/*
    * Licensed to the Apache Software Foundation (ASF) under one or more
    * contributor license agreements.  See the NOTICE file distributed with
    * this work for additional information regarding copyright ownership.
    * The ASF licenses this file to You under the Apache License, Version 2.0
    * (the "License"); you may not use this file except in compliance with
    * the License.  You may obtain a copy of the License at
    *
    *      http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  package org.apache.commons.io.file;
  
  import static org.apache.commons.io.file.CounterAssertions.assertCounts;
  import static org.junit.jupiter.api.Assertions.assertEquals;
  import static org.junit.jupiter.api.Assertions.assertNotEquals;
  import static org.junit.jupiter.api.Assertions.assertTrue;
  
  import java.io.IOException;
  import java.nio.file.FileVisitResult;
  import java.nio.file.Files;
  import java.nio.file.Path;
  import java.nio.file.Paths;
  import java.nio.file.attribute.BasicFileAttributes;
  import java.time.Duration;
  import java.util.ArrayList;
  import java.util.LinkedHashSet;
  import java.util.List;
  import java.util.Set;
  import java.util.concurrent.ExecutorService;
  import java.util.concurrent.Executors;
  import java.util.concurrent.TimeUnit;
  import java.util.concurrent.atomic.AtomicBoolean;
  import java.util.concurrent.atomic.AtomicInteger;
  import java.util.function.Supplier;
  import java.util.stream.Stream;
  
  import org.apache.commons.io.ThreadUtils;
  import org.apache.commons.io.filefilter.AndFileFilter;
  import org.apache.commons.io.filefilter.DirectoryFileFilter;
  import org.apache.commons.io.filefilter.EmptyFileFilter;
  import org.apache.commons.io.filefilter.PathVisitorFileFilter;
  import org.apache.commons.io.filefilter.TrueFileFilter;
  import org.junit.jupiter.api.Test;
  import org.junit.jupiter.api.io.TempDir;
  import org.junit.jupiter.params.ParameterizedTest;
  import org.junit.jupiter.params.provider.Arguments;
  import org.junit.jupiter.params.provider.MethodSource;
  
  /**
   * Tests both {@link AccumulatorPathVisitor} and {@link PathVisitorFileFilter}.
   */
  public class AccumulatorPathVisitorTest {
  
      static Stream<Arguments> testParameters() {
          // @formatter:off
          return Stream.of(
              Arguments.of((Supplier<AccumulatorPathVisitor>) AccumulatorPathVisitor::withLongCounters),
              Arguments.of((Supplier<AccumulatorPathVisitor>) AccumulatorPathVisitor::withBigIntegerCounters),
              Arguments.of((Supplier<AccumulatorPathVisitor>) () ->
                  AccumulatorPathVisitor.withBigIntegerCounters(TrueFileFilter.INSTANCE, TrueFileFilter.INSTANCE)));
          // @formatter:on
      }
  
      static Stream<Arguments> testParametersIgnoreFailures() {
          // @formatter:off
          return Stream.of(
              Arguments.of((Supplier<AccumulatorPathVisitor>) () -> new AccumulatorPathVisitor(
                  Counters.bigIntegerPathCounters(),
                  CountingPathVisitor.defaultDirFilter(),
                  CountingPathVisitor.defaultFileFilter())));
          // @formatter:on
      }
  
      @TempDir
      Path tempDirPath;
  
      /**
       * Tests the 0-argument constructor.
       */
      @Test
      public void test0ArgConstructor() throws IOException {
          final AccumulatorPathVisitor accPathVisitor = new AccumulatorPathVisitor();
          final PathVisitorFileFilter countingFileFilter = new PathVisitorFileFilter(accPathVisitor);
          Files.walkFileTree(tempDirPath, new AndFileFilter(countingFileFilter, DirectoryFileFilter.INSTANCE, EmptyFileFilter.EMPTY));
          assertCounts(0, 0, 0, accPathVisitor.getPathCounters());
          assertEquals(1, accPathVisitor.getDirList().size());
          assertTrue(accPathVisitor.getFileList().isEmpty());
          assertEquals(accPathVisitor, accPathVisitor);
          assertEquals(accPathVisitor.hashCode(), accPathVisitor.hashCode());
      }
  
