///////////////////////////////////////////////////////////////////////////////////////////////
   // checkstyle: Checks Java source code and other text files for adherence to a set of rules.
   // Copyright (C) 2001-2025 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;
  
  import java.util.BitSet;
  import java.util.List;
  
  import javax.annotation.Nullable;
  
  import org.antlr.v4.runtime.Token;
  
  import com.puppycrawl.tools.checkstyle.api.DetailAST;
  import com.puppycrawl.tools.checkstyle.utils.TokenUtil;
  import com.puppycrawl.tools.checkstyle.utils.UnmodifiableCollectionUtil;
  
  /**
   * The implementation of {@link DetailAST}. This should only be directly used to
   * create custom AST nodes and in 'JavaAstVisitor.java'.
   *
   * @noinspection FieldNotUsedInToString
   * @noinspectionreason FieldNotUsedInToString - We require a specific string format for
   *      printing to CLI.
   */
  public final class DetailAstImpl implements DetailAST {
  
      /** Constant to indicate if not calculated the child count. */
      private static final int NOT_INITIALIZED = Integer.MIN_VALUE;
  
      /** The line number. **/
      private int lineNo = NOT_INITIALIZED;
      /** The column number. **/
      private int columnNo = NOT_INITIALIZED;
  
      /** Number of children. */
      private int childCount;
      /** The parent token. */
      private DetailAstImpl parent;
      /** Previous sibling. */
      private DetailAstImpl previousSibling;
  
      /** First child of this DetailAST. */
      private DetailAstImpl firstChild;
  
      /** First sibling of this DetailAST.*/
      private DetailAstImpl nextSibling;
  
      /** Text of this DetailAST. */
      private String text;
  
      /** The type of this DetailAST. */
      private int type;
  
      /**
       * All tokens on COMMENTS channel to the left of the current token up to the
       * preceding token on the DEFAULT_TOKEN_CHANNEL.
       */
      private List<Token> hiddenBefore;
  
      /**
       * All tokens on COMMENTS channel to the right of the current token up to the
       * next token on the DEFAULT_TOKEN_CHANNEL.
       */
      private List<Token> hiddenAfter;
  
      /**
       * All token types in this branch.
       * Token 'x' (where x is an int) is in this branch
       * if branchTokenTypes.get(x) is true.
       */
      private BitSet branchTokenTypes;
  
      /**
       * Initializes this DetailAstImpl.
       *
       * @param tokenType the type of this DetailAstImpl
       * @param tokenText the text of this DetailAstImpl
       */
      public void initialize(int tokenType, String tokenText) {
          type = tokenType;
          text = tokenText;
      }
  
     /**
      * Initializes this DetailAstImpl.
      *
      * @param token the token to generate this DetailAstImpl from
      */
     public void initialize(Token token) {
         text = token.getText();
         type = token.getType();
         lineNo = token.getLine();
         columnNo = token.getCharPositionInLine();
     }
 
     /**
      * Add previous sibling.
      *
      * @param ast
      *        DetailAST object.
      */
     public void addPreviousSibling(DetailAST ast) {
         clearBranchTokenTypes();
         clearChildCountCache(parent);
         if (ast != null) {
             // parent is set in setNextSibling or parent.setFirstChild
             final DetailAstImpl previousSiblingNode = previousSibling;
             final DetailAstImpl astImpl = (DetailAstImpl) ast;
 
             if (previousSiblingNode != null) {
                 previousSiblingNode.setNextSibling(astImpl);
             }
             else if (parent != null) {
                 parent.setFirstChild(astImpl);
             }
 
             astImpl.setNextSibling(this);
         }
     }
 
     /**
      * Add next sibling, pushes other siblings back.
      *
      * @param ast DetailAST object.
      */
     public void addNextSibling(DetailAST ast) {
         clearBranchTokenTypes();
         clearChildCountCache(parent);
         if (ast != null) {
             // parent is set in setNextSibling
             final DetailAstImpl sibling = nextSibling;
             final DetailAstImpl astImpl = (DetailAstImpl) ast;
             astImpl.setNextSibling(sibling);
 
             setNextSibling(astImpl);
         }
     }
 
     /**
      * Adds a new child to the current AST.
      *
      * @param child to DetailAST to add as child
      */
     public void addChild(DetailAST child) {
         clearBranchTokenTypes();
         clearChildCountCache(this);
         if (child != null) {
             final DetailAstImpl astImpl = (DetailAstImpl) child;
             astImpl.setParent(this);
         }
         DetailAST temp = firstChild;
         if (temp == null) {
             firstChild = (DetailAstImpl) child;
         }
         else {
             while (temp.getNextSibling() != null) {
                 temp = temp.getNextSibling();
             }
 
