/*
    * 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.vfs2;
  
  import static org.junit.jupiter.api.Assertions.assertEquals;
  import static org.junit.jupiter.api.Assertions.assertFalse;
  import static org.junit.jupiter.api.Assertions.assertTrue;
  
  import java.util.Arrays;
  import java.util.Collection;
  import java.util.HashSet;
  import java.util.Set;
  
  import org.junit.jupiter.api.AfterAll;
  import org.junit.jupiter.api.BeforeAll;
  import org.junit.jupiter.api.Test;
  
  /**
   * Tests FileExtensionSelector.
   */
  public class FileExtensionSelectorTest {
  
      private static FileObject baseFolder;
  
      private static final int FILE_COUNT = 9;
  
      private static final int EXTENSION_COUNT = 3;
  
      private static final int FILES_PER_EXTENSION_COUNT = 3;
  
      /**
       * Creates a RAM FS.
       *
       * @throws Exception
       */
      @BeforeAll
      public static void setUpClass() throws Exception {
          baseFolder = VFS.getManager().resolveFile("ram://" + FileExtensionSelectorTest.class.getName());
          baseFolder.deleteAll();
          baseFolder.createFolder();
          baseFolder.resolveFile("a.htm").createFile();
          baseFolder.resolveFile("a.html").createFile();
          baseFolder.resolveFile("a.xhtml").createFile();
          baseFolder.resolveFile("b.htm").createFile();
          baseFolder.resolveFile("b.html").createFile();
          baseFolder.resolveFile("b.xhtml").createFile();
          baseFolder.resolveFile("c.htm").createFile();
          baseFolder.resolveFile("c.html").createFile();
          baseFolder.resolveFile("c.xhtml").createFile();
      }
  
      /**
       * Deletes RAM FS files.
       *
       * @throws Exception
       */
      @AfterAll
      public static void tearDownClass() throws Exception {
          if (baseFolder != null) {
              baseFolder.deleteAll();
          }
      }
  
      /**
       * Tests an empty selector.
       *
       * @throws Exception
       */
      @Test
      public void testEmpty() throws Exception {
          final FileSelector selector = new FileExtensionSelector();
          final FileObject[] foList = baseFolder.findFiles(selector);
          assertEquals(0, foList.length);
      }
  
      /**
       * Tests many extensions at once.
       *
       * @throws Exception
       */
      @Test
      public void testManyExtensions() throws Exception {
          final FileObject[] foArray = baseFolder.findFiles(Selectors.SELECT_FILES);
          assertTrue(foArray.length > 0);
          // gather file extensions.
         final Set<String> extensionSet = new HashSet<>();
         for (final FileObject fo : foArray) {
             extensionSet.add(fo.getName().getExtension());
         }
         final String message = String.format("Extensions: %s; files: %s", extensionSet.toString(),
                 Arrays.asList(foArray).toString());
         assertFalse(extensionSet.isEmpty(), message);
         assertEquals(EXTENSION_COUNT, extensionSet.size(), message);
         // check all unique extensions
         final FileSelector selector = new FileExtensionSelector(extensionSet);
         final FileObject[] list = baseFolder.findFiles(selector);
         assertEquals(FILE_COUNT, list.length);
     }
 
     /**
      * Tests a null selector.
      *
      * @throws Exception
      */
     @Test
     public void testNullCollection() throws Exception {
         final FileSelector selector0 = new FileExtensionSelector((Collection<String>) null);
         final FileObject[] foList = baseFolder.findFiles(selector0);
         assertEquals(0, foList.length);
     }
 
     /**
      * Tests a null selector.
      *
      * @throws Exception
      */
     @Test
     public void testNullString() throws Exception {
         final FileSelector selector0 = new FileExtensionSelector((String) null);
         final FileObject[] foList = baseFolder.findFiles(selector0);
         assertEquals(0, foList.length);
     }
 
     /**
      * Tests a one extension selector.
      *
      * @throws Exception
      */
     @Test
     public void testOneExtension() throws Exception {
         final FileObject[] foArray = baseFolder.findFiles(Selectors.SELECT_FILES);
         assertTrue(foArray.length > 0);
         // gather file extensions.
         final Set<String> extensionSet = new HashSet<>();
         for (final FileObject fo : foArray) {
             extensionSet.add(fo.getName().getExtension());
         }
         final String message = String.format("Extensions: %s; files: %s", extensionSet.toString(),
                 Arrays.asList(foArray).toString());
         assertEquals(EXTENSION_COUNT, extensionSet.size(), message);
         // check each extension
         for (final String extension : extensionSet) {
             final FileSelector selector = new FileExtensionSelector(extension);
             final FileObject[] list = baseFolder.findFiles(selector);
             assertEquals(FILES_PER_EXTENSION_COUNT, list.length);
         }
         // check each file against itself
         for (final FileObject fo : foArray) {
             final FileSelector selector = new FileExtensionSelector(fo.getName().getExtension());
             final FileObject[] list = baseFolder.findFiles(selector);
             assertEquals(FILES_PER_EXTENSION_COUNT, list.length);
         }
     }
 
 }