content: package act.util;
  
  /*-
   * #%L
   * ACT Framework
   * %%
   * Copyright (C) 2014 - 2017 ActFramework
   * %%
   * Licensed 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.
   * #L%
   */
  
  import act.app.ProjectLayout;
  import org.osgl.$;
  import org.osgl.util.C;
  import org.osgl.util.ListBuilder;
  
  import java.io.File;
  import java.util.ArrayList;
  import java.util.List;
  
  /**
   * A collection of file IO utilities
   */
  public enum Files {
      ;
  
      public static File file(File parent, String path) {
          return ProjectLayout.Utils.file(parent, path);
      }
  
      public static List<File> filter(File baseDir, $.F1<String, Boolean> filter) {
          ListBuilder<File> list = ListBuilder.create(500);
          filter(baseDir, filter, C.F.addTo(list));
          return list.toList();
      }
  
      public static void filter(File baseDir, $.F1<String, Boolean> filter, $.F1<File, ?> visitor) {
          File[] files = baseDir.listFiles();
          if (null == files) {
              return;
          }
          int n = files.length;
          for (int i = 0; i < n; ++i) {
              File file = files[i];
              if (isValidDir(file)) {
                  filter(file, filter, visitor);
              } else if (null == filter || filter.apply(file.getPath())) {
                  visitor.apply(file);
              }
          }
      }
  
      public static List<File> filter(List<File> baseDirs, $.F1<String, Boolean> filter) {
          ListBuilder<File> list = ListBuilder.create(500);
          filter(baseDirs, filter, C.F.addTo(list));
          return list.toList();
      }
  
      public static void filter(List<File> baseDirs, $.F1<String, Boolean> filter, $.F1<File, ?> visitor) {
          List<File> files = new ArrayList<>();
          for (File baseDir : baseDirs) {
              files.addAll(C.listOf(baseDir.listFiles()));
          }
          for (File file: files) {
              if (isValidDir(file)) {
                  filter(file, filter, visitor);
              } else {
                  visitor.apply(file);
              }
          }
      }
  
      private static boolean isValidDir(File file) {
          return file.isDirectory() && !isHiddenDir(file);
      }
  
      private static boolean isHiddenDir(File file) {
          return file.getName().startsWith(".");
      }
  }
  