifyName(AbstractVmNode node) {
          Token token = node.getFirstToken();
          StringBuilder sb = new StringBuilder();
          while (token.kind >= VmParserConstants.IDENTIFIER && token.kind < VmParserConstants.RCURLY) {
              if (token.kind != VmParserConstants.LCURLY) {
                  sb.append(token.image);
              }
              token = token.next;
          }
          return sb.toString();
      }
  
      /**
       * Check if reference is inside macro.
       *
       * @param node node
       * @return true/false
       */
      private boolean checkMacro(Node node) {
          List<ASTDirective> directiveParents = node.getParentsOfType(ASTDirective.class);
  
          for (ASTDirective directiveParent : directiveParents) {
              if (MACRO_NAME.equals(directiveParent.getDirectiveName())) {
                  return true;
              }
          }
  
          return false;
      }
  
  }
  