////////////////////////////////////////////////////////////////////////////////
   // 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.coding;
  
  import java.util.Objects;
  
  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.TokenTypes;
  
  /**
   * <p>
   * Check that the {@code default} is after all the cases in a {@code switch} statement.
   * </p>
   * <p>
   * Rationale: Java allows {@code default} anywhere within the
   * {@code switch} statement. But it is more readable if it comes after the last {@code case}.
   * </p>
   * <ul>
   * <li>
   * Property {@code skipIfLastAndSharedWithCase} - Control whether to allow {@code default}
   * along with {@code case} if they are not last.
   * Default value is {@code false}.
   * </li>
   * </ul>
   * <p>
   * To configure the check:
   * </p>
   * <pre>
   * &lt;module name=&quot;DefaultComesLast&quot;/&gt;
   * </pre>
   * <p>
   * To configure the check for skipIfLastAndSharedWithCase:
   * </p>
   * <pre>
   * &lt;module name=&quot;DefaultComesLast&quot;&gt;
   *   &lt;property name=&quot;skipIfLastAndSharedWithCase&quot; value=&quot;true&quot;/&gt;
   * &lt;/module&gt;
   * </pre>
   * <p>
   * Example when skipIfLastAndSharedWithCase is set to true.
   * </p>
   * <pre>
   * switch (i) {
   *   case 1:
   *     break;
   *   case 2:
   *   default: // No violation with the new option is expected
   *     break;
   *   case 3:
   *     break;
   * }
   * switch (i) {
   *   case 1:
   *     break;
   *   default: // violation with the new option is expected
   *   case 2:
   *     break;
   * }
   * </pre>
   *
   * @since 3.4
   */
  @StatelessCheck
  public class DefaultComesLastCheck extends AbstractCheck {
  
      /**
       * A key is pointing to the warning message text in "messages.properties"
       * file.
       */
      public static final String MSG_KEY = "default.comes.last";
  
      /**
       * A key is pointing to the warning message text in "messages.properties"
       * file.
       */
      public static final String MSG_KEY_SKIP_IF_LAST_AND_SHARED_WITH_CASE =
              "default.comes.last.in.casegroup";
  
      /** Control whether to allow {@code default} along with {@code case} if they are not last. */
      private boolean skipIfLastAndSharedWithCase;
 
     @Override
     public int[] getAcceptableTokens() {
         return getRequiredTokens();
     }
 
     @Override
     public int[] getDefaultTokens() {
         return getRequiredTokens();
     }
 
     @Override
     public int[] getRequiredTokens() {
         return new int[] {
             TokenTypes.LITERAL_DEFAULT,
         };
     }
 
     /**
      * Setter to control whether to allow {@code default} along with
      * {@code case} if they are not last.
      * @param newValue whether to ignore checking.
      */
     public void setSkipIfLastAndSharedWithCase(boolean newValue) {
         skipIfLastAndSharedWithCase = newValue;
     }
 
     @Override
     public void visitToken(DetailAST ast) {
         final DetailAST defaultGroupAST = ast.getParent();
         //default keywords used in annotations too - not what we're
         //interested in
         if (defaultGroupAST.getType() != TokenTypes.ANNOTATION_FIELD_DEF
                 && defaultGroupAST.getType() != TokenTypes.MODIFIERS) {
             if (skipIfLastAndSharedWithCase) {
                 if (Objects.nonNull(findNextSibling(ast, TokenTypes.LITERAL_CASE))) {
                     log(ast, MSG_KEY_SKIP_IF_LAST_AND_SHARED_WITH_CASE);
                 }
                 else if (ast.getPreviousSibling() == null
                     && Objects.nonNull(findNextSibling(defaultGroupAST,
                                                        TokenTypes.CASE_GROUP))) {
                     log(ast, MSG_KEY);
                 }
             }
             else if (Objects.nonNull(findNextSibling(defaultGroupAST,
                                                      TokenTypes.CASE_GROUP))) {
                 log(ast, MSG_KEY);
             }
         }
     }
 
     /**
      * Return token type only if passed tokenType in argument is found or returns -1.
      *
      * @param ast root node.
      * @param tokenType tokentype to be processed.
      * @return token if desired token is found or else null.
      */
     private static DetailAST findNextSibling(DetailAST ast, int tokenType) {
         DetailAST token = null;
         DetailAST node = ast.getNextSibling();
         while (node != null) {
             if (node.getType() == tokenType) {
                 token = node;
                 break;
             }
             node = node.getNextSibling();
         }
         return token;
     }
 
 }