      /**
      * Tests an empty folder.
      */
     @ParameterizedTest
     @MethodSource("testParameters")
     public void testEmptyFolder(final Supplier<AccumulatorPathVisitor> supplier) throws IOException {
         final AccumulatorPathVisitor accPathVisitor = supplier.get();
         final PathVisitorFileFilter countingFileFilter = new PathVisitorFileFilter(accPathVisitor);
         Files.walkFileTree(tempDirPath, new AndFileFilter(countingFileFilter, DirectoryFileFilter.INSTANCE, EmptyFileFilter.EMPTY));
         assertCounts(1, 0, 0, accPathVisitor.getPathCounters());
         assertEquals(1, accPathVisitor.getDirList().size());
         assertTrue(accPathVisitor.getFileList().isEmpty());
         assertEquals(accPathVisitor, accPathVisitor);
         assertEquals(accPathVisitor.hashCode(), accPathVisitor.hashCode());
     }
 
     @Test
     public void testEqualsHashCode() {
         final AccumulatorPathVisitor visitor0 = AccumulatorPathVisitor.withLongCounters();
         final AccumulatorPathVisitor visitor1 = AccumulatorPathVisitor.withLongCounters();
         assertEquals(visitor0, visitor0);
         assertEquals(visitor0, visitor1);
         assertEquals(visitor1, visitor0);
         assertEquals(visitor0.hashCode(), visitor0.hashCode());
         assertEquals(visitor0.hashCode(), visitor1.hashCode());
         assertEquals(visitor1.hashCode(), visitor0.hashCode());
         visitor0.getPathCounters().getByteCounter().increment();
         assertEquals(visitor0, visitor0);
         assertNotEquals(visitor0, visitor1);
         assertNotEquals(visitor1, visitor0);
         assertEquals(visitor0.hashCode(), visitor0.hashCode());
         assertNotEquals(visitor0.hashCode(), visitor1.hashCode());
         assertNotEquals(visitor1.hashCode(), visitor0.hashCode());
     }
 
     /**
      * Tests a directory with one file of size 0.
      */
     @ParameterizedTest
     @MethodSource("testParameters")
     public void testFolders1FileSize0(final Supplier<AccumulatorPathVisitor> supplier) throws IOException {
         final AccumulatorPathVisitor accPathVisitor = supplier.get();
         final PathVisitorFileFilter countingFileFilter = new PathVisitorFileFilter(accPathVisitor);
         Files.walkFileTree(Paths.get("src/test/resources/org/apache/commons/io/dirs-1-file-size-0"), countingFileFilter);
         assertCounts(1, 1, 0, accPathVisitor.getPathCounters());
         assertEquals(1, accPathVisitor.getDirList().size());
         assertEquals(1, accPathVisitor.getFileList().size());
         assertEquals(accPathVisitor, accPathVisitor);
         assertEquals(accPathVisitor.hashCode(), accPathVisitor.hashCode());
     }
 
     /**
      * Tests a directory with one file of size 1.
      */
     @ParameterizedTest
     @MethodSource("testParameters")
     public void testFolders1FileSize1(final Supplier<AccumulatorPathVisitor> supplier) throws IOException {
         final AccumulatorPathVisitor accPathVisitor = supplier.get();
         final PathVisitorFileFilter countingFileFilter = new PathVisitorFileFilter(accPathVisitor);
         Files.walkFileTree(Paths.get("src/test/resources/org/apache/commons/io/dirs-1-file-size-1"), countingFileFilter);
         assertCounts(1, 1, 1, accPathVisitor.getPathCounters());
         assertEquals(1, accPathVisitor.getDirList().size());
         assertEquals(1, accPathVisitor.getFileList().size());
         assertEquals(accPathVisitor, accPathVisitor);
         assertEquals(accPathVisitor.hashCode(), accPathVisitor.hashCode());
     }
 
     /**
      * Tests a directory with two subdirectories, each containing one file of size 1.
      */
     @ParameterizedTest
     @MethodSource("testParameters")
     public void testFolders2FileSize2(final Supplier<AccumulatorPathVisitor> supplier) throws IOException {
         final AccumulatorPathVisitor accPathVisitor = supplier.get();
         final PathVisitorFileFilter countingFileFilter = new PathVisitorFileFilter(accPathVisitor);
         Files.walkFileTree(Paths.get("src/test/resources/org/apache/commons/io/dirs-2-file-size-2"), countingFileFilter);
         assertCounts(3, 2, 2, accPathVisitor.getPathCounters());
         assertEquals(3, accPathVisitor.getDirList().size());
         assertEquals(2, accPathVisitor.getFileList().size());
         assertEquals(accPathVisitor, accPathVisitor);
         assertEquals(accPathVisitor.hashCode(), accPathVisitor.hashCode());
     }
 
