///////////////////////////////////////////////////////////////////////////////////////////////
   // 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.meta;
  
  import static com.google.common.truth.Truth.assertWithMessage;
  
  import java.nio.file.Files;
  import java.nio.file.Path;
  import java.util.LinkedHashSet;
  import java.util.List;
  import java.util.Set;
  import java.util.stream.Collectors;
  import java.util.stream.Stream;
  
  import org.junit.jupiter.api.Test;
  
  import com.puppycrawl.tools.checkstyle.AbstractModuleTestSupport;
  import com.puppycrawl.tools.checkstyle.internal.utils.CheckUtil;
  
  public final class MetadataGeneratorUtilTest extends AbstractModuleTestSupport {
  
      private static final Set<String> MODULES_CONTAINING_NO_METADATA_FILE = Set.of(
              "Checker",
              "TreeWalker"
      );
  
      @Override
      public String getPackageLocation() {
          return null;
      }
  
      /**
       * Verifies number of generated metadata modules match the number of Checkstyle modules.
       * Also verifies whether every Checkstyle module contains description.
       *
       * <p>When running this test directly from an IDE, run
       * {@code ./mvnw process-classes} first to generate the metadata files
       * under {@code target/classes}.
       *
       * @throws Exception if an I/O error occurs while reading metadata files
       */
      @Test
      public void testMetadataFilesGenerationAllFiles() throws Exception {
          final Path sourceMetadataDirectory = Path.of(System.getProperty("user.dir"),
                  "src", "main", "resources", "com", "puppycrawl", "tools", "checkstyle", "meta");
          final List<Path> metadataFiles;
          try (Stream<Path> fileStream = Files.walk(sourceMetadataDirectory)) {
              metadataFiles = fileStream
                      .filter(Files::isRegularFile)
                      .filter(path -> !path.toString().endsWith(".properties"))
                      .sorted()
                      .toList();
          }
          final Set<String> metaFiles = metadataFiles.stream()
                  .map(MetadataGeneratorUtilTest::getMetaFileName)
                  .collect(Collectors.toCollection(LinkedHashSet::new));
  
          final Path outputMetadataDirectory = Path.of(System.getProperty("user.dir"),
                  "target", "classes", "com", "puppycrawl", "tools", "checkstyle", "meta");
          for (Path metadataFile : metadataFiles) {
              final Path relativePath = sourceMetadataDirectory.relativize(metadataFile);
              final Path outputMetadataFile = outputMetadataDirectory.resolve(relativePath);
              assertWithMessage("Metadata differs in target/classes for %s", relativePath)
                      .that(Files.readString(outputMetadataFile))
                      .isEqualTo(Files.readString(metadataFile));
          }
          final Set<String> checkstyleModules =
                  CheckUtil.getSimpleNames(CheckUtil.getCheckstyleModules())
                          .stream()
                          .sorted()
                          .collect(Collectors.toCollection(LinkedHashSet::new));
          checkstyleModules.removeAll(MODULES_CONTAINING_NO_METADATA_FILE);
          assertWithMessage("Number of generated metadata files dont match with "
                  + "number of checkstyle module")
                  .that(metaFiles)
                  .isEqualTo(checkstyleModules);
      }
  
      /**
       * Get meta file name from full file name.
       *
       * @param file file to process
      * @return meta file name
      */
     private static String getMetaFileName(Path file) {
         final String fileName = file.getFileName().toString();
         final int lengthToOmit;
         if (fileName.contains("Check")) {
             lengthToOmit = "Check.xml".length();
         }
         else {
             lengthToOmit = ".xml".length();
         }
         return fileName.substring(0, fileName.length() - lengthToOmit);
     }
 
 }