             ((DetailAstImpl) temp).setNextSibling(child);
         }
     }
 
     @Override
     public int getChildCount() {
         // lazy init
         if (childCount == NOT_INITIALIZED) {
             childCount = 0;
             DetailAST child = firstChild;
 
             while (child != null) {
                 childCount += 1;
                 child = child.getNextSibling();
             }
         }
         return childCount;
     }
 
     @Override
     public int getChildCount(int tokenType) {
         int count = 0;
         for (DetailAST ast = firstChild; ast != null; ast = ast.getNextSibling()) {
             if (ast.getType() == tokenType) {
                 count++;
             }
         }
         return count;
     }
 
     /**
      * Set the parent token.
      *
      * @param parent the parent token
      */
     private void setParent(DetailAstImpl parent) {
         DetailAstImpl instance = this;
         do {
             instance.clearBranchTokenTypes();
             instance.parent = parent;
             instance = instance.nextSibling;
         } while (instance != null);
     }
 
     @Override
     public DetailAST getParent() {
         return parent;
     }
 
     @Override
     public String getText() {
         return text;
     }
 
     /**
      * Sets the text for this DetailAstImpl.
      *
      * @param text the text field of this DetailAstImpl
      */
     public void setText(String text) {
         this.text = text;
     }
 
     @Override
     public int getType() {
         return type;
     }
 
     /**
      * Sets the type of this AST.
      *
      * @param type the token type of this DetailAstImpl
      */
     public void setType(int type) {
         this.type = type;
     }
 
     @Override
     public int getLineNo() {
         int resultNo = -1;
 
         if (lineNo == NOT_INITIALIZED) {
             // an inner AST that has been initialized
             // with initialize(String text)
             resultNo = findLineNo(firstChild);
 
             if (resultNo == -1) {
                 resultNo = findLineNo(nextSibling);
             }
         }
         if (resultNo == -1) {
             resultNo = lineNo;
         }
         return resultNo;
     }
 
     /**
      * Set line number.
      *
      * @param lineNo
      *        line number.
      */
     public void setLineNo(int lineNo) {
         this.lineNo = lineNo;
     }
 
     @Override
     public int getColumnNo() {
         int resultNo = -1;
 
         if (columnNo == NOT_INITIALIZED) {
             // an inner AST that has been initialized
             // with initialize(String text)
             resultNo = findColumnNo(firstChild);
 
             if (resultNo == -1) {
                 resultNo = findColumnNo(nextSibling);
             }
         }
         if (resultNo == -1) {
             resultNo = columnNo;
         }
         return resultNo;
     }
 
     /**
      * Set column number.
      *
      * @param columnNo
      *        column number.
      */
     public void setColumnNo(int columnNo) {
         this.columnNo = columnNo;
     }
 
     @Override
     public DetailAST getLastChild() {
         DetailAstImpl ast = firstChild;
         while (ast != null && ast.nextSibling != null) {
             ast = ast.nextSibling;
         }
         return ast;
     }
 
     /**
      * Finds column number in the first non-comment node.
      *
      * @param ast DetailAST node.
      * @return Column number if non-comment node exists, -1 otherwise.
      */
     private static int findColumnNo(DetailAST ast) {
         int resultNo = -1;
         DetailAST node = ast;
         while (node != null) {
             // comment node can't be start of any java statement/definition
             if (TokenUtil.isCommentType(node.getType())) {
                 node = node.getNextSibling();
             }
             else {
                 resultNo = node.getColumnNo();
                 break;
             }
         }
         return resultNo;
     }
 
     /**
      * Finds line number in the first non-comment node.
      *
      * @param ast DetailAST node.
      * @return Line number if non-comment node exists, -1 otherwise.
      */
     private static int findLineNo(DetailAST ast) {
         int resultNo = -1;
         DetailAST node = ast;
         while (node != null) {
             // comment node can't be start of any java statement/definition
             if (TokenUtil.isCommentType(node.getType())) {
                 node = node.getNextSibling();
             }
             else {
                 resultNo = node.getLineNo();
                 break;
             }
         }
         return resultNo;
     }
 
     /**
      * Returns token type with branch.
      *
      * @return the token types that occur in the branch as a sorted set.
      */
     private BitSet getBranchTokenTypes() {
         // lazy init
         if (branchTokenTypes == null) {
             branchTokenTypes = new BitSet();
             branchTokenTypes.set(type);
 