     /**
      * Tests IO-755 with a directory with 100 files, and delete all of them midway through the visit.
      *
      * Random failure like:
      *
      * <pre>
      * ...?...
      * </pre>
      */
     @ParameterizedTest
     @MethodSource("testParametersIgnoreFailures")
     public void testFolderWhileDeletingAsync(final Supplier<AccumulatorPathVisitor> supplier) throws IOException, InterruptedException {
         final int count = 10_000;
         final List<Path> files = new ArrayList<>(count);
         // Create "count" file fixtures
         for (int i = 1; i <= count; i++) {
             final Path tempFile = Files.createTempFile(tempDirPath, "test", ".txt");
             assertTrue(Files.exists(tempFile));
             files.add(tempFile);
         }
         final AccumulatorPathVisitor accPathVisitor = supplier.get();
         final PathVisitorFileFilter countingFileFilter = new PathVisitorFileFilter(accPathVisitor) {
             @Override
             public FileVisitResult visitFile(final Path path, final BasicFileAttributes attributes) throws IOException {
                 // Slow down the walking a bit to try and cause conflicts with the deletion thread
                 try {
                     ThreadUtils.sleep(Duration.ofMillis(10));
                 } catch (final InterruptedException ignore) {
                     // e.printStackTrace();
                 }
                 return super.visitFile(path, attributes);
             }
         };
         final ExecutorService executor = Executors.newSingleThreadExecutor();
         final AtomicBoolean deleted = new AtomicBoolean();
         try {
             executor.execute(() -> {
                 for (final Path file : files) {
                     try {
                         // File deletion is slow compared to tree walking, so we go as fast as we can here
                         Files.delete(file);
                     } catch (final IOException ignored) {
                         // e.printStackTrace();
                     }
                 }
                 deleted.set(true);
             });
             Files.walkFileTree(tempDirPath, countingFileFilter);
         } finally {
             if (!deleted.get()) {
                 ThreadUtils.sleep(Duration.ofMillis(1000));
             }
             if (!deleted.get()) {
                 executor.awaitTermination(5, TimeUnit.SECONDS);
             }
             executor.shutdownNow();
         }
         assertEquals(accPathVisitor, accPathVisitor);
         assertEquals(accPathVisitor.hashCode(), accPathVisitor.hashCode());
     }
 
     /**
      * Tests IO-755 with a directory with 100 files, and delete all of them midway through the visit.
      */
     @ParameterizedTest
     @MethodSource("testParametersIgnoreFailures")
     public void testFolderWhileDeletingSync(final Supplier<AccumulatorPathVisitor> supplier) throws IOException {
         final int count = 100;
         final int marker = count / 2;
         final Set<Path> files = new LinkedHashSet<>(count);
         for (int i = 1; i <= count; i++) {
             final Path tempFile = Files.createTempFile(tempDirPath, "test", ".txt");
             assertTrue(Files.exists(tempFile));
             files.add(tempFile);
         }
         final AccumulatorPathVisitor accPathVisitor = supplier.get();
         final AtomicInteger visitCount = new AtomicInteger();
         final PathVisitorFileFilter countingFileFilter = new PathVisitorFileFilter(accPathVisitor) {
             @Override
             public FileVisitResult visitFile(final Path path, final BasicFileAttributes attributes) throws IOException {
                 if (visitCount.incrementAndGet() == marker) {
                     // Now that we've visited half the files, delete them all
                     for (final Path file : files) {
                         Files.delete(file);
                     }
                 }
                 return super.visitFile(path, attributes);
             }
         };
         Files.walkFileTree(tempDirPath, countingFileFilter);
         assertCounts(1, marker - 1, 0, accPathVisitor.getPathCounters());
         assertEquals(1, accPathVisitor.getDirList().size());
         assertEquals(marker - 1, accPathVisitor.getFileList().size());
         assertEquals(accPathVisitor, accPathVisitor);
         assertEquals(accPathVisitor.hashCode(), accPathVisitor.hashCode());
     }
 
 }