/*
    * SPDX-FileCopyrightText: Copyright (c) 2011-2026 Yegor Bugayenko
    * SPDX-License-Identifier: MIT
    */
   package com.qulice.checkstyle;
   
   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.AnnotationUtil;
  import java.util.ArrayList;
  import java.util.List;
  
  /**
   * Checks that final class doesn't contain protected methods unless they are
   * overriding protected methods from superclass.
   * @since 0.6
   */
  public final class ProtectedMethodInFinalClassCheck extends AbstractCheck {
  
      @Override
      public int[] getDefaultTokens() {
          return new int[] {
              TokenTypes.CLASS_DEF,
          };
      }
  
      @Override
      public int[] getAcceptableTokens() {
          return this.getDefaultTokens();
      }
  
      @Override
      public int[] getRequiredTokens() {
          return this.getDefaultTokens();
      }
  
      @Override
      public void visitToken(final DetailAST ast) {
          if (ast.getType() == TokenTypes.CLASS_DEF) {
              final DetailAST modifiers = ast.findFirstToken(
                  TokenTypes.MODIFIERS
              );
              if (modifiers.findFirstToken(TokenTypes.FINAL) != null) {
                  this.checkMethods(ast);
              }
          }
      }
  
      /**
       * Checks methods in current class have no protected modifier.
       * @param ast DetailAST of CLASS_DEF
       */
      private void checkMethods(final DetailAST ast) {
          final DetailAST objblock = ast.findFirstToken(TokenTypes.OBJBLOCK);
          for (final DetailAST method
              : ProtectedMethodInFinalClassCheck.findAllChildren(
                  objblock, TokenTypes.METHOD_DEF
              )
          ) {
              if (method
                  .findFirstToken(TokenTypes.MODIFIERS)
                  .findFirstToken(TokenTypes.LITERAL_PROTECTED) != null) {
                  if (AnnotationUtil.containsAnnotation(method, "Override")) {
                      this.log(
                          method.getLineNo(),
                          "Protected method is overriding default scoped method"
                      );
                  } else {
                      this.log(
                          method.getLineNo(),
                          "Final class should not contain protected methods"
                      );
                  }
              }
          }
      }
  
      /**
       * Search for all children of given type.
       * @param base Parent node to start from
       * @param type Node type
       * @return Iterable
       */
      private static Iterable<DetailAST> findAllChildren(final DetailAST base,
          final int type) {
          final List<DetailAST> children = new ArrayList<>(base.getChildCount());
          DetailAST child = base.getFirstChild();
          while (child != null) {
              if (child.getType() == type) {
                  children.add(child);
              }
              child = child.getNextSibling();
          }
          return children;
      }
  }