             // add union of all children
             DetailAstImpl child = firstChild;
             while (child != null) {
                 final BitSet childTypes = child.getBranchTokenTypes();
                 branchTokenTypes.or(childTypes);
 
                 child = child.nextSibling;
             }
         }
         return branchTokenTypes;
     }
 
     @Override
     public boolean branchContains(int tokenType) {
         return getBranchTokenTypes().get(tokenType);
     }
 
     @Override
     public DetailAST getPreviousSibling() {
         return previousSibling;
     }
 
     @Override
     @Nullable
     public DetailAST findFirstToken(int tokenType) {
         DetailAST returnValue = null;
         for (DetailAST ast = firstChild; ast != null; ast = ast.getNextSibling()) {
             if (ast.getType() == tokenType) {
                 returnValue = ast;
                 break;
             }
         }
         return returnValue;
     }
 
     @Override
     public String toString() {
         return text + "[" + getLineNo() + "x" + getColumnNo() + "]";
     }
 
     @Override
     public DetailAstImpl getNextSibling() {
         return nextSibling;
     }
 
     @Override
     public DetailAstImpl getFirstChild() {
         return firstChild;
     }
 
     @Override
     public int getNumberOfChildren() {
         return getChildCount();
     }
 
     @Override
     public boolean hasChildren() {
         return firstChild != null;
     }
 
     /**
      * Clears the child count for the ast instance.
      *
      * @param ast The ast to clear.
      */
     private static void clearChildCountCache(DetailAstImpl ast) {
         if (ast != null) {
             ast.childCount = NOT_INITIALIZED;
         }
     }
 
     /**
      * Clears branchTokenTypes cache for all parents of the current DetailAST instance, and the
      * child count for the current DetailAST instance.
      */
     private void clearBranchTokenTypes() {
         DetailAstImpl prevParent = parent;
         while (prevParent != null) {
             prevParent.branchTokenTypes = null;
             prevParent = prevParent.parent;
         }
     }
 
     /**
      * Sets the next sibling of this AST.
      *
      * @param nextSibling the DetailAST to set as sibling
      */
     public void setNextSibling(DetailAST nextSibling) {
         clearBranchTokenTypes();
         clearChildCountCache(parent);
         this.nextSibling = (DetailAstImpl) nextSibling;
         if (nextSibling != null && parent != null) {
             ((DetailAstImpl) nextSibling).setParent(parent);
         }
         if (nextSibling != null) {
             ((DetailAstImpl) nextSibling).previousSibling = this;
         }
     }
 
     /**
      * Sets the first child of this AST.
      *
      * @param firstChild the DetailAST to set as first child
      */
     public void setFirstChild(DetailAST firstChild) {
         clearBranchTokenTypes();
         clearChildCountCache(this);
         this.firstChild = (DetailAstImpl) firstChild;
         if (firstChild != null) {
             ((DetailAstImpl) firstChild).setParent(this);
         }
     }
 
     /**
      * Removes all children of this AST.
      */
     public void removeChildren() {
         firstChild = null;
     }
 
     /**
      * Get list of tokens on COMMENTS channel to the left of the
      * current token up to the preceding token on the DEFAULT_TOKEN_CHANNEL.
      *
      * @return list of comment tokens
      */
     public List<Token> getHiddenBefore() {
         List<Token> returnList = null;
         if (hiddenBefore != null) {
             returnList = UnmodifiableCollectionUtil.unmodifiableList(hiddenBefore);
         }
         return returnList;
     }
 
     /**
      * Get list tokens on COMMENTS channel to the right of the current
      * token up to the next token on the DEFAULT_TOKEN_CHANNEL.
      *
      * @return list of comment tokens
      */
     public List<Token> getHiddenAfter() {
         List<Token> returnList = null;
         if (hiddenAfter != null) {
             returnList = UnmodifiableCollectionUtil.unmodifiableList(hiddenAfter);
         }
         return returnList;
     }
 
     /**
      * Sets the hiddenBefore token field.
      *
      * @param hiddenBefore comment token preceding this DetailAstImpl
      */
     public void setHiddenBefore(List<Token> hiddenBefore) {
         this.hiddenBefore = UnmodifiableCollectionUtil.unmodifiableList(hiddenBefore);
     }
 
     /**
      * Sets the hiddenAfter token field.
      *
      * @param hiddenAfter comment token following this DetailAstImpl
      */
     public void setHiddenAfter(List<Token> hiddenAfter) {
         this.hiddenAfter = UnmodifiableCollectionUtil.unmodifiableList(hiddenAfter);
     }
 }