/*
 * Copyright 2016 Damien Carol <[email protected]>
 *
 * 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 hdfs.jsr203;

import java.io.IOException;
import java.nio.file.FileStore;
import java.nio.file.attribute.BasicFileAttributeView;
import java.nio.file.attribute.FileAttributeView;
import java.nio.file.attribute.FileStoreAttributeView;
import java.nio.file.attribute.PosixFileAttributeView;

import org.apache.hadoop.fs.FsStatus;

/**
 * Implements {@link FileStore}.
 */
public class HadoopFileStore extends FileStore {

  private HadoopFileSystem system;

  public HadoopFileStore(HadoopPath path) {
    this.system = path.getFileSystem();
  }

  @Override
  public String name() {
    return this.system.getHDFS().getCanonicalServiceName();
  }

  @Override
  public String type() {
    return "hdfs";
  }

  @Override
  public boolean isReadOnly() {
    return this.system.isReadOnly();
  }

  @Override
  public long getTotalSpace() throws IOException {
    return this.system.getHDFS().getStatus().getCapacity();
  }

  @Override
  public long getUsableSpace() throws IOException {
    return this.system.getHDFS().getStatus().getRemaining();
  }

  @Override
  public long getUnallocatedSpace() throws IOException {
    FsStatus status = this.system.getHDFS().getStatus();
    return status.getCapacity() - status.getUsed();
  }

  @Override
  public boolean supportsFileAttributeView(
      Class<? extends FileAttributeView> type) {
    if (type == BasicFileAttributeView.class) {
      return this.system.supportedFileAttributeViews().contains("basic");
    }
    if (type == PosixFileAttributeView.class) {
      return this.system.supportedFileAttributeViews().contains("posix");
    }
    // FIXME Implements all FileAttributeView checks
    return false;
  }

  @Override
  public boolean supportsFileAttributeView(String name) {
    return this.system.supportedFileAttributeViews().contains(name);
  }

  @Override
  public <V extends FileStoreAttributeView> V getFileStoreAttributeView(
      Class<V> type) {
    return null;
  }

  @Override
  public Object getAttribute(String attribute) throws IOException {
    return null;
  }

  @Override
  public String toString() {
    StringBuilder sb = new StringBuilder("/ (");
    sb.append(system.getHDFS().getCanonicalServiceName());
    sb.append(')');
    return sb.toString();
  }

}