////////////////////////////////////////////////////////////////////////////////
   // checkstyle: Checks Java source code for adherence to a set of rules.
   // Copyright (C) 2001-2019 the original author or authors.
   //
   // This library is free software; you can redistribute it and/or
   // modify it under the terms of the GNU Lesser General Public
   // License as published by the Free Software Foundation; either
   // version 2.1 of the License, or (at your option) any later version.
   //
  // This library 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
  // Lesser General Public License for more details.
  //
  // You should have received a copy of the GNU Lesser General Public
  // License along with this library; if not, write to the Free Software
  // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  ////////////////////////////////////////////////////////////////////////////////
  
  package com.puppycrawl.tools.checkstyle.checks.javadoc;
  
  import java.util.regex.Pattern;
  
  import com.puppycrawl.tools.checkstyle.StatelessCheck;
  import com.puppycrawl.tools.checkstyle.api.AbstractCheck;
  import com.puppycrawl.tools.checkstyle.api.DetailAST;
  import com.puppycrawl.tools.checkstyle.api.FileContents;
  import com.puppycrawl.tools.checkstyle.api.Scope;
  import com.puppycrawl.tools.checkstyle.api.TextBlock;
  import com.puppycrawl.tools.checkstyle.api.TokenTypes;
  import com.puppycrawl.tools.checkstyle.utils.ScopeUtil;
  
  /**
   * Checks that a variable has Javadoc comment. Ignores {@code serialVersionUID} fields.
   *
   */
  @StatelessCheck
  public class JavadocVariableCheck
      extends AbstractCheck {
  
      /**
       * A key is pointing to the warning message text in "messages.properties"
       * file.
       */
      public static final String MSG_JAVADOC_MISSING = "javadoc.missing";
  
      /** The scope to check. */
      private Scope scope = Scope.PRIVATE;
  
      /** The visibility scope where Javadoc comments shouldn't be checked. **/
      private Scope excludeScope;
  
      /** The pattern to ignore variable name. */
      private Pattern ignoreNamePattern;
  
      /**
       * Sets the scope to check.
       * @param scope a scope.
       */
      public void setScope(Scope scope) {
          this.scope = scope;
      }
  
      /**
       * Set the excludeScope.
       * @param excludeScope a scope.
       */
      public void setExcludeScope(Scope excludeScope) {
          this.excludeScope = excludeScope;
      }
  
      /**
       * Sets the variable names to ignore in the check.
       * @param pattern a pattern.
       */
      public void setIgnoreNamePattern(Pattern pattern) {
          ignoreNamePattern = pattern;
      }
  
      @Override
      public int[] getDefaultTokens() {
          return getAcceptableTokens();
      }
  
      @Override
      public int[] getAcceptableTokens() {
          return new int[] {
              TokenTypes.VARIABLE_DEF,
              TokenTypes.ENUM_CONSTANT_DEF,
          };
      }
  
      /*
       * Skipping enum values is requested.
       * Checkstyle's issue #1669: https://github.com/checkstyle/checkstyle/issues/1669
       */
      @Override
      public int[] getRequiredTokens() {
          return new int[] {
             TokenTypes.VARIABLE_DEF,
         };
     }
 
     @Override
     public void visitToken(DetailAST ast) {
         if (shouldCheck(ast)) {
             final FileContents contents = getFileContents();
             final TextBlock textBlock =
                 contents.getJavadocBefore(ast.getLineNo());
 
             if (textBlock == null) {
                 log(ast, MSG_JAVADOC_MISSING);
             }
         }
     }
 
     /**
      * Decides whether the variable name of an AST is in the ignore list.
      * @param ast the AST to check
      * @return true if the variable name of ast is in the ignore list.
      */
     private boolean isIgnored(DetailAST ast) {
         final String name = ast.findFirstToken(TokenTypes.IDENT).getText();
         return ignoreNamePattern != null && ignoreNamePattern.matcher(name).matches()
             || "serialVersionUID".equals(name);
     }
 
     /**
      * Whether we should check this node.
      * @param ast a given node.
      * @return whether we should check a given node.
      */
     private boolean shouldCheck(final DetailAST ast) {
         boolean result = false;
         if (!ScopeUtil.isInCodeBlock(ast) && !isIgnored(ast)) {
             Scope customScope = Scope.PUBLIC;
             if (ast.getType() != TokenTypes.ENUM_CONSTANT_DEF
                     && !ScopeUtil.isInInterfaceOrAnnotationBlock(ast)) {
                 final DetailAST mods = ast.findFirstToken(TokenTypes.MODIFIERS);
                 customScope = ScopeUtil.getScopeFromMods(mods);
             }
 
             final Scope surroundingScope = ScopeUtil.getSurroundingScope(ast);
             result = customScope.isIn(scope) && surroundingScope.isIn(scope)
                 && (excludeScope == null
                     || !customScope.isIn(excludeScope)
                     || !surroundingScope.isIn(excludeScope));
         }
         return result;
     }
 
 }