/*
    * Copyright 2014 The Codehaus Foundation.
    *
    * 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.
   */
  package org.codehaus.plexus.components.io.attributes;
  
  import javax.annotation.Nonnull;
  import javax.annotation.Nullable;
  
  import java.io.File;
  import java.io.IOException;
  import java.nio.file.Files;
  import java.nio.file.LinkOption;
  import java.nio.file.Path;
  import java.nio.file.attribute.BasicFileAttributes;
  import java.nio.file.attribute.FileOwnerAttributeView;
  import java.nio.file.attribute.PosixFileAttributes;
  import java.nio.file.attribute.PosixFilePermission;
  import java.util.HashSet;
  import java.util.Set;
  
  /**
   * @author Kristian Rosenvold
   */
  @SuppressWarnings("OctalInteger")
  public class AttributeUtils {
      /*
      Reads last-modified with proper failure handling if something goes wrong.
       */
      public static long getLastModified(@Nonnull File file) {
          try {
              BasicFileAttributes basicFileAttributes = Files.readAttributes(file.toPath(), BasicFileAttributes.class);
              return basicFileAttributes.lastModifiedTime().toMillis();
          } catch (IOException e) {
              throw new RuntimeException(e);
          }
      }
  
      public static void chmod(@Nonnull File file, int mode) throws IOException {
          final Path path = file.toPath();
          if (!Files.isSymbolicLink(path)) {
              Files.setPosixFilePermissions(path, getPermissions(mode));
          }
      }
  
      @Nonnull
      public static Set<PosixFilePermission> getPermissions(int mode) {
          Set<PosixFilePermission> perms = new HashSet<>();
          // add owners permission
          if ((mode & 0400) > 0) {
              perms.add(PosixFilePermission.OWNER_READ);
          }
          if ((mode & 0200) > 0) {
              perms.add(PosixFilePermission.OWNER_WRITE);
          }
          if ((mode & 0100) > 0) {
              perms.add(PosixFilePermission.OWNER_EXECUTE);
          }
          // add group permissions
          if ((mode & 0040) > 0) {
              perms.add(PosixFilePermission.GROUP_READ);
          }
          if ((mode & 0020) > 0) {
              perms.add(PosixFilePermission.GROUP_WRITE);
          }
          if ((mode & 0010) > 0) {
              perms.add(PosixFilePermission.GROUP_EXECUTE);
          }
          // add others permissions
          if ((mode & 0004) > 0) {
              perms.add(PosixFilePermission.OTHERS_READ);
          }
          if ((mode & 0002) > 0) {
              perms.add(PosixFilePermission.OTHERS_WRITE);
          }
          if ((mode & 0001) > 0) {
              perms.add(PosixFilePermission.OTHERS_EXECUTE);
          }
          return perms;
      }
  
      @Nonnull
      public static PosixFileAttributes getPosixFileAttributes(@Nonnull File file) throws IOException {
          return Files.readAttributes(file.toPath(), PosixFileAttributes.class, LinkOption.NOFOLLOW_LINKS);
      }
  
      @Nonnull
      public static BasicFileAttributes getFileAttributes(@Nonnull File file) throws IOException {
         return getFileAttributes(file.toPath());
     }
 
     public static BasicFileAttributes getFileAttributes(Path path) throws IOException {
         if (isUnix(path)) {
             try {
                 return Files.readAttributes(path, PosixFileAttributes.class, LinkOption.NOFOLLOW_LINKS);
             } catch (UnsupportedOperationException ignore) {
                 // Maybe ignoring is dramatic. Maybe not. But we do get the basic attrs anyway
             }
         }
         return Files.readAttributes(path, BasicFileAttributes.class, LinkOption.NOFOLLOW_LINKS);
     }
 
     public static boolean isUnix(Path path) {
         return path.getFileSystem().supportedFileAttributeViews().contains("unix");
     }
 
     @Nullable
     public static FileOwnerAttributeView getFileOwnershipInfo(@Nonnull File file) throws IOException {
         try {
             return Files.getFileAttributeView(file.toPath(), FileOwnerAttributeView.class, LinkOption.NOFOLLOW_LINKS);
         } catch (UnsupportedOperationException e) {
             return null;
         }
     }
 }