///////////////////////////////////////////////////////////////////////////////////////////////
   // checkstyle: Checks Java source code and other text files for adherence to a set of rules.
   // Copyright (C) 2001-2026 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.whitespace;
  
  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;
  import com.puppycrawl.tools.checkstyle.utils.TokenUtil;
  
  /**
   * <div>
   * Checks that there is no whitespace before the colon in a switch block.
   * </div>
   *
   * @since 8.45
   */
  @StatelessCheck
  public class NoWhitespaceBeforeCaseDefaultColonCheck
      extends AbstractCheck {
  
      /**
       * A key is pointing to the warning message text in "messages.properties"
       * file.
       */
      public static final String MSG_KEY = "ws.preceded";
  
      /**
       * Creates a new {@code NoWhitespaceBeforeCaseDefaultColonCheck} instance.
       */
      public NoWhitespaceBeforeCaseDefaultColonCheck() {
          // no code by default
      }
  
      @Override
      public int[] getDefaultTokens() {
          return getRequiredTokens();
      }
  
      @Override
      public int[] getAcceptableTokens() {
          return getRequiredTokens();
      }
  
      @Override
      public int[] getRequiredTokens() {
          return new int[] {TokenTypes.COLON};
      }
  
      @Override
      public boolean isCommentNodesRequired() {
          return true;
      }
  
      @Override
      public void visitToken(DetailAST ast) {
          if (isInSwitch(ast) && isWhiteSpaceBeforeColon(ast)) {
              log(ast, MSG_KEY, ast.getText());
          }
      }
  
      /**
       * Checks if the colon is inside a switch block.
       *
       * @param colonAst DetailAST to check.
       * @return true, if colon case is inside a switch block.
       */
      private static boolean isInSwitch(DetailAST colonAst) {
          return TokenUtil.isOfType(colonAst.getParent(), TokenTypes.LITERAL_CASE,
                  TokenTypes.LITERAL_DEFAULT);
      }
  
      /**
       * Checks if there is a whitespace before the colon of a switch case or switch default.
       *
       * @param colonAst DetailAST to check.
       * @return true, if there is whitespace preceding colonAst.
       */
      private static boolean isWhiteSpaceBeforeColon(DetailAST colonAst) {
          final DetailAST parent = colonAst.getParent();
          final boolean result;
          if (isOnDifferentLineWithPreviousToken(colonAst)) {
             result = true;
         }
         else if (parent.getType() == TokenTypes.LITERAL_CASE) {
             result = isWhitespaceBeforeColonOfCase(colonAst);
         }
         else {
             result = isWhitespaceBeforeColonOfDefault(colonAst);
         }
         return result;
     }
 
     /**
      * Checks if there is a whitespace before the colon of a switch case.
      *
      * @param colonAst DetailAST to check.
      * @return true, if there is whitespace preceding colonAst.
      */
     private static boolean isWhitespaceBeforeColonOfCase(DetailAST colonAst) {
         final DetailAST previousSibling = colonAst.getPreviousSibling();
         int offset = 0;
         if (previousSibling.getType() == TokenTypes.BLOCK_COMMENT_BEGIN) {
             offset = 1;
         }
         return colonAst.getColumnNo() != getLastColumnNumberOf(previousSibling) + offset;
     }
 
     /**
      * Checks if there is a whitespace before the colon of a switch default.
      *
      * @param colonAst DetailAST to check.
      * @return true, if there is whitespace preceding colonAst.
      */
     private static boolean isWhitespaceBeforeColonOfDefault(DetailAST colonAst) {
         final boolean result;
         final DetailAST previousSibling = colonAst.getPreviousSibling();
         if (previousSibling == null) {
             final DetailAST literalDefault = colonAst.getParent();
             result = colonAst.getColumnNo()
                     != literalDefault.getColumnNo() + literalDefault.getText().length();
         }
         else {
             result =
                     colonAst.getColumnNo() != getLastColumnNumberOf(previousSibling) + 1;
         }
         return result;
     }
 
     /**
      * Checks if the colon is on same line as of case or default.
      *
      * @param colonAst DetailAST to check.
      * @return true, if colon case is in different line as of case or default.
      */
     private static boolean isOnDifferentLineWithPreviousToken(DetailAST colonAst) {
         final DetailAST previousSibling;
         final DetailAST parent = colonAst.getParent();
         if (parent.getType() == TokenTypes.LITERAL_CASE) {
             previousSibling = colonAst.getPreviousSibling();
         }
         else {
             previousSibling = colonAst.getParent();
         }
         return !TokenUtil.areOnSameLine(previousSibling, colonAst);
     }
 
     /**
      * Returns the last column number of an ast.
      *
      * @param ast DetailAST to check.
      * @return ast's last column number.
      */
     private static int getLastColumnNumberOf(DetailAST ast) {
         DetailAST lastChild = ast;
         while (lastChild.hasChildren()) {
             lastChild = lastChild.getLastChild();
         }
         return lastChild.getColumnNo() + lastChild.getText().length();
     }
 
 }