/*
    * SPDX-FileCopyrightText: Copyright (c) 2011-2025 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;
  
  /**
   * Checks that there is no empty line between a javadoc and it's subject.
   *
   * <p>You can't have empty lines between javadoc block and
   * a class/method/variable. They should stay together, always.
   *
   * @since 0.3
   */
  public final class JavadocLocationCheck extends AbstractCheck {
  
      @Override
      public int[] getDefaultTokens() {
          return new int[] {
              TokenTypes.CLASS_DEF,
              TokenTypes.INTERFACE_DEF,
              TokenTypes.VARIABLE_DEF,
              TokenTypes.CTOR_DEF,
              TokenTypes.METHOD_DEF,
          };
      }
  
      @Override
      public int[] getAcceptableTokens() {
          return this.getDefaultTokens();
      }
  
      @Override
      public int[] getRequiredTokens() {
          return this.getDefaultTokens();
      }
  
      @Override
      public void visitToken(final DetailAST ast) {
          if (!JavadocLocationCheck.isField(ast)) {
              return;
          }
          final String[] lines = this.getLines();
          int current = ast.getLineNo();
          boolean found = false;
          final int start = current;
          --current;
          while (true) {
              if (current <= 0) {
                  break;
              }
              final String line = lines[current - 1].trim();
              if (line.endsWith("*/")) {
                  found = true;
                  break;
              }
              if (!line.isEmpty()) {
                  break;
              }
              --current;
          }
          if (found) {
              this.report(start, current);
          }
      }
  
      /**
       * Report empty lines between current and end line.
       * @param current Current line
       * @param end Final line
       */
      private void report(final int current, final int end) {
          final int diff = current - end;
          if (diff > 1) {
              for (int pos = 1; pos < diff; pos += 1) {
                  this.log(
                      end + pos,
                      "Empty line between javadoc and subject"
                  );
              }
          }
      }
  
      /**
       * Returns {@code TRUE} if a specified node is something that should have
       * a Javadoc, which includes classes, interface, class methods, and
       * class variables.
       * @param node Node to check
       * @return Is it a Javadoc-required entity?
       */
      private static boolean isField(final DetailAST node) {
          boolean yes = true;
          if (TokenTypes.VARIABLE_DEF == node.getType()) {
              yes = TokenTypes.OBJBLOCK == node.getParent().getType();
          }
         return yes;
     }
 }